| 摘要 |
A dot pattern reading unit for optically reading a dot pattern formed on the surface of a medium by means of a camera comprising a light source for irradiating the surface of a medium with light, a lens through which the reflected light from the dot pattern enters the camera, and a tubular nose section having a hollow portion provided, at the forward end thereof, with an opening through which the irradiation light from the light source and the reflected light from the surface of a medium pass. The light source and the lens are disposed in the hollow portion of the nose section to face the opening. The hollow portion surface defining the hollow portion of the nose section is mirror finished. The dot pattern is irradiated with the irradiation light from the light source reflected off the hollow portion surface of the nose section. The dot pattern can be irradiated efficiently by means of a small number of light sources while preventing highlight. |
