T 2090/11 () of 26.2.2015

Summary of Facts and Submissions

I. The applicant appealed against the decision of the examining division refusing European patent application No. 07006909.1 on the basis of Article 84 EPC (main and first auxiliary requests then on file).

II. The applicant requested that the decision of the examining division be set aside and a patent be granted on the basis of any of the main request or first to forth auxiliary requests filed with the statement setting out the grounds of appeal.

III. In response to the summons to oral proceedings, the applicant withdrew, with a letter dated 16 February 2015, the main request and the first to third auxiliary requests as filed with the grounds of appeal and requested, as its new main request, that a patent be granted on the basis of the fourth auxiliary request as filed with the statement setting out the grounds of appeal.

That previous fourth auxiliary request comprised the set of claims found allowable by the examining division and underlying the communication pursuant to Rule 71(3) EPC sent to the applicant on 19 November 2010.

IV. Independent claim 1 according to the main and sole request reads as follows:

"Optical transmission fiber comprising :

- a central core having an index difference Dn1 with an outer optical cladding, wherein the central core has a radius r1 comprised between 3.5 µm and 4.5 µm for an index difference with the outer optical cladding Dn1 comprised between 5.0x10**(-3)and 5.6x10**(-3);

- a first intermediate cladding having an index difference Dn2 with the outer optical cladding, wherein the first intermediate cladding has a radius r2 comprised between 9 µm and 12 µm;

- a first depressed cladding having an index difference Dn3 with the outer optical cladding which is between -5x10**(-3)and -15x10**(-3), wherein the first depressed cladding has a radius r3 comprised between 14 µm and 16 µm;

- a second intermediate cladding having an index difference Dn4 with the outer optical cladding;

- a second depressed cladding having an index difference Dn5 with the outer optical cladding which is inferior, in absolute value, to the index difference Dn3 of the first depressed cladding with the outer optical cladding, and wherein the index difference Dn5 between the second depressed cladding and the outer optical cladding is comprised between -0.3x10**(-3)and -3x10**(-3)and wherein the second depressed cladding has a radius r5 comprised between 25 µm and 40 µm;

and wherein the index difference between the central core and the first intermediate cladding (Dn1 - Dn2 ) is comprised between 4.5x10**(-3)and 6.0x10**(-3);

the optical fiber having a cable cut-off wavelength being less than or equal to 1260 nm and having, at a wavelength of 1625 nm, bending losses inferior or equal to 0.1 dB/10turns for a bending radius of 15 mm and bending losses inferior or equal to 0.5 dB/turn for a bending radius of 7.5 mm."

The main request further comprises claims 2 to 15 all referring directly or indirectly back to claim 1.

Reasons for the Decision

The board sees no reason to diverge from the view expressed by the examining division in its communication under Rule 71(3) EPC, proposing the grant of a patent on the basis of the present set of claims.

It follows that the present request meets the requirement of the EPC and that a patent can be granted on the basis thereof.

Order

For these reasons it is decided that:

1. The decision under appeal is set aside.

2. The case is remitted to the department of first instance with the order to grant a patent on the basis of the following documents:

- Claims 1 to 15 of the fourth auxiliary request as filed with the letter dated 22 July 2011,

- Description pages 1, 2, 10, 12 and 13 as originally filed and description pages 3, 3A, 4 to 9 and 11 as filed with the letter dated 16 February 2015,

- Drawing sheets 1/2 to 2/2 as originally filed.