EP0146257A1 — Machine readable markers for cartesian informatio…

Claim 1

Independent Claim 71 words

An information storage medium in which information is stored as multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized in that the medium further contains machine readable synchronization markers respectively positioned at the leading ends of the channels, which markers include one or more features of characteristic shape or dimension or characteristically located on the medium with respect to the associated channels.

Claim 2

Dependent Claim 71 words

An information storage medium in which information is stored as multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized in that the medium further contains machine readable synchronization markers respectively positioned at the leading ends of the channels, which markers include one or more features of characteristic shape or dimension or characteristically located on the medium with respect to the associated channels.

Claim 3

Dependent Claim 80 words

A medium according to claim 1 further characterized in that the markers are all geometrically similar and in that each said marker includes at least two edges parallel to and at predetermined distances, common to all markers, from the centre line of the first frame of the associated channel, and at least two edges parallel to the channel at predetermined distances, parallel to the first frame and also common to all markers, from the first data entry of that frame.

Claim 4

Dependent Claim 30 words

A medium according to claim 2 further characterized in that each of said edges has a length at least three times the extent of a data entry in that direction.

Claim 5

Dependent Claim 40 words

A medium according to claim 2 or 3 further characterized in that the edges of each said marker parallel to the said first frame include a pair of spaced co-linear edges for reference in determining the orientation of the medium.

Claim 6

Independent Claim 47 words

A medium according to any one of claims 1 to 4 further characterized in that each said marker includes a pair of relatively convergent or divergent edges for reference in determining the speed of travel of the read head over the medium parallel to the associated channel.

Claim 7

Independent Claim 106 words

A medium according to any one of claims 1 to 5 further characterized in that each said marker includes a part which is somewhat larger than a data entry in the direction parallel to the frames and has boundaries parallel to the channels, in that the centre-to-centre spacing of the·data entries is uniform and the distance between said boundaries relative to such centre-to-centre spacing is known accurately, whereby said part of the marker is suitable for reference in assessing any variation in either the physical size of the medium, or the observing apparatus which is equivalent or similar to changes in the size of the medium.

Claim 8

Dependent Claim 34 words

A medium according to claim 6 further characterized in that said boundaries parallel to the channels are separated by a distance which is an integral multiple of the centre-to-centre spacing of the data entries.

Claim 9

Independent Claim 47 words

A medium according to any one of claims 1 to 7 further characterized in that each said marker includes a part of an extent in any direction somewhat greater than a said data entry, for reference in assessing the maximum value to be expected from observing apparatus.

Claim 10

Independent Claim 47 words

A medium according to any one of claims 1 to 8 further characterized in that each said marker includes an arrangement of uniformly spaced parallel lines or bars for reference in determining the optical focus of the read head/medium system in terms of a modulation transfer function.

Claim 11

Dependent Claim 58 words

A medium according to claim 9 further characterized in that the lines or bars are parallel to the channels and their centres are spaced at intervals d given by where c is the centre-to-centre spacing of the data entries, m is a small integer, e.g. 1, 2, 3, and, n is the number of lines in the group

Claim 12

Independent Claim 54 words

A medium according to any one of claims 1 to 10 additionally characterized by further machine readable synchronization markers arranged in respective sets alongside the channels, each further marker being respectively positioned with respect to a said frame of data entries and including features characteristically located on the medium with reference to that frame.

Claim 13

Dependent Claim 58 words

A medium according to claim 11 further characterized in that each said further marker includes at least one edge parallel to and at a predetermined distance from the centre line of the associated frame, and a second edge parallel to the channel at a predetermined distance, parallel to the frame, from the first data entry of the frame.

Claim 14

Dependent Claim 27 words

A medium according to claim 12 further characterized in that said at least one edge is positioned substantially midway between the centre lines of the nearest frames.

