Hologram Generation Using Spatial Light Modulator Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hologram generation methods face challenges in accurately generating large holograms due to deviations in the movement of photosensitive materials, leading to inaccuracies in the alignment and connection of partial holograms, and require multiple original plates for unique holograms, making it difficult to achieve precise alignment.
Innovation Solution
A hologram generation apparatus and method that uses a spatial light modulator to modulate light, forming object and positioning hologram generation areas on a modulation surface, allowing for accurate positioning of subsequent holograms by determining the position of a second object hologram based on the positions of first and second positioning holograms, enabling precise alignment and connection of partial holograms without the need for expensive conveyance devices or multiple original plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the photosensitive material is moved on an XY-stage to perform successive exposures, then multiple holograms can be generated on the same photosensitive material, but a deviation occurs between successively-exposed hologram patterns due to stage movement accuracy
Solution Approach 1:
The patent uses a spatial light modulator to generate computer-calculated phase distributions or amplitude distributions directly, replacing the need for physical original plates. This digital copying approach allows precise reproduction of hologram patterns without mechanical movement, eliminating stage accuracy issues while maintaining successive exposure capability
Solution Approach 2:
The patent replaces the mechanical XY-stage movement system with a spatial light modulator that uses optical field modulation to position and align holograms. The spatial light modulator controls the phase and amplitude of light fields to achieve precise positioning without mechanical displacement, thereby maintaining alignment accuracy while enabling successive exposures
2Manufacturing precision
If multiple hologram original plates are prepared for unique holograms, then each hologram can be generated accurately, but it becomes very difficult to easily generate all holograms with accurate alignment
Solution Approach 1:
The spatial light modulator serves multiple functions: it generates object light by modulating phase and amplitude, creates positioning holograms for alignment, and enables successive exposures without requiring separate original plates for each hologram. This single device performs all functions previously requiring multiple specialized components
Solution Approach 2:
The patent changes the state of the original plate from physical to digital by using computer-calculated phase distributions and amplitude distributions on a spatial light modulator. This parameter change from physical geometry to optical field parameters allows easy reconfiguration and precise control without manufacturing new physical plates
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 the easy and accurate generation of large holograms by ensuring precise alignment and connection of partial holograms, improving positioning accuracy and reducing the need for costly equipment, while allowing for the generation of unique holograms without seams between them.
Implementation Method 1
a spatial light modulation unit configured to modulate incident light
Implementation Method 2
making the laser light interfere with reference right through a telecentric optical system, and applying the resultant light onto a photosensitive surface
Implementation Method 3
applying the resultant light onto a photosensitive surface
Data Source
AI summary
A hologram generation apparatus includes an LCOS, an LCOS display control unit configured to form a partial hologram generation display area and positioning hologram generation display areas on a display surface of the LCOS, an object light optical system configured to apply object light onto a recording medium and generate a partial hologram and positioning holograms, the object light being generated by the partial hologram generation display area and the positioning hologram generation display areas, and a position control unit configured to determine a position of an partial hologram to be generated next based on positions of the generated positioning holograms.