United States Court of Appeals
for the Federal Circuit
__________________________
RESEARCH CORPORATION TECHNOLOGIES,
INC.,
Plaintiff-Appellant,
v.
MICROSOFT CORPORATION,
Defendant-Appellee.
__________________________
2010-1037
__________________________
Appeal from the United States District Court for the
District of Arizona in case no. 01-CV-0658, Judge Robert
C. Jones.
___________________________
Decided: December 8, 2010
___________________________
J. MICHAEL JAKES, Finnegan, Henderson, Farabow,
Garrett & Dunner, LLP, of Washington, DC, argued for
plaintiff-appellant. With him on the brief were SUSAN Y.
TULL; and ERIKA H. ARNER, of Reston, Virginia. Of coun-
sel on the brief were M. MILLER BAKER, BLAIR M. JACOBS,
PAUL E. POIROT and NATALIA V. BLINKOVA, McDermott,
Will & Emery LLP, of Washington, DC; and MICHAEL J.
RUSING, Rusing & Lopez, PLLC, of Tucson, Arizona. Of
counsel were ISAAC CRUM, STEPHEN K. SHAHIDA and
RESEARCH CORP v. MICROSOFT CORP 2
BUREDEN J. WARREN, McDermott, Will & Emery LLP, of
Washington, DC.
JOHN D. VANDENBERG, Klarquist Sparkman, LLP, of
Portland, Oregon argued for defendant-appellee. With
him on the brief were STEPHEN J. JONCUS, TODD M.
SIEGEL, KRISTIN L. CLEVELAND and SALUMEH R. LOESCH.
Of counsel on the brief were STEPHEN P. MCGRATH, Micro-
soft Corporation, of Redmond, Washington; and JEFFREY
WILLIS, Snell & Wilmer, L.L.P., of Tucson, Arizona.
__________________________
Before RADER, Chief Judge, NEWMAN and PLAGER, Circuit
Judges.
RADER, Chief Judge.
Research Corporation Technologies, Inc. (“RCT”) ini-
tiated this action against Microsoft Corporation (“Micro-
soft”), alleging infringement of six related patents: U.S.
Patent Nos. 5,111,310 (“’310 patent”); 5,341,228 (“’228
patent”); 5,477,305 (“’305 patent”); 5,543,941 (“’941 pat-
ent”); 5,708,518 (“’518 patent”); and 5,726,772 (“’772
patent”). The United States District Court for the District
of Arizona held that certain claims of the ’310 and ’228
patents were invalid under 35 U.S.C. § 101. The district
court further held that certain claims of the ’772 and ’305
patents were not entitled to claim the benefit of earlier
filed applications that led to the ’310 and ’228 patents.
Because the ’310 and ’228 patents claim patent-
eligible subject matter, this court reverses the district
court on that point. This court also finds that claim 29 of
the ’305 patent deserves the earlier filing date and thus
reverses the district court’s effective date ruling and
remands. At the same time, this court affirms the district
3 RESEARCH CORP v. MICROSOFT CORP
court’s decision that claims 4 and 63 of the ’772 patent are
not entitled to the earlier effective filing date.
I
RCT’s six patents relate to digital image halftoning.
Digital images are, in fact, thousands of pixels arranged
in arrays of rows and columns. Each pixel in a black-and-
white image contains information about the gray level of
the image at that particular position. A black-and-white
image can have 256 shades of gray. A gray level 1 repre-
sents black and a gray level 256 represents white, with
intervening numbers representing various shades of gray.
For color images, a computer creates separate color-
specific arrays of pixels, one array for each primary color.
A color-specific array has pixels containing information
about the shade level of that color at that particular
position.
Digital images often show shades of gray and even a
spectrum of colors. Nonetheless, computer displays and
printers can only use a limited number of primary colors
to display these digital images. Halftoning bridges this
gap by simulating a continuous tone image through the
use of dots. Halftoning techniques allow computers to
present many shades and color tones with a limited
number of pixel colors. These techniques place the dots of
primary colors in a formation that gives the viewer the
illusion of many more shades of gray or varying colors.
Black-and-white printers use only black dots to give the
illusion of shades of gray. Color printers typically use
four primary colors—cyan, magenta, yellow, and black—
to give the illusion of a spectrum of colors. Color displays
often use three primary colors—red, green, and blue—to
achieve the same effect. Digital halftoning technology
thus allows computer displays and printers to render an
approximation of an image by using fewer colors or
RESEARCH CORP v. MICROSOFT CORP 4
shades of gray than the original image. For the most
part, this opinion discusses halftoning technology with
reference primarily to a black-and-white image with
varying shades of gray, rather than a color image. The
principles, however, are the same.
One method of generating a digital halftoned image is
called “thresholding.” The thresholding technique uses a
two-dimensional array called a “mask” that is populated
with predetermined threshold numbers, which are typi-
cally between 1 and 256. The thresholds do not relate at
all to the image to be halftoned. The thresholding tech-
nique compares the gray level at each pixel of the image
against the threshold that corresponds to the pixel’s
position. If the gray level exceeds the corresponding
threshold, the pixel is turned on, i.e., the computer places
a “1” in the appropriate memory space. The resulting
halftone image is a two-dimensional array of zeros and
ones.
