Abstract: The present invention provides an optical information reading apparatus capable of producing uniform and bright illumination light and of projecting the illumination light onto an appropriate position on an object of reading at all times. In the apparatus, a light-receiving optical system including a light-receiving sensor and an image formation lens is provided and illumination optical systems each including an LED and an illumination lens device are placed on both sides of the image formation lens. The illumination optical systems are integrally connected to each other through a connecting portion to form a lens-connected assembly. In an incident surface of the illumination lens device, a plurality of convex lens tiers and a plurality of concave lens tiers are alternately made smoothly to form a multi-tiered lens surface, and an output surface thereof is made into a gentle cylindrical configuration to form a rod-like lens surface.

Abstract: The present invention provides an optical information reading apparatus capable of producing uniform and bright illumination light and of projecting the illumination light onto an appropriate position on an object of reading at all times. In the apparatus, a light-receiving optical system including a light-receiving sensor and an image formation lens is provided and illumination optical systems each including an LED and an illumination lens device are placed on both sides of the image formation lens. The illumination optical systems are integrally connected to each other through a connecting portion to form a lens-connected assembly. In an incident surface of the illumination lens device, a plurality of convex lens tiers and a plurality of concave lens tiers are alternately made smoothly to form a multi-tiered lens surface, and an output surface thereof is made into a gentle cylindrical configuration to form a rod-like lens surface.

Abstract: A two-dimensional code made up of a matrix of cells formed with dark and light squares arranged in a pattern carrying an optically readable binary-coded data, and a method of reading such a two-dimensional code. The two-dimensional code features a structure in which at least two data regions are defined in a data field of the matrix. One of the data regions retains a code represented by the cells having a larger size, while the other data region retains a code represented by the cells having a smaller size. The use of cells of different sizes in representing the codes allows the codes to be read correctly under different conditions.