LED Stylus Tip Illumination for Reflective Displays in Low Light

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Solution Overview

Problem

Current electronic devices with reflective displays are ineffective in low-light environments without additional light sources, leading to user inconvenience and degraded experience.

Innovation Solution

A stylus equipped with LEDs, a control module, and sensors to provide light when needed, ensuring the reflective display functions in dark conditions while being energy-efficient and cost-effective.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If a reflective display is used to eliminate backlight, then energy consumption is reduced and manufacturing cost is lowered, but the display cannot function in dark environments without additional light sources

Engineering Contradiction:
Improveenergy consumptionVSAvoidenvironmental adaptability
Core Design Contradiction:
Use of energy by stationary objectVSAdaptability or versatility

Solution Approach 1:

The stylus acts as an intermediary light source between the user and the reflective display. It contains a light emitting device that projects light onto the reflective display surface, enabling the display to function in dark environments without requiring the display itself to have backlighting capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The stylus is designed with multi-functionality: it serves both as a touch input device and as a portable light source for the reflective display. This allows a single device to address multiple needs - interaction with the display and providing illumination when needed.

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

2Ease of operation

If conventional styluses with light-emitting elements are used, then touch detection is assisted, but they are not designed to address the specific needs of reflective displays in low-light environments

Engineering Contradiction:
Improvetouch operationVSAvoidenvironmental adaptability
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The light emitting device is positioned at the tip of the stylus, creating a localized light source exactly where it is needed - on the reflective display surface during touch interaction. This localized illumination ensures that only the necessary area is lit, improving visibility for touch detection while minimizing overall energy consumption.

Inventive Principle:
Principle #3Local quality

3Adaptability or versatility

If additional light sources are added to reflective displays, then dark environment functionality is enabled, but device complexity and cost increase

Engineering Contradiction:
Improveenvironmental adaptabilityVSAvoidsystem complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The light source functionality is extracted from the display system itself and placed into a separate, portable stylus device. This separation allows the display to remain simple and cost-effective while still enabling dark environment operation through the external stylus light source.

Inventive Principle:
Principle #2Taking out (Extraction)

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

The stylus enhances user experience by providing a reflective light source in dark environments, reducing power consumption, and maintaining low production costs.

Implementation Method 1

The light emitting device comprises a plurality of LEDs

Methodology Applied
Scientific EffectLight Emitting Diode: Light Emitting Diode

Implementation Method 2

The pen body is a solar panel that charges a power supply battery

Methodology Applied
Scientific EffectSolar Energy: Solar Energy

Data Source

PatentEP4235370B1Touch control stylus and touch control system
Publication Date: 2026.02.04 TCL COMM (NINGBO) CO LTD
  • EP4235370B1 patent drawingFigure 1
  • EP4235370B1 patent drawingFigure 2
  • EP4235370B1 patent drawingFigure 3

AI summary

The disclosure comprises a stylus and a touch control system. The stylus comprises a pen body, a pen tip, and a light emitting device. The light emitting device is provided at the pen tip. A non-contacting end of the pen tip is connected to a bottom end of the pen body. The pen body is provided with a control module inside the pen body. The control module is electrically connected to the light emitting device and controls the light emitting device to emit light when a contacting end of the pen tip is applied to a reflective display.