LED Driver Circuit Pulse Width Compensation
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Solution Overview
Problem
Existing driver circuits for light emitting diodes require precise components to produce precise input signals, leading to visible differences in light output due to small variations, which are costly and not compensated for by current technologies.
Innovation Solution
A driver circuit with a converter and adapter that measures and adjusts the pulse width based on amplitude differences between input and nominal signal values, allowing compensation for variations without the need for precise components, thereby maintaining consistent light output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If precise components are used to produce precise input signals, then light output consistency is improved, but device cost increases
Solution Approach 1:
The patent applies preliminary action by measuring the amplitude value of the input signal before conversion and storing it in memory. This pre-measurement allows the system to compensate for amplitude variations in advance by adjusting the pulse width accordingly, eliminating the need for expensive precise components while maintaining light output consistency.
Solution Approach 2:
The patent changes the parameter of pulse width based on the measured amplitude value. When the amplitude value deviates from the nominal value, the pulse width is adjusted to compensate for this deviation. This parameter change approach allows the system to maintain consistent light output using standard, inexpensive components rather than requiring precise components.
2Measurement precision
If precise components are used to produce precise input signals, then signal precision is improved, but device complexity increases
Solution Approach 1:
The patent introduces an intermediary measurement and compensation mechanism between the input signal and the light circuit. A measurement unit measures the amplitude value, stores it in memory, and a control unit adjusts the pulse width based on this stored value. This intermediary approach achieves signal precision without requiring expensive precise components, thereby maintaining simplicity.
3Manufacturing precision
If feedback circuits are used to compensate for variations, then light output consistency is improved, but device complexity and cost increase
Solution Approach 1:
Instead of using continuous feedback circuits, the patent applies preliminary action by measuring and storing the amplitude value before signal conversion. The compensation is performed in advance by adjusting the pulse width based on the stored amplitude value, eliminating the need for complex continuous feedback circuits while maintaining light output consistency.
Solution Approach 2:
The patent extracts the essential compensation function from complex feedback circuits and implements it through a simpler measurement-storage-adjustment mechanism. By separating the measurement, storage, and adjustment functions into distinct simple units, the system achieves compensation without the complexity of traditional feedback circuits.
Data Source
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AI summary
Driver circuits (20) for driving light circuits (21) comprising light emitting diodes are provided with converters (22) for converting input signals into output signals comprising pulses per cycle. The converters (22) comprise adapters (33) for, in response to differences between measured amplitude values of the input / output signals and nominal amplitude values of the input / output signals, adapting widths of the pulses. Then, signals having relatively precise amplitudes are no longer required. Said adapting may comprise increasing / decreasing the widths in case the measured amplitude value is smaller / larger, respectively, than the nominal amplitude value. The measured amplitude value divided by the nominal amplitude value is equal to a correction value. An adjusted duty cycle of the output signal may be made equal to a nominal duty cycle of the output signal divided by the correction value. Said adapting may be performed in a production / testing process environment.