Bypass Path Touch Controller Overlay Engine Latency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current input devices experience significant latency in updating displays in response to touch events, leading to delays in tracking user input, particularly noticeable in high-speed interactions where the user input location does not immediately correspond to the displayed trace, resulting in a noticeable lag.
Innovation Solution
A processing system that includes a touch controller and an overlay engine with a by-pass path, allowing touch data to be directly transmitted to the overlay engine, which modifies display frame data without relying on the host processor, thereby reducing latency by overlaying or replacing pixel data to reflect user input in real-time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If touch data is transmitted through the host processor for display updates, then processing completeness is improved, but latency increases
Solution Approach 1:
The display processing system is segmented into two independent paths: a complete processing path through the host processor for full display frame updates, and a bypass path directly to the overlay engine for touch feedback updates. This segmentation allows different types of data to be processed through appropriate channels, resolving the contradiction between processing completeness and latency.
Solution Approach 2:
The overlay engine acts as an intermediary component that receives touch data directly from the touch controller via the bypass path. It processes touch feedback independently and overlays it on the display without requiring host processor intervention, thereby reducing latency while maintaining processing reliability for other display elements.
2Speed
If a bypass path is implemented for low-latency updates, then responsiveness is improved, but system complexity increases
Solution Approach 1:
The overlay engine is merged with the display driver architecture, allowing it to leverage existing display output infrastructure. This integration enables the bypass path to reuse established hardware components and communication interfaces, reducing the overall system complexity despite adding a new processing path.
Solution Approach 2:
The overlay engine serves multiple functions: it processes touch feedback data, generates display updates, and overlays them on the main display output. This multi-functionality allows a single component to handle various update scenarios, reducing the need for separate dedicated systems and thereby managing complexity.
3Loss of time
If the overlay engine processes touch data independently, then latency is reduced, but processing accuracy may worsen
Solution Approach 1:
The system dynamically selects the processing path based on the type of update needed: the overlay engine handles time-critical touch feedback independently for low latency, while the host processor handles complex display elements requiring full processing accuracy. This dynamic routing ensures both latency reduction and processing accuracy are maintained where needed.
Solution Approach 2:
The overlay engine performs partial processing of touch data, focusing only on the essential feedback elements that require immediate display. It processes sufficient information to provide responsive touch feedback without performing the complete processing that would be needed for full display frame updates, thereby achieving low latency while maintaining adequate accuracy for touch feedback.
Data Source
AI summary
This disclosure generally provides an input device that includes a by-pass path for improving latency between a touch controller and a display driver. In one embodiment, the by-pass path directly connects the touch controller and display driver, thereby by-passing a host processor (e.g., a central processing unit (CPU) or graphic processing unit (GPU)) in the input device. By doing so, the input device can detect user input and update a display to reflect the user input faster than if the display driver had to wait until updated display frames are sent from the host processor. For example, the host processor may transmit touch data received from the touch controller to an application that uses the touch data to change the display. In some input devices, this process can take hundreds of milliseconds, which may be enough time for the user to notice a delay.