Claim 15

Dependent Claim 36 words

A medium according to claim 12 or 13 further characterized in that the further marker has an edge parallel to the channel which begins a zone which is wider than the.centre-to-centre spacing of said data entries.

Claim 16

Independent Claim 27 words

A medium according to any one of claims 1 to 14 further characterized in that said first-mentioned synchronization markers are positioned at intervals along the respective channels.

Claim 17

Dependent Claim 69 words

An information storage medium in which information is stored in multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized in that the medium further contains machine readable synchronization markers comprising a first set of similar markers respectively positioned at the leading ends of the channels and a second set of similar markers arranged in respective groups alongside the respective channels.

Claim 18

Dependent Claim 69 words

An information storage medium in which information is stored in multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized in that the medium further contains machine readable synchronization markers comprising a first set of similar markers respectively positioned at the leading ends of the channels and a second set of similar markers arranged in respective groups alongside the respective channels.

Claim 19

Independent Claim 75 words

A method of synchronizing a read head with respect to multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized by observing machine readable synchronization markers respectively positioned at the leading ends of the channels, and effecting said synchronization by reference to one or more features of the markers which are of characteristic shape or dimension, or which are characteristically located with respect to the associated channels.

Claim 20

Independent Claim 75 words

A method of synchronizing a read head with respect to multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized by observing machine readable synchronization markers respectively positioned at the leading ends of the channels, and effecting said synchronization by reference to one or more features of the markers which are of characteristic shape or dimension, or which are characteristically located with respect to the associated channels.

Claim 21

Dependent Claim 55 words

A method.according to claim 17 further characterized by utilizing said or other features of the markers to ascertain one or more of the orientation of the medium containing said frames, the speed of travel of the read head over the medium parallel to the channels, and the maximum value to be expected from observing apparatus.

Claim 22

Dependent Claim 47 words

A method according to claim 17 further characterized in that one of the said features comprises one or more groups of uniformly spaced lines or bars the spacing of which is such as to provide a good indication of the quality of focus of the observing apparatus.

Claim 23

Dependent Claim 75 words

A method according to claim 19 further characterized by arranging for the distances from the centre of each of said lines or bars to the centre of the nearest area observed by an element of a uniform linear detector array for said observing, to be distributed evenly over the possible range, and wherein the measurement is taken as the average of measurements computed from the outputs of elements observing each line over the said range.

Claim 24

Independent Claim 52 words

A method according to any one of claims 17 to 20 additionally characterized by observing further machine readable synchronization markers arranged alongside the respective channels and maintaining synchronization by reference to one or more features of the further markers which are characteristically located in relation to respective frames of the adjacent channel.

Claim 25

Dependent Claim 70 words

A method according to claim 21 further characterized by obtaining an observed position value for each further marker in turn, determining whether the observed position is outside a trend initially established by observations of markers such as those at the leading ends of channels and maintained by observations of the said further markers, by more than a predetermined margin, and if so, reducing the effect of that observed position value.

Claim 26

Dependent Claim 81 words

Apparatus for reading multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized by means to observe machine readable synchronization markers respectively positioned at the leading ends of the channels, and means to effect synchronization of the read head with respect to the data entries by reference to one or more features of the markers which are of characteristic shape or dimension, or which are characteristically located with respect to the associated channels.

Claim 27

Dependent Claim 81 words

Apparatus for reading multiple machine readable data entries arranged in frames which are themselves arranged in plural, generally parallel channels, characterized by means to observe machine readable synchronization markers respectively positioned at the leading ends of the channels, and means to effect synchronization of the read head with respect to the data entries by reference to one or more features of the markers which are of characteristic shape or dimension, or which are characteristically located with respect to the associated channels.

Claim 28

Dependent Claim 56 words

Apparatus according to claim 23 characterized by means for utilizing said or other features of the markers to ascertain one or more of the orientation of the medium containing said frames, the speed of travel of the read head over the medium parallel to the channels, and the maximum value to be expected from observing apparatus.

