T 1422/19 (Content item visibility/GOOGLE) 19-05-2021

1. The application

1.1 The application relates to determining "visibility of content" presented in a web browser (paragraph [0004] of the published application). Information on whether embedded content items, such as advertisements, are visible to the user is useful in the online advertising business.

1.2 According to paragraphs [0019] and [0020], certain existing techniques for determining/measuring the visibility of a content item do not work ("can be difficult") when the code that renders the content item runs from within a frame or iframe whose domain is distinct from the domain of the web page embedding the content item. In particular, browser security constraints may prevent access to information such as the size of the browser's viewport, the size of the content item, and the content's item location relative to the browser's viewport.

1.3 The application proposes a method that allows code to determine the visibility of a content item from within the content item's cross-domain iframe.

1.3.1 The visibility of the content item is determined by calculating the overlap of the rectangle corresponding to the "webpage viewing area" and the rectangle corresponding to the content item.

1.3.2 The rectangle corresponding to the web page viewing area is estimated by reading the size and location of the browser window from inside the iframe, i.e. by code included in the iframe, and correcting for browser user interface elements which are part of the browser window but not part of the web page viewing area (paragraphs [0023], [0024], [0043] and [0044]). The sizes of the browser user interface elements are estimated on the basis of statistical data obtained from historical measurements (paragraphs [0024] and [0025]).

1.3.3 The rectangle corresponding to the content item is determined by reading the location and size of the content item from inside the iframe. The position can be determined by means of browser-specific APIs (see paragraphs [0026], [0054] and [0055]) or by means of mouse events (as explained in paragraph [0050]). The size can be approximated as the size of the "inside portion" of the iframe (paragraphs [0022], [0054] and [0055]).

2. Added subject-matter - Article 123(2) EPC

2.1 Claim 1 is based on a combination of originally filed claims 1, 2, 6 and 10 with a number of further amendments based on the description as discussed below.

2.2 The term "viewport" has been replaced with "browser window". The application as filed uses these terms synonymously, as can been seen from paragraph [0026]: "if the browser's location is (200, 500) and the frame's location is (250, 510) in screen coordinates, then a determination can be made that the content item is located at (50, 10) in viewport coordinates".

2.3 The term "chrome elements" has been replaced with "browser elements". This is supported by paragraph [0023], which mentions scroll bars, universal resource locator bars and bookmark bars as examples of browser "chrome" elements.

2.4 The outer bound for the size of the browser window and the location of the iframe in screen coordinates are read "from inside the iframe" (paragraph [0011], second sentence).

2.5 Performing the statistical analysis includes "determining a browser header size based on historical measurements that are gathered as statistical data" (paragraph [0024], third sentence).

2.6 The "reporting visibility" step has been replaced with "reporting information about the visibility of the content item to a content sponsor" (paragraph [0059]).

2.7 Hence, the subject-matter of claim 1 and corresponding independent claims 8 and 10 has a basis in the application as filed.

2.8 Dependent claim 2 combines original dependent claims 4 and 5. Dependent claims 3 to 7 and 9 correspond to original claims 7, 8, 9, 11, 13 and 17, respectively.

2.9 The amended application therefore complies with Article 123(2) EPC.

3. Clarity - Article 84 EPC

3.1 The clarity objections raised by the board in its communication no longer apply to the current set of claims. In particular, the replacement of "viewport" with "browser window" has overcome the board's clarity objection in respect of the feature "a webpage viewing area of a viewport associated with a browser".

3.2 In the European search opinion, the search examiner objected to the feature "wherein the browser is a Firefox browser" of then claim 7, noting that "Mozilla Firefox" was a registered trademark and therefore had to be indicated as "Firefox®".

No provision of the EPC or of national or international law mandates that trademarks be marked as such. In some jurisdictions, trademark owners can use the ® symbol to give notice to the public that a trademark has been registered. However, the appellant is not the owner of the Firefox trademark.

Accordingly, the trademark symbol has been removed from present claim 5.

3.3 The board is aware that Part F, Chapter IV, 4.8 of the Guidelines for Examination in the EPO (March 2021) warns against the use of trademarks and similar expressions in claims as it is not normally guaranteed that the product or feature referred to is not modified while maintaining its name during the term of the patent.

Although the term "Firefox browser" in dependent claim 5 does not refer to a fixed product but to a family of web browsers which grows over time, this does not lead to a lack of clarity in the present case. The term "(web) browser", while covering an ever growing number of different browser implementations, is a standard term in the art and refers to a relatively well-defined set of technical features. The term "Firefox browser" merely limits the scope of the claim to embodiments in which the web browser is one that was released under the "Firefox" brand - a criterion that is easy to check. The question whether such a limitation implies additional technical features relevant to achieving a specific technical effect over the whole scope of the claim can be examined under inventive step if necessary. But since claim 5 is a dependent claim, this question need not be answered.

