Display Panel Driving Circuit Eliminates Voltage Buffer

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing display apparatus source drivers face challenges in miniaturization and power consumption due to large circuit areas and dynamic/static current consumption, leading to increased electromagnetic interference and reduced lifespan.

Innovation Solution

A driving circuit for display panels that includes a shift register, latch, level shifter, current source, and charge switch, eliminating the need for a voltage buffer by using current-based charging and discharging, which reduces power consumption and electromagnetic interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a voltage buffer is used to increase the current value of pixel voltage, then the driving power of pixel voltage is increased, but the circuit area increases and power consumption increases

Engineering Contradiction:

Improvedriving power of pixel voltageVSAvoidcircuit area

Core Design Contradiction:

PowerVSArea of stationary object

Solution Approach 1:

The patent removes the voltage buffer component from the source driver circuit. Instead of using a voltage buffer to amplify pixel voltage current, the invention directly uses a current source to provide charging current to the pixel, eliminating the need for voltage buffering and thereby reducing circuit area.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the voltage-based buffering mechanism with a current-based direct driving mechanism. Instead of amplifying voltage through a buffer, the system directly controls and provides current to the pixel, substituting the voltage amplification approach with a current control approach that reduces circuit complexity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Power

If a voltage buffer is used to increase the current value of pixel voltage, then the driving power of pixel voltage is increased, but static current is generated causing power consumption

Engineering Contradiction:

Improvedriving power of pixel voltageVSAvoidpower consumption

Core Design Contradiction:

PowerVSUse of energy by stationary object

Solution Approach 1:

The patent removes the voltage buffer component that generates static current. By eliminating the buffer, the circuit no longer consumes static power to maintain voltage levels, thereby reducing overall power consumption while still providing adequate driving current through the current source.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a current source that provides charging current periodically or as needed, rather than continuously maintaining voltage through a buffer. This periodic current provision eliminates static power consumption while maintaining the ability to drive pixels when required.

Inventive Principle:

Principle #19Periodic action

3Power

If DAC and voltage buffer are used, then gray-level data are converted and driving power is increased, but dynamic current and static current cause electromagnetic interference

Engineering Contradiction:

Improvedriving power of pixel voltageVSAvoidelectromagnetic interference

Core Design Contradiction:

PowerVSObject-generated harmful factors

Solution Approach 1:

The patent removes the voltage buffer that generates electromagnetic interference through dynamic and static current changes. By eliminating the buffer and using a current source directly, the circuit avoids the inrush current and current fluctuations that cause EMI, thereby reducing electromagnetic interference.

Inventive Principle:

Principle #2Taking out (Extraction)

4Adaptability or versatility

If the range of gray-level is increased, then display quality is improved, but the circuit area of DAC increases significantly

Engineering Contradiction:

Improvegray-level rangeVSAvoidcircuit area of DAC

Core Design Contradiction:

Adaptability or versatilityVSArea of stationary object

Solution Approach 1:

The patent replaces the DAC+voltage buffer system with a current source system. This substitution allows the circuit to handle increased gray-level ranges without requiring a larger DAC, because the current source directly provides the necessary current variations for different gray levels without needing voltage amplification.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS10102792B2Driving circuit of display panel and display apparatus using the same

Publication Date: 2018.10.16 NOVATEK MICROELECTRONICS CORP

AI summary

A driving circuit of a display panel and a display apparatus using the same are provided. The driving circuit includes a shift register, a latch, a level shifter, a current source and a charge switch. The shift register receives a trigger signal to provide a data latch signal. The latch couples to the shift register, and receives a gray-level data to latch and output the gray-level data according to the data latch signal. The level shifter couples to the latch and provides a charge switch signal according to the gray-level data. The current source provides a charge current. The charge switch couples between the current source and a pixel of the display panel, and receives the charge switch signal to determine whether the current source is coupled to the pixel according to the charge switch signal.