Light Sensor Touch Control for Screen-Free Input Detection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional electronic devices face limitations with physical buttons and virtual buttons, such as space utilization and eye-based position identification, while light sensors are underutilized for functions beyond ambient brightness adjustment.

Innovation Solution

A touch-control method and system utilizing a light sensor and processor to detect ambient brightness changes over a specific duration, determining matching brightness characteristics to trigger device operations, thereby functioning as a touch-control button.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If physical buttons are used for touch control, then operation reliability is improved, but device area increases and manufacturing complexity worsens

Engineering Contradiction:

Improveoperation reliabilityVSAvoiddevice area

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the light sensor's primary function (ambient brightness detection) with a secondary function (touch control detection). By combining these functions into a single component, the patent eliminates the need for separate physical buttons while maintaining touch control reliability through the light sensor's existing structure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The light sensor is designed to perform multiple functions: detecting ambient brightness for display adjustment and detecting touch control inputs for device operation. This multi-functionality reduces the overall device area by eliminating dedicated button structures while preserving operational reliability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Area of stationary object

If virtual buttons are used for touch control, then device area is reduced, but position identification requires eye-based detection worsening ease of operation

Engineering Contradiction:

Improvedevice areaVSAvoidposition identification

Core Design Contradiction:

Area of stationary objectVSEase of operation

Solution Approach 1:

The light sensor acts as an intermediary between the user's finger and the device's control system. Instead of requiring visual identification of virtual button positions, the light sensor detects the physical presence and movement of the finger through light blockage, providing tactile-like feedback without requiring screen space or visual attention.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If light sensor is used only for brightness detection, then function specialization is maintained, but adaptability worsens

Engineering Contradiction:

Improvefunction adaptabilityVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system dynamically adapts the light sensor's function based on operational context. The processor distinguishes between brightness adjustment mode and touch control mode by analyzing the temporal patterns and characteristics of light sensor signals, allowing the same hardware to serve different purposes without increasing physical complexity.

Inventive Principle:

Principle #15Dynamics

4Speed

If touch control duration threshold is set low, then response speed is improved, but misjudgment from unstable light sources increases

Engineering Contradiction:

Improveresponse speedVSAvoidtouch control accuracy

Core Design Contradiction:

SpeedVSReliability

Solution Approach 1:

The system performs preliminary analysis of light sensor signal characteristics before making touch control decisions. By pre-establishing criteria for distinguishing valid touch signals from invalid ones (such as signal duration, magnitude, and pattern), the system can quickly respond to genuine touches while filtering out false signals from unstable light sources.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses feedback mechanisms to validate touch control inputs by analyzing the temporal and spatial characteristics of light sensor signals. The processor compares incoming signals against established patterns to determine whether they represent intentional user input or environmental interference, adjusting the response accordingly to maintain both speed and accuracy.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables the use of light sensors for touch-control without requiring screen space and eye-positioning, reducing misjudgment from unstable light sources.

Implementation Method 1

obtaining an ambient brightness level via the light sensor

Methodology Applied

Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentUS12561019B2Touch-control method, electronic device, and touch-control system

Publication Date: 2026.02.24 GETAC TECH CORP

AI summary

A touch-control method, an electronic device, and a touch-control system are provided. The touch-control method includes: obtaining an ambient brightness level via a light sensor; recording a duration in which the ambient brightness level is lower than a threshold, and determining, in response to the duration being greater than a predetermined minimum time length and less than a predetermined maximum time length, whether or not a first brightness characteristic of the ambient brightness level before the duration matches a second brightness characteristic of the ambient brightness level after the duration; and determining, in response to determining that the first brightness characteristic matches the second brightness characteristic, occurrence of a touch-control behavior, and triggering the electronic device to perform an operation corresponding to the touch-control behavior.