LED Driver Circuit with Single Current Source and Path Controllers
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Solution Overview
Problem
The existing backlight systems for LCD devices require multiple constant-current providing circuits for each LED group, leading to increased complexity and cost due to the number of divided backlight regions, as well as complex wiring structures.
Innovation Solution
A device that drives multiple light emitting diode (LED) groups using a single constant-current providing unit, with current path controllers or switches to manage current distribution and activation across the LED groups, allowing for independent control of each group's luminance without the need for multiple constant-current circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple constant-current providing circuits are used for each LED group, then independent luminance control of each LED group is achieved, but device complexity and cost increase
Solution Approach 1:
The patent combines multiple constant-current providing circuits into a single shared circuit that serves multiple LED groups. The single constant-current circuit provides current to all LED groups simultaneously, eliminating the need for separate constant-current circuits for each group while maintaining the ability to independently control luminance through individual current path controllers.
Solution Approach 2:
The patent segments the current control function by introducing individual current path controllers for each LED group. These controllers independently regulate the current flow to their respective LED groups by adjusting switching duty cycles, allowing separate luminance control without requiring separate constant-current providing circuits.
2Adaptability or versatility
If backlight is divided into multiple regions with separate LED groups, then luminance control flexibility is improved, but wiring structure complexity increases
Solution Approach 1:
The patent merges the power supply wiring by connecting all LED groups in parallel to a single constant-current providing circuit. This consolidation reduces the complexity of wiring structures while maintaining the divided backlight region structure for flexible luminance control.
Solution Approach 2:
The patent introduces dynamic control through current path controllers that adjust switching duty cycles to regulate current flow to each LED group. This dynamic control mechanism enables flexible luminance adjustment for different backlight regions without requiring complex static wiring configurations.
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 solution simplifies the circuit construction and reduces costs by using a single constant-current providing unit to power multiple LED groups, enabling independent luminance control of each group, thereby reducing the complexity and expense associated with multiple backlight regions.
Implementation Method 1
a light emitting diode (LED) display
Implementation Method 2
The light source for the backlight of the LCD device includes three LED groups
Data Source
AI summary
A device for driving a plurality of light emitting diodes includes a plurality of light emitting diode groups in series; a current providing unit for providing a current to the plurality of light emitting diode groups; and at least one current path controller in parallel with a corresponding one of the light emitting diode groups for turning off the corresponding one of the light emitting diode groups in accordance with a control signal.