Touch Input Security Verification via Image Data Check Codes

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Solution Overview

Problem

Touch input devices, such as touchscreens, introduce additional error sources when used for safety-critical applications due to the complexity of hardware and software components involved in input recording and processing, making it time-consuming and expensive to ensure accurate and secure input of safety-relevant data.

Innovation Solution

A method and device that reads touch input separately from conventional recognition, using a test unit connected to the display's image data line to generate and verify check codes for selected monitoring areas, ensuring that only valid inputs are processed and allowing for real-time validation of operator actions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If touch input devices are used for safety-critical applications, then input accuracy and operator convenience are improved, but system complexity and certification effort increase significantly

Engineering Contradiction:
Improveinput accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the touch input verification process into separate functional components: a test unit that independently reads touch input coordinates, a check code generation unit that creates verification codes based on display image data, and a security computer that validates the input. This segmentation allows each component to be independently tested and certified, reducing overall system certification complexity while maintaining input accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a check code as an intermediary element between the touch input and the system processing. The check code is generated from display image data and used to verify that the touched position corresponds to the intended target. This intermediary mechanism enables accurate input verification without requiring direct complex validation of the entire input system.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If comprehensive safety testing is performed on all touch screen components, then system reliability is improved, but time consumption and cost increase

Engineering Contradiction:
Improvesystem reliabilityVSAvoidcertification time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements preliminary safety verification by generating check codes from display image data before the actual touch input is processed. This allows the system to pre-validate that the displayed elements correspond to the expected input targets, reducing the need for extensive post-input testing and accelerating the certification process while maintaining reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent establishes a feedback mechanism where the security computer receives both the touch input coordinates and the corresponding check code, then validates whether they match. This feedback loop enables rapid verification of input accuracy without requiring comprehensive manual testing of each component, thereby improving reliability while reducing certification time.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2551787B8Device and method for input of security-relevant information using a display device with touch input
Publication Date: 2015.03.11 DEUTA WERKE GMBH

AI summary

The invention relates to a method and a device for safety-relevant input on a display device 14 with a detection component 16 for detecting different touch inputs 20 on the display. To increase input security, a test unit 30 is connected to the image data line 24 to the display device 14. This test unit 30 is connected to a detection component 34 for reading data and identifies a monitoring area that corresponds to the portion of the display within which a touch input 20 occurred. Furthermore, the test unit 30 generates a test code for that portion of the image data intended for display in the monitoring area. The test code generated by the test unit 30 is used for safety purposes, in particular to confirm or reject the value determined to have been entered on the display device.