Automated Lens Measurement System Project 05427

Automated Lens Measurement System Project # 05427

Team Members Matt Place Frank Capristo Paul Thompson Melissa Groginski John Spalding Rhiannon Casale

Presentation Overview Ø Introduction/Project Overview Ø Needs assessment Ø Concept research Ø Feasibility Ø Top companies Ø Summary of Senior Design I Ø Action plan for Senior Design II

Introduction Ø Bausch & Lomb has requested our team to research and evaluate methods and devices available to perform an automated, non-contact central thickness measurement Ø Upon evaluation of devices and systems available, the team will develop a fully functional offline station to test the top measurement systems available Ø Once testing is complete, a cost benefit analysis will be performed an integration plan will be developed for the device/system that will best suit B&L’s needs Ø If time allows, the system will be integrated into either a Pure. Vision or a Soflens production line

Process Flow Chart Molding Casting / Cure Release Hydration Inspection Packaging

Importance of Central Thickness ØOptical properties ØDurability ØComfort

Current Process Ø Ø Manual offline, mechanical contact method Lens must be discarded after inspection Lens is in wet state Audit level of ~1 – 2 %

Damage from Lens Handling O-ring Signature Extraction Tray Marks Tweezers Mark

Desired Process Ø Non-contact method Ø Automated and fully integrated into line Ø No manual, non-value added labor Ø Increased sampling rate Ø No discarding of good lenses after measurement is performed Ø Measurement performed at an earlier stage of production

Possible Points of Integration Ø Dry State: Ú In the assembled mold Ú After mold de-capping Ú After lens is released from mold Ø Wet State: Ú During cosmetic inspection Ú In blister package

Automated System Benefits Ø Ability to initiate SPC plan Ø Potential to perform 100% inspection Ø Reduces non-value added labor Ø Portable to future automated lines Ø Reduces individual lens cost by ~1 -2%

Key Senior Design I Milestones Task Finish Date Needs Assessment Fri 12/17/05 Research Compilation and Review Thu 1/6/05 Vendor CDA Agreements Wed 1/19/05 Peer Presentation Fri 1/28/05 Feasibility Assessment Tue 2/8/05 Vendor Selection Summit Wed 2/9/05 Sample Testing / Capability of Vendors Thu 2/11/05 B&L Presentation Wed 2/16/05 Preliminary Design Packet Thu 2/17/05 Order Demo Systems Fri 2/18/05 PDR Presentation Fri 2/18/05

Needs Assessment Mission Statement: To provide Bausch & Lomb with the most cost effective, non contact solution for accurately measuring the central thickness of a contact lens.

Requirements of New Process Ø Non-Contact method of measurement Ø Measure thickness range of 20 – 250 μm Ø Measurement tolerance of ± 10 μm Ø Gauge R&R of ≤ 18% Ø User Interface Ø PLC Interface Plan Ø Extensibility to future products

Goals & Objectives Ø Satisfy Bausch & Lomb requirements Ø Research and test possible solutions Ø Determine most cost effective solution Ø Design all fixturing Ø Provide Bausch & Lomb with a cost benefit analysis Ø Provide Bausch & Lomb with an integration plan

Constraints Ø Ø Ø Project requirements Measurement size Timeline Available technologies Vendor testing turnaround time Ø Fixturing tolerances Ø Cycle Time

Concept Research What: Companies and technologies Capable Of: Measuring the central thickness of a contact lens to Bausch & Lomb’s specifications Sources: Google, Thomas Registrar, Global Spec. , and Bausch & Lomb Experts

Concepts Researched Ø Mechanical Ø Vision System Ø Capacitance Ø Laser Triangulation Ø Laser Autofocus Ø Optical Ø Ultrasonic

Eliminated Companies Ø Measurement spot size too large Ø Unacceptable measurement range Ø Improper measurement tolerances Ø Unable to measure due to product properties

