| 摘要 |
PROBLEM TO BE SOLVED: To provide a small-sized irregular pattern reader whose entire length is short. SOLUTION: This reader is provided with a detection prism 4 provided with a detection plane 42 for placing an irregular pattern, an incident plane 41 for making an incident luminous flux for irradiating the irregular pattern be incident and an emission plane 43 for emitting the reflected luminous flux of the irregular pattern and provided with an angle among the respective planes so as to irradiate the irregular pattern with the incident luminous flux and to emit the reflected luminous flux from the detection plane 42 from the emission surface 43, an incident light convergence means 3 for paralleling or converging the incident luminous flux L from a light source 1 to the optical axis of incident light and making it be incident on the incident plane, an image pickup device 7 for picking up a reflected image emitted from the detection prism 4, a convergence optical system 6 for paralleling or converging the emitted luminous flux emitted from the emission plane 43 and converging it on the image pickup plane of the image pickup device and a processor 8 for specifying the irregular pattern, based on the image picked up by the image pickup device 7. The image pickup plane of the image pickup device 7 is provided on a position closer to the side of the emission plane more than the focus position of the convergence optical system 6. |
