LED Touch Interface Using Daisy-Chain Data Feedback

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing touch-sensitive technologies require dedicated electrical circuits and micro-controllers for each touch-sensitive area, leading to complex wiring and increased manufacturing costs, especially for larger and customizable touch-sensitive surfaces.

Innovation Solution

A device and method utilizing a daisy-chain arrangement of individually controllable LED light sources, where control data is fed back through a feedback line to associate touchpad positions with LED light sources, eliminating the need for dedicated circuits and micro-controllers by using the existing wiring infrastructure for touch sensing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If capacitive based touch-sensitive technology is used to enable embedding a user interface into an electronic product, then the user interface functionality is improved, but the wiring complexity and manufacturing costs increase due to requiring separate connections for each touch sensitive area

Engineering Contradiction:
Improveuser interface functionalityVSAvoidwiring complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent makes the LED light sources multi-functional by enabling them to serve both their primary function (light emission) and a secondary function (touch sensing). The same LED components that emit light are also configured to detect touch events, eliminating the need for separate touch-sensitive circuits. This is achieved by monitoring changes in the LED's electrical characteristics when touched, allowing one component to fulfill multiple roles and thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the touch sensing function with the existing LED light source circuitry. Instead of combining separate LED circuits and separate touch-sensitive circuits as in prior art, the invention integrates touch detection capability directly into the LED control system. The controller monitors the LED's electrical parameters (such as forward voltage or current) to detect touch events, thereby combining two previously separate functions into a unified system that reduces wiring and component count.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If dedicated electrical circuits and micro-controllers are used for each touch-sensitive area to achieve accurate touch detection, then the touch sensing precision is improved, but the manufacturing costs and device complexity increase

Engineering Contradiction:
Improvetouch sensing precisionVSAvoidmanufacturing costs
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent makes the LED light sources multi-functional by enabling them to serve both their primary function (light emission) and a secondary function (touch sensing). The same LED components that emit light are also configured to detect touch events, eliminating the need for separate touch-sensitive circuits. This is achieved by monitoring changes in the LED's electrical characteristics when touched, allowing one component to fulfill multiple roles and thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The LED light sources perform self-diagnosis by monitoring their own electrical characteristics to detect touch events. The same LED circuit that drives the light emission also monitors for changes in its own electrical parameters (such as forward voltage drop or current) that occur when the LED is touched. This self-service capability eliminates the need for external dedicated touch sensing circuits and micro-controllers, thereby reducing manufacturing costs while maintaining touch detection accuracy.

Inventive Principle:
Principle #25Self-service

3Area of stationary object

If larger and customizable touch-sensitive surfaces are implemented with traditional capacitive technology, then the touch interface area is improved, but the wiring complexity and scalability are worsened due to increased number of separate connections required

Engineering Contradiction:
Improvetouch sensitive surface areaVSAvoidwiring complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent makes the LED light sources multi-functional by enabling them to serve both their primary function (light emission) and a secondary function (touch sensing). The same LED components that emit light are also configured to detect touch events, eliminating the need for separate touch-sensitive circuits. This is achieved by monitoring changes in the LED's electrical characteristics when touched, allowing one component to fulfill multiple roles and thereby reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent segments the touch-sensitive surface into multiple zones, with each zone associated with one or more LED light sources. Each LED or group of LEDs serves as an independent touch sensing element, allowing the large surface to be divided into manageable segments. This segmentation approach enables scalable design where the touch surface can be extended by adding more LED segments without proportionally increasing wiring complexity, as each segment uses the same simple LED-based sensing mechanism.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP3646154B1A device with a touch user interface for controlling a load, a system and a method thereof
Publication Date: 2023.08.09 SIGNIFY HOLDING BV
  • EP3646154B1 patent drawingFigure 1
  • EP3646154B1 patent drawingFigure 2
  • EP3646154B1 patent drawingFigure 3~4

AI summary

The invention provides an improved device with a touch user interface for controlling a load. The device comprising: an array of individually controllable LED light sources; data lines for interconnecting successive LED light sources to obtain a daisy-chain of successive LED light sources in said array and for rippling control data through the daisy- chain to a particular LED light source in said array, wherein the particular LED light source in said array is arranged for removing one or more bits from the control data and for providing resulting control data downstream (i.e. e.g. to a successive LED light source) in the daisy-chain; a feedback line for feeding back the resulting control data; a touchpad for connecting, when in use touched, one of the data lines and the feedback line; a controller comprising (i) an output for sending the control data over said data lines to the particular LED light source, and (ii) an input for receiving the resulting control data over the feedback line when the touchpad is touched; and the controller being arranged for (i) comparing said sent control data with said received resulting control data for associating the touchpad, when in use touched, with a position in the array of individually controllable LED light sources of the particular LED light source, and (ii) providing a control signal for controlling the load based on said position.