environment. Additionally, the shutters
should operate in a safe mode that is defined by the designers.
Answering the right questions
Once you have identified the need for
a shutter, you must understand how to
achieve the best performance for the sys-
tem. Shutters, though deceptively simple,
have many important decision points, and
it’s critical to maintain high standards for
quality and reliability in all key features.
Here are some of the key elements of
shutter design that must be understood:
Blade coating: There are unlimited options that support life span and sensor
calibration requirements. High emissivity coatings and blade materials are a specialized science requiring years of experience to master. Many coatings provide
sufficient performance, but often the best
option will make the difference between
an average system and a superior system.
Speed: Many commercial cameras
need shutters that function with micro-
second precision, traveling from closed to
open (or vice versa) in 10 to 25 ms or less.
Lifecycle/reliability: Varying applica-
tions require lifecycles of 100,000 up to
20 million cycles before shutters need replacement. Millions of lifecycles are nec-
essary for the high demands of the commercial life science industry.
Power: Power is a unique concern for
every design. Some systems deliver a large
amount of power to the camera, such as
when mounted in a vehicle. Usually, this
is not the case, and power management is
essential through electronic design.
Noise: This is one of the most important specifications to meet, especially in
mission critical environments and with
stringent MIL specs.
Environmental: When using cameras
in caustic environments or in wide rang-
es of thermal heat/cold, robust require-
ments can be very difficult to achieve con-
sistently. Although the external elements
in laboratories are not challenging, they
have their own requirements for safety.
Physical size requirements: Here the
system size trades off with the aperture
size; e.g, more blades can reduce the size
of the shutter as a whole but the system
increases in complexity. As a result, the
shutter dimensions and aperture size relative to the optical path and the mechan-
ical footprint must be considered.
Catalog vs. custom design: An extensive catalog portfolio can save time and
effort. If a catalog does not meet sys-
tem requirements, then the product development team should include experts
in optical and shutter designs. The experts should function as an extension of
the OEM design team.
Michael J. Tenalio is director of product
management and Tyler Moore is regional
sales manager at Melles Griot, 55 Science
Parkway, Rochester NY 14620; email: