COMMISSIONER'S DECISION
Patentable Subject Matter, cited art: The two part centering structure to obtain and fix the alignement
of optical parts and the two parts was held patentable in view of the cited art. Amended claim 1 was
refused for not defining the inventive features. Rejection modified.
This decision deals with Applicant's request for review by the Commissioner
of Patents of the Examiner's Final Action on application 442,294 (Class
33-53). The application was filed on November 30, 1983, by Thomson-CSF and
is entitled ALIGNMENT PROCESS OF AN ELECTRO-OPTICAL DEVICE. The inventors
are R. Henry. J.-C. Carballes, E. Duda, E. Grand. The Examiner in charge
issued a Final Action on June 23, 1986, refusing to allow the application.
By letter dated August 18, 1988 the Applicant withdrew the request for a
Hearing.
The invention relates to a process of aligning an optical head housing
having a first part supporting an optical solid state device and a second
part containing an optical fiber, whereby when the optical elements are
aligned, they and the housing parts may be rigidly fixed, as shown by
figure 3 reproduced below:
<IMG>
The first part of the housing includes a centering element 16 fixed to a
support 12 holding a semiconductor element 2 and its external connections
9. The second part 13 centrally supports optical fiber 4 adjacent element
2, and provides trough means 14 which holds molten solder for covering the
immersed end of the centering element. During movement of the centering
element for proper optical alignment of elements 2 and 4, the element 16
remains immersed in the trough, and on alignment the molten material is
hardened, thus obtaining a sealed housing and aligned optics.
The Examiner refused the application in view of the following references:
British Patent
2,022,280 December 12, 1979 Goodfellow et al
(United Mates Patent
4,357,072 November 2, 1982 Goodfellow et al)
European Patent Application
0,021,473 January 7, 1981 Kock
The British patent provides means for sealing an optical fiber in alignment
with a light emitting diode as shown in figure 4 below:
(see formula I)
Diode 6, to be aligned with optic fiber 10, is supported on base 4 which is
welded to cover 2. Cupped aperture 8 of cover 2 contains solder 9 and a
restriction 2a designed to limit flow of the solder on heating. The
metallized coating 11 on the fiber is etched to leave the fiber
non-metallized 12 adjacent the diode. On its outer surface, copper collar
16 has a tinned portion 1d for adherance to the solder, and is secured on
its inner surface to coating 11. The collar with the fiber attached acts
as a centering element and is placed in a positioning means, not shown, to
enable the collar to be moved to align the fiber and the diode. After
nitrogen is introduced to obtain an inert atmosphere about the fiber and
the diode, solder 9 is melted to adhere to surface 18 of the collar. Upon
final optical alignment, the solder is allowed to cool, forming a seal and
ensuring alignment, and the positioning means is removed from the collar.
The European Patent shows a multi part device that obtains alignment of an
optic fiber and a diode, and fixes the fiber once centered, as shown in
figure 2 reproduced below:
<IMG>
The base 31 supports the diodes 35 and 51 and a cover 33, and provides for
the connections to the diodes. A centering holder 37 is mounted on cover
33 by means of indium solder 59. The holder has a glass plate 39a attached
to it by indium solder, and lens 39b is joined to the plate by epoxy
resin. The holder supports block 43 through which the optic fiber 45 is
suspended. By pressing on holder 37, plastic deformation of solder 59
occurs to enable the fiber 45 to be aligned with the lens and the diodes,
and on alignment block 43 is glued to the holder and the fiber is glued in
place.
In taking his Final Action, the examiner said in part, as follows:
...
The references relate to a dynamic sealing means as in
the present case. In other words, the elements to be
sealed can be maneuvered, one with respect to the
other, while they retain their seal to obtain proper
alignment.
The references further disclose that the sealing
material, as in the present case, is in a fluid state
when maneuvering the elements with respect to each
other and is allowed to harden when the desired
alignment of the elements has been obtained.
Further Kock discloses a method and a device for
aligning a semi-conductor and an optical fibre in a
sealed chamber by the presently disclosed and claimed
method.
Applicant's letter of December 30, 1985.
United States patent No. 4,357,072 to Goodfellow dated
November 2, 1982 was published in Great Britain
December 12, 1979 and is citable under Section 28 of
the Patent Act.
