Laser Illuminated Projectors - IEEE · 2014-12-01 · Laser Illuminated Projectors: Science, Safety and Regulations Pete Ludé Senior VP, Innovation RealD, Inc Past -Chairman LIPA

Laser Illuminated Projectors:

Science, Safety and Regulations

Pete Ludé

Senior VP, Innovation RealD, Inc

Past -Chairman LIPA

Past-President SMPTE

IEEE Product Safety

Engineering Society 18 November 2014

Today’s Topics

BACKGROUND: current projector technology

BASICS: What is laser light?

BLUEPRINT: About laser projectors

BENEFITS: Why would you want one?

BUMPS: Regulatory Roadmap

2

Current LIPs on the Market

Professional/Cinema Solutions Consumer/Small Room Solutions

3

Background: Xenon arc-lamps -- a quick history

1898: Xenon discovered

1947: Xenon arc-lamps investigated

1954: First xenon projection bulb marketed

1983: Emmy award for Osram XBO lamp

4

Xenon lamps have very similar spectrum to sunlight

Xenon lamps emit very uniform spectrum

5

Anode Cathode

Thoriated Tungston

Fused Quartz

20-50,000v striking pulse

2000°C

Anatomy of a high-pressure Xenon short-arc lamp

6

//upload.wikimedia.org/wikipedia/commons/9/9e/Xenon_short_arc_1.jpg

Plasma temp 6,200° K

(~ 6,000 ° C)

Light emission from plasma arc

7

34% Infrared

Visible light

UV

11%

55%

2/3 of light output

is not visible

Xenon Lamp Characteristics

8

• UV output is very intense

• Resulting hazard is comparable to welding or carbon arcs

• Sunburn and cancer hazard for exposed skin

• Many wavelengths present: UV-A, UV-B, and some UV-C

• Each band is hazardous to a different part of the eye

• Even brief viewing can create permanent damage

• Requires #12 welding glass or sun-viewing filters

• Most other dark transparent materials can transmit too much IR, allowing thermal

damage to eye

Xenon Lamp Characteristics: UV Radiation

9

Xenon Lamp Characteristics: Thermal

• Running lamp temperatures can be 1050°C (1920°F) at the

envelope

• Fused Quartz melting point is 1300 ° C

• Socket design and connecting wires must be of high temperature

construction

• Circulating air can be hot enough to be hazardous

• IR output is high, can damage absorbent materials without need for

thermal path

10

• Cold lamp has internal pressure ~ 5 to 10 atmospheres

• Hot lamp can triple envelope pressure (up to 440 psi)

• Explosion of a running lamp creates high velocity shards of

red hot glass

• Scratches or nicks too small to see can build up strain,

lead to sudden failure

• Do not touch the lamp with bare skin

• Skin oils on a hot lamp permanently etch the quartz (devitrification),

causing local overheating.

• Strain buildup leads to premature, catastrophic failure

Xenon Lamp Characteristics: Explosion

11

Today’s Topics






12

What’s different about laser light?

Coherence

Monochromaticity

Radiance

13


Coherence

Monochromaticity

Radiance

Coherence is the cause of speckle (not injury)

14


Coherence

Monochromaticity

Radiance

15


Coherence

Monochromaticity

Radiance

High energy per area W/cm2

sr

Collimated beam

Retinal injury Safe

16

Comparison of Radiance Values

Light Source Radiance Value Units

5mW laser pointer 70 MW/m2 sr

The SUN

(visible λ) 7 MW/m2 sr

30,000 lumen

cinema projector 2 MW/m2 sr

17 Contact LIPA at [email protected]

Today’s Topics






18

Types of Laser Projectors

Spot Scanner Line Scanner Area Illumination

Laser Focus Collimated Focused on H axis

Diverging on V axis Diverging on both axis

Instantaneous

Laser Power

Density

on screen

Very High High Low

Implementation Pico Projectors

(Microvision)

GLV Projectors

(Sony, Evans &

Sutherland)

2D Microdisplay

(DLP, LCoS)

19

Lamp based Optical Architecture

FDA/CDRH Meeting 20

FDA/CDRH Meeting 21

laser-like light

lamp-like light

RGB Laser Projector Optical Architecture

FDA/CDRH Meeting 22

Laser-pumped Phosphor Optical Architecture

Today’s Topics






23

Summary of Benefits

Laser projectors have the potential of…

• Dramatically improved image quality

Pete Ludé 24

Summary of Benefits



• Substantially Lower power consumption

Pete Ludé

Potential energy savings:

415 million kW/hours

(Enough electricity for a town of 60,000)

25

Summary of Benefits




• Lower operating costs

Pete Ludé

$-

$1,000

$2,000

$3,000

$4,000

$5,000

$6,000

Xenon

Projector

Laser

Projector

Cooling

Electric

$5,125

$3,075

26

Summary of Benefits





• Reduced environmental impact

Pete Ludé

Potential reduction in carbon emissions

300,000 metric tons

27

Summary of Benefits





• Reduced environmental impact

• Flexible design / boothless theater

28

Today’s Topics

BACKGROUND: A word about current projector technology




BUMPS: What could slow this down?

