Phase and Spatial Light Modulator Cascade for Projection Efficiency
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Solution Overview
Problem
Traditional image projection is inefficient, with most light being wasted as it uses a subtractive process, leading to high energy consumption and heat generation, despite advancements in projector architectures and modulation techniques.
Innovation Solution
A system combining a phase light modulator and a spatial light modulator in a two-stage cascade architecture, where the phase light modulator steers light to where it's needed, using a novel variation of the Gerchberg-Saxton algorithm and light field estimation to minimize light loss, and a controller determines phase maps for both modulators based on image data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a spatial light modulator is used in traditional subtractive projection, then an image can be generated, but most of the light is wasted and discarded into a light dump
Solution Approach 1:
The projection system is divided into two independent modulators: a phase light modulator and a spatial light modulator. The phase modulator segment handles light steering and redirection, while the spatial light modulator segment handles image formation. This segmentation allows each component to perform its function optimally without the light wastage inherent in traditional single-stage subtractive systems.
Solution Approach 2:
The phase light modulator acts as an intermediary between the light source and the spatial light modulator. It pre-steers and redirects light onto the spatial light modulator in a controlled manner, ensuring that light is delivered efficiently to where it is needed for image formation, rather than being discarded as in traditional systems.
2Illumination intensity
If high intensity light sources are used to compensate for light loss, then brightness can be maintained, but energy consumption and heat generation increase
Solution Approach 1:
The system converts the traditionally wasted light (which goes into the light dump) into a beneficial resource by using the phase light modulator to redirect it onto the spatial light modulator. This converts what was previously harmful waste into useful illumination, maintaining image brightness without requiring additional energy input or higher intensity light sources.
3Loss of energy
If a two-stage cascade architecture with phase light modulator and spatial light modulator is used, then light efficiency is improved, but device complexity increases
Solution Approach 1:
The system merges two different modulation technologies (phase modulation and spatial light modulation) into a unified cascade architecture. By combining these complementary approaches, the system achieves superior light efficiency that neither modulator could achieve alone, while the integrated design manages the complexity through coordinated control of both stages.
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
This approach significantly reduces light wastage, enhancing the efficiency of the projection process by utilizing more of the available light, thereby reducing energy consumption and heat generation compared to traditional subtractive methods.
Implementation Method 1
a phase light modulator arranged such that light reflected from the phase light modulator illuminates the spatial light modulator
Implementation Method 2
light reflected from the phase light modulator illuminates the spatial light modulator
Data Source
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AI summary
A device, system and method for modulating light using a phase light modulator (PLM) and a spatial light modulator (SLM). A device determines a target-destination wave, representative of an image, to be formed at an image plane of the PLM using image data, defining the image for projection, and a random seeding of spatial values of a spatially varying phase of the target-destination wave at the image plane, the image plane located between the PLM and SLM, the SLM and PLM arranged such that light reflected from the PLM illuminates the SLM. The device determines a target-source wave to be formed at the PLM, based on: a free space transfer function between the PLM and the image plane; and the target-destination wave. The device determines, from the target-source wave, a phase map for controlling the PLM to form the image. The device controls the PLM using the phase map.