This imaging field uses various ways to measure the
quality of a halftoning process. One method examines the
“dot profiles” produced by the halftoning process. A dot
profile is a halftone image that would be produced if the
original image were a single shade of gray, (i.e., all of the
pixels have the same gray level). A dot profile is essen-
tially a pattern of black dots on a white piece of paper. A
dot profile for an original image with a high gray level
would have more ones and thus more black dots than a
dot profile for an image with a low gray level. Closely
spaced dots are said to occur at a high frequency, and
those far apart are said to occur at a low frequency.
Because the human visual system is more sensitive to low
frequencies than to high frequencies, viewers consider dot
profiles with few low-frequency dots visually pleasing.
5 RESEARCH CORP v. MICROSOFT CORP
Another way to observe the quality of a halftone is to
use a power spectrum associated with each dot profile
obtained from the halftoning process. A power spectrum
is a graph showing the relative frequency of dots in the
dot profile at a particular gray level. The shape of the
power spectrum characterizes the type of “noise” that the
dot profiles exhibit. For example, a dot profile with a
“white noise” exhibits a power spectrum where the fre-
quencies are approximately equal across the graph. In
contrast, a dot profile with a “blue noise” exhibits a power
spectrum with primarily high frequency components and
negligible low frequency components.
Figure 1 of the ’310 patent shows an ideal blue noise
power spectrum, which is unattainable in the real world.
’310 patent fig.1. The horizontal axis represents the
radial frequency, which is the reciprocal of the average
spacing between the dots in the dot profile. A blue noise
power spectrum has negligible frequency components
below the principal frequency and high frequency compo-
nents above the principal frequency. The principal fre-
quency, fg, varies from one gray level g to another:
RESEARCH CORP v. MICROSOFT CORP 6
Id. col.6 ll.25-38. In this equation, R is the distance
between addressable dots on the display and the gray
level g is normalized from zero to one. The principal
frequency assumes its highest value for 50% gray level
because at this level there are equal numbers of black and
white dots. Each dot profile exhibits a power spectrum
with a different radial frequency because as the gray level
increases, so does the number of dots in the dot profile.
Drs. Kevin J. Parker and Theophano Mitsa, the
named inventors of the six RCT patents, conceived of an
improved blue noise mask. The inventors’ halftoning
technique used a blue noise mask, which was stored in a
computer’s memory, to carry out a pixel-by-pixel compari-
son of the mask to the digital image. Their halftoning
technique compares the gray level of each pixel in a
digital image to the corresponding threshold number in
the blue noise mask to produce a halftone image.
The claimed blue noise mask has unique first and sec-
ond order properties. When thresholded at A% of the
maximum level, exactly A out of every 100 pixels will be
greater than the threshold value. For example, when the
blue noise mask is thresholded at 50% of the maximum
level, exactly half of the pixels will be turned on. In
addition, the dots are distributed so that they form a blue
noise pattern, which means that “the resulting dot profile
is a locally aperiodic and isotropic binary pattern with
small low-frequency components.” Id. col.5 ll.60-63. The
blue noise mask also has wraparound properties such that
a smaller blue noise mask can be used to halftone a larger
7 RESEARCH CORP v. MICROSOFT CORP
image by tiling the mask over an appropriate number of
periods.
In constructing the claimed blue noise mask, one of
skill in this art would first create a dot profile that corre-
sponds to the 50% gray level. Next, the skilled artisan
would sequentially construct the dot profiles for other
gray levels. The dot profile for the next gray level g + Δg
is built from the dot profile for the gray level g by convert-
ing a given number of pixels. If the next gray level is
higher, a certain number of zeros are converted into ones;
if the next gray level is lower, a certain number of ones
are converted into zeros. The pixel that was turned on for
a gray level g remains turned on for all dot profiles with a
gray level g or higher. As these pixels change value from
one sequential profile to the next, the mask keeps track of
those changes. The pixel-value conversion that occurs at
every pixel location is encoded in a cumulative array.
When all dot profiles are built, the cumulative array
becomes the blue noise mask. Compared to prior art blue
noise masks, Drs. Parker and Mitsa’s inventive mask
produces higher quality halftone images while using less
processor power and memory space.
RCT alleges that Microsoft infringes all six patents.
The following claims are at issue on appeal: claims 1 and
2 of the ’310 patent; claim 11 of the ’228 patent; claims 4
and 63 of the ’772 patent; and claim 29 of the ’305 patent.
The ’310 patent issued on May 5, 1992, based on a De-
cember 4, 1990 application (“the 1990 Application”).
Asserted claims 1 and 2 recite:
1. A method for the halftoning of gray scale im-
ages by utilizing a pixel-by-pixel comparison of
the image against a blue noise mask in which the
blue noise mask is comprised of a random non-
deterministic, non-white noise single valued func-
RESEARCH CORP v. MICROSOFT CORP 8
tion which is designed to produce visually pleas-
ing dot profiles when thresholded at any level of
said gray scale images.
