Ex Parte Schroeder et al

Board of Patent Appeals and Interferences

Nov 10, 2009

10687431 (B.P.A.I. Nov. 10, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte DALE W. SCHROEDER,
MARSHALL T. DEPUE, RAMAKRISHNA KAKARALA,
TONG XIE, and GREGORY D. VANWIGGEREN
____________

Appeal 2009-003096
Application 10/687,431
Technology Center 2600
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Decided: November 10, 2009
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Before KENNETH W. HAIRSTON, JOHN A. JEFFERY, and
CARL W. WHITEHEAD, Jr., Administrative Patent Judges.
HAIRSTON, Administrative Patent Judge.

DECISION ON APPEAL
This is an appeal under 35 U.S.C. §§ 6(b) and 134 from the final
rejection of claims 21 to 50.1 We will reverse.

1 Claims 1 to 20 have been canceled.
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2
The disclosed invention relates to a method and device for optically
tracking motion across a surface by creating an interference pattern (i.e., a
speckle) by reflecting light from the surface (Figs. 1 and 7; Spec. ¶¶ [0001]-
[0003]; Abstract). The interference pattern is detected by a plurality of
sensors arranged in a sensor cluster to generate first and second signals
representative of the speckles to determine distance (claims 21 and 34; Spec.
¶¶ [0004], [0014]-[0018], [0020]-[0024]).
Claim 34 is representative of the claims on appeal, and it reads as
follows:
34. A device for determining a first distance along a movement path
on a surface over which an optical tracking device is moved by a user,
comprising:
a coherent light source configured to project a first coherent light
beam along the movement path and onto the surface as an incident light
beam, the coherent light source being configured in respect of the surface
to produce a plurality of light interference speckles resulting from the first
light beam and a second light representing at least portions of the first light
beam reflected form the surface interfering with one another, the speckles
having a first average spatial dimension;
a plurality of light sensors arranged in a sensor cluster and
operatively associated with the coherent light source and the processor,
each of the plurality of light sensors having a second spatial dimension
that is less than the first average spatial dimension of the speckles, each of
the light sensors further being configured to generate a first signal when one
of the plurality of speckles is detected thereby and to generate a
second signal when one of the plurality of speckles is not detected
thereby, and
a processor configured to determine the first distance on the basis
of the plurality of first and second signals generated by the plurality of light
sensors as the device is moved over the surface.
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The prior art relied upon by the Examiner in rejecting the claims on
appeal is:
Victor US 4,751,380 Jun. 14, 1988
Jackson US 4,794,384 Dec. 27, 1988
The Examiner rejected claims 21 to 50 under 35 U.S.C. § 103(a)
based upon the teachings of Jackson and Victor.
Jackson describes a system in which an optical mouse 10 (Fig. 1) or
20 (Fig. 2) generates and detects speckles and detects movement based on
the observation of changes in the speckle pattern (Abstract; col. 2, l. 37 to
col. 4, l. 29; col. 4, l. 63 to col. 5, l. 17; col. 5, l. 64 to col. 6, l. 38; col. 7, ll.
53-60; col. 8, l. 51 to col. 9, l. 31). Jackson employs a detector array 16 to
sense changes in the speckle pattern by “determin[ing] the number of
detector cells in the array that have detected light features” (col. 3, ll. 23-25),
then comparing that number to a predetermined value to determine sample
validity and relative motion (col. 3, ll. 5-29; col. 7, ll. 53-59; col. 8, ll. 62-67;
col. 9, ll. 1-12). Jackson compares instantaneously-determined speckle
patterns with later determined valid sampled speckle patterns to determine
motion (col. 7, ll. 53-59), and the speckle pattern used to determine motion
moves with the mouse (see col. 5, l. 68 to col. 6, l. 7). In other words,
Jackson relies upon the speckle pattern itself to determine movement. Such
an optical mouse is capable of working on smooth surfaces, i.e., “[t]he
reflecting surface need not be a patterned surface in the sense of the
specially prepared patterns required in the optical mice of [referenced prior
art] patents” (col. 3, l. 67 to col. 4, l. 2).
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Victor describes a three-by-three detector array 35 that allows an
optical mouse (Fig. 1) to detect light emitted from LED 15 and reflected
from surface 13 and determine relative motion of the mouse as it moves over
a surface having a grid pattern (Abstract; col. 3, l. 18 to col. 4, l. 34). As
seen from Figure 1, the optical mouse of Victor depends upon a grid pattern
