Optical Rotary Encoder with Integrated Push-Button

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Solution Overview

Problem

Existing rotary encoders face challenges in accurately measuring the angular position and motion of a shaft while also detecting user input and speed, particularly in compact devices like smartphones and smartwatches, where space and complexity are limited.

Innovation Solution

An optical rotary encoder system with a rotary shaft having markings of varying reflectivity, coupled with a computational unit that processes light signals from a radiation source and receiving elements to determine angular position, motion, and user input, including longitudinal movement and speed, using a microprocessor or microcontroller for signal correlation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional rotary encoders are used to measure angular position and detect user input, then measurement precision is improved, but device complexity and physical size increase

Engineering Contradiction:
Improveangular position measurement precisionVSAvoidencoder structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines the rotary encoder functionality with a push-button input mechanism into a single integrated structure. The rotary shaft serves dual purposes: measuring angular position through optical encoding and detecting push-button presses through longitudinal movement. This merging eliminates the need for separate encoder and button components, reducing overall device complexity while maintaining measurement precision.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotary shaft is designed to perform multiple functions simultaneously: it acts as both the rotating element for angular position measurement and the actuated element for push-button input detection. By making the rotary shaft universal, the patent reduces the number of separate components needed, thereby reducing device complexity while preserving measurement capabilities.

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

2Ease of operation

If traditional rotary encoders with separate push-button mechanisms are used, then user input detection is improved, but physical size and manufacturing complexity increase

Engineering Contradiction:
Improveuser input detection capabilityVSAvoiddevice physical size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent merges the push-button mechanism with the rotary encoder by integrating the push-button actuation into the rotary shaft structure. When a user presses the button, the rotary shaft undergoes longitudinal movement that can be detected optically, combining button functionality with the existing encoder structure without adding separate mechanical components.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The rotary shaft is designed to detect both rotational movement for encoding and longitudinal movement for push-button input. This multi-functional design allows a single component to handle both user input methods, reducing the overall device volume while maintaining ease of operation.

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

3Volume of moving object

If compact design is implemented in portable devices, then device portability is improved, but measurement precision and reliability may deteriorate

Engineering Contradiction:
Improvedevice physical sizeVSAvoidangular position measurement precision
Core Design Contradiction:
Volume of moving objectVSMeasurement precision

Solution Approach 1:

The patent replaces traditional mechanical contact-based push-button detection with an optical detection system. By using light sources and light-dependent resistors to detect longitudinal movement of the rotary shaft, the system eliminates mechanical wear and contact issues, maintaining measurement precision in a compact form factor suitable for portable devices.

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

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 precise measurement of angular position and motion, as well as detection of user input and speed, in a compact and efficient manner, suitable for use in portable devices, reducing physical size and complexity while enhancing reliability and manufacturing efficiency.

Implementation Method 1

a portion of the rotary shaft is operable to reflect light generated from the at least one light generating element onto the at least one light detecting element

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

at least one light detecting element operable to detect light and convert the detected light into a signal

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Data Source

PatentEP3749929B1Optical rotary encoder with integrated optical push-button
Publication Date: 2022.09.28 AMS OSRAM ASIA PACIFIC PTE LTD
  • EP3749929B1 patent drawingFigure 1
  • EP3749929B1 patent drawingFigure 2
  • EP3749929B1 patent drawingFigure 3

AI summary

An example optical encoder includes a rotary shaft having a rotational axis. The rotary shaft is actuatable along the rotational axis. The optical encoder also includes at least one light generating element operable to generate light, and at least one light detecting element operable to detect light and convert the detected light into a signal. The rotary shaft includes a portion operable to reflect light generated from the at least one light generating element onto the at least one light detecting element wherein the signal is generated. The portion is configured such that an actuation of the rotary shaft from a first position to a second position generates a corresponding change in the signal generated in the at least one light detecting element.