Compact matrix code and one-touch device and method for code reading

A two-dimensional code, comprising:

• a plurality of data cells that optically stores information on a surface, individual ones of said plurality of data cells having predetermined shapes and positions and having one of at least two optical properties, where individual ones of said plurality of data cells do not adjoin others of said plurality of data cells on all sides, and
• a plurality of target elements that provides reference positions relative to said plurality of data cells, wherein individual ones of said target elements have predetermined optical properties and positions relative to said predetermined position of said plurality of data cells, wherein said plurality of target elements are confined within a perimeter, where said perimeter is the perimeter of a defined shape having the minimum area to confine said plurality of target elements, and wherein the distance between any two points of said plurality of target elements is within 15% of the predetermined shapes and positions of said plurality of target elements.

A two-dimensional code comprising:

• a plurality of data cells that optically stores information, wherein said plurality of data cells individually have one of at least two optical properties and where said plurality of data cells are located on a regular grid and are confined within a periphery;
• and
• a target having predetermined optical properties and boundaries relative to a position of said plurality of data cells, where at least a portion of said boundaries does not lie on said regular grid, where a portion of said target is in proximity to said periphery, and where a portion of said target has approximately radial features distinct from said plurality of data cells.

A two-dimensional code comprising:

• a plurality of data cells that optically stores information, individual ones of said plurality of data cells having predetermined shapes and positions and having one of at least two optical properties;
• and
• a target having predetermined optical properties, shapes, and positions relative to the position of said plurality of data cells, where a portion of said target has n-fold radial symmetry, where n is equal to three.

A two-dimensional code comprising:

• a plurality of data cells that optically stores information, individual ones of said plurality of data cells having predetermined shapes and positions and having one of at least two optical properties;
• and
• a target having predetermined optical properties, shapes, and positions relative to the position of said plurality of data cells, such that a portion of said target is distinct and the code is easily recognizable.

A two-dimensional code comprising:

• a plurality of data cells that optically stores information, individual ones of said plurality of data cells having predetermined shapes and locations and having one of at least two optical properties, and said plurality of data cells having a data centroid;
• and
• a target having predetermined optical properties, shapes, and locations relative to a position of said plurality of data cells, said target enclosed within an enclosed curvilinear shape having a periphery and a target centroid, where a portion of said target has approximately radial features distinct from said plurality of data cells, where said target centroid is adjacent to said data centroid, and where said plurality of data cells are substantially enclosed within said periphery.

A two-dimensional code comprising:

• a plurality of data cells that optically stores information, individual ones of said plurality of data cells having predetermined shapes and locations and having one of at least two optical properties;
• and
• two or more symbols comprising equal numbers of said plurality of data cells, where said predetermined shapes and locations of said plurality of data cells are arranged such that adjoining data cells are more likely to belong to the same symbol than to a different symbol such that the code is tolerant of printing errors.

An optical code formed on a surface of a substrate, comprising:

• a perimeter defining an outer extent of the code,
• at least one cluster within the perimeter of a plurality of data cells that adjoin one another in a two-dimensional pattern, individual ones of the plurality of data cells having a predetermined shape and one of at least first and second optical properties according to data being stored therein, and wherein none of the plurality of data cells having the first optical property are totally surrounded by others of the plurality of data cells having the same first optical property, and
• a plurality of target elements within the perimeter and having one of said at least first and second optical properties, a fixed spatial relationship with said at least one cluster of a plurality of data cells and which contain no data.

An optical code formed on a surface of a substrate, comprising:

• a perimeter defining an outer extent of the code,
• a plurality of two-dimensional clusters of data cells spaced apart within the perimeter, the individual clusters including a plurality of hexagon shaped data cells adjoining one another, individual ones of the plurality of data cells either being printed or not-printed in accordance with a bit of data being stored therein, and wherein hexagon shaped areas within the clusters are not used as data cells so that none of the plurality of data cells that are printed can be surrounded by others of the plurality of data cells that are also printed, and
• a plurality of target elements within the perimeter that are printed and have a fixed spatial relationship with the plurality of clusters of data cells.