29

Today’s Topics





BUMPS: Speckle

Color Reproduction

Regulatory Roadmap

30

What is Speckle?

• Interference pattern that occurs when coherent light is

scattered off an optically rough surface (i.e. screen)

• Visible noise on uniform areas of scene

• Decreases perceived contrast

• Most visible on uniform, bright scene elements (e.g. sky)

• More visible when you move your head back and forth

(“subjective” speckle)

• Figure of merit: Speckle contrast ratio

Source: K.O. Apeland (5)

=σ

𝑖 SCR =

𝑆𝑡𝑎𝑛𝑑𝑎𝑟𝑑 𝐷𝑒𝑣𝑖𝑎𝑡𝑖𝑜𝑛

𝑀𝑒𝑎𝑛 𝐼𝑛𝑡𝑒𝑛𝑠𝑖𝑡𝑦

31

Methods to reduce speckle

In Theory:

• Polarization diversity

• Temporal averaging

• Wavelength diversity

• Angle diversity

• Temporal coherence reduction

• Spatial coherence reduction

In Practice:

• Array of multiple emitters

• Slightly different frequencies (wavelength diversity)

• Spatially separated (angle diversity)

• Rotating diffusers

• Vibrating diffusers

• Hadamard matrices

• Vibrating screen

• Other methods…

Difficult to measure speckle! 32

Metamerism

METAMER Colour stimuli that have different spectral radiant

power distributions but are perceived as

identical for a given observer.

Two ways of making yellow…

METAMERIC FAILURE Tendency of an object to change appearance

under different light sources.

OBSERVER METAMERIC FAILURE Colour stimuli emitted by narrow-bandwidth

primaries is perceived differently by different

observers.

33

Observer Metameric Failure

Broadening these color

primaries will:

• Reduce speckle

• Eliminate

Metameric

Disparity

34

REGULATIONS

35

Pete Ludé 36

37

“It was the coolest show I've ever seen! Unbelievable. They had those glitter balls you'd see later in discos hung all over the place and they'd shoot

a laser into one in the center which was spinning and the laser would ricochet to the other balls

that were spinning and you felt like you were in a war zone. They seemed to be coming from all directions. They had rings

with lasers, guns with lasers and those strobe light laser guns!”

Pete Ludé 38

Pete Ludé 39

August 8, 1978

Pittsburgh Press

Pete Ludé 40

Laser Light Show Variance

•Requirements (Partial list)

– File specifications on laser equipment prior to use

– Prior Reporting of every show

– Annual Reporting of prior shows

– Safety Checks before every show

– Regular Variance Renewal, extensive paperwork and logging

– Subject to Federal Show Inspection, each set-up

– 3 to 6 meters minimum vertical separation distance

Pete Ludé 41

Pete Ludé 42

43

Study conducted

LIPA Commissioned Study: Tested optical

characteristics of 35mm film projector

Current Xenon short-arc digital cinema projectors

Prototype laser projectors

Lead Researcher: Dr. David Sliney Casey Stack, Laser Compliance

Jay Parkinson, Phoenix Laser Safety

David Schnuelle, Dolby Laboratories

Eight projectors tested in various locations over 7

months.

44 Contact LIPA at [email protected] 44

Scientific peer-reviewed study published

Published in Health Physics, March 2014 Radiation Safety Journal

Official Journal of the Health Physics Society

Peer review complete

Cover story!

Additional analysis presented at

Society of Motion Picture & Television Engineers Conference – October 22, 2013.


Comparing Radiance: Lamp vs. Laser

0

5

10

15

20

25

30

35

40

Proj 6 Proj 2 Proj 1 Proj 4 Proj 5

Laser Laser Laser Xenon Xenon

No

rmal

ized

Mea

sure

d R

adia

nce

(W •

cm

-2 •

sr -1

)

30,000 17,000 5,000 2,000 55,000 Actual Luminance Power (Lumens): 5,000 5,000 5,000 5,000 5,000 Normalized Luminance Pwr (Lumens):


Conclusion

47

Traditional lamp projectors

and new laser-illuminated projectors,

when of equal luminance power,

emit almost identical radiance.

