US Patent 7397057 Optical information readout apparatus

An optical information readout apparatus is disclosed having an image forming optical section 4 operative to shift first and second lenses 24, 25 along an optical axis “O” at areas in front of a photodetector 3. A cylindrical body 23 incorporates a lens holder means, including permanent magnets 26 to 28, by which the first lens 24 is halted and held in any of positions a1, a2 and the second lens 24 is halted and held in any of positions b1, b2. Coils 31, 32, 75, 76 and a control circuit 16 drivingly shift the lenses. The control circuit is operative to independently move the lenses to change a focusing range of the image forming optical section in four different stages in the occurrence of a failure in reading out a two-dimensional code.