Low-Latency Touch Overlay System for Display Lag Reduction

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Solution Overview

Problem

Current touch-enabled computing devices experience high latency due to processing delays between touch sensor panels and application processors, resulting in noticeable lag when responding to user inputs, which affects the responsiveness of the user interface.

Innovation Solution

A low-latency overlay system that processes touch events and video images independently of the application processor, using a touch path module, lookup table generator, control module, rendering module, and overlay buffer to generate a combined display image by interpolating or extrapolating touch paths and overlaying visual feedback ahead of the application processor's rendering, thereby reducing display lag.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If touch events are processed by high level application software on the application processor, then comprehensive processing operations can be performed, but high latency (70 to 100 milliseconds) is introduced due to non-deterministic processing time and delays from other computational tasks

Engineering Contradiction:

Improvecomprehensive processingVSAvoidlatency

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent divides the touch processing system into two independent segments: a low-level touch controller that handles immediate touch events with deterministic timing, and a high-level application processor that performs comprehensive software processing. This segmentation allows the time-critical functions to be separated from computationally intensive tasks, resolving the contradiction between comprehensive processing and low latency.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a low-level touch controller as an intermediary between the touch sensor panel and the application processor. This intermediary handles immediate touch event processing independently, providing deterministic response times without burdening the application processor, thus reducing overall system latency while maintaining comprehensive processing capabilities.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If multiple processing operations are performed between the touch sensor panel and the application processor, then thorough touch event handling is achieved, but display lag increases due to the number of processing steps

Engineering Contradiction:

Improvetouch event handlingVSAvoiddisplay lag

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent segments processing operations into immediate low-level handling by the touch controller and deferred high-level handling by the application processor. This allows critical path operations to be minimized in the time-sensitive path while maintaining thorough processing in the non-time-critical path, reducing display lag without sacrificing handling quality.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The low-level touch controller performs preliminary processing of touch events immediately upon detection, preparing data and generating initial responses before the application processor begins its comprehensive processing. This preliminary action reduces the perceived latency by having ready-to-display information available earlier in the processing pipeline.

Inventive Principle:

Principle #10Preliminary action

3Device complexity

If the application processor handles all touch processing tasks, then centralized control is maintained, but responsiveness to user inputs decreases due to processing bottlenecks

Engineering Contradiction:

Improvecentralized controlVSAvoidresponsiveness

Core Design Contradiction:

Device complexityVSEase of operation

Solution Approach 1:

The patent segments the centralized control architecture into distributed processing units: a low-level touch controller for immediate responsive operations and a high-level application processor for comprehensive management. This segmentation maintains centralized coordination while enabling parallel processing paths, improving responsiveness without completely decentralizing control.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The low-level touch controller acts as an intermediary that bridges the gap between the touch sensor panel and the application processor. It provides immediate local processing for responsive user interaction while maintaining communication with the centralized application processor, thus improving responsiveness while preserving centralized control architecture.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9710098B2Method and apparatus to reduce latency of touch events

Publication Date: 2017.07.18 SAMSUNG DISPLAY CO LTD

AI summary

A system includes: a touch path module to receive a plurality of touch events and to generate an output based on the touch events; and a rendering module to: receive a video image; receive the output of the touch path module; determine a plurality of points defining a boundary of a shape, the shape being determined based on the output of the touch path module; combine the video image with overlay data in accordance with the plurality of points to generate a combined display image; and output the combined display image.