Contact LIPA at [email protected] 47

IEC Laser Regulations

IEC 60825-1 Ed 2 (2007) Safety of Laser Products

Part 1: Equipment classification & Requirements

• All laser product

requirements are defined in

60825

• Medical

• Industrial

• Laboratory use

• Laser Welding

• Laser Illuminated Projectors

IEC 60825-1 Ed 3 (2014?) Safety of Laser Products


IEC 62471 Ed 1 (2006) Photobiological safety of lamps and lamp systems

Carve-out for devices with irradiance < 1 MW / m2sr

α


IEC 60825-1 Ed 3 (2014?) Safety of Laser Products


IEC 62471-5 Ed 1 (2015?) Photobiological safety of Lamp Systems

for Image Projectors


Status

• IEC 60825-1 Edition 3 (Laser safety standard)

• Work started within IEC TC76 WG9 in 2011

• Broad input from worldwide experts

• Publication this past June

• IEC 62471-5 (Lamp Image Projector safety standard)

• Work statement approved; work started in June 2013

• Balloting underway

• Publication expected in early 2015

51

Regulatory landscape in the EU

52

Exposure Limits vs. Injury Threshold

Pete Ludé 53

Example:

1 ms pulse duration

Green wavelength

Varying spot size

OLD LIMITS were needlessly low

Restricting performance of device

New limits still have large safety margin (>250%)

FDA Regulatory Policy

• FDA CDRH defines conditions under

which laser devices can be used in

public display (“Demonstration lasers”)

• 21 CFR §1040.10 – 1040.11

• In 2007, CDRH issued “Guidance” to

harmonize with IEC regulations

• Laser Notice No. 50

54

From Laser Notice 50

55

Exactly 6 years later…

56

• FDA CDRH published update in the

Federal Register on June 24, 2013

• Laser Product Proposed

Amendment to Performance

Standard

• Docket No. FDA-2001-N-0070

• Comment period closed September

23, 2013

Exactly 6 years later…

57

• FDA CDRH published update in the

Federal Register on June 24, 2013

• Laser Product Proposed

Amendment to Performance

Standard

• Docket No. FDA-2001-N-0070

• Comment period closed September

23, 2013

US Regulatory Landscape: Latest News

• FDA has agreed to issue a new “Laser Notice”

• Specific to Laser Illuminated Projectors

• Expected to adopt IEC-60825-1 (2014) Edition 3

• Timeframe: December or Jan

• After FDA action is taken, many other regulatory bodies will

incorporate the changes by reference

• ANSI, OSHA

• States and municipalities

• FAA, NFPA

• LIPA will examine all applicable regulations to determine if other

changes need to be made

58

US Regulator Landscape

59

ACGIH Z.136.7 Eyewear

Z136.6 Outdoors

Z156.6 Schools

Z136.3 Medical

Z156.4 Measure

ANSI Z136.2

Fiber

FDA 21 CFR

ANSI B11.21

IEC/EN 60825

FAA 7400.2

SAE-G10

Laser

Z136.1 Main

NFPA

Nat’l

Elec

Code

115

Fire States

OSHA Pub 8-1.7

Ch. 17

New

Laser

Notice

Part AA CRCPD

Model

State

US State Laser Regulations

60

0 0 100 Km

100 Miles

500 Miles

0 500 KM

0

0 500 Miles 0 500 Km

HI

AK

AL

AZ

AR

CA CO

CT

DE

FL

GA

ID

IL IN

OA

KS

KY

LA

ME

MD

MA

MI

MN

MS

MO

MT

NB NV

NH

NJ

NM

NY

NC

ND

OH

OK

OR

PA

RI

SC

SD

TN

TX

UT

VT

VA

WA

WV

WI

WY

No relevant laser regulations

Some relevant laser regulations

Most involved & potentially

burdensome

Contact LIPA at [email protected] 2/19/14

LIPA will speed the adoption of laser illuminated

projectors through cooperative industry activity

62

Mission Statement

Advocate for a positive regulatory environment

that will facilitate commercial adoption of laser

illuminated projectors.

63

LIPA Objective

LIPA Membership

64 Contact LIPA at [email protected] 2/19/14

www.LIPAinfo.org

To learn more or to become a member…

Pete Ludé

[email protected]

@Lude3D for 3D FunFacts

digidrivel.blogspot.com

LinkedIn.com/in/PeteLude

Documents

Laser Illuminated Projectors - IEEE · 2014-12-01 · Laser Illuminated Projectors: Science, Safety and Regulations Pete Ludé Senior VP, Innovation RealD, Inc Past -Chairman LIPA