This is the
sixth issue of Directions, a newsletter from TechRoadmap Inc. discussing intellectual property issues and
ideas. As always, we hope to stimulate you to examine and improve your own IP
In this month's issue
we examine the effects of the apparent imprecise use of language
in the specification portion of the patent. If you ask what a patent is
protecting, everyone will tell you to look at the claims. But the claims
don't tell the whole story in many instances. For example, the claims
sometimes use expressions that are defined in the specification, Another
example in which the claims do not stand alone is when the invention
incorporates prior art technology - your patent is not expected to
detail what is common practice in your field. The issue raised in S3
Incorporated vs. nVidia Corporation is about the degree of latitude you
can expect if you are imprecise with your definitions and rely on what
you think is commonly understood knowledge.
Feel free to share this newsletter (see copyright notice below)
and to provide feedback by e-mail to: email@example.com
precisely what I think I might have meant to say!
clients question the elaborate patent documents that result from their
short but sweet invention disclosures. "Lawyers get paid by the
word." is a comment heard more than once, with the implication that
the length of the patent specification is due more to financial
considerations than to legal requirements.
month's patent case shows the fine line between excess verbiage and a
defensible patent. The patent in question has only about one and a half
pages of detailed description. A model, perhaps, of conciseness.
Unfortunately, S3's competitor, nVidia, felt too much had been left to
the reader's imagination and was able to convince the District Court the
many of the claims were fatally indefinite. Although S3 was ultimately triumphant
on appeal, they could have saved themselves time and expense by being a
bit more expansive in their specification.
were two problems in their specification. First, the internal definition
of what the VGA controller produced was imprecise. The focus of the
invention was the integration of multiple video functions into a single
IC; it was not the controller function per se. Thus, when referring to a
secondary mode of operation (the direct mode) the specification blithely
states that the controller provides video display information
directly to the D to A converter. Unfortunately, up to this point, the
controller had only sent "video information" to RAM in which
it was converted to "video display information", and it was
upon this small point that nVidia jumped. Thus, by not being precise
about what the controller could or could not produce or what was meant
by video information versus video display information, S3 had a problem.
second problem in the specification was its failure to provide at least
an example structure for carrying out a function included in the claims.
That is, the claims call for a means to select one or the other inputs
to the DAC, but the description never says what that might be. Thus, S3
relied on what they felt was common knowledge, at least within their
field. The difficulty here, of course, is knowing a priori what will be
taken as common knowledge. Although ultimately vindicated by the Appeals
Court, S3 could have avoided this difficultly by at least making a
reference to an appropriate selector structure - it was one of only five
major functional blocks in their invention.
what can you do?
the definitions in your application - make sure that every term
you use is used consistently in the document. Also be sure that each
term that is not guaranteed to be generic is defined in the
examples of how functions are performed - surely there are one
or more alternative ways to perform the function you are
claiming...that's probably why you want to claim the function in the
on the side of explaining "the obvious" - although you
don't want to start every patent at the beginning of time, don't let
your familiarity with the subject blind you to the need to teach
your invention adequately. Remember, almost by definition, you are
an expert, someone more knowledgeable than a person of
ordinary skill in the art.
in the preceding article should be construed as legal advice. TechRoadmap
Inc serves as an interface between companies and their legal counsel.
The risk in having an imprecise
S3 Inc. v. nVidia Corp, S3 appealed the summary judgment that
invalidated many claims in its patent US 5,581,279 on the ground of
indefiniteness. The patent describes an integrated circuit for use in a
computer video display card. The patent describes two modes of
operation; the direct mode and the indexed mode. In both modes a video
controller produces a data stream that in some sense defines the
sequence of pixel values for the display. In the direct mode, the 8-bit
output of the [VGA] video controller is selected by a
"selector" and sent directly to a digital-to-analog converter
(DAC), whose output is the signal that drives the monitor. The video
controller output is also sent to an random access memory (RAM) that
acts as a lookup table, converting the 8-bit controller output into 256 different
words, each of which can be 18 or 24 bits wide. In direct mode these
data are ignored. In indexed mode, however, the selector selects the RAM
output for transmission to the DAC and ignores the signals coming
directly from the controller.
argued successfully before the District Court that seven of the patent's
claims where invalid on the grounds of indefiniteness. The basis of
their argument was that in both the specification and in the claims the
terms "video information data" and "video display
information data" are used in ways that make the claims unclear; so
unclear that they did not meet the statutory requirement of
"particularly pointing out and distinctly claiming the subject
matter which the applicant regards as his invention". Basically
they argued that it was unclear whether the controller produces
"video information" (which feeds the RAM) or "video
display information" (which feeds the DAC and is produced by the
District Court agreed. The Court also held that the claim language
"digital-to-analog means...for selectively receiving
either..." of the two data streams was also indefinite because the
structure claimed by the selectivity limitation is not disclosed in the
specification as required.
Appeals Court majority rejected the decision of the District Court,
saying that while it is true that the claims require two different
outputs from the video controller and this requirement is (arguably) inconsistent
with the description in the specification, they "conclude that a
person of skill in this field would understand the claims when viewed in
the light of the description". They said "the claims
are not a self-contained explanation of every step. That is not the
role of claims". "The purpose of claims is not to explain
the technology or how it works, but to state the legal boundaries of the
patent grant". The Appeals Court pointed out a single line in
the specification - "In certain modes it may be desirable for the
VGA controller to...provide video display information directly to the
DAC" and concluded "that a person skilled in this field would
understand the meaning and scope of the data streams as set forth in the
claims." Thus, it ruled, there was no indefiniteness in the claims.
District Court had also ruled that the use of the terms
"means...for selectively receiving", without either a
description of the electronic structure of the selector or the details
of its electronic operation in the specification, was indefinite. The
District Court stated that "the disclosure must be judged on the
basis of the 'common experience' of 'those outside the relevant art'.
" [emphasis added] The Appeals Court strongly stated that this
ruling was "incorrect, and must be reversed" The Appeals Court
noted that "patent documents need not include subject matter
that is known in the field of the invention [emphasis added],
for patents are written for persons experienced in the field..." To
hold otherwise, they continued, "would require every
patent [to be] a technical treatise for the unskilled reader."
Finally, referencing an earlier decision, "Patents are written to
enable those skilled in the art to practice the invention, not the
US Patent office
Searchable database of all US Patents and, now, published patent
The Patent Cafe - an on-line source of interesting insights into
current IP issues.
EKMS Inc. - a company with whom
we've worked that provides a range of IP management services including
portfolio analysis, deal-making, and process improvement.