Dual-Capacitor Power Supply for Ripple-Stable Display Driving

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Solution Overview

Problem

Existing display devices experience image quality deterioration due to ripples in high-potential and low-potential power output from DC-DC converters when driving methods are switched, leading to instability in the driving current.

Innovation Solution

A power supply system with independent operations in first and second modes, utilizing capacitors and switches to minimize power loss by reducing switching frequency and transitioning control signals quickly, ensuring reliable power supply voltage output.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the DC-DC converter operates with high switching frequency to maintain stable power output, then power supply stability is improved, but power loss increases

Engineering Contradiction:

Improvepower supply stabilityVSAvoidpower loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The power supply is divided into two independent modes (first mode and second mode) with separate capacitor operations. The first capacitor handles high-potential power clamping while the second capacitor handles low-potential power clamping, allowing each to operate independently at optimized frequencies rather than forcing the entire system to use a high switching frequency for stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements periodic switching between first mode and second mode operations, where capacitors are charged and discharged in alternating cycles. This periodic action allows the system to maintain stability through rhythmic power clamping while reducing average switching frequency compared to continuous high-frequency operation.

Inventive Principle:

Principle #19Periodic action

2Loss of energy

If the switching frequency is reduced to minimize power loss, then power loss is reduced, but the transition time of control signal increases

Engineering Contradiction:

Improvepower lossVSAvoidtransition time of control signal

Core Design Contradiction:

Loss of energyVSLoss of time

Solution Approach 1:

The capacitors are pre-charged to clamp voltages during their respective charging phases before power mode switching occurs. This preliminary charging action ensures that when switching between first and second modes, the already-charged capacitors can immediately provide clamping voltage, reducing transition time without requiring high switching frequency.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The capacitors act as intermediary energy storage elements that bridge the transition between first mode and second mode operations. By storing energy in advance and releasing it during transitions, the capacitors mediate the switching process, allowing faster transitions at lower overall switching frequencies.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Loss of energy

If the first capacitor and second capacitor operate independently in first and second modes, then power loss is reduced, but device complexity increases

Engineering Contradiction:

Improvepower lossVSAvoiddevice complexity

Core Design Contradiction:

Loss of energyVSDevice complexity

Solution Approach 1:

Both the first capacitor and second capacitor are designed to perform dual functions: they can be charged during their respective modes and discharged during mode transitions. This multi-functionality allows the system to maintain simplicity in each individual capacitor design while achieving overall system efficiency through their coordinated independent operations.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the clamping functions of high-potential and low-potential power into a unified dual-capacitor system. Instead of using separate complex clamping circuits for each power type, the system combines both clamping functions into two capacitors that operate independently but work together to reduce overall power loss.

Inventive Principle:

Principle #5Merging (Combining)

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 system improves image quality by stabilizing power supply and reducing power loss through optimized switching frequencies and modes, enhancing the reliability of the power supply voltage.

Implementation Method 1

a first capacitor configured to discharge a first clamp voltage to a first resistor in a first mode and be charged with the first clamp voltage in a second mode

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

a second capacitor configured to be charged with a second clamp voltage in the first mode and discharge the second clamp voltage to the first resistor in the second mode

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS20250372016A1Power supply, display device including the same, and electronic device including the same

Publication Date: 2025.12.04 SAMSUNG DISPLAY CO LTD

AI summary

A power supply includes: a converter configured to output a power supply voltage based on an output control signal; a first capacitor configured to discharge a first clamp voltage to a first resistor in a first mode and be to charged with the first clamp voltage in a second mode; and a second capacitor configured to be charged with a second clamp voltage in the first mode and to discharge the second clamp voltage to the first resistor in the second mode.