Symbology reader illumination system

An illuminator for producing a desired illumination pattern for illuminating a symbology in an object plane of a symbology reader, comprising:

• a planar base;
• at least three illuminating sources, each having a body portion with leads connected at a selected location on the planar base with a space between the body portion and the planar base, each of the illuminating sources when energized emitting a beam of light along a principal emission vector relative to its body portion, the leads of each of the body portions of the illuminating sources being bent to align its principal emission vector with a corresponding desired beam vector toward the object plane, the desired beam vectors being selected to provide the desired illumination pattern when the illuminating sources are energized;
• and
• an alignment board positioned adjacent to the planar base, between the planar base and the object plane, the alignment board having at least three alignment recesses therein, each alignment recess corresponding to one of the illuminating sources, each alignment recess being defined by an inner surface conforming to the shape of the body portion of the corresponding illuminating source and having an angularly oriented sidewall portion and being offset from the selected location of the illuminating source on the planar base, the inner surface defining each alignment recess engaging the body portion and holding the leads in their bent state to maintain the alignment of the principal emission vector with the desired beam vector for the corresponding illuminating source, the alignment board being substantially transparent to light from the illuminating sources.

An illuminator for producing a desired illumination pattern for illuminating a symbology in an object plane of a symbology reader, comprising:

• a planar base;
• at least three illuminating sources, each having a body portion with leads connected at a selected location on the planar base with a space between the body portion and the planar base, each of the illuminating sources when energized emitting a beam of light along a principal emission vector relative to its body portion, the leads of each of the body portions of the illuminating sources being bent to align its principal emission vector with a corresponding desired beam vector toward the object plane, the desired beam vectors being selected to provide the desired illumination pattern when the illuminating sources are energized;
• and
• an alignment board positioned adjacent to the planar base, between the planar base and the object plane, the alignment board having an upper surface having at least three beveled surface portions, each beveled surface portion corresponding to one of the illuminating sources, each beveled portion being transversely aligned to the desired beam vector of its corresponding illuminating source, and being offset from the selected location of the illuminating source on the planar base, the beveled surface fixedly engaging a lower surface of the body portion and holding the leads in their bent state to maintain the alignment of the principal emission vector with the desired beam vector for the corresponding illuminating source.

A symbology reader for reading a symbology within a target area on a target object substantially in an object plane, comprising:

• a planar base;
• an area detector having a predetermined sensitivity pattern corresponding to positions on the object plane;
• at least three illuminating sources, each of the illuminating sources producing a beam of light having a predetermined beam pattern in the object plane, the illuminating sources being oriented so that their beams are directed to illuminate at least three different regions of the target area in the object plane, with a different one of the beams illuminating each region, and to produce an illuminating pattern in the object plane substantially inversely proportional to the sensitivity of the area detector;
• and
• a planar alignment board mounted in a fixed position and at a selected distance from the planar base, between the planar base and the object plane, the alignment board having at least three alignment apertures therethrough, each corresponding to one of the illuminating sources, each of the alignment apertures being defined by a sidewall, each sidewall having an engagement wall portion shaped to conform to a body portion of the corresponding illuminating source and being positioned in the alignment board to engage and hold the body portion of the corresponding illuminating source in an angular orientation with the illuminating source beam directed at an angle relative to the alignment board to produce the illumination pattern.

A symbology reader for reading a symbology located within a target area on a target object substantially in an object plane, comprising:

• a housing having a reader aperture providing a passageway for light into and out of the housing;
• a spotter beam illuminating source for producing a spotter beam mounted to the housing and having a predetermined orientation to produce a spotter image on the target object to indicate alignment of the symbology reader to the target area;
• a plurality of illuminating sources mounted to the housing for producing light to illuminate the target area, each of the illuminating sources having a predetermined angular orientation to emit an illuminating beam of light through the reader aperture with the illuminating beams being directed to illuminate at least two different regions of the target area with at least one illuminating beam illuminating each of the regions;
• an area detector mounted within the housing and positioned to receive light through the reader aperture from the illuminating sources after being first reflected from the target object;
• a base mounted within the housing;
• and
• an alignment board mounted within the housing in a fixed position and at a selected distance from the base, between the base and the object plane, the alignment board having a plurality of alignment apertures therethrough, each corresponding to one of the illuminating sources, each of the alignment apertures being defined by a sidewall engaging a corresponding one of the illuminating sources to hold the engaged illuminating source in its predetermined angular orientation.

A method of constructing an illuminator for illuminating a target object in an object plane of a symbology reader having a plurality of illuminating sources and an area detector, each of the illuminating sources including a source body portion and having a principal emission vector relative to its source body portion along which the illuminating source emits a beam of light having a known beam pattern, comprising the steps of:

• determining a desired illumination pattern in the object plane;
• selecting locations on a substantially planar base for the illuminating sources;
• selecting an orientation angle for each of the selected source locations relative to the base based upon the known beam pattern of the illuminating source to be located at the selected source location and the desired illumination pattern in the object plane;
• mounting to the base one of the illuminating sources at each of the selected source locations;
• and
• after mounting all of the illuminating sources, positioning an alignment board having a plurality of apertures therethrough, with each aperture corresponding to one of the illuminating sources, between the planar base and the object plane in a fixed position and at a selected distance from the planar base, with each of the apertures being laterally offset from its corresponding illuminating source such that a sidewall of the aperture engages and moves the corresponding source body portion to angularly orient the principal emission vector of the corresponding illuminating source in alignment with the selected orientation angle.

A method of constructing an illuminator for illuminating a target object in an object plane of a symbology reader having a plurality of illuminating sources and an area detector, each of the illuminating sources including a source body portion and having a principal emission vector relative to its source body portion along which the illuminating source emits a beam of light having a known beam pattern, comprising the steps of:

• determining a desired illumination pattern in the object plane by
• determining the sensitivity of the area detector to light directed toward the area detector from a plurality of locations in the object plane;
• and
• computing, for all of the plurality of locations in the object plane, an illumination intensity inversely proportional to the sensitivity of the area detector to light from that location;
• selecting locations on a substantially planar base for the illuminating sources;
• selecting an orientation angle for each of the selected source locations relative to the base based upon the known beam pattern of the illuminating source to be located at the selected source location and the desired illumination pattern in the object plane;
• mounting to the base one of the illuminating sources at each of the selected source locations;
• and
• after mounting each of the illuminating sources, positioning an alignment board having a plurality of apertures therethrough, with each aperture corresponding to one of the illuminating sources, between the base and the object plane in a fixed position and at a selected distance from the planar base, with each of the apertures being laterally offset from its corresponding illuminating source such that a sidewall of the aperture engages and moves the corresponding source body portion to angularly orient the principal emission vector of the corresponding illuminating source in alignment with the selected orientation angle.