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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
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
BACKGROUND: current projector technology
BASICS: What is laser light?
BLUEPRINT: About laser projectors
BENEFITS: Why would you want one?
BUMPS: Regulatory Roadmap
12
What’s different about laser light?
Coherence
Monochromaticity
Radiance
13
What’s different about laser light?
Coherence
Monochromaticity
Radiance
Coherence is the cause of speckle (not injury)
14
What’s different about laser light?
Coherence
Monochromaticity
Radiance
15
What’s different about laser light?
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 info@lipainfo.org
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
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
BACKGROUND: current projector technology
BASICS: What is laser light?
BLUEPRINT: About laser projectors
BENEFITS: Why would you want one?
BUMPS: Regulatory Roadmap
23
Summary of Benefits
Laser projectors have the potential of…
• Dramatically improved image quality
Pete Ludé 24
Summary of Benefits
Laser projectors have the potential of…
• Dramatically improved image quality
• 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
Laser projectors have the potential of…
• Dramatically improved image quality
• Substantially Lower power consumption
• 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
Laser projectors have the potential of…
• Dramatically improved image quality
• Substantially Lower power consumption
• Lower operating costs
• Reduced environmental impact
Pete Ludé
Potential reduction in carbon emissions
300,000 metric tons
27
Summary of Benefits
Laser projectors have the potential of…
• Dramatically improved image quality
• Substantially Lower power consumption
• Lower operating costs
• Reduced environmental impact
• Flexible design / boothless theater
28
Today’s Topics
BACKGROUND: A word about current projector technology
BASICS: What is laser light?
BLUEPRINT: About laser projectors
BENEFITS: Why would you want one?
BUMPS: What could slow this down?
29
Today’s Topics
BACKGROUND: current projector technology
BASICS: What is laser light?
BLUEPRINT: About laser projectors
BENEFITS: Why would you want one?
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 info@lipainfo.org 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.
45 Contact LIPA at info@lipainfo.org
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):
46 Contact LIPA at info@lipainfo.org
Conclusion
47
Traditional lamp projectors
and new laser-illuminated projectors,
when of equal luminance power,
emit almost identical radiance.
Contact LIPA at info@lipainfo.org 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
Part 1: Equipment classification & Requirements
IEC 62471 Ed 1 (2006) Photobiological safety of lamps and lamp systems
Carve-out for devices with irradiance < 1 MW / m2sr
α
IEC Laser Regulations
IEC 60825-1 Ed 3 (2014?) Safety of Laser Products
Part 1: Equipment classification & Requirements
IEC 62471-5 Ed 1 (2015?) Photobiological safety of Lamp Systems
for Image Projectors
IEC Laser Regulations
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 info@lipainfo.org 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 info@lipainfo.org 2/19/14
www.LIPAinfo.org
To learn more or to become a member…
Pete Ludé
PLude@reald.com
@Lude3D for 3D FunFacts
digidrivel.blogspot.com
LinkedIn.com/in/PeteLude
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