’310 patent col.10 ll.23-30.
2. The method of claim 1, wherein said blue noise
mask is used to halftone a color image.
Id. col.10 ll.31-32.
The ’228 patent issued on August 23, 1994, based on a
December 3, 1991 Application (“the 1991 Application”).
The ’228 patent is a continuation-in-part of the ’310
patent. Claim 11 recites:
11. A method for the halftoning of color images,
comprising the steps of utilizing, in turn, a pixel-
by-pixel comparison of each of a plurality of color
planes of said color image against a blue noise
mask in which the blue noise mask is comprised of
a random non-deterministic, non-white noise sin-
gle valued function which is designed to provide
visually pleasing dot profiles when thresholded at
any level of said color images, wherein a plurality
of blue noise masks are separately utilized to per-
form said pixel-by-pixel comparison and in which
at least one of said blue noise masks is independ-
ent and uncorrelated with the other blue noise
masks.
’228 patent col.20 ll.3-14.
The remaining four patents—the ’305, ’941, ’518, and
’772 patents—claim the benefit under 35 U.S.C. § 120 of
the effective filing dates of the 1990 and 1991 Applica-
tions. The ’941 patent is a continuation of the ’228 patent;
the ’305 and ’518 patents are continuations of the ’941
patent; and the ’772 patent is a continuation of the ’305
9 RESEARCH CORP v. MICROSOFT CORP
patent. These five patents share the same specification.
The asserted claims 4 and 63 of the ’772 patent depend
from independent claims 1 and 57, respectively.
1. [not asserted] A machine comprising a com-
puter readable storage device which stores a
dither matrix for use in halftoning image informa-
tion and a comparator responsive to said com-
puter readable storage device, said dither matrix
comprising at least one array, said at least one ar-
ray, when thresholded at a number of levels pro-
duces a number of dot profiles, a plurality of said
number of dot profiles each having a power spec-
trum substantially characteristic of a blue noise
power spectrum for the level at which such dot
profile is produced.
’772 patent col.16 ll.52-61.
4. The machine of claim 1, wherein substantially
all of said number of dot profiles have a power
spectrum substantially characteristic of a blue
noise power spectrum for the level at which such
dot profile is produced.
Id. col.17 ll.1-4 (emphasis added).
57. [not asserted] A computer readable memory
device comprising a thresholdable halftoning
mask, said halftoning mask designed to produce a
plurality of visually pleasing dot profiles when
thresholded at a number of levels and a compara-
tor responsive to said computer readable memory
device.
Id. col.19 ll.38-43.
RESEARCH CORP v. MICROSOFT CORP 10
63. The computer readable memory device of
claim 57, wherein said halftoning mask is de-
signed to produce substantially all visually pleas-
ing dot profiles when thresholded at a number of
levels.
Id. col.19 ll.58-61 (emphasis added).
Claim 29 of the ’305 patent recites:
29. Apparatus for the halftoning of color images
comprising a comparator for comparing, on a
pixel-by-pixel basis, a plurality of color planes of
said color image against a blue noise mask in
which the blue noise mask is comprised of a ran-
dom non-deterministric, non-white noise single
valued function which is designed to provide visu-
ally pleasing dot profiles when thresholded at any
level of said color images, wherein an output of
said comparator is used to produce a halftoned
image.
’305 patent col.19 ll.48-56 (emphasis added).
II
On December 21, 2001, RCT filed suit against Micro-
soft alleging that Microsoft’s operating systems, office
suites, and other applications infringe RCT’s patents.
This court has heard an earlier appeal in this case and
reversed the district court’s finding of inequitable conduct.
Research Corp. Techs., Inc. v. Microsoft Corp., 536 F.3d
1247, 1254 (Fed. Cir. 2008). This court vacated the dis-
trict court’s grant of Microsoft’s motion for summary
judgment of invalidity and non-infringement. Id. Finally,
this court remanded with instructions to reassign the case
to a new judge. Id. at 1255.
11 RESEARCH CORP v. MICROSOFT CORP
On remand, the district court held on summary judg-
ment that the asserted claims of the ’310 and the ’228
patents were invalid under 35 U.S.C. § 101. The district
court also held on summary judgment that the asserted
claims of the ’772 patent were not entitled to claim prior-
ity to the 1990 and 1991 Applications. The district court
found that the invention disclosed in the 1990 and 1991
Applications were limited to a blue noise mask and thus
did not provide written description support for the as-
serted claims of the ’772 patent, which claimed more than
the disclosed blue noise mask. Id.
After the district court’s effective date ruling for the
’772 patent, RCT and Microsoft stipulated that no accused
Microsoft product infringes a valid, asserted claim of the
’305, ’941, ’518, and ’772 patents that does not recite a
“blue noise mask.” Among those later-filed claims, only
claim 29 of the ’305 patent, which expressly claims a “blue
noise mask,” remained for trial. On the eve of trial, the
district court ruled from the bench that claim 29 of the
’305 patent was not entitled to claim the benefit of an
earlier filing date. The parties stipulated to invalidity of
claim 29. On the same day, the parties filed a written
stipulation dismissing the suit on the merits pursuant to
the Federal Rules of Civil Procedure Rule 41(a)(1)(A)(ii).
