Test Circuit for Display Panel Static Protection
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Solution Overview
Problem
Conventional test circuits for display panels face issues with static electricity damage and manufacturing cost due to direct connection of test signal lines and the use of transistors, which can lead to abnormal display results and mura situations.
Innovation Solution
A test circuit design incorporating multiple test signal lines, test signal transmitters with transmission gates, and static electricity protection devices placed between gate lines to prevent static electricity damage and average transistor parameter differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If test signal lines are directly connected to the pixel array and drive circuit, then the test circuit structure is simple, but static electricity damage and manufacturing cost increase
Solution Approach 1:
The patent introduces a test signal transmitter as an intermediary component between the test signal line and the pixel array. This transmitter includes transmission gates controlled by gate lines, acting as a mediator that prevents direct connection while enabling test signal transmission. The intermediary structure protects against static electricity damage while maintaining test functionality.
2Ease of operation
If transistors are used as switches in the test circuit, then the test signal can be controlled, but transistor parameter differences cause mura situations on the display panel
Solution Approach 1:
The patent extracts the switching function from the pixel array transistors and places it in dedicated test signal transmitters. By separating the test signal control path from the normal display path, the patent eliminates the influence of transistor parameter variations in the pixel array on display uniformity, while maintaining test signal control capability through the dedicated transmitters.
3Ease of manufacture
If the laser cut process is used to cut off test signal lines, then the test circuit can be removed after testing, but the manufacturing cost increases
Solution Approach 1:
The patent designs the test circuit with built-in test signal transmitters that can be controlled to disconnect from the pixel array during normal operation. This preliminary design allows the test circuit to serve its function during manufacturing and then be electrically isolated without requiring additional laser cutting processes, reducing manufacturing costs while maintaining the ability to remove the test circuit after testing.
Data Source
AI summary
A test circuit adapted in a display panel of an electronic device is provided. The test circuit is to test the pixel array function of the display panel, wherein the test circuit comprises: a plurality of test signal lines, a plurality of test signal transmitters, a plurality of gate lines and at least one static electricity protection device. The test signal lines receive a plurality of corresponding test signals respectively. The test signal transmitters comprises a plurality test signal transmitter groups comprising at least one transmitter, wherein each transmitter group corresponds to a test signal line and connects the test signal line and the to pixel array. Each gate line connects to the gate of the at least one transmitter. The static electricity protection device is placed between two of the gate lines.