Display Driving Device Staggered Latch Timing for Noise Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional display driver ICs generate large power noise and electromagnetic interference due to simultaneous changes in image data across all channels, leading to current concentration.
Innovation Solution
The display driving device includes sampling latches, holding latches, and level shifters, with a signal generation circuit that allows image data bits to be changed at different times for each color or position, dispersing the latch timings to prevent current concentration and reduce electromagnetic interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If image data for all channels is changed simultaneously, then the display updates efficiently, but large power noise and electromagnetic interference are generated due to current concentration
Solution Approach 1:
The patent divides the image data update process into multiple segments by grouping latch cells into different latch groups (first latch group, second latch group, third latch group). Each group updates image data at different timings rather than simultaneously. This segmentation disperses the current consumption across time, preventing current concentration while maintaining efficient display updates.
2Speed
If all level shifters operate simultaneously to change image data voltage levels, then the data is processed quickly, but current concentration occurs generating large power noise
Solution Approach 1:
The patent segments the level shifter operations by controlling different latch groups at different timings. The first latch group's level shifters operate at a first timing, the second latch group's level shifters operate at a second timing, and the third latch group's level shifters operate at a third timing. This temporal segmentation prevents simultaneous operation of all level shifters, dispersing current consumption and reducing power noise while maintaining overall processing speed.
3Productivity
If bits of image data are changed at the same time for all colors, then the image rendering is efficient, but electromagnetic interference with external circuits increases
Solution Approach 1:
The patent segments image data bits into different latch groups that operate at different timings. By controlling when each latch group updates its image data bits, the patent prevents simultaneous switching of all bits across all colors. This reduces electromagnetic interference with external circuits while maintaining efficient image rendering through coordinated sequential updates.
Solution Approach 2:
The patent implements periodic action by establishing a structured sequence of latch operations across different latch groups. Each latch group operates in a periodic manner with defined timing relationships to other groups, creating a rhythmic pattern of data updates that reduces electromagnetic interference compared to simultaneous updates, while maintaining overall rendering efficiency.
Data Source
AI summary
A display driving device according to the present disclosure capable of changing image data at a different time for each color when the image data is changed includes: a first array composed of sampling latches configured to latch n-bit image data for each channel; a second array composed of holding latches configured to latch the image data latched in the sampling latches at a latch timing determined for each latch group; a signal generation circuit configured to generate a latch enable signal which causes the holding latches to perform a latch operation at the latch timing determined for each latch group; and a third array including level shifters configured to shift a voltage level of the image data output from the holding latches.