Patent ID: 7731092

Claim:
An optical information reading apparatus comprising: a pickup unit having a predetermined reading field and configured to optically read an information code from a target when the information code is located in the reading field; and a marker beam irradiating unit comprising: a light beam source configured to emit a diffused light beam; a collective lens arranged at a diffused light beam emitting side of the light beam source and configured to collect the diffused light beam emitted from the light beam source; a beam pattern forming lens arranged such that the collected light beam enters into the beam pattern forming lens, the beam pattern forming lens being configured to irradiate a marker beam based on the collected light beam, the marker beam having a predetermined beam pattern composed of at least one linear beamlet to indicate the reading position of the pickup unit; and an imaging lens arranged between the beam pattern forming lens and the target and configured to form a marker beam image on the target based on the marker beam with the predetermined beam pattern, wherein the marker beam indicates the reading field without reading the information code, and wherein the pickup unit reads the information code, and wherein the diffused light beam emitted from the light beam source has a substantially prolate ellipsoid profile in a first direction orthogonal to an optical axis of the light beam source, and the collective lens has an output surface facing the beam pattern forming lens, the output surface being concavely curved in a second direction orthogonal to the optical axis and the first direction, the output surface of the collective lens collecting the diffused light beam emitted from the light beam source incident into the collective lens so that the collected light beam is substantially circular in a lateral cross section thereof.