Integrated Circuit Power Supply Control for EPD Panels
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Solution Overview
Problem
Existing electro-optical panel driving technologies face challenges in reducing power consumption while maintaining optical properties, particularly in EPD panels, due to leakage currents and resistance components, leading to increased power consumption during DC voltage application.
Innovation Solution
An integrated circuit device employs a power supply control unit that adjusts the current supply capability in phases, generating multiple driving voltages based on display data and setting the capability to different levels to minimize power consumption, with options including standard and low power modes, and intermittent operation, while monitoring temperature and voltage to optimize performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If DC voltage is applied to the EPD panel to maintain display state, then the panel maintains optical properties, but power is consumed due to leakage current and resistance components
Solution Approach 1:
The patent applies periodic rectangular wave voltage instead of continuous DC voltage. The voltage is applied in cycles (on-period and off-period) to refresh the electrophoretic particles periodically. This periodic action maintains the display state while allowing the particles to settle during off-periods, reducing continuous power consumption from leakage current.
Solution Approach 2:
The patent changes the voltage parameter from static DC to time-varying rectangular wave with specific duty ratios. By adjusting the duty ratio (ratio of on-period to total cycle period) and voltage amplitude, the system optimizes between maintaining adequate electric field for particle positioning and reducing power consumption during off-periods when voltage is reduced or zero.
2Productivity
If voltage is applied to change display content, then the display updates, but power is consumed for driving capacitance components
Solution Approach 1:
The patent applies a preliminary voltage phase before the main display update phase. This preliminary action prepares the electrophoretic particles by applying voltage in a specific pattern that facilitates smoother transitions during the main update, reducing the peak current required and thereby reducing power consumption during content changes.
Solution Approach 2:
The display update process is divided into multiple periodic phases including initialization phase, update phase, and stabilization phase. By spreading the voltage application across these periodic phases rather than applying full voltage continuously, the patent reduces peak power consumption while ensuring complete display updates.
3Power
If high current supply capability is maintained, then voltage changes are supported, but power consumption increases
Solution Approach 1:
The patent dynamically adjusts the current supply capability of the power supply circuit based on the driving phase. During voltage change phases, the current capability is set to a first level to support rapid particle movement. During stable display phases, it is reduced to a second level to minimize power consumption. This dynamic adjustment matches supply capability to actual demand.
Solution Approach 2:
The power supply circuit operates in periodic cycles, providing high current capability only during necessary voltage transition periods and reducing capability during stable periods. This periodic modulation of power supply capability reduces average power consumption while maintaining adequate capability when needed for display updates.
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 effectively reduces power consumption during driving operations while preserving the optical properties of the electro-optical panel by dynamically managing current supply based on phase timing, temperature, and voltage conditions.
Implementation Method 1
By applying a voltage between the top plane electrode and the segment electrodes to apply an electric field to the electrophoretic particles, the electrophoretic particles move in accordance with the direction of the electric field
Data Source
AI summary
An integrated circuit device that drives an electro-optical panel using a driving waveform which is set in a plurality of phases includes: a driving voltage generation unit that operates while receiving a supply of a power supply voltage generated by a power supply circuit, and generates a plurality of driving voltages to be applied to a plurality of electrodes in the electro-optical panel in each of a plurality of phases, in accordance with display data; and a power supply control unit that sets current supply capability of the power supply circuit to a first level synchronously with a timing of start of a phase, and sets the current supply capability to a second level, which is lower than the first level.