TOF Depth Sensor Brightness-Adaptive Laser Selection

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Solution Overview

Problem

Conventional Time of Flight (TOF) technology for depth information acquisition experiences low accuracy in bright environments due to high interference from light beams of specific wavelengths, leading to inaccurate depth identification.

Innovation Solution

A depth information acquisition system with a laser beam emission device featuring multiple laser sources corresponding to different environment brightness values, a photoelectric sensing device with multiple photosensitive regions for various wavelengths, and a processor to select the appropriate laser source based on environment brightness, reducing interference and improving accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a laser beam with wavelength of 850 nm is used for TOF depth detection, then the system can acquire depth information in general environments, but the reference noise increases significantly in bright environments, reducing depth identification accuracy

Engineering Contradiction:

Improvedepth identification accuracyVSAvoidreference noise from environmental light

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the wavelength parameter of the laser source based on environmental conditions. It provides multiple laser sources with different wavelengths (including 850 nm and other wavelengths) and selects the appropriate wavelength according to the brightness of the environment. In bright environments, a wavelength with less environmental interference is selected, while in dark environments, the 850 nm wavelength is used. This dynamic parameter adjustment resolves the contradiction between maintaining depth detection capability and reducing environmental light interference.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If multiple laser sources with different wavelengths are introduced to reduce environmental interference, then depth identification accuracy improves in diverse lighting conditions, but the device complexity increases

Engineering Contradiction:

Improvedepth identification accuracy in diverse lightingVSAvoidnumber of laser sources and selection mechanism

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a dynamic selection mechanism where the system automatically adjusts the laser wavelength based on real-time environmental brightness detection. A brightness detection unit monitors the environment and controls the laser source selection accordingly. This dynamic adaptation allows the system to maintain high measurement precision across varying lighting conditions while managing device complexity through automated control rather than manual configuration.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs self-adjustment by automatically detecting environmental brightness and selecting the appropriate laser wavelength without external intervention. The brightness detection unit and control unit work together to autonomously optimize the laser source selection, reducing the need for complex external control mechanisms and simplifying the overall device architecture while maintaining high measurement accuracy.

Inventive Principle:

Principle #25Self-service

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

Enhances the accuracy of depth information acquisition by selecting the appropriate laser source matching the environment brightness, thereby minimizing interference and improving the precision of depth information in diverse lighting conditions.

Implementation Method 1

a modulated near-infrared light beam is emitted by a sensor to the to-be-measured object, and then reflected by the to-be-measured object back to the sensor

Methodology Applied

Scientific EffectLight emission and reflection: Light

Implementation Method 2

A time difference or a phase difference between the emitted light beam and the reflected light beam is calculated, so as to calculate a distance of the to-be-measured object

Methodology Applied

Scientific EffectTime of Flight measurement: Time of Flight

Implementation Method 3

the reflected light beam is calculated, so as to calculate a distance of the to-be-measured object

Methodology Applied

Scientific EffectPhotoelectric detection: Photoelectric Effect

Data Source

PatentUS11644570B2Depth information acquisition system and method, camera module, and electronic device

Publication Date: 2023.05.09 VIVO MOBILE COMM CO LTD

AI summary

A depth information acquisition system, a depth information acquisition method, a camera module, and an electronic device are provided. The depth information acquisition system includes a laser beam emission device, a laser beam reception device, a photoelectric sensing device and a processor, the laser beam reception device and the photoelectric sensing device are located on a laser beam transmission route of the laser beam emission device, and both the laser beam emission device and the photoelectric sensing device are electrically connected to the processor. The laser beam emission device includes at least two laser sources corresponding to different environment brightness values, the processor is configured to acquire depth information of a to-be-measured object based on a laser transmission time of a target laser source, and the target laser source is a laser source matching brightness value of an environment where the to-be-measured object is located.