Bi-directional Scanning Line Driving Circuit Eliminates Dummy Shift Registers
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Solution Overview
Problem
Existing scanning line driving circuits for electro-optical devices require dummy unit shift registers for bi-directional scanning, increasing the area and cost of the circuit due to the need for additional components.
Innovation Solution
A multi-stage shift register design that eliminates the need for dummy unit shift registers by using transistors of a single conductivity type and switching levels of voltage signals to change scanning direction, allowing for bi-directional scanning without the requirement of additional circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If dummy unit shift registers are added for bi-directional scanning, then the scanning capability is improved, but the circuit area increases
Solution Approach 1:
The patent makes the unit shift register capable of performing multiple functions by enabling bi-directional operation through control signals. The same circuit structure can scan in both forward and backward directions without requiring separate dummy registers, thus achieving multi-functionality with a single circuit unit.
Solution Approach 2:
The patent implements backward scanning capability by inverting the normal scanning operation. When a backward scan is required, the shift register operates in reverse direction by controlling the clock signals and data input/output directions, eliminating the need for separate dummy registers that would otherwise be needed for reverse operation.
2Adaptability or versatility
If dummy unit shift registers are added for bi-directional scanning, then the scanning capability is improved, but the manufacturing cost increases
Solution Approach 1:
By designing the unit shift register to be universally applicable in both forward and backward scanning modes through control signal management, the patent eliminates the need for additional dummy registers. This reduces the total component count and simplifies the manufacturing process, thereby reducing production costs.
Solution Approach 2:
The patent changes the operational parameters of the shift register (such as clock signal phases and data flow direction) to achieve bi-directional scanning without structural modifications. This parameter-based control approach avoids the need for additional hardware components, simplifying manufacturing and reducing costs.
3Adaptability or versatility
If dummy unit shift registers are added for bi-directional scanning, then the scanning capability is improved, but the device complexity increases
Solution Approach 1:
The patent achieves bi-directional scanning by making the existing unit shift register universal through control logic that manages scanning direction. This approach maintains a single circuit structure that can operate in multiple modes, avoiding the increased complexity that would result from adding separate dummy registers for each direction.
Solution Approach 2:
The patent introduces dynamic control mechanisms that allow the shift register to adapt its operation mode (forward or backward scanning) based on control signals. This dynamic reconfigurability enables bi-directional scanning without requiring additional static circuit components, thereby maintaining circuit simplicity while achieving versatility.
Data Source
AI summary
Provided are a bi-directional scanning type gate line driving circuit that does not require a dummy unit shift register and a method of driving the same. In a gate line driving circuit including a multi-stage shift register capable of bi-directional shifting, a start pulse is input to a unit shift register at a first stage and a unit shift register at the last stage of the multi-stage shift register. In forward shifting, a clock signal supplied to the unit shift register at the last stage is kept at a deactivation level during a period from a time at which an activation period of an output signal of the unit shift register at the last stage ends to a time at which the start pulse is activated during a subsequent frame period.