Dual-Camera 3D Scanner for Intraoral Geometry Mapping

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current 3D scanning technologies for intraoral applications face challenges in accurately capturing the geometry of teeth surfaces with shallow depth of field, requiring multiple perspectives and precise alignment, which can be cumbersome and time-consuming, especially in confined oral cavities.

Innovation Solution

A focus scanning apparatus with a dual-camera system, where the first camera captures images with a shallow depth of field for precise geometry mapping and the second camera provides a large depth of field image, allowing for simultaneous scanning with multiple perspectives and color texture overlay, enhancing scanning efficiency and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a shallow depth of field is used for precise geometry mapping, then measurement precision is improved, but the scanning process becomes time-consuming and complex due to requiring multiple perspectives and precise alignment

Engineering Contradiction:
Improvegeometry mapping precisionVSAvoidscanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent divides the imaging function into two separate camera systems: a first camera with shallow depth of field for precise geometry mapping, and a second camera with large depth of field for capturing color texture and providing operator guidance. This segmentation allows each camera to be optimized for its specific function, eliminating the need for multiple scans from different perspectives while maintaining high measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent adds a temporal dimension by capturing geometry and color texture simultaneously at the same moment in time using both cameras. This eliminates the need for sequential scanning from multiple perspectives, reducing scanning time while maintaining precision through the first camera's shallow depth of field imaging.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If multiple scans from different perspectives are performed for accurate 3D mapping, then measurement precision is improved, but device complexity and ease of operation worsen due to requiring precise alignment

Engineering Contradiction:
Improve3D mapping accuracyVSAvoidalignment complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges the geometry capture function and color texture capture function into a single integrated imaging system with two cameras positioned at different perspectives simultaneously. The first camera captures precise geometry with shallow depth of field while the second camera captures color texture with large depth of field, both at the same time from the same device position, eliminating the need for complex alignment procedures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The imaging system performs multiple functions simultaneously: the first camera provides precise geometry mapping, the second camera provides color texture capture and operator guidance. This multi-functionality allows a single device position to capture all necessary information for accurate 3D mapping without requiring complex alignment procedures.

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

3Measurement precision

If a shallow depth of field is used for precise geometry capture, then measurement precision is improved, but ease of operation worsens due to difficulty in guiding the scanning process

Engineering Contradiction:
Improvegeometry capture precisionVSAvoidoperator guidance
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent segments the imaging functions by assigning the first camera to capture precise geometry with shallow depth of field and the second camera to provide operator guidance with large depth of field. The second camera's large depth of field allows the operator to see the entire field of view including areas outside the narrow focus plane of the first camera, making it easier to navigate and position the scanner accurately.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The second camera with large depth of field acts as an intermediary that provides the operator with a broader view of the scanning area. This intermediary imaging system helps the operator locate and position the region of interest before the first camera captures the precise geometry, improving ease of operation without compromising measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If sequential scanning for geometry and color texture is performed, then measurement precision is improved, but productivity decreases due to multiple scanning steps

Engineering Contradiction:
Improveseparate geometry and color captureVSAvoidscanning efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent merges the geometry capture process and color texture capture process into a single simultaneous operation using two cameras. The first camera captures precise geometry while the second camera captures color texture, both at the same time from the same device position. This eliminates the need for sequential scanning steps, doubling the productivity while maintaining the measurement precision of separate captures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The imaging system performs continuous useful action by capturing both geometry and color texture information simultaneously in a single scan. Both cameras operate continuously at the same time, eliminating idle time between geometry scanning and color texture scanning, thereby maximizing productivity while maintaining measurement precision.

Inventive Principle:
Principle #20Continuity of useful 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

Enables fast and accurate 3D scanning of teeth surfaces with improved depth of field and color texture integration, reducing the need for multiple scans and enhancing operator guidance during intraoral procedures.

Implementation Method 1

a first optical system for imaging with a first depth of field on the first camera at least part of the transmitted light rays returned from the object to the array of sensor elements

Methodology Applied
Scientific EffectOptical imaging: Lens

Implementation Method 2

a second optical system for imaging at least some of the selected light rays onto the second camera with a second depth of field

Methodology Applied
Scientific EffectOptical imaging: Lens

Implementation Method 3

means for transmitting the probe light rays towards the object thereby illuminating at least a part of the object, means for transmitting light rays returned from the object to the array of sensor elements

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP2654607B1Optical system in 3D focus scanner
Publication Date: 2019.04.24 3SHAPE AS
  • EP2654607B1 patent drawingFigure 1
  • EP2654607B1 patent drawingFigure 2
  • EP2654607B1 patent drawingFigure 3

AI summary

Disclosed is a scanner (200) for obtaining and/or measuring a 3D geometry of at least a part of a surface of an object (290), said scanner comprising: - a first camera (230) comprising an array of sensor elements, - a first means (210) for generating a probe light, - means (240) for transmitting the probe light rays towards the object thereby illuminating at least a part of the object (290), - means (240) for transmitting light rays returned from the object to the array of sensor elements, - a first optical system (240) for imaging with a first depth of field on the first camera (230) at least part of the transmitted light rays returned from the object to the array of sensor elements, - means for varying the position of the focus plane on the object, - means (310) for obtaining at least one image from said array of sensor elements, - means for determining the in-focus position(s) of: - each of a plurality of the sensor elements for a range of focus plane positions, or - each of a plurality of groups of the sensor elements for a range of focus plane positions, and - means for transforming the in-focus data into 3D coordinates.