Autodesk® Simulation Moldflow® Insight Stress Birefringence

Transcript

Autodesk® Simulation Moldflow® Insight Stress Birefringence Prediction in Active-Shutter 3D Glasses Roger Corn Engineering Manager, Sony Corporation © 2012 Autodesk Class Summary In this class, you will learn how we used Autodesk Simulation Moldflow Insight Ultimate software to successfully design and develop active-shutter 3D glasses for LCD television. We will focus on the prediction and mitigation of stress birefringence in an optically sensitive injection-molded component. Anyone who is interested in learning more about applying the powerful and specialized modules of Moldflow Insight software in the early stages of product design will gain from this class. © 2012 Autodesk Learning Objectives At the end of this class, you will be able to:  Use Moldflow Insight for design investigation before tooling release  Use Moldflow Insight to develop optically sensitive injection-molded parts  Describe how stress birefringence is manifested and evaluated in polarized light applications  Make your designs better and more robust using Moldflow Insight © 2012 Autodesk Introduction Consumer Electronics Group B2B Solutions Group © 2012 Autodesk Introduction Television Business Group Osaki, Tokyo Designed and built by NIKKEN using AUTODESK software … http://www.nikken.co.jp/en/projects/office/hq/sony-osaki-west-building.html © 2012 Autodesk Active-Shutter 3D Glasses Stress Birefringence Prediction and Mitigation © 2012 Autodesk  Stress Birefringence what it is and why it occurs  3D Technologies creating 3D images on 2D displays  Stress Birefringence in 3D Glasses how stress birefringence affects 3D glasses performance  Prediction and Mitigation using ASMI to predict and mitigate birefringence © 2012 Autodesk  Stress Birefringence what it is and why it occurs  3D Technologies creating 3D images on 2D displays  Stress Birefringence in 3D Glasses how stress birefringence affects 3D glasses performance  Prediction and Mitigation using ASMI to predict and mitigate birefringence © 2012 Autodesk birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light (thanks Wikipedia !) ergo … when polarized light passes through a birefringent material a change in the polarization (angle) and retardation (phase) of the light is induced © 2012 Autodesk stress birefringence from injection molding process in clear plastics clear plastics viewed in polarized light exhibiting stress birefringence effects (rainbow or white clouding) ф : polarization Δn ・ d : retardation λ : wavelength polarization term retardation term optimize (minimize) the polarization and retardation birefringence effects through calculation with ASMI in order to mitigate stress birefringence effects © 2012 Autodesk  Stress Birefringence what it is and why it occurs  3D Technologies creating 3D images on 2D displays  Stress Birefringence in 3D Glasses how stress birefringence affects 3D glasses performance  Prediction and Mitigation using ASMI to predict and mitigate birefringence © 2012 Autodesk why we see 3D : binocular disparity © 2012 Autodesk Active Shutter 3D Glasses liquid crystal shutters in glasses alternately block left & right images to create 3D effect when shutter does not block image completely  crosstalk  © 2012 Autodesk Active Shutter 3D Glasses transformation of polarized light due to birefringence in clear plastic causes degradation in performance of LCD shutter and crosstalk in 3d glasses LCD polarizer standard LCD has two polarizers clear plastic polarized light from television © 2012 Autodesk  Stress Birefringence what it is and why it occurs  3D Technologies creating 3D images on 2D displays  Stress Birefringence in 3D Glasses how stress birefringence affects 3D glasses performance  Prediction and Mitigation using ASMI to predict and mitigate birefringence © 2012 Autodesk white clouding due to birefringence plastic w/ birefringence  crosstalk  stress birefringence in clear plastic creates crosstalk or light leakage through LCD shutter plastic w/out birefringence (no crosstalk) how to mitigate stress birefringence in clear plastic part and prevent crosstalk ??? successfully mitigated stress birefringence no crosstalk or light leakage through LCD shutter © 2012 Autodesk  Stress Birefringence what it is and why it occurs  3D Technologies creating 3D images on 2D displays  Stress Birefringence in 3D Glasses how stress birefringence affects 3D glasses performance  Prediction and Mitigation using ASMI to predict and mitigate birefringence © 2012 Autodesk Getting started  ASMI Ultimate stress birefringence module  Characterized material stress-optical coefficients and viscoelastic retardation spectrum  Mesh study various gating configurations © 2012 Autodesk Mesh model part and hot runner in CAD allign Z azis to optical axis in part 660k tetras Set global length and elements through thickness All others at default settings © 2012 Autodesk Mesh Place hot runner tetras in separate layer Assign Hot Runner (3D) property one or multiple injection cones at hot runner tetras © 2012 Autodesk Process Settings Fill + Pack + Warp analysis (must have Warp results for birefringence) Check Birefringence Analysis box All other settings at default values for initial analysis © 2012 Autodesk Results fill time sink marks no flow balance issues potential areas for sink identified initial values for amount of sink may be acceptable Standard results evaluation © 2012 Autodesk Results Phase shift and Retardation are default results with birefringence analysis Retardation tensor (polarization) needs to be added as user plot © 2012 Autodesk Results select user plot then plot properties Choose 「Tensor Principle Vector as Darts」 and 「Principle Value : First」 © 2012 Autodesk Evaluation Specify scaling : 0 ~500nm Color : from red to blue Select retardation plot then plot properties Overlay retardation tensor (polarization) on retardation results plot © 2012 Autodesk Evaluation ф : polarization Δn ・ d : retardation λ : wavelength polarization term retardation term  polarization term zero when ф is 0°or 180° (tensors straight up or down)  retardation term zero when (Δn ・ d ) is 0 or multiple of π (color red and uniform) birefringence (white clouding) birefringence mitigated © 2012 Autodesk Gate option ① : direct gate large change in polarization around gate cause of white clouding in polarized light and crosstalk in 3D glasses fairly even retardation distribution © 2012 Autodesk Gate option ② : side gate change in polarization more uniform but not straight up or down (0°or 180°) cause of white clouding in polarized light and crosstalk in 3D glasses improved retardation distribution © 2012 Autodesk Gate option ③ Slight deviation from straight up / down (0°or 180°) with good uniformity mitigated white clouding in polarized light and eliminate crosstalk acceptable retardation distribution © 2012 Autodesk Gate option summary Gate ① Gate ② Gate ③ © 2012 Autodesk Birefringence summary plastic w/ birefringence  crosstalk  plastic w/out birefringence (no crosstalk) Birefringence from various gating options analyzed No prototype or proof of concept tool produced Best gate option chosen produced acceptable parts from first shot off production tool © 2012 Autodesk Results sink marks potential areas for sink identified Select CAD faces Output .fbx file Import to SHOWCASE © 2012 Autodesk Results sink marks potential areas for sink identified Evaluate with SHOWCASE sink level acceptable © 2012 Autodesk Results sink marks potential areas for sink identified Always Face Surface Normals to Cameras © 2012 Autodesk Autodesk, AutoCAD* [*if/when mentioned in the pertinent material, followed by an alphabetical list of all other trademarks mentioned in the material] are registered trademarks or trademarks of Autodesk, Inc., and/or its subsidiaries and/or affiliates in the USA and/or other countries. All other brand names, product names, or trademarks belong to their respective holders. Autodesk reserves the right to alter product and services offerings, and specifications and pricing at any time without notice, and is not responsible for typographical or graphical errors that may appear in this document. © 2012 Autodesk, Inc. All rights reserved. © 2012 Autodesk