Stage Light Angular Detector Using Electromagnetic Coupling

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Solution Overview

Problem

Existing stage light fixtures face positioning inaccuracies due to interference from intense light and magnetic field attenuation, leading to significant deviations in light spot projection.

Innovation Solution

A stage light fixture with an angular detector using a stator and rotor assembly, where the stator has a magnet exciting coil generating a high-frequency alternating magnetic field and a receiving coil inducing electromotive force, coupled with a positioning bearing to ensure accurate rotational positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a photoelectric encoder is used for rotational positioning, then the positioning device can detect rotation angle, but the intense light in the stage light fixture interferes with the photoelectric encoder causing positioning error

Engineering Contradiction:
Improvepositioning accuracyVSAvoidlight interference
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a magnetic field as an intermediary medium between the rotor and stator. The rotor assembly with magnets generates a magnetic field that couples with the stator assembly's coils, enabling rotation detection without direct optical or electrical contact. This intermediary magnetic field transmits rotational information while isolating the sensing system from light interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the photoelectric (optical) encoding system with an electromagnetic coupling system. Instead of using light to detect rotation, the system uses magnetic field coupling between the rotor and stator assemblies. This substitution eliminates the vulnerability to light interference while maintaining rotation detection capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a magnetic encoder is used for rotational positioning, then the positioning device can detect rotation angle, but the magnetic field intensity rapidly attenuates under high temperature causing reduced positioning accuracy

Engineering Contradiction:
Improvepositioning accuracyVSAvoidhigh temperature
Core Design Contradiction:
Measurement precisionVSTemperature

Solution Approach 1:

The patent employs a high-frequency periodic alternating current to continuously generate and refresh the magnetic field in the stator assembly. This continuous regeneration of the magnetic field prevents attenuation and maintains stable electromagnetic coupling between the rotor and stator, ensuring consistent positioning accuracy even under high temperature conditions.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent uses high-frequency periodic alternating current and voltage to generate an alternating magnetic field that continuously oscillates and refreshes. This periodic action prevents magnetic field attenuation by constantly renewing the magnetic flux, maintaining reliable electromagnetic coupling between the rotor and stator assemblies under high temperature operation.

Inventive Principle:
Principle #19Periodic action

3Measurement precision

If photoelectric or magnetic encoders are used for rotational positioning, then the positioning device can detect rotation angle, but the intrinsic positioning accuracy remains relatively low causing light spot deviation

Engineering Contradiction:
Improvepositioning accuracyVSAvoidpositioning precision
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent implements a feedback mechanism where the electromagnetic coupling strength between the rotor and stator is continuously measured and used to determine the rotation angle. The system monitors the induced electromotive force in the stator coils resulting from rotor rotation, providing continuous feedback on positional information to achieve high-precision angular detection.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent detects rotation angle by measuring changes in electromagnetic coupling strength between the rotor and stator assemblies. As the rotor rotates, the magnetic coupling parameters change, and these parameter variations are converted into angular position information, enabling high-precision positioning through parameter transformation.

Inventive Principle:
Principle #35Parameter changes

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 solution provides stable and accurate rotational positioning by minimizing environmental interference and maintaining a continuous magnetic field, ensuring precise light projection without attenuation.

Implementation Method 1

a magnet exciting coil (611) adapted to form an alternating magnetic field in the region of the stator assembly (610) by high-frequency periodic alternating current and voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

a receiving coil (612) arranged in the alternating magnetic field which is adapted to form an induced electromotive force

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 3

The rotor assembly (620) is configured to change electromagnetic coupling strength between the magnet exciting coil (611) and the receiving coil (612)

Methodology Applied
Scientific EffectElectromagnetic coupling: Electromagnetic Induction

Data Source

PatentEP4502464B1Stage light fixture with high-stable rotational positioning
Publication Date: 2026.03.04 GUANGZHOU HAOYANG ELECTRONICS CO LTD
  • EP4502464B1 patent drawingFigure 1
  • EP4502464B1 patent drawingFigure 2
  • EP4502464B1 patent drawingFigure 3

AI summary

A stage light fixture with high-stable rotational positioning including a base, a pivoting arm pivoted to the base through a pivoting shaft, and a light head pivoted to the pivoting arm through another pivoting shaft. An angular detector for detecting a rotation angle of the light head and/or the pivoting arm is further provided, which includes a stator assembly and a rotor assembly oppositely arranged each other, wherein the stator assembly has a magnet exciting coil adapted to form an alternating magnetic field in a region of the stator assembly by high-frequency periodic alternating current and voltage and a receiving coil arranged in the alternating magnetic field adapted to form an induced electromotive force; and the rotor assembly is configured to change electromagnetic coupling strength between the magnet exciting coil and the receiving coil during rotation thereof relative to the stator assembly.