Applicant states in the letter of December 30, 1985
that the present invention relates to a process for
aligning an optical fiber and a semi-conductor
component. However it is clear from the present
disclosure that the electro-optical devices can be a
photodiode, emitting devices or a semiconductive
laser. Said devices are as in Goodfellow, who
discloses diode packages, laser packages, detectors,
directional couplers and connectors or as in the cited
British publication which discloses semi-conductor
lasers and other elements. From the cited reference it
is therefor clear that the components or elements are
the same or equivalent to the present components.
The present recess 15 is not patentably significant for
the following reasons:
Goodfellow discloses that the aperture 8 is cupped so
that when the solder is molten it is prevented from
flowing out of the cover and patent No. 0,021,473
(Kock) discloses a thick sealing material. By reason
of the structures disclosed by Goodfellow and Kock the
support of the fiber can be moved along more than two
directions. The foregoing is not specifically stated
but is evident from the disclosure.
...
In holding the application was not open to the refusal on the grounds the
Examiner advanced, the Applicant amended claim 1 and argued in part, as
follows:
...
In comparison with the prior art, in applicant's
invention, the semiconductor component 2 is fixed on
its support 12, without any excessive precision, and
the fiber 4 is fixed on its support 13, machined
without any excessive precision also. Then, the two
elements are aligned with precision (from 1 to 5
microns); this is due to the fact that one support
comprises a centering element (in the form of a
cylinder 16 to 21) and that the other support comprises
at least one recipient 14 (in the form of a trough) or
three recipients 28 (in the form of cups in which
penetrate three lugs 29). The centering elements 10,
21 or 29 and the recipients 14 or 28 are also machined
without any excessive precision.
Therefore, what is essential in the present invention
is that the centering elements must be immersed in
these recipients for the adjusting procedure.
UNITED STATES PATENT NO. 4,357,072 (GOODFELLOW)
This patent shows an optical fibar 10 which is provided
with a collar 16 having a tinned layer 18 which is
aligned relative to a diode 6 by means of a
micromanipulator (see column 3, lines 50 and
following), the solder annulus 9 being in a cold state,
such as represented in fig. 1, and leaving a free
passage for the fiber 10. Once alignment is obtained,
the annulus is melted (see column 4, lines 5 and
following) and the solder adheres, by capillarity, to
the collar 16 and the encapsulation cover 2.
Applicant recognizes that, once solder 9 is melted, it
is possible, as Goodfellow states, to adjust the
position of the fiber 10 as it is shown in figure 4,
but this is practically impossible in the case of
figure 5. It is to be noted that an optical fiber has
a diameter in the range of 100 microns: with such a
length of molten solder 9, it is the fiber that will
bend if it is displaced.
In any event, in Goodfellow, while the diode o is
indeed mounted on a support, the fiber 10 is not fixed
on a second support and there is no centering elements
nor recipients to allow one support to move relative to
another support and to subsequently fix them together.
EUROPEAN PATENT APPLICATION 0,021,473 (KOCK)
The semiconductor component 35 of this reference is
mounted on a complex support that includes the cover 33
and the flange 61 while the fiber 45 is mounted on a
support 43. However, assuming that element 37
constitutes a centering element, it does not penetrate
in a recipient (such as trough 14 or cups 28 in
applicant's system). Indeed, applicant achieves
alignment by adjustingly penetrating the centering
element 16 in the recipient 14, whereas Kock monitors
the alignment by deforming the thick layer of indium
59. This is entirely different from that described and
claimed in applicant's application.
Applicant fails to understand why the Examiner states
that the recess 14 (and not 15) is not patentable. If
Goodfellow foresees a constriction 2a in the aperture 8
(which, by the way. is not present in fig.5), it is to
retain this solder 8 by capillarity. It should be
reminded that Goodfellow has previously aligned the
optical fiber, the solder annulus 9 being solid and
cold.
It is therefore believed that claim 1, patentably
distinguishes from any of these two references, taken
singly or in combination. It is contended that one
would not arrive at applicant's process after having
read the teachings of Goodfellow and Kock.
On the other hand, claim 1 has been revised to better
define one of the important steps of the present
invention, one which is not taught by the prior art,
i.e., one mechanical support is moved relative to the
other mechanical support by adjusting dynamically the
centering element along three directions in the recess
in which the material is present prior to be hardened,
or in unhardened form.