The district court granted the stipulation on September 3,
2009.
RCT appeals the district court’s section 101 ruling
and the effective filing date rulings. This court has juris-
diction under 28 U.S.C. § 1295(a)(1).
III
This court reviews a grant of summary judgment
without deference. Liebel-Flarsheim Co. v. Medrad, Inc.,
481 F.3d 1371, 1377 (Fed. Cir. 2007). This court also
reviews questions about patent-eligible subject matter
RESEARCH CORP v. MICROSOFT CORP 12
under 35 U.S.C. § 101 without deference. In re Ferguson,
558 F.3d 1359, 1363 (Fed. Cir. 2009). This court also
reviews without deference whether a patent is entitled to
an earlier priority date. Go Med. Indus. Pty, Ltd. v.
Inmed Corp., 471 F.3d 1264, 1270 (Fed. Cir. 2006).
IV
The Patent Act of 1952 sets forth the categories of
subject matter eligible for patent protection:
Whoever invents or discovers any new and useful
process, machine, manufacture, or composition of
matter, or any new and useful improvement
thereof, may obtain a patent therefore, subject to
the conditions and requirements of this title.
35 U.S.C. § 101. Section 101 emphasizes that “any”
subject matter in the four independent categories and
“any” improvement in that subject matter qualify for
protection. The Supreme Court recently reemphasized
the significance of these broad statutory categories with
the broadening double “any” exhortation as well. Bilski v.
Kappos, 130 S. Ct. 3218, 3225 (2010). In that recent case,
the Supreme Court also focused on the Patent Act’s
definition for “process,” the statutory category at issue in
this case:
The term “process” means process, art, or method,
and includes a new use of a known process, ma-
chine, manufacture, composition of matter, or ma-
terial.
35 U.S.C. § 100(b); Bilski, 130 S. Ct. at 3225.
In its Bilski decision, the Supreme Court invoked
again some of its earlier cases that have relevance to this
case as well. For instance, the Bilski court relied on
Diamond v. Diehr, 450 U.S. 175 (1981), and Diamond v.
13 RESEARCH CORP v. MICROSOFT CORP
Chakrabarty, 447 U.S. 303 (1980). Bilski, 130 S. Ct. at
3225. Chakrabarty recited that “Congress plainly con-
templated that the patent laws would be given wide
scope.” 447 U.S. at 308. Therefore, the Supreme Court
has “more than once cautioned that courts ‘should not
read into the patent laws limitations and conditions
which the legislature has not expressed.’” Diehr, 450 U.S.
at 182 (quoting Chakrabarty, 447 U.S. at 308). The
Supreme Court has articulated only three exceptions to
the Patent Act’s broad patent-eligibility principles: “laws
of nature, physical phenomena, and abstract ideas.”
Chakrabarty, 447 U.S. at 309. The Supreme Court rea-
soned that laws of nature and natural phenomena fall
outside the statutory categories because those categories
embrace “the basic tools of scientific and technological
work.” Gottschalk v. Benson, 409 U.S. 63, 67 (1972).
Abstractness, also a disclosure problem addressed in the
Patent Act in section 112, also places subject matter
outside the statutory categories.
The section 101 patent-eligibility inquiry is only a
threshold test. See Bilski, 130 S. Ct. at 3225. Moreover,
the statutory provision that approves the broad categories
of subject matter, section 101, itself directs primary
attention to “the conditions and requirements of [Title
35].” 35 U.S.C. § 101. Indeed, the Supreme Court re-
cently emphasized this statutory framework and faulted
this court’s “machine or transformation” test for eligibility
as nonstatutory. Bilski, 130 S. Ct. at 3227. In refocusing
the eligibility inquiry on the statute, the Supreme Court
advised that section 101 eligibility should not become a
substitute for a patentability analysis related to prior art,
adequate disclosure, or the other conditions and require-
ments of Title 35. In other words, section 101 does not
permit a court to reject subject matter categorically
because it finds that a claim is not worthy of a patent.
RESEARCH CORP v. MICROSOFT CORP 14
See Bilski, 130 S. Ct. at 3238 (Stevens, J., concurring)
(“Given the many moving parts at work in the Patent Act,
there is a risk of merely confirming our preconceived
notions of what should be patentable or of seeing common
attributes that track ‘the familiar issues of novelty and
obviousness’ that arise under other sections of the statute
but are not relevant to § 101.” (quoting Parker v. Flook,
437 U.S. 584, 588 (1978)).
In this case, the subject matter is a “process” for ren-
dering a halftone image. As a process, the subject matter
qualifies under both the categorical language of section
101 and the process definition in section 100. Therefore,
this court proceeds to examine the Supreme Court’s three
exceptions. The parties do not dispute, and this court
agrees, that the inventors do not purport to have invented
laws of nature or physical phenomena. Therefore, this
court turns to abstractness. Indeed, the Supreme Court
in Bilski refocused this court’s inquiry into processes on
the question of whether the subject matter of the inven-
tion is abstract. The Supreme Court did not presume to
provide a rigid formula or definition for abstractness. See,
e.g., Bilski, 130 S.Ct. at 3236 (The Court has “never
provide[d] a satisfying account of what constitutes an
unpatentable abstract idea.” (Stevens, J., concurring)).