16 or 18 (see Fig. 1a) in surface 13 to detect movement across uniformly
spaced vertical grid lines 41/43 and horizontal grid lines 37/39 (col. 3, l. 67
to col. 4, l. 14; col. 5, ll. 49-55; Fig. 4). As the sensor array 35 detects
movement across the grid patterns 16 or 18, signals are generated which are
used to determine relative motion (col. 7, l. 66-68; col. 8, ll. 55-66). Thus,
for Victor, the presence of a grid pattern on the surface over which the
mouse moves is crucial to the operation of the mouse and for making a
relative motion determination. Stated another way, Victor needs the grid
pattern in order to operate properly. The grid pattern is stationary and does
not move with the mouse.
The Examiner acknowledges (Ans. 3-4) that “Jackson does not
disclose the plurality of light sensor[s][sic] arranged in a sensor cluster,” nor
does Jackson generate “a first signal when one of the plurality of speckles is
detected” and “a second signal when one of the plurality of speckles is not
detected” to determine the distance as the device is moved over a surface.
According to the Examiner (Ans. 4), Victor teaches a sensor cluster (three-
by-three detector array 35 in Fig. 3) where each sensor in the cluster is
configured to generate the first and second signals as recited in claim 34, and
a processor for determining the distance based on the first and second
signals. The Examiner contends (Ans. 4) that it would have been obvious to
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one of ordinary skill in the art “to modify the optical device of Jackson to
have the light sensors arranged in a sensor cluster and the processor as
taught by Victor so as to provide a compact optical mouse due to the use of a
three-by-three detector array, and the system reliably determines relative
motion between the mouse and the surface (col. 8, line[s][sic] 55-67 of
Victor).”
Appellants argue inter alia (App. Br. 5) that the skilled artisan would
not have made the modification suggested by the Examiner because Jackson
uses a large detector array to detect speckles and compare array values
stored in a register with array values taken at an earlier or later time, while
Victor seeks to detect relation motion by sensing grid lines in a grid pattern
(Reply Br. 51). Indeed, Victor requires a grid for operation, while Jackson
operates only on light interference patterns. Appellants’ contention (Reply
Br. 54) that there is no basis for modifying the teachings of Jackson with
those of Victor to arrive at the invention of claims 21 to 50 is thus
convincing.
As indicated supra, Jackson uses speckles to determine movement.
Victor uses a sensor cluster to generate signals used to calculate movement,
but requires the use of a fixed grid pattern to determine movement.
Inasmuch as the system in Jackson relies on only the reflected light and
snapshots of speckle (i.e., interference) patterns taken at different times,
Jackson does not have any need of a grid pattern as taught by Victor.
Accordingly, Appellants’ contention (Reply Br. 57) that Jackson and Victor
represent “fundamentally incompatible techniques and technologies” is
persuasive. We agree with Appellants that “[e]ither the navigation
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techniques of Victor, or the navigation techniques of Jackson, but not both,
would be employed by one of ordinary skill in the art” (Reply Br. 58
(emphasis added)).
Notably, the portion of Victor (col. 8, ll. 55 to 67) relied upon by the
Examiner (see Ans. 4) as providing the motivation for modifying Jackson
describes detecting motion when a detector cell “crosses grid lines during
motion of the mouse over the grid” (col. 8, ll. 57-58). Thus, the portion of
Victor cited by the Examiner discusses the need for a grid pattern to
determine movement, and does not promote the proposed combination with
the speckle and time-based detection of Jackson.
Although Victor uses a sensor cluster to determine directional
movement, he specifically seeks to avoid the use of speckles due to light
interference. As noted, Victor uses a grid and gridlines. Thus, we agree
with the Appellants’ arguments (Reply Br. 52-58) that the skilled artisan
would not have combined the teachings of the applied references to arrive at
the claimed invention. In summary, the obviousness rejection of claims 21
to 50 is reversed because the Examiner’s articulated reasons for combining
the teachings of the references to Jackson and Victor do not support a legal
conclusion of obviousness. See KSR Int’l Co. v. Teleflex, Inc., 550 U.S. 398,
418 (2007).
The decision of the Examiner is reversed.

REVERSED

Appeal 2009-003096
Application 10/687,431

7

KIS

KATHY MANKE
AVAGO TECHNOLOGIES LIMITED
4380 ZIEGLER ROAD
FORT COLLINS, CO 80525