Orientation discrimination in a position-coding pattern
AssigneeAnoto AB
InventorsMats Petter Pettersson, Tomas Edso
Life of this patent
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Abstract
A position code is applied on a surface to code positions in one or more directions. The code is based on a main number series which has the property that the place in the main number series of each number sequence of a first predetermined length is unambiguously determined. A position is determined based on one or more such number sequences of the first predetermined length. The orientation of the position code is discriminable from the main number series, but only for number sequences of a second predetermined length that exceeds the first predetermined length.
Claims63
A product for determining a position, comprising:
- a surface;
- and
- a code on said surface for determination of at least one position in a first direction,
- wherein said code for position-coding in said first direction comprises at least one first main number series, which has the property that the place in the first main number series of each number sequence of a first predetermined length is unambiguously determined, said position being determinable based on at least one such number sequence of the first predetermined length, and
- wherein the orientation of said code is discriminable from the first main number series, but only for number sequences of a second predetermined length that exceeds the first predetermined length.
A method for providing a code on a surface, to code at least one position in a first direction on the surface, said method comprising:
- using at least one first main number series, which has the property that the place in the first main number series of each number sequence of a first predetermined length is unambiguously determined and which also discriminates the orientation of the code, but only for number sequences of a second predetermined length that exceeds the first predetermined length;
- determining at least one number sequence of the first predetermined length that codes said at least one position;
- and
- applying to the surface at least one number sequence of the second predetermined length that includes the thus-determined number sequence(s) of the first predetermined length.
A method of determining a position, in a first direction, of an arbitrary partial surface of a predetermined size on a surface which is provided with a position code, which for the position coding in the first direction is based on at least one first main number series, which has the property that the place in the first main number series of each number sequence of a first predetermined length is unambiguously determined and which discriminates the orientation of said position code, but only for number sequences of a second predetermined length that exceeds the first predetermined length, said method comprising:
- identifying at least one number sequence of the second predetermined length from the position code on the partial surface;
- identifying a correct orientation of said partial surface based on the thus-identified number sequence of the second predetermined length,
- identifying a correctly oriented number sequence of the first predetermined length from the position code on the partial surface;
- and
- determining said position based on said correctly oriented number sequence of the first predetermined length.
A computer-readable medium storing a computer program with instructions to cause a computer to implement a method for providing a code on a surface, to code at least one position in a first direction on the surface, said method comprising:
- using at least one first main number series, which has the property that the place in the first main number series of each number sequence of a first predetermined length is unambiguously determined and which also discriminates the orientation of the code, but only for number sequences of a second predetermined length that exceeds the first predetermined length;
- determining at least one number sequence of the first predetermined length that codes said at least one position;
- and
- applying to the surface at least one number sequence of the second predetermined length that includes the thus-determined number sequence(s) of the first predetermined length.
A device for position determination, comprising a sensor for producing an image of a partial surface of a surface which is provided with a position code, and image processing means which are arranged to calculate based on the subset of the position code which is to be found in the image of the partial surface a position of the partial surface in accordance with a method of determining position, in a first direction, of the arbitrary partial surface of a predetermined size on the surface which is provided with the position code, which for the position coding in the first direction is based on at least one first main number series, which has the property that the place in the first main number series of each number sequence of a first predetermined length is unambiguously determined and which discriminates the orientation of said position code, but only for number sequences of a second predetermined length that exceeds the first predetermined length, said method comprising:
- identifying at least one number sequence of the second predetermined length from the position code on the partial surface;
- identifying a correct orientation of said partial surface based on the thus-identified number sequence of the second predetermined length,
- identifying a correctly oriented number sequence of the first predetermined length from the position code on the partial surface;
- and
- determining said position based on said correctly oriented number sequence of the first predetermined length.
Dependencies are inferred from the claim text.