...
The issue before the Board is whether the application contains patentable
subject matter in view of the references cited. Amended claim 1 reads:
A process for aligning an electro-optical device that
includes:
- a semiconductor component for emitting or receiving
light, said semiconductor component being fixed on a
first mechanical support; and
- an optical fiber fixed on a second mechanical
support;
said first and second mechanical supports being
independent from each other, one of said mechanical
supports comprising a centering element while the other
of said mechanical supports comprise at least one
recess containing a material which can be hardened,
said centering element being immersed in said material,
the volume of said recess and the volume of said
material being such as to allow said centering element
to move in said recess along three different
directions, said process comprising the steps of:
- moving said one mechanical support relative to said
other mechanical by adjusting dynamically said
centering element along three directions in said
recess, containing said material in unhardened form, to
reach an optimum position between said semiconductor
component and said optical fiber; and
- hardening said material when said optimum position
has been reached.
Both the cited references disclose devices permitting movement in three
directions for optically aligning a diode and an optic fiber. They show
different means to seal the moveable means in position after optical
alignment is attained, as well as means to fix the optic fiber. The
Applicant's invention resides in the general field of these two patents.
However, it presents particular structure whereby in the two relatively
moveable supports provided, one has a recess for molten material, and the
other is so formed and positioned that an end is immersed at all times in
the molten material during the alignment procedure. When positioning is
attained, the molten material may be hardened thus ensuring alignment and
sealing of both the supports and the optic elements. We consider that the
Applicant's arrangement relates to an invention that is different from the
subject matter of the cited references.
We now look at the claimed subject matter. In reviewing the proposed
amendment to claim 1, we note that the Applicant's intent in revising it is
to stress that one mechanical support moves relative to the other
mechanical support in order to achieve dynamic adjustment of the centering
element in three directions of movement in the recess containing the
material that is hardened once alignment is obtained. From the description
of the invention, we learn that the Applicant's device is a two piece
structure, one end of the adjusting or centering part having means immersed
at all times in a recess or trough means in the other part during alignment
of the diode and the optic fiber, and that the trough means holds molten
material that is caused to harden on achieving optical positioning of the
diode and optic fiber. In view of the cited references, we think proposed
claim 1 does not define clearly the invention that is described.
The Applicant's claim 2 as dependent on the proposed claim 1, sets forth
that the centering part is tubular, and that the recess formed in the other
part has a form appropriate to receive the tubular part so that it is
covered by the molten material.
The British patent sets out an arrangement where one mechanical support
moves relative to another and achieves a dynamic adjustment of a centering
element in three directions of movement in the recess containing the
material that is to be hardened. In our opinion, the Applicant's amended
claim 1 is directed to the arrangement described in the British patent.
The Applicant's claim 2 however, in defining a tubular part which
cooperates with a trough containing molten material covering the end of the
tubular part, is not found in the British patent.
The European patent provides a two part centering device having one part
moveable in three directions and supported at its edges on the other part.
However, it does not include any recess for containing hardenable material,
not is there any provision for immersion of a tubular centering element in
hardenable material contained in a trough on the other part. In our
opinion, this patent does not set forth the features found in the
Applicant's specification.
We recommend withdrawal of the refusal of the application for not being
directed to patentable subject matter. Regarding the proposed amended
claims, we recommend that amended claim 1 should be refused for not
patentably distinguishing over the cited British patent, whereas claim 2 as
it depends from amended claim 1 should be acceptable over the cited art.
M.G. Brown S.D. Kot
Acting Chairman, Member
Patent Appeal Board
I concur with the findings and the recommendation of the Patent Appeal
Board. Accordingly, I withdraw the refusal of the application, and I
refuse to grant a patent containing amended claim 1. The Applicant has six
months within which to appeal my decision to the Federal Court of Canada,
under Section 42 of the Patent Act.
Goudreau, Gage, Dubuc & Martineau, Walker
3400 La Tour de la Bourse
J.H.A. Gari‚py Case Postale 242, Place Victoria,
Commissioner of Patents Montreal, Quebec
H4Z 1E9
Dated at Hull, Quebec
this 27 th day of February 1989.