Automatic optical projection scanner for omni-directional reading of bar code symbols within a confined scanning volume

An optical projection scanner for producing a confined scanning volume for scanning code symbols presented therein, while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume, the optical projection scanner comprising:

• (a) a housing having an optically admissive window through which optical energy can exit said housing and travel towards an object bearing a code symbol;
• at least a portion of the optical energy reflecting from the object, traveling back through the window, and entering the housing;
• whereby a central reference axis extends, in a substantially longitudinal direction, through the housing;
• (b) an optical energy generation mechanism disposed within the housing for producing a beam of optical energy;
• (c) a beam sweeping mechanism disposed within the housing for rotation about a rotational axis;
• the beam sweeping mechanism having a plurality of rotating optically reflective surfaces each being disposed at a different acute angle with respect to the rotational axis, for sweeping the beam about the rotational axis along a plurality of different paths, the rotational axis intersecting the central reference axis to thereby define a central reference plane;
• (d) a stationary array of at least first, second, third, fourth, and fifth stationary optically reflective surfaces disposed within the housing and fixedly mounted with respect to the central reference axis;
• the first stationary optically reflective surface having a transverse axis extending substantially perpendicularly with respect to the central reference plane,
• the second and third stationary optically reflective surfaces being substantially symmetrically disposed on opposite sides of the central reference plane, respectively, and adjacent the first optically reflective surface, and
• the fourth and fifth stationary optically reflective surfaces being substantially symmetrically disposed on opposite sides of the central reference plane, and substantially adjacent to the second and third stationary optically reflective surfaces, respectively, and substantially adjacent to the beam sweeping mechanism;
• (e) an optical energy collection mechanism disposed within the housing and fixedly mounted with respect to the central reference axis, the collection mechanism including
• (1) a collection mirror fixedly mounted along the central reference plane, so as to permit the beam produced by the optical energy generation mechanism to pass from the collection mirror, substantially along the central reference plane, to the beam sweeping mechanism, for sweeping the beam about the rotational axis thereof along the plurality of different paths, and
• (2) an optical energy receiving mechanism for receiving optical energy from the collection mirror at a point substantially within the central reference plane, and detecting the received optical energy and producing an electrical signal indicative of the detected optical energy;
• (f) a processing and control mechanism within the housing, for processing the electrical signal, and for controlling the operation of at least one of:
• (i) the optical energy generation mechanism, and (ii) the beam sweeping mechanism, so that, during scanner operation, optical energy produced by the optical energy generation mechanism passes from the collection mirror, substantially along the central reference plane, and in a sequential manner to each of a plurality of the rotating optically reflective surfaces of the beam sweeping mechanism, and as the beam sequentially reflects off each of the plurality of rotating optically reflective surfaces, the beam is swept across the first, second, third, fourth and fifth stationary optically reflective surfaces, so as to produce first, second, third, fourth and fifth groups of plural scan lines, respectively, which are projected out through the window and intersect about a projection axis extending from the window, and within a confined scanning volume extending from substantially adjacent the window to at least about six inches from the window so as to produce a substantially collimated projected scanning pattern within the confined scanning volume, by which a code symbol can be scanned omni-directionally while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume,
• each scan line in the first group of scan lines being substantially parallel to each other scan line in the first group of scan lines,
• each scan line in the second group of scan lines being substantially parallel to each other scan line in the second group of scan lines,
• each scan line in the third group of scan lines being substantially parallel to each other scan line in the third group of scan lines,
• each scan line in the fourth group of scan lines being substantially parallel to each other scan line in the fourth group of scan lines, and
• each scan line in the fifth group of scan lines being substantially parallel to each other scan line in the fifth group of scan lines,
• whereby, when a code symbol is presented to the collimated projected scanning pattern within the confined scanning volume, the code symbol is scanned within the collimated projected scanning pattern and at least a portion of the optical energy reflected from the scanned code symbol is directed through the window, reflected off the first, second, third, fourth and fifth stationary optically reflective surfaces, sequentially reflected off the rotating optically reflective surfaces of the beam sweeping mechanism, collected by the collection mirror, and received by the receiving mechanism for detection, whereupon the electrical signal is produced.

An optical projection scanner for producing a confined scanning volume for scanning code symbols presented therein, while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume, the optical projection scanner comprising:

• (a) a housing having an optically admissive window through which optical energy can exit said housing and travel towards an object bearing a code symbol;
• at least a portion of the optical energy reflecting from the object, traveling back through the window, and entering the housing;
• whereby a central reference axis extends, in a substantially longitudinal direction, through the housing;
• (b) an optical energy generation mechanism disposed within the housing for producing a beam of optical energy;
• (c) a beam sweeping mechanism disposed within the housing for rotation about a rotational axis;
• the beam sweeping mechanism having a plurality of rotating optically reflective surfaces each being disposed at a different acute angle with respect to the rotational axis, for sweeping the beam about the rotational axis along a plurality of different paths, the rotational axis intersecting the central reference axis to thereby define a central reference plane;
• (d) a stationary reflection mechanism including a plurality of stationary optically reflective surfaces disposed within the housing and fixedly mounted with respect to the central reference axis;
• wherein the plurality of stationary optically reflective surfaces includes at least a first stationary optically reflective surface having a transverse axis extending substantially perpendicularly with respect to the central reference plane;
• (e) an optical energy collection mechanism disposed within the housing and fixedly mounted with respect to the central reference axis, the collection mechanism including
• (1) a collection mirror fixedly mounted along the central reference plane, so as to permit the beam produced by the optical energy generation mechanism to pass from the collection mirror, substantially along the central reference plane, to the beam sweeping mechanism, for sweeping the beam about the rotational axis thereof along the plurality of different paths, and
• (2) an optical energy receiving mechanism for receiving optical energy from the collection mirror at a point substantially within the central reference plane, and detecting the received optical energy and producing an electrical signal indicative of the detected optical energy;
• (f) a processing and control mechanism within the housing, for processing the electrical signal, and for controlling the operation of at least one of:
• (i) the optical energy generation mechanism, and (ii) the beam sweeping mechanism, so that, during scanner operation, optical energy produced by the optical energy generation mechanism passes from the collection mirror, substantially along the central reference plane, and in a sequential manner to each of a plurality of the rotating optically reflective surfaces of the beam sweeping mechanism, and as the beam sequentially reflects off each of the plurality of rotating optically reflective surfaces, the beam is sequentially swept across each of the plurality of stationary optically reflective surfaces of the stationary reflection mechanism, so as to produce a corresponding plurality of plural scan line groups which are projected out through the window and intersect about a projection axis extending from the window, and within a confined scanning volume extending from substantially adjacent the window to at least about six inches from the window so as to produce a substantially collimated projected scanning pattern within the confined scanning volume, by which a code symbol can be scanned omni-directionally while preventing unintentional scanning of code symbols on objects located outside of the confined scanning volume,
• the plural scan line groups including at least a first group of scan lines wherein each scan line in the first group is substantially parallel to each other scan line in the first group;
• whereby, when a code symbol is presented to the collimated projected scanning pattern within the confined scanning volume, the code symbol is scanned within the collimated projected scanning pattern and at least a portion of the optical energy reflected from the scanned code symbol is directed through the window, sequentially reflected off each of the plurality of stationary optically reflective surfaces of the stationary reflection mechanism and sequentially reflected off the rotating optically reflective surfaces of the beam sweeping mechanism, collected by the collection mirror, and received by the receiving mechanism for detection, whereupon the electrical signal is produced.