Asymmetric Drum Light Guide for Uniform Appliance Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light-emitting devices for household appliances face challenges in providing uniform illumination due to the narrow aperture angle of light-emitting diodes, which results in uneven light distribution and sensitivity to assembly tolerances, and are difficult to integrate into rotating drums like those of washing machines and tumble dryers due to power supply and visibility issues.
Innovation Solution
A light-emitting device with a housing and a light-guiding device that deflects the light beam asymmetrically with respect to the optical axis, using prism-type elements and a light-bunching device to create a parallel light beam with a smaller angular spectrum, allowing for oblique emission and improved illumination of rotating components with reduced assembly tolerances and simplified cabling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a light-emitting diode with a narrow aperture angle (3° to 10°) is used, then the light intensity is concentrated, but the illumination becomes uneven and highly sensitive to assembly tolerances
Solution Approach 1:
The patent employs an asymmetric light-guiding device with a specifically designed asymmetric exit surface that redirects light asymmetrically relative to the optical axis. This asymmetric geometry compensates for the narrow aperture angle of the LED, distributing light more evenly across the drum surface while reducing sensitivity to assembly variations. The asymmetric design transforms the concentrated light beam into a more uniform illumination pattern.
Solution Approach 2:
The patent changes the angular parameters of light emission by using the light-guiding device to redirect light at specific angles (preferentially between 20° to 70° relative to the optical axis). This parameter transformation converts the narrow aperture angle output into a broader, more uniform angular distribution that is less sensitive to assembly tolerances while maintaining high illumination intensity.
2Illumination intensity
If lighting means are arranged on the rotating drum, then the drum can be illuminated from within, but power supply becomes difficult and complex
Solution Approach 1:
The patent extracts the lighting system from the rotating drum environment and relocates it to the stationary housing. The light-emitting device is mounted in the housing with the drum rotating in front of it, eliminating the need for rotating power connections. This extraction resolves the power supply complexity issue while maintaining effective drum illumination through the oblique light beam design.
Solution Approach 2:
The patent introduces the oblique light beam as an intermediary between the stationary light source and the rotating drum. By directing light at angles preferentially between 20° to 70° relative to the optical axis, the system creates an effective illumination path that bridges the stationary housing-mounted light source and the rotating drum surface, achieving illumination without requiring the light source to rotate.
3Device complexity
If lighting means are arranged in front of the drum, then power supply is simplified, but visibility into the drum is impaired
Solution Approach 1:
The asymmetric light-guiding device directs the light beam obliquely at angles preferentially between 20° to 70° relative to the optical axis, creating an asymmetric illumination pattern that shines into the drum interior without blocking the viewer's line of sight. This asymmetric redirection allows the light source to be positioned in front of the drum while maintaining both simplified power supply and good visibility.
4Length of stationary object
If the gap between drum and housing is kept small for structural reasons, then the appliance is more compact, but integrating a light-emitting device becomes more difficult
Solution Approach 1:
The patent utilizes the angular dimension by directing light obliquely at preferentially 20° to 70° relative to the optical axis. This angular redirection allows the light-emitting device to be integrated into the existing compact structure with small gap between drum and housing, as the oblique beam path fits within the limited spatial envelope while still effectively illuminating the drum interior.
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 a more uniform and tolerant light-emitting device that can effectively illuminate rotating components with reduced manufacturing variations, maintaining high intensity and reducing the need for additional components, thus enhancing the illumination of household appliance drums while minimizing the gap between the drum and housing.
Implementation Method 1
a light-guiding device, through which the light beam passes and which deflects the entering light beam in such a way that the light beam emerges from the light-guiding device asymmetrically with respect to the optical axis
Data Source
AI summary
A household appliance light emitting device has a light diode that emits a light beam having a cross-section area and a light deflection device through which the light beam travels and that deflects the entering light beam such that the light beam exits asymmetrically to the optical axis of the household appliance light emitting device from the light deflection device. The light deflection device is designed integrally with a housing where the light diode is arranged.