ToF Camera Module Light Control for Close-Range Saturation

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Solution Overview

Problem

Existing camera modules face issues with high power consumption and image degradation when photographing close objects due to light saturation, particularly in ToF camera modules used for biometric authentication.

Innovation Solution

A camera module design that includes a light-emitting unit with multiple light-emitting areas, controlled by a control unit to adjust optical signal intensity and frequency, and a sensor unit to manage light reception, minimizing power consumption and reducing light saturation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If a ToF camera module uses constant light intensity emission irrespective of distance, then distance information can be quickly provided in real time, but power consumption is greatly increased

Engineering Contradiction:
Improvereal-time distance information provisionVSAvoidpower consumption
Core Design Contradiction:
SpeedVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the light emission intensity variable rather than constant. The control unit dynamically adjusts the light emission intensity based on the photographed distance, emitting higher intensity when the object is far and lower intensity when the object is close, thereby optimizing power consumption while maintaining real-time measurement capability

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of light emission intensity based on distance measurements. By adjusting this parameter dynamically according to the object distance, the system achieves both real-time performance and power efficiency

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a ToF camera module photographs a close object, then detailed vein pattern recognition is possible, but light saturation occurs causing image quality degradation

Engineering Contradiction:
Improvevein pattern recognition accuracyVSAvoidlight saturation
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent changes the light emission intensity parameter based on object distance. When photographing close objects, the control unit reduces light emission intensity to prevent saturation, while maintaining sufficient intensity for distant objects, thus avoiding image quality degradation while enabling detailed vein pattern recognition

Inventive Principle:
Principle #35Parameter changes

3Reliability

If light emission intensity is increased to improve signal strength for distant objects, then measurement range is extended, but power consumption increases and close objects become overexposed

Engineering Contradiction:
Improvemeasurement rangeVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts light emission intensity based on the measured distance to the object. For distant objects, higher intensity extends the measurement range, while for close objects, lower intensity prevents overexposure and reduces power consumption

Inventive Principle:
Principle #15Dynamics

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 design enables high-quality imaging at short distances with reduced power consumption and prevents light saturation, allowing for efficient operation and miniaturization of the camera module.

Implementation Method 1

a light-emitting unit (110) to output an optical signal

Methodology Applied
Scientific EffectLight emission: Light

Implementation Method 2

a sensor unit (130) to receive the optical signal

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Implementation Method 3

controlled by a control unit to adjust optical signal intensity and frequency

Methodology Applied
Scientific EffectOptical signal intensity modulation:

Data Source

PatentEP3962065B1Camera module
Publication Date: 2026.03.18 LG INNOTEK CO LTD
  • EP3962065B1 patent drawingFigure 1~3
  • EP3962065B1 patent drawingFigure 4
  • EP3962065B1 patent drawingFigure 5

AI summary

A camera module according to an embodiment of the present invention comprises: a light emitting unit which includes a plurality of light emitting areas and drives at least one of the plurality of light emitting areas according to a first control signal so as to output an optical signal; a light receiving unit for collecting the optical signal; a sensor unit which includes a plurality of light receiving areas corresponding to the plurality of light emitting areas, respectively, and drives at least one of the plurality of light receiving areas according to a second control signal to generate an image signal on the basis of the collected light signal; and a control unit which generates at least one of the first control signal and the second control signal on the basis of the image signal and controls at least one of the light emitting unit and the sensor unit on the basis of at least one of the first control signal and the second control signal.