Laser Light Source Control for Uniform Spot Detection

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Solution Overview

Problem

In distance measuring devices, the luminance of bright spots on images captured by image sensors is not uniform due to manufacturing variations, temperature fluctuations, and optical system characteristics, leading to inaccurate coordinate detection and poor sensing performance.

Innovation Solution

A light source device with a drive unit that adjusts the light emission parameters of laser light emitting elements based on captured data from the image sensor, ensuring uniform light reception by varying the power, timing, and number of light emissions per predetermined unit, including temperature compensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If exposure is adjusted according to a dark spot, then a bright spot will be saturated, but if exposure is adjusted according to a bright spot, then a dark spot will not appear

Engineering Contradiction:
Improvecoordinate detection accuracyVSAvoidluminance uniformity
Core Design Contradiction:
Measurement precisionVSIllumination intensity

Solution Approach 1:

The patent applies local quality by dividing the image into multiple regions and setting different exposure values for each region based on its luminance characteristics. This allows each region to be exposed appropriately according to its local luminance level, preventing both saturation in bright areas and underexposure in dark areas, thereby resolving the contradiction between measurement precision and illumination intensity uniformity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamic exposure adjustment by automatically determining exposure values for different regions based on real-time luminance detection. The exposure parameters are dynamically adapted to the actual lighting conditions of each region, enabling the system to maintain optimal coordinate detection accuracy across varying luminance conditions without manual intervention.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If uniform light emission is controlled, then manufacturing variations and temperature fluctuations cannot be compensated, but if individual adjustment is made, then device complexity increases

Engineering Contradiction:
Improvesensing accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs feedback mechanisms by detecting the actual luminance output of each light emitting element and using this information to adjust exposure settings. This feedback loop compensates for manufacturing variations and temperature fluctuations without requiring complex individual control of each element, as the compensation is achieved through intelligent image processing rather than hardware complexity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-service by automatically compensating for its own deficiencies through internal detection and adjustment. The image sensor detects luminance variations caused by manufacturing variations and temperature effects, and the processing unit automatically adjusts exposure parameters to compensate, eliminating the need for external calibration or complex control systems.

Inventive Principle:
Principle #25Self-service

3Reliability

If standard exposure is used, then bright spots become saturated, but if reduced exposure is used, then dark spots do not appear

Engineering Contradiction:
Improvesensing performanceVSAvoidcoordinate information
Core Design Contradiction:
ReliabilityVSLoss of information

Solution Approach 1:

The patent applies segmentation by dividing the image into multiple regions and applying different exposure values to each region. This segmentation allows the system to preserve detail in both bright and dark areas simultaneously, preventing information loss in coordinate detection while maintaining reliable sensing performance across the entire field of view.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements parameter changes by dynamically adjusting exposure parameters based on the luminance characteristics of different regions. By changing the exposure parameter locally rather than uniformly, the system prevents both saturation and underexposure, ensuring that coordinate information is preserved in all regions while maintaining high sensing reliability.

Inventive Principle:
Principle #35Parameter changes

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 configuration allows for accurate coordinate detection and improved sensing performance by controlling luminance variations, ensuring appropriate exposure and image capturing, and enhancing the signal-to-noise ratio.

Implementation Method 1

a plurality of laser light emitting elements

Methodology Applied
Scientific EffectLaser: Laser

Data Source

PatentEP3832252B1Light source device, imaging device, and sensing module
Publication Date: 2024.05.22 SONY SEMICON SOLUTIONS CORP
  • EP3832252B1 patent drawingFigure 1
  • EP3832252B1 patent drawingFigure 2A~2B
  • EP3832252B1 patent drawingFigure 3

AI summary

In a case where laser light is emitted to an object to perform distance measurement, object recognition, and the like, image capturing suitable for detection is performed on the image sensor side. Therefore, a light source device includes a plurality of laser light emitting elements and a drive unit. The drive unit drives each of the laser light emitting elements according to a light emission parameter that defines a light emission operation of the laser light emitting elements per predetermined unit, the light emission parameter being set on the basis of captured data by an image sensor that receives and captures light emitted from the laser light emitting elements and reflected by a subject.