Optical information reader and method of manufacturing the optical information reader

A method of manufacturing an optical information reader,

• the optical information reader comprising:
• an area sensor that receives reflected light from an information code via an imaging lens, the information code being optically read based on a signal outputted from the area sensor;
• a holder to which the area sensor is fixed;
• and
• a lens retainer that retains the imaging lens and is assembled, in this state, into the holder, the lens retainer including a reference surface that is parallel to an optical axis of the imaging lens, wherein
• the holder is provided with a guide surface with which the reference surface is brought into surface contact and against which the reference surface is brought into slidable contact, the surface contact being achieved when the lens retainer is assembled into the holder so that light passing through the imaging lens produces an image on the area sensor, the slidable contact being achieved when the lens retainer is moved along the optical axis, and
• the method comprising steps of:
• assembling the lens retainer retaining the imaging lens into the holder, to which the area sensor is fixed, whereby the reference surface is brought into surface contact with the guide surface;
• assembling an arm movable along the optical axis to the lens retainer;
• sequentially measuring resolution of the area sensor, while the arm is moved in a direction along the optical axis so that the reference surfaces is brought into slidable contact with the guide surface;
• fixing the lens retainer, with the arm being assembled thereto, to the holder at a peak position where measured resolution is regarded to be a peak;
• and
• detaching the arm from the lens retainer.

An optical information reader comprising:

• an area sensor that (i) has a rectangular light-receiving surface having mutually orthogonal long and short sides, (ii) has a light-receiving axis, and (iii) receives reflected light from an information code at the rectangular light-receiving surface, the information code being optically read based on a signal outputted from the area sensor;
• an imaging lens located in a path of the reflected light reflected by the imaging code and configured to image the reflected light on the area sensor;
• a first illuminant emitting visible light and a second illuminant emitting invisible light toward an imaging field of view of the area sensor, the visible light and the invisible light serving as illumination light, wherein
• the first illuminant and the second illuminant are arranged in line via the imaging lens located between the first and second illuminant in a direction along the short side of the light-receiving surface when viewed along the light-receiving axis.