Information Collection Ø Onsite visits ÚLumetrics ÚMicro-Epsilon Ø Teleconferences ÚAll other vendors Ø Major requirements captured

Patent Search Ø 13 related patents found ÚVisual Inspection Systems ÚLens Production ÚContact Methods Ø No conflicts Ø Key Words: ÚThickness Measurement ÚThin Films ÚContact lenses

Product Specification Research Ø Contact Lens Quick Reference Guide Ø Base Curve Ø Mold information Ø Cost research

Feasibility Ø Judging criteria ÚRequirements Document Ø Weighting criteria Ú 5 = Most Important Ú 1 = Least Important Ø Scoring Ú 1 = Not quite able to meet needs Ú 3 = Exceeds needs

Feasibility Matrix

Feasibility Matrix (Cont. ) Ø Device Model # Ø Working Height Ø Lens State for Measurement Ø Sensor/Controller Ratio Ø Sample Lead Time Ø Demo Lead Time Ø Length of Demo Period Ø System Lead Time

Test Results Ø Lumetrics ÚExcellent results, agrees with current system Ø Micro-Epsilon ÚExcellent results, agrees with current system Ø Panametrics ÚExcellent Results, agrees with current system Ø Mission Peak Optics ÚFree lens only, fair results

The Top Three Ø Lumetrics Ø Micro-Epsilon Ø Panametrics - NDT

Lumetrics Places the DI 330 Optigauge can measure: Ø With both halves of mold Ø With bottom mold half Ø Free lens

Lumetrics (Cont. ) Possible install locations: Ø Before mold separation Ø Immediately before/after lens release from mold

Micro-Epsilon Places the opto. NCDT 2400 can measure: Ø With bottom mold half Ø Free lens

Micro-Epsilon (Cont. ) Possible install locations: Ø Immediately before/after lens release from mold Ø Before the lenses are placed on the trays

Panametrics - NDT Ø Lens in wet state ÚInspection cell ÚBlister package

Panametrics – NDT (Cont. ) Ø In-line on wet lens transfer machine

Design concerns Ø Capability of the sensor Ø Size of the sensor Ø Fixturing on the line Ø Accessibility for maintenance Ø What to do with reject lenses Ø Requirements of Bausch & Lomb

Summary of Senior Design I Ø Focused on research of companies and technologies available Ø 22 companies researched were narrowed down to 8 Ø 8 companies were sent samples Ø Feasibility analysis allowed team to separate top vendors Ø Top 3 companies chosen

Goals for Senior Design II Ø Present to Bausch & Lomb final recommendations for most cost effective functional device Ø Fully functional offline system Ø Integration plan

Action Plan for Senior Design II Ø Design and create fixtures for device and lens positioning Ø Bring in and test demonstration units from top vendors Ø Cost analysis Ø Evaluate manufacturing lines to develop an integration plan

Thank You Ø Bausch & Lomb Ø Bill Appleton – Project Coordinator Ø Ryan Williams – Project Sponsor Ø Dave Martz – Metrology Support Ø Kevin Beebe – Process Support Ø Prof. Stiebitz – R. I. T. Coordinator Ø Prof. Esterman – R. I. T. Mentor

Questions Any further questions?

Backup Slides

Experimentation Plan Ø Small initial trial Ø Based on results, large trial, or halt trials Ø Gauge R&R Ø DOE as necessary

Senior Design II Timeline Ø SD II Timeline Ø Test Results: end of break ¾ Ø Me-fixturing-initial designs-(3/11); fabrication-(4/1) Ø Demo Units-1 st units ordered (by spring)-2 week increments depending on L. T. Ø All-testing(doe)-(3/4)-(4/1): 4 wks Ø IE-Gauge r&r-(3/4)-(4/1): 4 wks Ø Wet/Dry correlation-verification (3/18/05) Ø Cost analysis-on-going until (4/8) Ø Me-pfmea-4/8 Ø Final recommendations-4/8