Instead, the Supreme Court invited this court to develop
“other limiting criteria that further the purposes of the
Patent Act and are not inconsistent with its text.” Id. at
3231.
With that guidance, this court also will not presume
to define “abstract” beyond the recognition that this
disqualifying characteristic should exhibit itself so mani-
festly as to override the broad statutory categories of
eligible subject matter and the statutory context that
directs primary attention on the patentability criteria of
the rest of the Patent Act. In that context, this court
15 RESEARCH CORP v. MICROSOFT CORP
perceives nothing abstract in the subject matter of the
processes claimed in the ’310 and ’228 patents. The ’310
and ’228 patents claim methods (statutory “processes”) for
rendering a halftone image of a digital image by compar-
ing, pixel by pixel, the digital image against a blue noise
mask.
The invention presents functional and palpable appli-
cations in the field of computer technology. These inven-
tions address “a need in the art for a method of and
apparatus for the halftone rendering of gray scale images
in which a digital data processor is utilized in a simple
and precise manner to accomplish the halftone render-
ing.” ’310 patent col.3 ll.33-40. The fact that some claims
in the ’310 and ’228 patents require a “high contrast film,”
“a film printer,” “a memory,” and “printer and display
devices” also confirm this court’s holding that the inven-
tion is not abstract. Indeed, this court notes that inven-
tions with specific applications or improvements to
technologies in the marketplace are not likely to be so
abstract that they override the statutory language and
framework of the Patent Act.
This court also observes that the claimed methods in-
corporate algorithms and formulas that control the masks
and halftoning. These algorithms and formulas, even
though admittedly a significant part of the claimed com-
bination, do not bring this invention even close to ab-
stractness that would override the statutory categories
and context. The Supreme Court has already made
abundantly clear that inventions incorporating and
relying upon even “a well known mathematical equation”
do not lose eligibility because “several steps of the process
[use that] mathematical equation.” Diehr, 450 U.S. at
185. Indeed, the Supreme Court counseled:
RESEARCH CORP v. MICROSOFT CORP 16
In determining the eligibility of respondents’
claimed process for patent protection under sec-
tion 101, their claims must be considered as a
whole. It is inappropriate to dissect the claims
into old and new elements and then to ignore the
presence of the old elements in the analysis. This
is particularly true in a process claim because a
new combination of steps may be patentable even
though all the constituents of the combination
were well known and in common use before the
combination was made.
Id. at 188. Borrowing from the reasoning of the Supreme
Court in Diehr, this court observes that the patentees
here “do not seek to patent a mathematical formula.
Instead, they seek patent protection for a process of”
halftoning in computer applications. Id. at 187. More-
over, because the inventions claimed in the ’310 and ’228
patents are directed to patent-eligible subject matter, the
process claims at issue, which claim aspects and applica-
tions of the same subject matter, are also patent-eligible.
In the context of the statute, this court notes that an
invention which is not so manifestly abstract as to over-
ride the statutory language of section 101 may nonethe-
less lack sufficient concrete disclosure to warrant a
patent. In section 112, the Patent Act provides powerful
tools to weed out claims that may present a vague or
indefinite disclosure of the invention. Thus, a patent that
presents a process sufficient to pass the coarse eligibility
filter may nonetheless be invalid as indefinite because the
invention would “not provide sufficient particularity and
clarity to inform skilled artisans of the bounds of the
claim.” Star Scientific., Inc. v. R.J. Reynolds Tobacco Co.,
537 F.3d 1357, 1371 (Fed. Cir. 2008). That same subject
matter might also be so conceptual that the written
17 RESEARCH CORP v. MICROSOFT CORP
description does not enable a person of ordinary skill in
the art to replicate the process.
Accordingly, this court reverses the district court’s
summary judgment that the ’310 and ’228 patents do not
claim patent-eligible inventions.
V
The Patent Act provides: “An application for patent
for an invention disclosed in the manner provided by the
first paragraph of this title in an application previously
filed in the United States . . . shall have the same effect,
as to such invention, as though filed on the date of the
prior application . . . .” 35 U.S.C. § 120. To obtain the
benefit of a parent application’s filing date under section
120, “the claims of the later-filed application must be
supported by the written description in the parent ‘in
sufficient detail that one skilled in the art can clearly
conclude that the inventor invented the claimed invention
as of the filing date sought.’” Anascape, Ltd. v. Nintendo
of Am., Inc., 601 F.3d 1333, 1335 (Fed. Cir. 2010) (quoting
Lockwood v. Am. Airlines, Inc., 107 F.3d 1565, 1572 (Fed.
