Page 369 - Design for Six Sigma a Roadmap for Product Development

Theory of Inventive Problem Solving (TRIZ) 339

a telephotographic mode and a relatively short focal length suitable
for a wide-angle photographic mode. This system is equipped with a
focal-length-hanging mechanism consisting of a rotatable focal-
length-varying member driven by a motor, a lever-displacing member
provided on the rotatable focal-length-varying member, a motor-
switching lever engageable with the lever-displacing member for
switching a motor switch, and a focal-length-changing member for
varying the focal length of the taking lens on rotation of the rotatable
changing member.
Since 1990, an optical fluid lens has been developed to replace the con-
ventional solid lens in specific circumstances. Here is one of the patents
applying this concept:

U.S. Patent 4,466,706 (1984): Optical fluid lens. A lens designed espe-
cially for applications requiring a large lens eliminates costly grinding
and polishing operations. The lens embodies an adjustable chamber
containing an optical fluid which can be pressurized in varying degrees
by altering the size of the chamber. The curvatures of the resilient opti-
cal diaphragms at the ends of the chamber change in response to vari-
ations in the pressure of the fluid in the chamber to produce a lens of
fixed or variable focal length.

9.10 Physical, Chemical, and
Geometric Effects Database
Technical systems are designed and produced to deliver functions. As
we discussed earlier, to deliver a function, we need at least three ele-
ments, a subject, an action, and an object. Subjects and objects are sub-
stances; actions are usually delivered by various fields. Therefore the
knowledge base on the properties of substances and fields are very
important in developing superior technical systems.
Many TRIZ software programs have huge databases on substances
and fields properties, and their physical, chemical, and geometric
effects. An example is the software developed by Invention Machine
Corporation. This kind of database is very helpful in creating inventive
solutions.

9.11 Comparison of Axiomatic Design
and TRIZ
The following table summarizes the possible relations between
axiomatic design (AD) (Chap. 8) and TRIZ design problem-solving
tools. Seven corollaries and three theorems in AD (Suh 1990) are
selected for comparison with TRIZ tools. Seven corollaries, which
serve as the design rules, are derived from two axioms directly, so