Low Power LCD Driver Circuit Adaptive Voltage Generation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing driver circuits for liquid crystal displays (LCDs) in portable devices face challenges in reducing power consumption and extending battery life, as they often require multiple voltage levels and lack efficient mechanisms to adapt to decreasing battery voltage levels.
Innovation Solution
A driver circuit with a DC-DC converter and charge pumps that utilize a reference voltage to generate multiple driving voltages through division and multiplication, allowing for adaptive operation modes to minimize power consumption and prolong battery life by dynamically switching between voltage levels based on battery voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If multiple voltage levels are generated using traditional resistance-dividing schemes or charge pumps, then the display can be driven with required voltage levels, but power consumption increases and battery lifetime decreases
Solution Approach 1:
The patent implements dynamic voltage level selection based on battery voltage thresholds. The controller monitors battery voltage and switches between different voltage generation modes (direct output, charge pump multiplication, or resistance division) to optimize power consumption at different battery states, thereby extending battery lifetime while maintaining display operation
Solution Approach 2:
The system changes operating parameters by selecting different voltage multiplication factors (2x, 3x, 4x) based on battery voltage levels. When battery voltage drops below thresholds, the system transitions from direct charge pump output to resistance-divided voltage levels, adapting parameters to maintain efficient operation across varying battery conditions
2Power
If charge pumps are used to generate higher voltage levels from a low voltage reference, then the required driving voltages are achieved, but the circuit complexity increases
Solution Approach 1:
The patent designs the voltage generation circuit to serve multiple functions: it can directly output charge pump voltages when battery voltage is sufficient, switch to resistance-divided voltages when battery voltage drops, and provide intermediate voltage levels. This multi-functional design reduces the need for separate dedicated circuits for each voltage generation mode, thereby managing complexity while achieving required driving voltages
3Reliability
If the driver circuit operates with fixed voltage levels, then the display performance is maintained, but power consumption cannot be optimized as battery voltage decreases
Solution Approach 1:
The patent implements a feedback mechanism where the controller continuously monitors battery voltage levels and adjusts the voltage generation strategy accordingly. When battery voltage drops below predefined thresholds, the controller switches from direct charge pump output to resistance-divided voltage levels, maintaining display performance while optimizing power consumption based on real-time battery conditions
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
The solution effectively reduces total power consumption and prolongs battery life by using a DC-DC converter and charge pumps to generate required voltage levels efficiently, while enabling the driver circuit to adapt to decreasing battery voltage levels.
Implementation Method 1
a driver circuit with a DC-DC converter and charge pumps that utilize a reference voltage to generate multiple driving voltages through division and multiplication
Data Source
Figure 1~2
Figure 3~4
AI summary
The present invention relates in one aspect to a driver circuit for an electronic display, comprising: - a power supply system (12) configured to provide a reference voltage (Vref), - a DC-DC converter (15) having an input (16) connected to the power supply system and having at least a first output (17) configured to provide a first driving voltage (VL1), a second output (18) configured to provide a second driving voltage (VL2) and a third output (19) configured to provide a third output voltage (VL3), wherein the second output voltage is higher than the first output voltage and wherein the third output voltage is higher than the second output voltage, - wherein the DC-DC converter comprises at least a first charge pump (20), and wherein the input is directly connectable to the second output to provide the reference voltage as the second output voltage.