Cir. 1997)). Entitlement to a filing date extends only to
subject matter that is disclosed; not to that which is
obvious. Lockwood, 107 F.3d at 1571-72. Therefore, the
parent application must actually or inherently disclose
the elements of the later-filed claims. PowerOasis, Inc. v.
T-Mobile USA, Inc., 522 F.3d 1299, 1306 (Fed. Cir. 2008).
On appeal, RCT challenges the district court’s deter-
mination that claims 4 and 63 of the ’772 patent are not
entitled to claim the benefit of the filing dates of the 1990
Application (December 4, 1990) or the 1991 Application
(December 3, 1991). RCT also asserts that the district
court erred by later ruling from the bench that claim 29 of
the ’305 patent was not entitled to an earlier filing date.
RESEARCH CORP v. MICROSOFT CORP 18
This court notes that the ’772 and ’305 patents share
the same specification with the ’228 patent into which the
1991 Application matured. Therefore, whether the later-
filed claims in the ’772 and ’305 patents are supported by
the 1991 Application under 35 U.S.C. § 120 essentially
asks whether the later-filed claims are supported by their
own written descriptions under 35 U.S.C. § 112. How-
ever, because the parties have presented the issue as an
effective filing date question rather than a written de-
scription question and the trial court has adopted the
parties’ characterization of the issue, this court will
analyze the issue under section 120.
This court first considers whether the district court
misplaced the burden of showing the ’772 patent’s enti-
tlement to an earlier effective date. A patent is presumed
valid and the party asserting invalidity has the burden of
persuasion to show the contrary by clear and convincing
evidence. Tech. Licensing Corp. v. Videotek, Inc., 545 F.3d
1316, 1329 (Fed. Cir. 2008). The challenger has the
burden of going forward with invalidating prior art. Id.
The patentee then has the burden of going forward with
evidence to the contrary, i.e., the patentee must show that
the prior art does not actually invalidate the patent or
that it is not prior art because the asserted claim is enti-
tled to the benefit of an earlier filing date. Id.; see also
PowerOasis, 522 F.3d at 1304-06 (holding that the pat-
entee had the burden to come forward with evidence to
prove entitlement to an earlier filing date when it was
undisputed that a certain reference was invalidating prior
art).
Microsoft’s summary judgment motion was couched as
“Microsoft’s Motion for Partial Summary Judgment that
the Asserted Claims of the ’772 patent are not Entitled to
the Effective Filing Date of the 1991 or 1990 Applications
under 35 U.S.C. § 120.” Br. of Def.-Microsoft Corp. at 1,
19 RESEARCH CORP v. MICROSOFT CORP
Research Corp. Techs., Inc. v. Microsoft Corp., No. 01-658
(Dkt. 845) (D. Ariz. Feb. 13, 2009). In fact, this motion
had the effect of asserting invalidity. Microsoft pointed
out in its motion that RCT sought the 1990 and 1991
effective dates to “avoid intervening art” and identified
the ’310 patent as one such reference. Id. The district
court recognized that “[b]ecause [Microsoft] is moving on
validity of RCT’s ’772 patent, Microsoft has the burden of
persuasion to prove invalidity by clear and convincing
evidence.” Research Corp. Techs., Inc. v. Microsoft Corp.,
No. 01-658, slip. op. at 11 (D. Ariz. June 5, 2009).
RCT argues that Microsoft did not show initially that
the ’310 patent anticipated the asserted claims of the ’772
patent. However, in response to Microsoft’s motion, RCT
only argued that the ’310 patent was not prior art because
the ’772 patent was entitled to the same effective filing
date as the ’310 patent. Br. of Pl.-Research Corp. Techs.,
Inc., Research Corp. Techs., Inc. v. Microsoft Corp., No.
01-658 (Dkt. 885) (D. Ariz. Feb. 19, 2009). RCT did not
contest before the district court (and thus waived on
appeal) that the ’310 patent did not meet each and every
element of the ’772 patent claims or present a disclosure
that rendered the ’772 patent claims obvious. Accord-
ingly, RCT did not put into dispute that the ’310 patent
was an invalidating prior art reference. Because Micro-
soft effectively satisfied its initial burden by coming
forward with invalidating prior art, the burden was on
RCT to come forward with evidence to show that the ’310
patent was not actually prior art. The district court
therefore correctly placed the burden on RCT to come
forward with evidence to show entitlement to an earlier
filing date.
This court must next examine the scope of the later-
filed claims in determining whether the written descrip-
tion of the 1990 and 1991 Applications support the later-
RESEARCH CORP v. MICROSOFT CORP 20
filed claims. Claim 4 of the ’772 patent recites an array
“when thresholded at a number of levels produces a
number of dot profiles . . . wherein substantially all of
said number of dot profiles have a power spectrum sub-
stantially characteristic of a blue noise power spectrum for
the level at which such dot profile is produced.” ’772
patent col.17 ll.1-4 (emphasis added). Claim 63 of the
’772 patent recites a “halftoning mask [that] is designed
to produce substantially all visually pleasing dot profiles
when thresholded at a number of levels.” Id. col.19 ll.58-
61 (emphasis added). A “visually pleasing dot profile” is a
“blue noise dot profile.” Research Corp. Techs., Inc. v.
