Zoom Lens Camera System with Linear Encoder Feedback

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Solution Overview

Problem

Existing camera systems in laser trackers face inaccuracies due to the lack of direct feedback in the linear positioning of movable zoom optic assemblies, leading to potential measurement errors and device damage from wear and shock.

Innovation Solution

A camera system with a guide system that includes movable zoom optic assemblies carried by optics carriers, guided within a lens tube using ball cages or sliding elements, and equipped with a position encoder element such as a glass scale for precise linear positioning, ensuring accurate axial mobility and feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If motor step counting is used to determine carriage position, then device complexity is reduced, but measurement precision deteriorates due to inaccuracies from motor aging and wear

Engineering Contradiction:

Improveposition feedback systemVSAvoidcarriage position accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent implements direct feedback by mounting a position encoder element (glass scale) on the carriage and using a scanning sensor to read its position. This provides real-time, accurate position information directly from the carriage rather than inferring it from motor steps, resolving the contradiction between simple device structure and precise measurement.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent replaces the indirect mechanical step-counting method with an optical measurement system. The glass scale and scanning sensor create an optical feedback mechanism that directly measures carriage position, substituting the mechanical inference method with a more precise optical measurement approach.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of operation

If motor-driven carriage movement is used, then ease of operation is improved, but reliability deteriorates due to potential missed steps from shock and wear

Engineering Contradiction:

Improvecarriage positioningVSAvoidposition accuracy

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The direct position feedback from the glass scale and scanning sensor allows the system to verify actual carriage position regardless of motor performance. This feedback mechanism prevents reliability issues by providing accurate position information even when motor steps are missed due to shock or wear.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The patent prepares for potential motor failures by implementing a redundant position measurement system. The glass scale provides a backup position reference that protects against position errors from missed motor steps, cushioning against reliability problems before they occur.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Device complexity

If no direct position feedback is provided, then device complexity is reduced, but harmful factors increase due to potential device damage from position errors

Engineering Contradiction:

Improveposition monitoring systemVSAvoiddevice damage risk

Core Design Contradiction:

Device complexityVSObject-generated harmful factors

Solution Approach 1:

The position feedback system provides real-time position information that enables the control system to detect and correct positioning errors before they cause device damage. This feedback mechanism prevents harmful effects by maintaining accurate position control throughout operation.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system uses its own position feedback to automatically detect and correct positioning errors. The glass scale and scanning sensor enable the system to self-monitor and self-correct position deviations, preventing harmful effects without external intervention.

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

The solution provides improved precision in the linear positioning of the carriage, reducing measurement errors and potential damage by enabling accurate tracking and alignment of the camera system, enhancing the overall performance of the laser tracker.

Implementation Method 1

each carriage (20, 30) has a position encoder element (21, 31), which contains in particular an optically or capacitively acquirable position code

Methodology Applied

Scientific EffectOptical encoding:

Implementation Method 2

The carriages are guided in a lens tube, wherein ball cages or sliding elements form the contact points or touch points with the lens tube

Methodology Applied

Scientific EffectFriction reduction through ball bearing: Ball Bearing

Data Source

PatentUS10509192B2Camera system comprising a zoom lens and a linear encoder

Publication Date: 2019.12.17 LEICA GEOSYSTEMS AG

AI summary

A camera system comprising a zoom lens is disclosed. The camera system may be used in a measuring apparatus, having a tube-like guide system having a tube body, which defines a tube interior and an optical axis, a sensor module disposed downstream of the guide system and an optical sensor for detecting optical radiation, at least one first carriage which has an optical assembly having at least one optical element and an optical system carrier, is arranged in a manner linearly moveable along the optical axis in the tube interior and is mounted in a manner guided substantially without play through the tube body in a plane perpendicular to the optical axis, and a first drive system for moving the first carriage along the optical axis, said first drive system being decoupled from the guide system.