T 1678/19 26-07-2022

1. The invention as claimed

1.1 In a foldable display the displayed content in a distorted region of the screen is to be adapted to a viewer by means of sensors and a control signal such that the impairments or distortions of the content displayed in the folded region are compensated. The sensors are strain sensors detecting the position and degree of folding.

1.2 The alleged objective of the invention is an improved compensation of the distortion. This problem is solved by determining the kinds and degrees of distortion that may be experienced by a viewer - i.e. assuming that the display device is viewed from a particular / typical viewing angle - and mathematically determining the compensation.

2. Article 123(2) EPC

2.1 Basis for amended Features (G) / (G') is provided in the combination of paragraphs [0025] and [0026]. The Board agrees with the arguments of the Appellant that the skilled reader would read paragraphs [0025] and [0026] together and would recognise that paragraph [0026] relates to alternative embodiments where the disclosed methods of compensating for distortion could be applied to the teaching disclosed in paragraph [0025].

2.2 Consequently, the application complies with the requirements of Article 123(2) EPC.

3. Inventive Step

3.1 Closest prior art

D2 is considered closest prior art, because it has most features in common with claim 1. D4 is from a more remote technical field.

3.2 Disclosure of D2

3.2.1 D2 discloses a foldable screen. The screen is an electronic paper within a plastic frame which contains several parts (Fig. 12, reference signs 904, 905). The frame together with the electronic paper screen can be folded like a paper sheet as is shown in Fig. 12. Sensors, such as Hall sensors 918, 920 and magnets 917, 919 detect which parts of the screen are folded out. A control circuit receives the sensor signals and adapts the displayed content, which can be text or an image.

FORMULA/TABLE/GRAPHICFORMULA/TABLE/GRAPHICD2

3.2.2 D2 discloses in Fig. 12 that displayed content is adapted in the fold region in the area between sub-screen 912 and 913. The sub-region with the reference sign 908 in Fig. 12 is kept free of text, because in this constellation the electronic paper is too much deformed such that it is not suitable for displaying text. The same is shown in Fig. 17 for regions 907 and 908 (see paragraph [0039]).

3.3 Difference

3.3.1 D2 therefore discloses Features (A) to (F). D2 discloses (paragraphs [0033]-[0039]) that the format change compensates for impairment of the visual information in the deformation area by displaying the visual information in compensated format in the formation area by means of

(a) adapted text spacing / positioning,

(b) adapted text font size or

(c) scaling an image.

D2 does not disclose that the compensation is mathematically determined based on distortion experienced by a viewer at an assumed viewing angle.

3.3.2 Present claim 1 therefore differs from D2 in Feature (G), i.e. in that the format change compensates for impairment of the visual information in the deformation area by displaying the visual information in compensated format in the deformation area, the compensation being mathematically determined based on distortion experienced by a viewer at an assumed viewing angle.

3.4 Effect

The effect of this difference is that the entirety of the flexible screen is used even after deformation and that the readability in the deformation zone is improved.

3.5 Problem

The objective technical problem can therefore be formulated as to use the entirety of the flexible screen for display and to improve the readability in the deformation zone.

3.6 Non-Obviousness

3.6.1 The Examining Division referred to document D4, arguing that compensation based on the assumed position of the observer is disclosed in paragraphs [0047] to [0050] of D4. D4 taught in this passage to adapt the projected content to the curved surface of the screen.

3.6.2 The Appellant argued that the skilled person would not have turned to document D4 from a consideration of the objective technical problem. D4 clearly related to a fixed surface with no flexibility, and contained no teaching in relation to identification of a fold region, let alone any compensation for impairment of visual information in a deformation area caused by folding. The skilled person would therefore not have turned to D4 based on the objective technical problem.

As the geometry of the display was already known in D4, the key point was purely understanding the field of view. This was equated to the observer but in a way that was different from the claim feature according which the compensation was mathematically determined based on distortion experienced by a view at an assumed viewing angle. In D4 the field of view was presented as a rigid mathematical element irrespective of any assumed viewing angle.

3.6.3 The Board agrees with the Appellant that even if the skilled person had turned to document D4 and by combining the teachings of D2 and D4, it would not have arrived at the combination of Features (A) to (G). D2 teaches only the adaptation to the viewer by scaling the image/text or by introducing blank spaces. D2 discloses inclination sensors to detect which part of the electronic book is opened, but not in order to determine a viewing angle. Nothing in D2 and D4 teaches for a foldable screen to first determine a viewing angle of the reader and then to adapt the distortion of the image / text according to the viewing angle.

3.6.4 Therefore, the subject-matter of claim 1 is inventive over the teachings of D2 and D4 alone or in combination (Articles 52(1) and 56 EPC).

3.6.5 Features (A') to (G') of method claim 9 and the corresponding features of computer implemented method claim 10 correspond to Features (A) to (G) of claim 1. Therefore, the same reasoning applies to claims 9 and 10.

4. Conclusion

Hence, and in the light of the conclusion reached above, the Board judges that the subject-matter of claims 1, 9 and 10 of the sole request involves an inventive step within the meaning of Articles 52(1) and 56 EPC. Claims 2-8 of the Main Request involve an inventive step at least by reason of their dependence on claim 1. The Board is satisfied that the description has been suitably adapted to the claims of the sole request.