Optoelectronic Module Refresh Control for Distance Sensing Power Savings

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Solution Overview

Problem

Time-of-flight (TOF) and triangulation-based optoelectronic modules in devices like smartphones consume significant energy due to frequent light source activation for distance measurements, leading to rapid battery discharge, especially when high refresh rates are required for accurate movement detection.

Innovation Solution

Implementing a refresh control method that alternates between actual distance measurements and extrapolation of distance data, where the decision to measure or extrapolate is based on the number of consecutive extrapolations and object speed, reducing the need for continuous light emission and thus lowering power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the light source is activated frequently to maintain high refresh rate for distance measurements, then the accuracy of movement detection is improved, but the power consumption increases significantly

Engineering Contradiction:

Improveaccuracy of movement detectionVSAvoidpower consumption

Core Design Contradiction:

Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system implements periodic actual distance measurements interspersed with extrapolation periods. Instead of continuous measurement, the light source is activated at specific intervals to perform actual measurements, while intermediate distance values are generated through extrapolation based on previous measurement data and object motion characteristics.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system creates copies of distance information through extrapolation rather than continuously acquiring new measurements. By using previously obtained distance data and object velocity information, the system generates approximate distance values that replicate the function of actual measurements without requiring light source activation.

Inventive Principle:

Principle #26Copying

2Reliability

If actual distance measurements are performed continuously to ensure data accuracy, then the reliability of distance data is improved, but the battery discharge rate increases

Engineering Contradiction:

Improvereliability of distance dataVSAvoidbattery discharge rate

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system uses feedback from actual distance measurements to update extrapolation models. By comparing extrapolated values with subsequent actual measurements, the system refines its understanding of object motion patterns, improving the accuracy of future extrapolations and reducing the frequency of actual measurements needed.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs partial measurements rather than continuous measurements. By conducting actual distance measurements only when necessary (at specified intervals or when extrapolation confidence is low) and using extrapolation for intermediate values, the system achieves sufficient reliability without the excessive energy consumption of continuous measurement.

Inventive Principle:

Principle #16Partial or excessive action

3Loss of time

If the refresh rate is increased to detect object movement more quickly, then the latency in movement detection is reduced, but the power consumption increases

Engineering Contradiction:

Improvelatency in movement detectionVSAvoidpower consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The system performs preliminary actual distance measurements at strategic intervals to establish baseline data and object motion characteristics. These preliminary measurements provide the foundation for subsequent extrapolation, allowing the system to maintain low latency detection capability while reducing overall measurement frequency and power consumption.

Inventive Principle:

Principle #10Preliminary action

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

This approach reduces overall power consumption by up to 45% while maintaining the desired refresh rate and accuracy, allowing for longer device operation and improved latency in detecting object movement.

Implementation Method 1

light projected from the light source and reflected by an object in a scene may be focused onto the pixel array via the optical elements

Methodology Applied

Scientific EffectLight reflection: Reflection

Implementation Method 2

Time-of-flight (TOF) is a technique used to determine the distance to an object or objects in a three-dimensional scene

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 3

The demodulation pixel and supporting circuitry, may detect a phase shift in the reflected light, wherein the phase shift may be further correlated to the distance the light traveled

Methodology Applied

Scientific EffectPhase shift detection: Phase Modulation

Data Source

PatentUS10605920B2Power savings through refresh control for distance sensing devices

Publication Date: 2020.03.31 AMS OSRAM ASIA PACIFIC PTE LTD

AI summary

The present disclosure describes refresh control methods for generating distance data and optoelectronic modules that are operable to provide distance information at a predetermined refresh rate, but with a reduction in overall power consumption attributable to the distance determinations.