Gate-on Voltage Generator for Low-Temperature LCD Drivers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Liquid crystal display (LCD) gate drivers with integrated gate driving ICs face reduced driving capacity at lower ambient temperatures, leading to insufficient gate-on voltage and deteriorated display quality.
Innovation Solution
A gate-on voltage generator comprising a temperature sensor and charge pumping unit that adjusts the gate-on voltage based on ambient temperature, using a boost converter and switching unit to maintain a stable pulse signal amplitude, ensuring adequate voltage levels for LCD operation across temperature variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the gate driver is integrated on the liquid crystal panel to achieve miniaturization, then the device size is reduced and manufacturability is improved, but the driving capacity of TFTs decreases at low temperatures resulting in insufficient gate-on voltage
Solution Approach 1:
The gate-on voltage generator dynamically adjusts the gate-on voltage level based on ambient temperature. The voltage output is not fixed but varies with temperature conditions, allowing the system to maintain adequate driving capacity across different temperature ranges while keeping the integrated gate driver structure
Solution Approach 2:
The patent changes the voltage parameter of the gate-on signal based on temperature. At low temperatures, the gate-on voltage is increased to compensate for reduced TFT driving capacity, while at normal temperatures the voltage returns to standard levels. This parameter adjustment resolves the contradiction between miniaturization and low-temperature reliability
2Reliability
If the gate-on voltage is increased to maintain driving capacity at low temperatures, then the display quality is improved, but the voltage level becomes excessive at normal temperatures potentially causing operational issues
Solution Approach 1:
The gate-on voltage generator implements dynamic voltage adjustment where the output voltage level is modulated according to real-time temperature sensing. This allows the system to adapt the voltage to appropriate levels for each temperature condition, maintaining display quality at low temperatures while preventing excessive voltage at normal temperatures
Solution Approach 2:
The system incorporates temperature sensing feedback to control the gate-on voltage generation. The temperature-dependent control signal ensures that voltage increases only when actually needed at low temperatures, and returns to normal levels when temperature rises, achieving both display quality and voltage compatibility
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
Enhances display quality at low temperatures by increasing gate-on voltage levels when ambient temperature decreases, thereby maintaining effective driving capacity and image quality.
Implementation Method 1
a temperature sensor including an operational amplifier configured to receive a driving voltage and produce a temperature-dependent variable voltage, the level of which varies according to the ambient temperature
Implementation Method 2
a charge pumping unit shifting the temperature-dependent variable voltage by the amplitude of a pulse signal and generating a gate-on voltage
Implementation Method 3
a boost converter that receives and boosts a first input voltage and outputs a pulse signal, where the driving voltage and an amplitude of the pulse signal are not influenced by an ambient temperature
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A gate-on voltage generator (440) that can enhance display quality at low temperatures, a driving device (400), and a display apparatus having the same, in which the gate-on voltage generator includes a temperature sensor (420) having an operational amplifier configured to receive a driving voltage and produce a temperature-dependent variable voltage (VARV), the level of which varies according to the ambient temperature, and a charge pumping unit (430) shifting the temperature-dependent variable voltage by the voltage level of a pulse signal and generating a gate-on voltage (Von).