Optical Positioning Device Multi-Direction Reference Mark
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical position measuring devices face challenges in determining relative positions of movable objects with high precision along multiple directions, particularly in ensuring reliable detection of reference markings and generating periodic incremental signals regardless of the scanning unit's position.
Innovation Solution
An optical position measuring device with two scanning units and a scale featuring incremental graduations at an angle of 0° to 90°, integrated reference markings with both periodic and aperiodic components, and a detector arrangement to generate consistent incremental and reference signals along multiple measuring directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If reference marks are integrated into incremental divisions, then device complexity is reduced and manufacturing is simplified, but reliable detection of reference marks and generation of periodic incremental signals may be compromised
Solution Approach 1:
The reference mark is segmented into two distinct components: a periodic component with the same period as the incremental divisions, and an aperiodic component with varying spacing. This segmentation allows the system to maintain both simplified integration into the incremental scale and reliable detection, as each component serves a specific function in signal generation and reference detection.
Solution Approach 2:
Different regions of the reference mark are assigned different optical properties and structures. The periodic component provides regular signal generation, while the aperiodic component provides unique positional identification. This local differentiation ensures reliable detection throughout the measurement range while maintaining structural integration.
2Adaptability or versatility
If incremental divisions are arranged at an angle between 0° and 90°, then measurement capability along multiple directions is enabled, but signal consistency during scanning may be affected
Solution Approach 1:
The periodic component of the reference mark is designed with the same period as the incremental divisions, ensuring that periodic incremental signals are generated consistently regardless of the scanning position or angle. This periodic structure maintains signal reliability while the angled arrangement enables multi-directional measurement capability.
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 precise relative position determination along multiple directions by ensuring periodic incremental signals are generated consistently, allowing for accurate absolute position referencing regardless of the scanning unit's position, thereby improving measurement reliability and precision.
Implementation Method 1
scanning the incremental scale whose divisions are oriented perpendicular to the first measuring direction, periodic incremental signals can be generated
Implementation Method 2
two incremental divisions, which are arranged periodically, form an angle between 0° and 90° with each other
Implementation Method 3
each comprising at least one light source, one or more gratings, and a detector arrangement
Data Source
Figure 1a~1b
Figure 2~3
Figure 4~5
AI summary
The present invention relates to an optical position measuring device for determining the relative position of two objects that are movable relative to each other along at least two measuring directions. The device comprises two scanning units connected to one of the two objects, each comprising at least one light source, one or more gratings, and a detector arrangement. Furthermore, a scale is connected to the other object, having two tracks extending along a first measuring direction with incremental divisions, each consisting of division areas with different optical properties arranged periodically along an incremental division direction. The two incremental division directions form an angle between 0° and 90° with each other.Each of the two incremental divisions incorporates at least one reference mark, from whose scanning a reference signal can be generated at a defined reference position along each measurement direction; the reference mark contains both aperiodic and periodic components (Fig. 3).