Ex Parte Abramsohn

Patent Trial and Appeal Board

Nov 18, 2013

10836894 (P.T.A.B. Nov. 18, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte DENNIS A. ABRAMSOHN1
__________

Appeal 2011-010063
Application 10/836,894
Technology Center 2600
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Before ERIC GRIMES, MELANIE L. McCOLLUM, and ERICA A.
FRANKLIN, Administrative Patent Judges.

McCOLLUM, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 involving claims to a half-
tone calibration method and system. The Examiner has rejected the claims
as obvious. We have jurisdiction under 35 U.S.C. § 6(b). We reverse.
STATEMENT OF THE CASE
Claims 1-23 are pending and on appeal (App. Br. 5). Claim 10 is
illustrative and reads as follows:

1 Appellant identifies the real party in interest as Hewlett-Packard
Development Company (App. Br. 3).
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10. A system in a printer for half-tone calibration, comprising:
a processor circuit having a processor and a memory;
a half-tone calibration system stored in the memory and executable by
the processor, the half-tone calibration system comprising:
logic that directs the performance of a plurality of calibration
cycles for a same half-tone density over a period of time;
logic that directs the acquisition of a plurality of half-tone
density values each from a respective one of a plurality of test patches each
generated on a belt in the printer during a respective one of the plurality of
calibration cycles over the period of time, each of the plurality of test
patches embodying the same half-tone density;
logic that generates a mathematically smoothed half-tone
density value from the plurality of half-tone density values acquired from the
plurality of test patches during the performance of the plurality of calibration
cycles for the same half-tone density over the period of time; and
logic that calibrates a half-tone density in the printer based upon
the mathematically smoothed half-tone density value.
Claims 1-4, 6-15, and 17-23 stand rejected under 35 U.S.C. § 103(a)
as obvious over Denton et al. (US 7,006,250 B2, Feb. 28, 2006) in view of
Furukawa et al. (US 6,272,260 B1, Aug. 7, 2001) (Ans. 3).
Claims 5 and 16 stand rejected under 35 U.S.C. § 103(a) as obvious
over Denton in view of Furukawa and Nakayasu (US 6,434,347 B2,
Aug. 13, 2002) (Ans. 15).
I
The Examiner relies on Denton for disclosing many features of the
claims (Ans. 4-6). However, the Examiner finds that “Denton does not
disclose generating a mathematically smoothed half-tone density value” (id.
at 6). Instead, the Examiner relies on Furukawa for teaching “generating the
mathematically smoothed half-tone density value” (id.). The Examiner
concludes that it would have been obvious “to modify the system of Denton
. . . by applying the known technique of ‘generating a mathematically
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smoothed half-tone density value’ as taught by Furukawa . . . to improve the
quality of halftone density calibration to prevent artifacts such [as] moirés
and deterioration” (id. at 6-7).
Findings of Fact
1. The Specification discloses: “There are several approaches that
may be employed to generate the mathematically smoothed half-tone density
value. For example, a straight running average may be calculated from the
multiple half-tone density values. Alternatively, a weighted average of the
multiple half-tone density values may be calculated.” (Spec. ¶ [0026].)
2. Furukawa discloses that “smoothing processing . . . is realized
by simple or weighted averaging of density values of pixels which are
located within the smoothing area” (Furukawa, col. 12, ll. 3-6).
3. Denton discloses “a method of calibrating an
electrophotographic machine having an image-bearing surface. A
reflectivity of the image-bearing surface is estimated based upon an amount
of usage of the electrophotographic machine. At least one
electrophotographic condition is adjusted dependent upon the estimating
step.” (Denton, col. 2, ll. 1-7.)
4. In particular, Denton discloses:
Experiments have shown that the reflectivity of intermediate
belt 36 increases over life from about 3.3% to about 5-6%. The
rate of increase and the long-term reflectivity value appears to
depend on how much toner is transferred to belt 36. Locally
heavy toner usage . . . can produce visibly different reflective
properties over the width of belt 36. The belt reflectivity at the
patch sensor location can be modeled using an exponential
form. . . . Under this model, the amount of toner passing under
the patch sensor 56 can be estimated from one or more of the
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following parameters: page count, toner addition cycles, local
pixel counting in the fast scan direction at the patch sensor
position, and the number of toner patch sensor calibration
cycles that have taken place.
(Id. at col. 3, l. 47, to col. 4, l. 2.)
5. In addition, Denton discloses:
Printer 10 performs the density check procedure in the
following eleven steps:
1) Belt reflectivity is estimated using an empirical model
based on belt cycles. . . .
2) Saturated reflection ratio values are estimated for each
color of toner using the estimated belt reflectivity and
experimentally determined values of the toner reflectivity. . . .
3) A total of twenty-five solid area test patch locations
are defined on the surface of belt 36. . . . These patch locations
