Chiplet Pixel Drivers for Passive-Matrix Displays
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Passive-matrix display devices are limited in size and number of light-emitting elements due to flicker issues and high power requirements, while active-matrix devices face lower electrical performance and non-uniformity with thin-film transistors.
Innovation Solution
The use of chiplet pixel drivers with row and column electrode connections reduces connection pads and size, improves luminance uniformity, and employs chiplets to drive both row and column electrodes, reducing flicker and power requirements, and enhancing heat distribution and aperture ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If passive-matrix control is used, then device complexity is reduced, but display size and number of light-emitting elements are limited due to flicker and power requirements
Solution Approach 1:
The display is divided into multiple pixel groups, with each pixel group controlled by a dedicated chiplet. This segmentation allows the display to scale to larger sizes by adding more pixel groups without proportionally increasing the complexity of the control structure, as each chiplet independently manages its assigned pixel group.
Solution Approach 2:
Each chiplet is designed to perform multiple functions: it controls both row and column electrodes within its assigned pixel group, and can drive multiple pixels simultaneously. This multi-functionality reduces the overall system complexity while enabling larger display areas through scalable chiplet arrays.
2Device complexity
If passive-matrix control is used, then device complexity is reduced, but power requirements increase
Solution Approach 1:
By dividing the display into multiple pixel groups each driven by a separate chiplet, the total power consumption is distributed across multiple independent control units. Each chiplet manages power for its specific pixel group, preventing the high peak power demands of a single centralized controller and enabling more efficient power management.
Solution Approach 2:
Each chiplet drives only a subset of the total pixels (its assigned pixel group) rather than controlling all pixels simultaneously. This partial action approach reduces the instantaneous power requirements compared to a system where a single controller must drive the entire display at once, while still achieving full display coverage through coordinated operation of multiple chiplets.
3Reliability
If thin-film transistors are used in active-matrix devices, then electrical performance improves, but luminance uniformity deteriorates
Solution Approach 1:
Instead of fabricating thin-film transistors directly on the display substrate (which creates variability), the invention uses discrete chiplets that are manufactured separately with higher precision using standard semiconductor processes. These chiplets are then copied and distributed across the display, ensuring consistent electrical performance and luminance uniformity without the manufacturing variations inherent in direct TFT fabrication on flexible substrates.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A passive-matrix display device having a plurality of chiplets, each chiplet associated with one or more independent column electrodes located in the display area, each chiplet electrically connected to and driving a separate subset of the independent column electrodes and electrically connected to and driving a subset of the row electrodes to cause the light-emitting material in each pixel to emit light, wherein each chiplet includes a serial luminance shift register for shifting pixel luminance values corresponding to each independent column electrode from one chiplet to another and a column driver for driving each of the independent column electrodes to which it is connected with the corresponding pixel luminance values; and wherein each chiplet further includes a row driver for driving each corresponding row electrode to which it is connected and a row control shift register for controlling the row drivers.