T 0454/91 18-12-1991

I. European patent application No. 87 200 986.5 (publication No. 0 255 152) was refused by a decision of the Examining Division dated 17 April 1991. That decision was taken on the basis of Claims 1 to 22 as filed on 17 September 1990 and comprised the amendments suggested in Applicant's letters of 7 December 1990 and 30 January 1991.

II. It is understood from the decision that the reason for the refusal was that the independent Claims 1 and 18 as well as the dependent Claim 7 contained subject-matter that extended beyond the content of the application as filed (Article 123(2) EPC). Moreover Claims 1 and 18 were considered to be obscure.

Refused Claim 1 reads as follows:

"A method of recording video information in a record carrier with the record carrier having a nominal speed, and of reproducing said video information from the record carrier, wherein during recording each picture (1) to be recorded of a sequence of pictures comprising NxM picture elements is divided into subpictures (2) of nxm picture elements, the video information of each subpicture being encoded in accordance with a transform coding (T1, T2, ...) in such a way that the video information of corresponding subpictures of a specific picture and of a next picture are compared with each other, a subpicture (11.1) of a specific picture (B1) is encoded in accordance with a first transform coding (T1) and the corresponding subpicture (11.2) of the next picture (B2) is encoded in accordance with the same transform coding (T1) if the difference between the video information of the two subpictures exceeds a specific first value and in that the corresponding subpicture (11.2) of the next picture is encoded in accordance with a second transform coding (T2) if the difference between the video information of the two subpictures is smaller than or equal to the first value, so that utilizing the results of the first transform coding (T1) applied to the first-mentioned subpicture (11.1), the second transform coding (T2) provides a more accurate coding of the video information of the subpicture (11.2) of the next picture, the encoded information of each subpicture being recorded on the record carrier (10), together with transform coding information about the kind of transform coding applied to the video information of the subpicture (fig. 4a), wherein during reproduction with the record carrier (10) having a nominal speed, the encoded information of each subpicture together with the corresponding transform coding information is read from the record carrier, and the encoded information of each subpicture is decoded in accordance with a specific transform decoding in relation to the transform coding information corresponding to the relevant subpicture, such that if the relevant subpicture (12.1) of the picture read at the relevant instant has been coded in accordance with the first transform coding (T1) during recording, the information of the relevant subpicture thus read is subjected to a coding which is the inverse of said first transform coding (T1-1) and, if the relevant subpicture (12.2) of the picture read at the relevant instant has been encoded in accordance with the second transform coding (T2) during recording, the information of the relevant subpicture thus read is subjected to a coding which is the inverse of said transform coding (T2-1) so as to obtain a more accurate subpicture at said instant (fig. 5a) and the video information for consecutive pictures of NxM picture elements is derived from the video information of consecutive subpictures of nxm picture elements, characterized in that during recording a first motion code (mc1) is assigned to the subpicture (11.1) of the first mentioned picture (B1) and, if the difference between the video information of the two subpictures is smaller than or equal to the first value the first motion code (mc1) is assigned to the subpicture (11.2) of the next picture (B2), and that if the difference between the video information of the two subpictures (20.2, 20.3) exceeds the first value, a second motion code (mc2) is assigned to the subpicture of the next picture, and in that the motion codes together with the encoded video information and the transform coding information of the associated subpictures are recorded on the record carrier, and in that during reproduction together with the encoded video information of and the transform coding information for each subpicture, the motion code associated with said subpicture is read from the record carrier, and if during reproduction with the record carrier having a speed other than the nominal speed (fig. 6), the transform coding information of a subpicture of a picture read at a specific instant relates to the second transform coding, and the transform coding information of a corresponding subpicture of a previously read picture relates to the first transform coding and if the motion codes of both subpictures are not the same, the information of the subpicture read from the record carrier at said specific instant is not subject to the coding which is the inverse of the second transform coding so as to provide a more accurate subpicture at said instant."

Claims 7 and 18 also included the phrase "the record carrier having a speed other than the nominal speed" in accordance with Claim 1.

The Examining Division pointed out that the said phrase "during reproduction the record carrier has a speed other than the nominal speed" also "comprises speeds which are lower than the nominal". However, such lower speeds were said not to be disclosed in the original description and therefore it was concluded that the subject-matters of said claims were not supported by the original disclosure.

Moreover the Examining division stated:

"In the last three lines of present Claim 1, there is indicated that "... the information of the subpicture read from the record carrier at said specific instant is not subjected to the coding which is the inverse of the second transform coding so as to provide a more accurate subpicture at said instant". This statement, however, leaves it open as to what information is in fact used to obtain the subpicture of the picture read at said specific instant. Original Claim 15 and original descriptive page 28, lines 23-28 and present sub-claim 2 as well clearly indicate in this context that the corresponding subpicture of the picture previously read is repeated. However, such a feature is not claimed in Claim 1 so that this claim appears to be incomplete since it does not contain any information as to in what manner the information read from the record carrier at said specific instant is to be decoded."

Therefore Claim 1 was also considered to be "obscure and incomplete with respect to the wording in the three last lines of this claim". Also Claim 18 contained a corresponding obscurity.

III. The Appellant lodged an Appeal against the decision on 5 June 1991. In the Statement of Grounds he contested the findings of the decision of the Examining Division and requested a cancellation of the said decision.

IV. In a communication pursuant to Article 11(2) of the RPBA the Board expressed its provisional view that the Claims 1, 7 and 18 contained features which violated Article 123(2) EPC and that Claims 1 and 18 did not appear to contain all essential features (Article 84 EPC).

V. With a letter filed before the oral proceedings the Appellant filed a set of claims of a main request and moreover four sets of claims according to four auxiliary requests. However, in the course of the oral proceedings the Appellant withdrew his previous requests and requested only that the decision under Appeal be set aside and that the case be remitted to the first instance for further prosecution.

The Appellant argued that the original application documents in fact did disclose that during reproduction the record carrier according to the invention could have a speed lower than the nominal speed. He stated that it would be implicitly clear to a skilled man that the method disclosed in connection with Figure 6 in the application would be applicable also to lower speeds than the nominal speed. From the said Figure and the corresponding text it was self-evident to a skilled man that the motion codes according to the invention had to be used when some of the subpictures were skipped (i.e. when they were not read). It was therefore self-evident to a skilled man that this method also should be used when having a lower speed, since in that case it was also necessary to skip intermediate subpictures before a decodable subpicture (a sub-picture that was "in-phase" with the one previously read) could be found.

Having regard to the second objection made by the Examining Division as well as the Board, the Appellant argued that it was implicitly disclosed in the application that it was not necessary to repeat the corresponding subpicture of the picture previously read according to the invention. It was up to the skilled man to choose whether he wanted to repeat one of the subpictures previously read or not. Also other solutions were possible, e.g. not to decode at all (a mute subpicture). Thus there were different possibilities to get a simplified reproduction. In order to avoid misunderstandings the Appellant had according to all of the said withdrawn requests in Claim 1 deleted the last phrase of the refused Claim 1 "so as to provide a more accurate subpicture at said instant".