LED Chip Time Multiplexing Reduces Connection Density
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Solution Overview
Problem
The existing image display devices with LEDs face challenges in reducing the number and density of electrical connection elements required for individual control of sub-pixels, leading to increased complexity and cost.
Innovation Solution
The solution involves integrating multiple sub-pixels onto a single elementary chip, where individual adjustment signals for each sub-pixel are time multiplexed onto a single terminal, and a control circuit demultiplexes these signals to apply appropriate bias signals to each LED, reducing the number of external connection terminals needed on the transfer substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If each sub-pixel is controlled by separate electrical connection elements, then precise control over each sub-pixel is achieved, but the number and density of connection elements increases
Solution Approach 1:
The patent applies time-division multiplexing where individual adjustment signals for multiple LEDs are transmitted periodically through a single shared connection element. Each LED receives its dedicated control signal in alternating time slots, enabling precise individual control while reducing the number of physical connection elements required on the transfer substrate.
2Quantity of substance
If multiple sub-pixels are integrated onto a single chip, then the number of connection elements is reduced, but the control mechanism becomes more complex
Solution Approach 1:
The control mechanism is segmented into distinct functional blocks: a demultiplexing circuit that separates the time-multiplexed signal into individual LED control signals, and separate bias signal generation circuits for each LED. This modular segmentation manages complexity by organizing the control function into manageable, independent units while maintaining integration benefits.
Solution Approach 2:
The patent introduces a demultiplexing circuit as an intermediary component between the single shared connection element and the multiple LED control circuits. This intermediary receives the time-multiplexed signal and converts it into separate control signals for each LED, simplifying the overall control architecture while enabling precise individual control.
3Quantity of substance
If a single terminal receives time multiplexed signals, then the density of electrical connection elements is reduced, but signal synchronization becomes more difficult
Solution Approach 1:
The control circuit incorporates synchronization mechanisms that monitor the incoming time-multiplexed signal and adjust the demultiplexing timing accordingly. This feedback-based synchronization ensures that each LED receives its control signal at the correct time slot, maintaining precise timing control even with a single shared connection element.
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 approach reduces the number of electrical connection elements required on the transfer substrate, simplifying the control mechanism and potentially lowering production costs while maintaining precise control over each sub-pixel's brightness.
Implementation Method 1
the individual adjustment signals of the different LEDs of the chip being time multiplexed on said first terminal; and a control circuit adapted to demultiplex the signals received on said first terminal
Data Source
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AI summary
The invention relates to an emissive display device including: a backing substrate including electrical connection elements; and a plurality of semiconductor chips (310) joined to the substrate and connected to the electrical connection elements of the substrate so as to be controlled, each chip including: a plurality of LEDs (120r, 120g, 120b); a first terminal (Vdata) for connection to the substrate, which terminal is intended to receive, for each LED of the chip, an individual adjustment signal (Vdatar, Vdatag, Vdatab) for the LED, the individual adjustment signals for the various LEDs of the chip being temporally multiplexed on said first terminal (Vdata); and a control circuit designed to demultiplex the signals received on said first terminal and to apply, to each LED of the chip, a bias signal dependent on the individual adjustment signal for the LED received on said first terminal (Vdata).