are arranged in six groups of four patches (yellow, cyan,
magenta and black) plus one bare reference patch. . . . The first
group of test patches is formed using laser power and developer
bias test values for condition 1, i.e., Z=1, in the table of FIG. 3.
The remaining ones of the six groups of test patches are formed
using conditions 2-6, respectively. . . . Multiple pulse readings
are taken for each patch and the signal values are averaged
together to produce an average patch voltage. . . . The average
voltage from each patch is compared to the corresponding bare
belt voltage for the same location on the belt. The ratio of the
two voltage signals is computed for each toner patch. In this
manner, twenty-four reflection ratio (RR) values are obtained
from the twenty-four solid area test patches.
. . .
6) Electrophotographic operating conditions are selected
using the twenty-four measured reflection ratios described
above.
. . .
9) Printer 10 sets the laser power and developer bias to
the new operating conditions and prints a series of forty-eight
test patches in four colors, with twelve halftone patterns per
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color. . . . The screens used for each color are the uncorrected
600 dots per inch (dpi)/20 pages per minute (ppm) screens.
These patterns are printed to belt 36. . . . These halftone test
patches are sensed with toner patch sensor 56 and reflection
ratios are computed for each patch. The reflection ratios are all
converted into L* or b* values using unique conversion
coefficients for each test patch. These L* and b* values are
then used to correct or linearize the halftone printing curve for
the 20 ppm process mode.
10) The process speed is reduced to 10 ppm and the
engine enters into 1200 dpi mode. . . . [T]he halftone series is
again printed to belt 36, but this time the halftone screens used
are those associated with 10 ppm (1200 dpi) printing. The
forty-eight halftone patches are read by patch sensor 56,
reflection ratios are obtained, and L* or b* values are estimated
for each test patch. These values are then used to correct or
linearize the 1200 dpi halftone printing curve.
11) The calibration information (laser power, developer
bias, and linearization) is stored in memory and used to print
new customer images until the next calibration cycle.
(Id. at col. 5, l. 15, to col. 8, l. 25.)
6. Denton also provides various conditions under which a density
check can be initiated (id. at col. 4, l. 62, to col. 5, l. 14).
Analysis
As noted by the Examiner (Ans. 4), Denton discloses performing a
plurality of calibration cycles over a period of time (Findings of Fact (FF) 4-
6). In addition, each calibration cycle includes the acquisition of half-tone
density values from test patches (FF 5 (steps 9-10)). However, we agree
with Appellant that the Examiner has not adequately explained why one of
ordinary skill in the art would have averaged, or mathematically smoothed,
half-tone density values from test patches of the same half-tone density from
different calibration cycles (App. Br. 14-15).
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As noted by Appellant (id. at 13), Denton does disclose that
“[m]ultiple pulse readings are taken for each patch and the signal values are
averaged together to produce an average patch voltage” (FF 5 (step 3)
(emphasis added)). However, as pointed out by Appellant (App. Br. 13),
this teaching does not disclose averaging density values from different test
patches, much less from test patches of the same half-tone density from
different calibration cycles, and, in fact, relates to solid area test patches, not
half-tone test patches (FF 5 (compare step 3 with steps 9-10)). In addition,
the Examiner has not shown that Furukawa discloses averaging density
values from different test patches, specifically from test patches of the same
half-tone density from different calibration cycles (Ans. 6 & 18-19).
As noted by the Examiner, “the full calibration cycle in Denton . . .
includes computing halftone patch reflection ratio (RR or density value) for
20 pages per minute (20 PPM), and again for the 10 ppm process mode” and
“halftone density values of each test patch, or RR is obtained for 20 ppm,
and again for 10 ppm process mode” (id. at 18). However, we conclude that
the Examiner has not adequately explained why one of ordinary skill in the
art would have averaged, or mathematically smoothed, these half-tone
density values. On the contrary, the values from the 20 ppm process are
“used to correct or linearize the halftone printing curve for the 20 ppm
process mode” and the values from the 10 ppm process are “used to correct
or linearize the 1200 dpi halftone printing curve” (FF 5 (steps 9-10)).
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Conclusion
The Examiner has not set forth a prima facie case that Denton and
Furukawa suggest Appellant’s claimed invention. We therefore reverse the
obviousness rejection of claims 1-4, 6-15, and 17-23.
II
In rejecting claims 5 and 16, which depend from claims 4 and 15,
respectively, the Examiner additionally relies on Nakayasu (Ans. 15).
However, the Examiner does not explain how Nakayasu overcomes the
deficiencies of Denton and Furukawa discussed above (id. at 15-16). Thus,
we conclude that the Examiner has not set forth a prima facie case that
Denton, Furukawa, and Nakayasu suggest claims 5 and 16. We therefore
also reverse the obviousness rejection of claims 5 and 16.

REVERSED

cdc