3.4 Hence, the application complies with the requirements of Article 84 EPC.

4. Inventive step

4.1 Document D1 relates to determining whether a predefined percentage of an advertisement is within the browser's viewport (see abstract and paragraphs [0003] and [0004]). It is undisputed that document D1 represents the closest prior art for the subject-matter of claim 1.

It is clear from Figure 2 and paragraph [0012] that document D1 uses the term "viewport" in its standard meaning of the visible area within a browser window that displays (a portion of) the web page. This corresponds to the "webpage viewing area" of claim 1.

Document D1 discloses, in paragraphs [0012], [0013], [0016] and Figures 2 and 4, a method of determining, by a program embedded in an advertisement unit of a web page, whether the advertisement is visible by determining

- the size and the location on the screen of the browser's viewport (Figure 2; paragraph [0012], "upper left corner viewport x, y display dimensions 28"; paragraph [0016], "dimensions and the x,y coordinates of the viewport") and

- the size and the location of the advertisement (paragraph [0012], "upper left corner x, y coordinates 34 and a total area of the Ad"; paragraph [0016], "x, y coordinates and the dimensions of the Ad unit")

and then calculating how much of the advertisement is visible, which is equivalent to determining the area of overlap between the rectangle corresponding to the viewport and the rectangle corresponding to the advertisement (see Figure 2).

The advertisement may be enclosed in an iframe (paragraph [0022]). The board agrees with the examining division that, since the advertisement is retrieved from a separate ad server (see paragraph [0011]), the iframe is a cross-domain iframe. However, document D1 contains no discussion on cross-domain security restrictions and the measures used to overcome them.

The determined visibility is reported to interested parties, including "ad placement clients", i.e. content sponsors (paragraphs [0012] and [0019]).

4.2 Document D1 does not disclose that the size of the viewport/web page viewing area is determined by reading the size of the browser window and subtracting from the size of the browser window the average size of one or more browser elements as determined by a statistical analysis based on historical measurements.

This distinguishing feature addresses the problem of estimating the size of the browser's viewport from within a cross-domain iframe. Due to security constraints, the size of the viewport cannot be accessed directly from within a cross-domain iframe (see paragraph [0020] of the published application).

4.3 In its decision, the examining division argued that, although the determination of the estimated size of the viewport was performed with technical means, it corresponded to a technical implementation of a non-technical requirement, which was the rule used to compute the estimated size. This rule was non-technical because it was based on a business requirement and, since the determined output size was an estimated value, it circumvented the technical problem of actually measuring the viewing area rather than addressing it.

4.4 It is true that the method of claim 1 does not include a technical use of the calculated/estimated content visibility. In fact, the claim specifies that the information about the visibility of the content item is reported to a content sponsor. However, the method does not merely calculate this information from numerical input data but measures "raw" information about a running web browser and processes this information to produce an estimate of a technically meaningful parameter, namely the extent to which a content item displayed within a web page is visible to the user, and on the basis of technical considerations relating to what is possible with an unmodified browser that enforces standard security constraints. Such an indirect measurement is normally of a technical nature (see decision G 1/19, not yet published in the OJ EPO, point 99).

4.5 As for the examining division's argument that the claim "circumvents" rather than addresses the technical problem of actually measuring the viewing area, the board notes that finding a way to circumvent a technical problem may well form the basis for a patentable invention.

The examining division's argument appears to be based on decision T 258/03, OJ EPO 2004, 575, Reasons 5.7, where the deciding board argued that "[m]ethod steps consisting of modifications to a business scheme and aimed at circumventing a technical problem rather than solving it by technical means cannot contribute to the technical character of the subject-matter claimed".

However, no business or other non-technical scheme is modified in the present case.

4.6 In its communication, the board suggested that in view of document D5, which disclosed that the width and the height of the browser window including browser elements such as toolbars and scroll bars could be obtained by means of the "window.outerWidth" and "window.outerHeight" properties, it would have been obvious to estimate the size of the browser's viewport in terms of width and height by determining the width and height of the browser window by means of these properties and correcting for browser elements. Since the sizes of browsers elements varied from browser to browser, they would have to be estimated, for example on the basis of statistical data.

4.7 However, on reconsideration the board is not convinced that, faced with the problem of obtaining the approximate size of the browser's viewport, the skilled person would, without any hint, decide to obtain instead the size of the browser window and then correct for browser elements.

Since such a hint is not present in document D5 or in any of the other prior-art documents on file, the board considers that the subject-matter of claim 1 is not rendered obvious by the cited prior art.

4.8 Hence, the subject-matter of claim 1 and of the corresponding independent claims 10 and 12 involves an inventive step over the cited prior art.

5. Conclusion

Since, moreover, the description has been adapted, the board is satisfied that the sole substantive request complies with the requirements of the EPC and that the appeal is therefore allowable.