3D Glasses Design Project

1. 3D Glasses Design Project October 2010 LG Electronics, New Jersey Office Englewood Cliffs, NJ

2. Executive summary Objective The goal of this research project is to explore various considerations relevant to the design of glasses meant for viewing 3D-TV programming to improve the comfort and appeal of the glasses to consumers. Particularly, durability, comfort, and sizing are the focus of improvements to existing LGE offerings. Areas of exploration encompass the structure of the glasses, including the design of a suitable hinge mechanism and selection of material properties for an effective compliant arm, and the interface between the glasses and wearer, including specification of appropriate sizes and measures of user comfort and fatigue. The final design should be light, comfortable, possess high durability, and have a low production cost. The design of both active glasses (SG) and passive glasses (PG) are considered. Summary of research efforts Research efforts included a patent search, benchmarking of current product offerings, digitization and prototyping of existing LG glasses, experimentation with regard to comfort and fatigue, design of an improved hinge and arm incorporating biomimicry and compliance, specification of optimal sizes with respect to the head size of wearers, configuration and development of CAD and physical prototypes, and finally, virtual and physical assessment of prototypes.

3. Introduction to Penn State and the team

4. Pennsylvania State University • State-related university, established in 1855 • Penn State, University Park, is ranked inthe top 15 nationally for public universities • 45,000 students at UP and 87,000 across all locations • Penn State College of Engineering was established in 1896 and is one of the most comprehensive in the U.S. • Mechanical and Nuclear Engineering ranks 15 and 16 for undergraduate and graduate programs • Industrial Engineering is one of the top five programs in the county

5. Industrial and Manufacturing Engineering • The First Industrial Engineering Department in the World (1909) • Ranking: 4th-ranked university in Industrial Engineering (U.S. News & World Report, 2010) • Research: Ergonomics/Information Technology/Quality Management/Operations Research/Manufacturing Field • Corporate Partnership: Partnerships with 37 major U.S. companies (3M, Boeing, Fedex, IBM, P&G, UPS, Wal-Mart, etc.)

6. The Learning Factory

7. Faculty contributors

8. Student contributors

9. Project objectives

10. Project objectives • Assess weaknesses in current LG offerings • Determine requirements for improved glasses • Benchmarking • Patent search • Experimentation • Specify design elements • Recommend improvements to specific components • Recommend size and shape • Recommend common platform elements for SG, PG glasses

11. Current design weaknesses • Durability • Fragile hinge joint • Cracking issues • Comfort • Severe pressure at ear • Too much load on nose surface due to weight of glasses • Sizing • Inappropriate size; current 3D glasses were designed for Korean market

12. Defining requirements of improved glasses

13. Requirements for improved glasses LG-specified requirements Lightweight Comfortable Durable Low production cost (competitively priced) • Design goals • Reduce weight • Improve balance • Improve structure of glasses • Simplify folding mechanism • Standardize components • Properly size glasses

14. Competitor benchmarking highlights

15. User experiments • Conducted to assess parameters relevant to comfort • Weight balance experiment • Assess relationship between nose load and center of mass (CM) • Assess relationship between subjective discomfort and center of mass • Endurance experiment (duration = 1 hr, 30 min) • Determine subjective discomfort rating while wearing glasses • Measure neck muscle fatigue while wearing glasses • Tail pressure experiment • Measure pressure at tip of arms according to changes in distance between arms

16. Weight balance experiment • Objective: Correlate change of nose load with subjective discomfort rating for different locations of Center of Mass (CM) on 3D glasses • 4 different CM conditions and 1 reference condition (LG PG) • Test glasses used same weight as current LG 3D glasses (41g) Front Middle Ear Rear Reference 1.5 cm 7 cm 9 cm 15 cm : Location of circuit board and battery (total: 12 g)

17. Weight balance experiment results • Front showed the highest discomfort rating of the nose and the highest nose load • There are no significant different results among Middle, Ear, and Rear (p=0.0002) (p<0.001) Nose load SE SE A A B B B B B B B 36%  41%  52%  Discomfort 0 : no discomfort100 : extremely strong discomfort • Passive: LG PG style 3D glasses • SNK group (post-hoc analysis) • - A: Statistically higher discomfort group • B: Statistically lower discomfort group Middle location was chosen for the next experiment

18. Endurance experiment and result • Objective: Observe subjective ratings and neck muscle fatigue while wearing 3D glasses for 1 hour, 30 minutes • 3 different 3D glasses having the same weight (41 g) • Neck muscle fatigue was observed by using EMG analysis, but there were no significant differences among 3 different 3D glasses Overall Discomfort Middle (prototype) LG SG Samsung SG

19. Tail pressure experiment • Objective: measure tail pressure according to the change of span between arms for existing glasses LG Samsung Adjustable jig

20. The improved design

21. Design element 1: New hinge mechanism • Biomimetic design • Apply concepts from natural mechanisms to hinge design to resolve durability issues • Minimize number of parts involved • Permits detach-ability Current Proposed

22. Design element 2: Compliant arm design • Reduces pressure at temples, keeping it relativelyconstant across different-sized users • Durability is increased by improving flexibility

23. Compliance enhances comfort • Compliance in arm means perpendicular force at the ear stays relatively constant over variation in head size, depending on selected material and cross-sectional geometry (elastic modulus, E, and area moment of inertia, I) • Material may be selected to yield desired force at ear

24. Optimal sizing ensures comfort for all • Compliance in the arms allows for one (smaller) size to fit a large variety of head sizes • So, design arms for the largest width at the temple (face breadth) and the smallest width at the ear (head breadth) Smallest wearer not a factor in sizing Largest wearer

25. Optimal dimensions • For adults, ranges in relevant head dimensions (in mm) are available directly from CAESAR data: Head Breadth:  min = 123, max = 204 Bizygomatic breadth: min = 118, max = 168 • For youth, ranges in relevant head dimensions (in mm) are derived from a combination of AnthroKids + NHANES data: Head Breadth:  min = 132, max = 200 Bizygomatic breadth: min = 108, max = 172

26. Prototype dimensions • Cost vs. benefit led team to retain existing LG 3D glasses dimensions for adults, with a face breadth width of 155 mm • Dimensions of 3D glasses for youth were scaled down proportionately according to a face breadth width of 150 mm. This represents the 99th percentile value of face breadth using the AnthroKids + NHANES data. • Small differences between adults and youth glasses indicate that one standard size may be appropriate

27. Virtual assessment: 3D head scans

28. Design element 3: Detachable components Reduces weight and promotes platform commonality

29. Summary of prototypes

30. Final CAD prototypes SG PG

31. Summary of improvements