Wet – Dry Correlation Ø Correlation exists for Sof. Lens products Ø Theoretical correlation for Pure. Vision, need to verify with data

Company Research Long List Ø Ø Ø Lumetrics Ø Keyence Ø Elektrophysik Ø FRT of America Ø Mission Peak Optics Ø Micro-Photonics Ø Filmetrics Ø Thermo Electron Corp. Ø ABB Ø Adetech Ø Onosokki Ø Short List MTI Instruments Inc. LMI Technologies Micro-Epsilon Beta Laser Mike ORYX Panametrics Accu. Sentry Norman N. Axelrod and Associates Dr. Schenk Inspection Systems Optical Data Associates, LLC. Solve TECH Inc Ø Ø Ø Ø Lumetrics Mission Peak Optics Filmetrics MTI Instruments LMI Technologies, Inc. Micro-Epsilon ORYX Panametrics

Eliminated Companies Ø Beta Laser Mike: – transmit and receive laser – Focal diameter too large for the application – Only good for flat applications Ø FRT of America: – They were not confident they could measure a curved surface such as a contact lens. Ø Micro. Photonics: – Could only measure up to 50 microns Ø Solve. Tech: – – Capacitive method Requires a much larger spot size than required Develop fixture to position the lens accurately between two plates Separation distance to small

Eliminated Companies Ø Keyence: – Device incapable of measuring the size and accuracy required Ø Accu. Sentry: – camera or vision system – Entire concept of a vision system discarded due to the current lack in adequate technology. Ø Norman N. Axelrod and Associates: – Do not sell a specific technology – On-site visit , analyze the problem, and custom develop a solution. Ø Adtech, ABB and Thermoelectron: – No response when contacted

Eliminated Companies Ø Dr. Schenk inspection systems: – Sell products to measure thin films – All products are meant to be installed on a high speed manufacturing line – Take a measurement based on the profile view of the thin film Ø Optical Data Associates, LLC: – Specializes in high precision inspection of various components for their optical properties – This company is just a testing firm and therefore would not be able to help or sell any technology that would meet the needs of the application. Ø Onosokki: – Contact method systems for measurement

Patent Search Several patents were found that are within the realm of the given application. The topics varied from a contact probe that measured the actual thickness of a contact lens, other technologies used in taking measurements of a contact lens, to automated visual inspections of a contact lens. Since the application that is being dealt with is more process oriented on the measurement of the central thickness of a contact lens the patents are not being infringed upon by our application.

Patent Search (Cont. ) Ø Patent number 4, 665, 624 – deals with a soft contact lens analyzing apparatus. – This apparatus utilizes a fixturing device and several measurement scales to determine the diameter, sagittal depth and central thickness of a contact lens. All of the scales use probes that must come into contact with the actual lens. – A mechanical, contact system which is not what our application calls for. Ø Patent number 4, 403, 420 – Digital gauge for measuring the sagittal depth and thickness of a lens, and the related systems and methods – This method involves a fixturing device and several linear encoders to measure the diameter, sagittal depth and central thickness of a lens. Each of the encoders is connected to some type of probe that needs to come into contact with the lens. – A mechanical contact system in which our application will not infringe on.

Patent Search (Cont. ) Ø Patent number 6, 134, 342: – Visual inspection method and apparatus for a contact lens. – The method described is automated. The visual inspection system is looking for defects such as foreign material, scratches, breakage and so forth. – No quantitative dimensional measurements performed and therefore does not have to do with our application. Ø Patent number 6, 765, 661: – A lens (such as contact lens) inspection method. – This system looks for such flaws as tears or surface defects. – No quantitative dimensional measurements preformed and therefore our application will not infringe with this patent.

