3D Drum Optical Encoder for Low-Stack Autolacing Footwear
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Solution Overview
Problem
Conventional optical encoders used in motorized lacing systems for footwear are fragile and have a high stack-up, which can compromise the performance and robustness of athletic footwear, and their manufacturing precision raises costs and reliability issues.
Innovation Solution
A three-dimensional optical encoder based on a rotary drum design is developed, which is more compact, robust, and easier to manufacture, featuring a cylindrical shape with segments on its exterior or interior surface, allowing for greater variance in manufacturing processes and improved durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional optical encoders are used in motorized lacing systems, then rotational tracking function is provided, but the encoder is fragile and has high stack-up compromising footwear performance
Solution Approach 1:
The patent transitions from a conventional two-dimensional planar encoder disk to a three-dimensional drum-shaped encoder. This dimensional change allows the encoder to achieve compactness (reduced stack-up) while improving durability through the drum structure, directly resolving the contradiction between reliability and device complexity.
2Measurement precision
If conventional optical encoders are used, then rotational measurement is achieved, but manufacturing precision requirements raise costs and reliability issues
Solution Approach 1:
The drum-shaped encoder incorporates segmented reflective and non-reflective regions on its curved surface. This segmentation approach simplifies manufacturing compared to precision planar encoders, as the segments can be applied to the drum surface without requiring extremely tight tolerances on the base drum geometry, thereby reducing manufacturing costs while maintaining measurement precision.
Solution Approach 2:
By moving to a 3D drum structure, the patent creates additional design freedom in the encoder geometry. This allows for more tolerant manufacturing processes compared to flat encoders, as the curved surface can accommodate variations more easily while still providing accurate rotational tracking when viewed from the optical sensor perspective.
3Volume of moving object
If compact encoder design is implemented, then footwear performance is improved, but encoder robustness may be compromised
Solution Approach 1:
The drum-shaped encoder achieves compactness by utilizing three-dimensional space efficiently. The cylindrical form factor reduces the overall stack-up height while maintaining sufficient structural thickness for robustness, solving the contradiction between small volume and structural strength.
Solution Approach 2:
The drum's curved cylindrical surface provides inherent structural strength compared to flat encoders. The curved geometry distributes mechanical stresses more effectively, enhancing robustness while maintaining a compact form factor suitable for footwear applications.
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 three-dimensional optical encoder enhances the reliability and durability of motorized lacing systems, reducing manufacturing costs and improving the performance of athletic footwear by providing accurate rotational tracking with reduced fragility and increased robustness.
Implementation Method 1
an optical sensor and a drum-shaped encoder including a drum portion... segments on its exterior or interior surface
Implementation Method 2
an optical sensor and a drum-shaped encoder including a drum portion
Data Source
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AI summary
An article of footwear and related method includes a midsole, an upper secured with respect to the midsole, and a lace extending through the upper. A motorized lacing system positioned within the midsole, configured to engage with the lace to increase and decrease tension on the lace. The motorized lacing system includes a motor, including a motor shaft, a spool, coupled to the motor shaft, configured to spool and unspool the lace based on the turning of the motor shaft, a processor circuit, and an optical encoder. The optical encoder comprises a three-dimensional encoder defining a major axis and having a surface having a first plurality of segments positioned between a second plurality of segments, and an optical sensor, positioned within optical range of the cylindrical encoder, configured to output a signal to the processor circuit indicative of a detected one of a first and second plurality of segments.