Claim 29

Dependent Claim 35 words

Apparatus.according to claim 23 or 24 further characterized in that said second mentioned and/or utilizing means comprises computing means programmed with data concerning said feature(s) and with instructions so as to comprise the aforesaid means.

Claim 30

Dependent Claim 57 words

Apparatus according to claim 25 further characterized by means to store position values derived from observation of said synchronization markers, means to determine whether an observed position value for a marker is outside a selected trend established by said stored values by more than a predetermined margin, and if so, to reduce the effect of that value.

Claim 31

Independent Claim 69 words

A method of observing a succession of machine readable position markers in a medium characterized by: observing the markers in turn and storing observed values indicating marker position for a predetermined number of markers preceding each marker being observed; determining whether each observed value is outside a selected trend established by the stored values by more than a predetermined margin: and, if so, reducing the effect of that value.

Claim 32

Independent Claim 69 words

A method of observing a succession of machine readable position markers in a medium characterized by: observing the markers in turn and storing observed values indicating marker position for a predetermined number of markers preceding each marker being observed; determining whether each observed value is outside a selected trend established by the stored values by more than a predetermined margin: and, if so, reducing the effect of that value.

Claim 33

Dependent Claim 34 words

A method according to claim 27 further characterized in that the selected trend is initially established by first observing a special marker which is able to be observed with greater confidence in the observation.

Claim 34

Dependent Claim 26 words

A method..according to claim 27 or 28 further characterized in that wherein the trend utilized for said determination is a simple average of the stored values.

Claim 35

Dependent Claim 45 words

A method according to claim 27 or 28 further characterized in that wherein the trend utilized for said determination is a weighted average of the stored values in which weights, which may be positive or negative, are assigned to the values according to their age.

Claim 36

Independent Claim 37 words

A method according to any one of claims 27 to 30 further characterized in that said reduction of the effect of the observed value comprises rejecting the observed value and substituting the value predicted by the trend.

Claim 37

Independent Claim 37 words

A method according to any one of claims 27 to 30 further characterized in that said reduction of the effect of the observed value comprises replacing the observed value with a limit which that value has exceeded.

Claim 38

Dependent Claim 75 words

Apparatus for observing a succession of machine readable position markers in a medium characterized by; means to observe the markers in turn; means to store observed values indicating marker position for a predetermined number of markers preceding each marker being observed; and means to determine whether each observed value is outside a selected trend established by the stored values by more than a predetermined margin, and, if so, to reduce the effect of that value.

Claim 39

Dependent Claim 75 words

Apparatus for observing a succession of machine readable position markers in a medium characterized by; means to observe the markers in turn; means to store observed values indicating marker position for a predetermined number of markers preceding each marker being observed; and means to determine whether each observed value is outside a selected trend established by the stored values by more than a predetermined margin, and, if so, to reduce the effect of that value.

Claim 40

Dependent Claim 33 words

Apparatus according to claim 33 further characterized in that said determining and effect reducing means is arranged so that the trend utilized for said determination is a simple average of the stored values.

Claim 41

Dependent Claim 51 words

Apparatus according to claim 33 further characterized in that said determining and effect reducing means is arranged so that the trend utilized for said determination is a weighted average of the stored values in which weights, which may be positive or negative, are assigned to the values according to their age.

Claim 42

Dependent Claim 44 words

Apparatus according to claim 33, 34 or 35 further characterized in that said determining and effect reducing means is arranged so that said reduction of the effect of the observed value comprises rejecting the observed value and substituting the value predicted by the trend.

Claim 43

Dependent Claim 51 words

Apparatus according to any one of claims 33 to 36 further characterized in that said determining and effect reducing means comprises computer means programmed with details in respect to said trend, said predetermined number of markers, said predetermined margin and with instructions for effecting said determination and, if necessary, said rejection.

Machine readable markers for cartesian information storage media

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