Polygon Scan Line Alignment for Stable Ophthalmic Imaging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Ophthalmic imaging instruments face issues with varying scan line alignment and length due to manufacturing tolerances in optical elements, leading to image jitter and unsatisfactory image quality.
Innovation Solution
An ophthalmic imaging instrument with a detector positioned in a fixed relation to an optical element, such as a curved mirror, to generate a signal indicating the start of each scan line, allowing for synchronized alignment of scan lines and compensation for variations in facet characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If standard manufacturing tolerances are used for optical elements, then manufacturing cost and ease of assembly are improved, but scan line alignment precision deteriorates causing image jitter
Solution Approach 1:
The patent applies preliminary action by pre-determining the actual facet characteristics (length, orientation) of each polygon scanning mirror facet during manufacturing or initial setup. These predetermined values are stored and used to calculate individualized scan line alignment parameters for each facet, enabling precise alignment compensation before actual imaging operation begins. This eliminates the need for complex real-time adjustment mechanisms while maintaining high precision.
Solution Approach 2:
The patent changes parameters by using individually determined facet characteristics (length, orientation angles) for each polygon scanning mirror facet rather than assuming uniform standard values. These parameter variations are compensated through customized scan line alignment calculations specific to each facet, transforming the problem from one requiring tight manufacturing tolerances to one that accommodates and corrects for actual manufacturing variations.
2Manufacturing precision
If tight manufacturing tolerances are applied to optical elements, then scan line alignment precision is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The system applies self-service by automatically measuring and determining the actual facet characteristics of each polygon scanning mirror facet, then using this information to calculate and apply individualized alignment corrections. The system serves itself by compensating for its own manufacturing variations through automated characterization and computational correction, eliminating the need for external precision adjustment mechanisms or complex mechanical alignment systems.
Solution Approach 2:
The patent implements feedback by measuring the actual facet characteristics (length, orientation) of each polygon scanning mirror facet and using this feedback information to calculate appropriate scan line alignment parameters. This closed-loop approach allows the system to automatically compensate for manufacturing variations without requiring tight tolerances or complex mechanical adjustment mechanisms.
3Manufacturing precision
If complex alignment control mechanisms are implemented, then image quality is improved, but system complexity increases
Solution Approach 1:
The patent replaces complex mechanical alignment control mechanisms with computational methods. Instead of using additional mechanical actuators, adjustable mounts, or complex optical adjustment mechanisms, the system uses software-based calculations that determine individualized scan line alignment parameters based on measured facet characteristics. This substitution of mechanical complexity with computational simplicity maintains high image quality while reducing overall system complexity.
4Reliability
If additional alignment control elements are added, then scan line synchronization is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies universality by using the existing polygon scanning mirror and its facet characteristics data for multiple purposes: both for generating the scan lines and for determining the alignment correction parameters. The same facet length and orientation measurements that define the scanning geometry are also used to calculate the alignment compensation, eliminating the need for separate alignment control elements or additional sensing mechanisms.
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
Improves image quality by reducing image jitter through efficient synchronization of scan lines, maintaining system complexity at an acceptable level.
Implementation Method 1
a polygon scanning mirror comprising a plurality of reflecting facets; a driver arranged to rotate during operation said polygon scanning mirror, such that each facet reflects the beam of light at a varying angle
Implementation Method 2
an optical element arranged to guide the beam reflected at a varying angle toward an eye of a subject
Implementation Method 3
a detector arranged to detect light of the reflected beam incident from a respective one of said reflecting facets
Data Source
Figure 1~2
Figure 3A~3B
Figure 4
AI summary
An ophthalmic imaging instrument comprising a light source emitting a beam of light; a polygon scanning mirror comprising a plurality of reflecting facets; a driver arranged to rotate during operation said polygon scanning mirror, such that each facet reflects the beam of light at a varying angle; an optical element arranged to guide the beam reflected at a varying angle toward an eye of a subject, and a detector arranged to detect light of the reflected beam incident from a respective one of said reflecting facets and positioned in a fixed relation arrangement with said optical element.