Gate Driver Back Gate Voltage Control for Display Shading

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Solution Overview

Problem

Existing display apparatuses face challenges in controlling the slew rate of scanning signals effectively, leading to shading issues due to production tolerance and temperature changes, which are difficult to manage with fixed configurations.

Innovation Solution

A display apparatus with a driving circuit unit that includes a gate driver capable of controlling the back gate voltage of field effect transistors in the output buffer, allowing for sequential control of the slew rate of scanning signals, thereby inhibiting shading. This control is achieved by using a combination of transistors with different or same conductive types and referencing temperature information from sensors to adjust the back gate voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed configuration is used for the driver output stage, then the device complexity is reduced, but the ability to control slew rate sequentially and compensate for production tolerance and temperature changes is lost

Engineering Contradiction:

Improveslew rate control capabilityVSAvoiddriver circuit configuration

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the output stage configuration changeable rather than fixed. Multiple transistor groups (first, second, third groups) are provided with different conductive types and configurations, allowing the driver to dynamically select and switch between different transistor groups based on temperature conditions and production tolerance requirements, thereby achieving sequential slew rate control while managing device complexity

Inventive Principle:

Principle #15Dynamics

2Adaptability or versatility

If the number of transistors operated is controlled to achieve individual control, then production tolerance compensation is possible, but the control becomes discrete rather than sequential

Engineering Contradiction:

Improveindividual control capabilityVSAvoidcontrol continuity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent applies segmentation by dividing the output stage into multiple distinct transistor groups (first, second, third groups) with different conductive types and configurations. Each group can be independently controlled through separate control signals, enabling discrete control of individual transistor groups while maintaining the overall sequential operation of the driver circuit

Inventive Principle:

Principle #1Segmentation

3Object-affected harmful factors

If capacitance is added to the scanning line to slow down the signal, then shading is decreased, but the control is fixed and cannot adapt to temperature changes

Engineering Contradiction:

Improveshading effectVSAvoidtemperature adaptability

Core Design Contradiction:

Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by utilizing transistors with different conductive types (n-channel and p-channel) in various configurations within the output stage. By switching between different transistor groups with different electrical parameters, the driver can adjust the slew rate of scanning signals to compensate for temperature changes and production tolerance, thereby adaptively reducing shading effects

Inventive Principle:

Principle #35Parameter changes

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 enables effective inhibition of shading by allowing sequential control of the slew rate of scanning signals, addressing variability in production tolerance and temperature changes, thereby improving image quality.

Implementation Method 1

a gate driver configured to feed a scanning signal to the scanning line such that a back gate voltage of a field effect transistor configuring an output buffer for generating the scanning signal is capable of controlling

Methodology Applied

Scientific EffectField effect transistor back gate control:

Data Source

PatentUS9640101B2Display apparatus and electronic device including the same

Publication Date: 2017.05.02 MAGNOLIA BLUE CORP

AI summary

There is provided a display apparatus including a display panel where display elements connected to a scanning line and a signal line are arrayed in a two dimensional matrix, and a driving circuit unit configured to drive the display panel, the driving circuit unit including a gate driver configured to feed a scanning signal to the scanning line such that a back gate voltage of a field effect transistor configuring an output buffer for generating the scanning signal is capable of controlling. Also, there is provided an electronic device including the display apparatus.