Multiplexer Circuit Driving Method for Uniform OLED Sub-pixel Charging
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Solution Overview
Problem
In Active Matrix Driving OLED (AMOLED) display devices, the power consumption is increased due to the repeated switching of multiplexing signals, leading to uneven charging of sub-pixels in the first and last rows, resulting in bright lines and reduced display effectiveness.
Innovation Solution
A multiplexer circuit configuration that alternates the multiplexing signal turn-on sequences for odd and even rows in different frames, ensuring uniform charging time for all sub-pixels by complementing the multiplexing signal driving sequences, thereby reducing power consumption and eliminating bright lines.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sub-pixels are driven row by row according to a turn-on sequence from a first multiplexing signal to a second multiplexing signal, then the number of data lines is reduced and resolution is improved, but power consumption increases due to repeated switching of multiplexing signals
Solution Approach 1:
The patent applies periodic action by alternating the multiplexing signal turn-on sequences between odd and even rows in different frames. In odd frames, odd rows use sequence 1→2 and even rows use sequence 2→1, while in even frames the sequences are reversed. This periodic alternation ensures that over two frames, all rows experience both sequences, achieving uniform charging while reducing the net power consumption compared to always using one sequence.
2Device complexity
If sub-pixels are driven row by row according to a turn-on sequence from a first multiplexing signal to a second multiplexing signal, then the device complexity is reduced, but uneven charging occurs in the first and last rows resulting in bright lines
Solution Approach 1:
The patent uses periodic alternation of multiplexing signal sequences to ensure uniform charging. By switching between two sequences (1→2 and 2→1) in different frames for odd and even rows, the system maintains simple row-by-row driving architecture while compensating for the uneven charging of first and last rows, thus eliminating bright lines without increasing device complexity.
Solution Approach 2:
The patent applies inversion by using opposite turn-on sequences for odd and even rows. When odd rows use sequence 1→2, even rows use sequence 2→1, and vice versa in different frames. This inverted approach ensures that sub-pixels in the first and last rows, which would otherwise be undercharged, receive adequate charging time, achieving uniform brightness across all rows.
3Device complexity
If a multiplexer circuit repeatedly switches multiplexing signals to drive sub-pixels row by row, then the number of data lines is reduced, but the power consumption of the device increases
Solution Approach 1:
The patent implements periodic action by alternating the multiplexing signal sequences between frames. Odd frames use sequence 1→2 for odd rows and 2→1 for even rows, while even frames reverse this assignment. This periodic switching reduces the overall power consumption compared to repeatedly using the same sequence, while still maintaining the benefit of reduced data line count through the multiplexer circuit.
Data Source
AI summary
A display panel includes a source driving circuit, a multiplexer circuit, and multiple sub-pixels arranged in an array. The multiplexer circuit is configured to, under the control of a first multiplexing signal to an Nth multiplexing signal, control the source driving circuit to be connected with sub-pixels of one or more columns; and in a jth frame, a multiplexing signal turn-on sequence for sub-pixels of an odd row is from a Jth multiplexing signal to sequentially increasing to the Nth multiplexing signal and from the first multiplexing signal to sequentially increasing to a (J−1)th multiplexing signal, and a multiplexing signal turn-on sequence for sub-pixels of an even row is completely opposite to the multiplexing signal turn-on sequence for the sub-pixels of the odd row.