Patent Search (Cont. ) Ø Patent number 6, 490, 028: – Variable pitch grating for diffraction range finding system – What is described is a very precise method to determine the range or distance from a reference point to an object. Utilizing a variable pitch grating does this. – This system uses a completely different methodology than any of the apparatuses the team has evaluated for the given application. Ø Patent number 6, 815, 947: – A method and system for thickness measurements of thin conductive layers – This system utilizes an electrically conductive method known as eddy current. Extremely thin films that also have conductive properties are the only applicable item that may be measured using this system. – Due to its limitations, the team ruled out this technology initially. None of the systems being evaluated use this or any related technology.

Patent Search (Cont. ) Ø Patent number 6, 847, 458: – A method and apparatus for measuring the shape and thickness variation of polished opaque plates – In this system dual interferometers are used. One is placed on each side of the plate to perform its surface mapping and other calculations. Since the system is attempting to measure opaque plates two interferometers must be used. – This system is different from any of the researched systems that have been evaluated because it is a dual interferometer system. All of the systems researched used only one interferometer. – Also, this is for measuring opaque substances, as our application is to measure optically clear lenses.

Patent Search (Cont. ) Ø Patent number 6, 822, 745: – Optical systems for measuring form and geometric dimensions of precision engineered parts – This patent does describe a similar technology that we will be utilizing. However, it describes the specific equipment and not the overall process of the measurement. Whichever piece of equipment that is decided upon to use in our application, should be protected by that respective companies patents. – Other than that, no process issues are present that would violate this patent. Ø Patent number 6, 791, 691: – A measuring method that uses attuention in total reflection – This patent describes a similar technology that we will be utilizing. Furthermore, it describes the specific equipment and not the overall process of measuring the object. That respective companies patent should protect whichever piece of equipment the team decides to use in our application. – No process issues are present.

Patent Search (Cont. ) Ø Patent number 6, 301, 005: – Inspection system for optical components – This system contains a device to hold the optical component into place. It has the means to inspect the optical component for any apparent defects. – No quantitative dimensional measurements are taken into account thus, compared to our application is not the same and will not infringe. Ø Patent number 6, 791, 696: – An automated optical measurement apparatus and method – This patent describes the method to measure lens properties, such as central thickness, utilizing a wavefront analysis. – None of the technologies researched involve this type of technology. For this reason, our application will not infringe on this patent

Patent Search (Cont. ) Ø Patent number 5, 206, 076: – A self aligned manufacturing system and method – This method does not pertain to the metrology of contact lenses. It describes a method on how to actually produce contact and intra-ocular lenses. – Since this is describing the manufacturing process and not a measurement process our application does not conflict. Ø Patent number 6, 775, 003: – Apparatus and method for total internal reflection spectroscopy – This also describes a similar technology that is being evaluated. Again, although it has a similar technology it does not describe the process. – Therefore, the researched technologies respective companies patent should protect the equipment in the end that the team decides to put into use. – No process issues are present.

Product Specification Research Ø Contact Lens Quick Reference Guide – Research was completed to create a reference guide for Bausch & Lomb’s contact lens specifications. – The specifications include: • • • Product line Lens type Monomer used Diameter and tolerance of the lenses Wet central thickness range and tolerance of the lenses Sagittal depth range and tolerance of the lenses Power range of each lens Refractive index of each lens If the lens is tinted Finished Product Specification

Product Specification Research (Cont. ) Ø Radius of curvature – During research the radius of curvature (base curve) was questioned by some of the vendors as this could potentially pose a problem in obtaining the central thickness measurement. – This is another area where experts at Bausch & Lomb were able to inform the team of the dimension. – Due to proprietary information this measurement may not be released. Ø Mold Information – During the early stages of the project the mold material was introduced as Polypropylene and PVC depending on which contact lens it will contain. – The refractive index is unknown at this point for any of the molds, but is being investigated in one of Bausch & Lomb’s labs.

Product Specification Research (Cont. ) Ø Cost Research – Research was done to identify what the overall cost is to actually make the lens. – Cost was broken down by each stage of the lens making process. – The cost of material and operator were gathered. – If the apparatus was eventually integrated into the line as an automated system, in order to cost justify the equipment such costs would need to be known.