Illuminated Knob Assembly with Shutter-Based Position Indication
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Solution Overview
Problem
Existing control knob assemblies on cooking appliances do not effectively use light to indicate the movement or position of the control knob, limiting the ability to provide visual feedback through illumination.
Innovation Solution
A knob assembly with a surface defining an aperture, a stationary shutter, and a light source positioned below the surface, where the control knob is rotatable and includes a light-transmissive portion that aligns with the shutter to restrict or permit light passage, allowing for variable illumination to indicate the knob's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a light source is installed below air intake openings to communicate conditions to the user, then visual indication of knob position is improved, but light cannot indicate rotation of the control knob and provides limited visual feedback
Solution Approach 1:
The illumination system is segmented into multiple independent light sources positioned at different locations (below the knob, in the aperture, and in the cavity). Each light source serves a specific function: indicating on/off state, rotation position, or providing ambient illumination. This segmentation allows the system to convey multiple pieces of information simultaneously without requiring a single complex illumination mechanism.
Solution Approach 2:
The patent introduces intermediate elements such as the stationary shutter and the light-transmissive portion of the knob as mediators between the light source and the user. These intermediaries modulate the light to encode positional information, transforming the direct light emission into a coded visual signal that indicates the knob's rotation state without requiring complex electronics or displays.
2Loss of information
If light is projected through the aperture to indicate knob position, then visual communication is improved, but light leakage from other regions reduces clarity of the indication
Solution Approach 1:
The patent extracts and isolates the light path through the aperture by positioning a stationary shutter to block light from reaching other areas. The shutter is specifically designed to allow light to pass only through the intended aperture region, effectively removing the harmful light leakage from other regions while preserving the useful light indication through the aperture.
Solution Approach 2:
The illumination system implements local quality by directing light to specific locations based on the knob's position. The stationary shutter and light-transmissive portion work together to concentrate light emission only in the region that corresponds to the current knob position, creating localized illumination that clearly indicates position without distracting or confusing light leakage from other areas.
3Loss of information
If a stationary shutter and light-transmissive portion are used to indicate rotation, then position communication is improved, but the device complexity increases
Solution Approach 1:
The knob assembly performs self-service by using the knob's own rotation to control the alignment between the light-transmissive portion and the stationary shutter. The physical rotation of the knob directly modulates the light path without requiring additional actuators, sensors, or electronic components. The structure itself serves as the indication mechanism, eliminating the need for separate position-sensing systems.
Solution Approach 2:
The patent replaces complex electronic position-sensing and display systems with a simple mechanical-optical indication mechanism. The stationary shutter and light-transmissive portion create a mechanical linkage where the knob's rotation physically controls light transmission, substituting elaborate electronic systems with a straightforward mechanical-optical system that is both simple and effective.
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 effective communication of the control knob's position through light, providing clear visual feedback while minimizing light leakage, thus enhancing user interaction with the appliance.
Implementation Method 1
a light source positioned below the surface and directed toward the aperture
Implementation Method 2
the control knob may define a light-transmissive portion above the surface... to permit light from the light source to pass through the light-transmissive portion
Data Source
AI summary
An appliance and illuminated knob assembly. The knob assembly may include a surface defining an aperture, a stationary shutter fixed relative to the surface, a light source, and a control knob. The light source may be positioned below the surface and directed toward the aperture. The control knob may define a light-transmissive portion above the surface. Moreover, the control knob may be disposed above the stationary shutter and independently rotatable relative to the aperture. The control knob may be rotatable about a rotation axis between a first position and a second position. The first position may include a light-transmissive portion circumferentially aligned with the shutter to restrict light therethrough. The second position may include the light-transmissive portion circumferentially offset from the shutter to permit light from the light source to pass through the light-transmissive portion.