Microsoft Corp., No. 01-658, slip. op. at 15 (D. Ariz. June
5, 2009). A “blue noise dot profile,” in turn, is a “dot
profile that has substantial characteristics of a blue noise
power spectrum; is locally aperiodic; has low anisotropy;
and has a lack of low-frequency graininess.” Id. Accord-
ingly, both claims 4 and 63 of the ’772 patent claim half-
tone masks that produce a number of dot profiles,
“substantially all” of which have substantial characteris-
tics of a blue noise power spectrum. Significantly, not all
dot profiles that the claimed halftone masks produce need
to have blue noise characteristics, i.e., be locally aperiodic,
have low anisotropy, or lack low-frequency graininess.
In contrast, the 1990 and 1991 Applications limit the
invention to a “blue noise mask,” which is “[a] halftone
mask with wraparound properties that produces blue
noise and visually pleasing dot profiles at any level of
gray.” Research Corp. Techs., Inc. v. Microsoft Corp., No.
01-658, slip. op. at 4 (D. Ariz. Oct. 1, 2002) (emphasis
added). At the outset, the 1990 and 1991 Applications are
entitled “Method and Apparatus for Halftone Rendering
of a Gray Scale Image Using a Blue Noise Mask.” ’310
patent abstract; ’228 patent abstract. Indeed, the specifi-
cations repeatedly refer to a blue noise mask as “the
21 RESEARCH CORP v. MICROSOFT CORP
present invention.” See, e.g., ’310 patent col.1 ll.8-11
(“[T]he present invention relates to a method of and
system for rendering a halftone by utilizing a pixel-by-
pixel comparison of the gray scale image against a blue
noise mask.”); see also id. col.2 l.68-col.3 l.4 (“In the pre-
sent invention . . . dot profiles are built ‘on top of’ the
profiles from lower gray levels, such that a single valued
2-dimensional function, that is, the cumulative array or
blue noise mask, can be constructed.”). These references
to “the present invention” strongly suggest that the
claimed invention is limited to a blue noise mask. See
Trading Techs. Int’l, Inc. v. eSpeed, Inc., 595 F.3d 1340,
1353 (Fed. Cir. 2010). The specification also explains that
the “objects of the invention are accomplished by generat-
ing a blue noise mask which, when thresholded at any
gray level g, produces a blue noise binary pattern appro-
priate for that gray level.” Id. col.3 ll.50-54 (emphases
added). Beyond this language, the figures in the patent
only illustrate various aspects of a blue noise mask.
Finally, all fifteen approved claims of the 1990 Applica-
tion and all ten approved claims of the 1991 Application
recite a “blue noise mask.” Id. col.10 l.23-col.12 l.13; ’228
patent col.17 l.56-col.20 l.15. Accordingly, the 1990 and
1991 Applications disclose only a blue noise mask.
Moreover, the inventors’ testimony indicate that they
were in possession of only a blue noise mask at the time of
filing the 1990 and 1991 Applications. Dr. Parker admit-
ted in his deposition that the 1991 Application did not
describe any masks other than a blue noise mask. (J.A.
4426-28 at 146:24-147:3; 148:3-6.) He repeatedly ac-
knowledged that the 1991 Application’s disclosure was
limited to a blue noise mask. Dr. Mitsa also characterized
“the invention” as “the blue noise mask.” (J.A. 6425 at
188:5-10.) The 1990 and 1991 Applications and the
inventors’ testimony show that Drs. Parker and Mitsa
RESEARCH CORP v. MICROSOFT CORP 22
only described a blue noise mask in the 1990 and 1991
Applications. Given the inventors’ admission that they
only described a blue noise mask, a person of ordinary
skill would not understand from the 1990 and 1991 Appli-
cations that the inventors were in possession of a mask
other than the disclosed “blue noise mask.”
RCT argues that the district court erred by according
little weight to RCT’s expert Dr. Bobby R. Hunt’s January
7, 2004 expert declaration, which explained that the 1990
Application provided written description support for the
later-filed claims. Dr. Hunt’s expert declaration, however,
was five years old at that time and addressed patent
claims that are not at issue in the present appeal—claim
2 of the ’518 patent; claim 42 of the ’305 patent; and claim
1 of the ’772 patent. Thus, the trial court did not err by
deeming the declaration insufficient. Also, RCT criticizes
the district court for limiting the 1990 and 1991 Applica-
tions to the “ideal” blue noise mask depicted in figure 1.
However, at no point did the district court state or imply
that the applications’ disclosure was so limited. RCT does
not provide any substantive evidence as to why a person
of ordinary skill would understand from the 1990 and
1991 Applications that the inventors possessed masks
that produced dot profiles that did not have substantially
blue noise characteristics at every level of gray.
Accordingly, claims 4 and 63 of the ’772 patent are
broader than the invention disclosed in the 1990 and 1991
Applications. A person of ordinary skill in the art would
not understand from the 1990 and 1991 Applications that
the inventors had disclosed halftone masks that substan-
tially produced dot profiles with substantially blue noise
characteristics. This court affirms the district court’s
decision that claims 4 and 63 of the ’772 patent are not
entitled to claim the benefit of their parent applications’
filing dates.
23 RESEARCH CORP v. MICROSOFT CORP
Claim 29 of the ’305 patent recites an apparatus “for
comparing, on a pixel-by-pixel basis, a plurality of color
planes of said color image against a blue noise mask . . . .”
Unlike the asserted claims of the ’772 patent, claim 29
expressly claims a “blue noise mask.” The district court
nonetheless held that claim 29 was not entitled to claim
the benefit of an earlier filing date on the ground that the
1990 and 1991 Applications limited the invention to a
blue noise mask that was created according to a specific
algorithm recited in figure 2 of the applications while
claim 29 did not require any particular algorithm. Figure
2 is “a flow chart for the design of the blue noise mask of
the present invention.” ’310 patent col.4 ll.8-9. The
algorithm shown in the flow chart requires that one
“apply a blue noise filter” to a dot profile to create a blue
noise mask. Id. fig.2. Claim 29 does not require an
application of a blue noise filter to create a blue noise
mask.
“Courts must generally take care to avoid reading
process limitations into an apparatus claim . . . because
the process by which a product is made is irrelevant to the
question of whether that product infringes a pure appara-
tus claim.” Baldwin Graphic Sys., Inc. v. Siebert, Inc.,
512 F.3d 1338, 1344 (Fed. Cir. 2008) (citations omitted);
see also Vanguard Prods. Corp. v. Parker Hannifin Corp.,
234 F.3d 1370, 1372 (Fed. Cir. 2001) ("A novel product
that meets the criteria of patentability is not limited to
the process by which was made.").
As noted, the applications describe a blue noise mask
in terms of its first and second order properties and not
how it is made. See, e.g., ’310 patent col.8 ll.54-58 (“The
blue noise mask is constructed such that when thresh-
olded at any level, the resulting dot profile is a locally
aperiodic and isotropic binary pattern with small low-
frequency components, which in the halftoning literature,
RESEARCH CORP v. MICROSOFT CORP 24
is known as a blue noise pattern.”). Claim 29 is a pure
apparatus claim and has no process limitations. Thus,
claim 29 is not limited to any particular process or
method of making the claimed blue noise mask.
Microsoft relies on this court’s decision in LizardTech,
Inc. v. Earth Resource Mapping, Inc., 424 F.3d 1336 (Fed.
Cir. 2005), to argue that the 1990 and 1991 Applications
only support a blue noise mask that is created in a par-
ticular way. In LizardTech, the patent-at-issue recited a
method for “selectively viewing areas of an image at
multiple resolutions” that included forming and using a
“seamless” discrete wavelet transform (“DWT”). Id. at
1343-44. The specification provided only one method for
creating a seamless DWT but the claim was directed to
creating any seamless array of DWT coefficients. Id. This
court found that the claim lacked written description
support. Id. at 1346-67.
Microsoft’s reliance on LizardTech is misplaced. Liz-
ardTech involved a method claim, while claim 29 is an
apparatus claim. Apparatus claims do not need to recite
every method of making the claimed apparatus. Microsoft
would require apparatus claim 29 to include method steps
for making a blue noise mask. Microsoft improperly tries
to mix method and apparatus claims. Claim 29, which
covers a blue noise mask that is calculated in any way,
has written description support even if it does not recite
the exact method steps described in the specification or
any other methods for making a blue noise mask.
Accordingly, the 1990 and 1991 Applications provide
written description support for claim 29 of the ’305 pat-
ent. In the event this court disagrees with the district
court’s judgment as to claim 29, Microsoft argues that this
court should vacate, not reverse, the summary judgment
because Microsoft has alternate arguments as to why the
25 RESEARCH CORP v. MICROSOFT CORP
claims are not entitled to the earlier filing dates, namely,
the lack of enablement. Microsoft’s “motion, however,
[was] not based on the lack of enablement.” Br. of Def.-
Microsoft Corp. at 9, Research Corp. Techs., Inc. v. Micro-
soft Corp., No. 01-658 (Dkt. 845) (D. Ariz. Feb. 13, 2009).
Because Microsoft’s summary judgment motion was solely
based on written description, which should have been
denied, this court reverses the district court’s summary
judgment. The 1990 and 1991 Applications provide
written description support for claim 29.
VI
Accordingly, this court reverses the district court’s
summary judgment that the asserted claims of the ’310
and ’228 patents are invalid under 35 U.S.C. § 101. This
court affirms the district court’s decision that the asserted
claims of the ’772 patent cannot claim the benefit of its
parent applications’ filing dates. This court reverses the
effective date ruling as to the asserted claim of the ’305
patent and remands.
AFFIRMED-IN-PART, REVERSED-IN-PART, AND
REMANDED
COSTS
No costs.