1 2
HAND HELD BAR CODE DATAFORM optical path of the oscillating light beam which defines the
READER HAVING A ROTATABLE READING reading plane is fixed with respect to the housing and the exit
ASSEMBLY window. To use such a bar code reader, the exit window was
pointed toward or "aimed" at the bar code dataform to be
FIELD OF THE INVENTION 5 read and a reading actuation mechanism was actuated to
energized the bar code reading assembly and read the bar
This invention relates to a hand held bar code dataform code Such bar code readers were often configured in the
reader and, more particularly, to a hand held bar code sh of a „ „ n s pa{ No 5 130 520 to Shepard et al.
dataform reader having a bar code reading assembly is a t ical example of a proposed "gun"-type bar code
mounted on a rotatable support permitting a plurality of J0 dataform reader.
reading orientations. ... „ . , , . r . , ,. .. , ,,
e A gun -type bar code dataform reader has limited flex
BACKGROUND OF THE INVENTION ibility due to the fixed orientation of the bar code dataform
reading assembly with respect to the housing and exit
Hand held bar code dataform readers have achieved window. The reading assembly cannot be reoriented to
widespread use in a variety of industrial and commercial 15 provide a different bar code reading orientation. That is, to
applications. Hand held readers are advantageously utilized change the reading plane the reader housing would have to
by manufacturers, merchandisers, and service firms for berepositionedtoaimatatargetof interest. This has proven
production and inventory control purposes and product and to be a significant disadvantage in situations where bar code
package routing control. dataforms to be read are affixed to items that are in close
Hand held bar code dataform readers generally comprise 20 proximity. Closely spaced items often will prevent the
a housing which supports a bar code dataform reading "gun"-type bar code dataform reader from being positioned
assembly. The reading assembly includes a light source to "aim" at and read the target item bar code dataforms.
component such as a laser or a plurality of light emitting Additionally, even if a "gun"-type dataform reader can be
diodes which, upon actuation of the assembly emits a light oriented to "aim" at the dataforms desired to be read, the
beam. The assembly also includes an optical component 25 fixed orientation of the reading assembly with respect to the
such as a focusing lens and a mirror for focusing and housing may result in ergonomic problems. For example, if
directing the light beam along an optical path toward the bar the bar code dataforms to be read are positioned such that the
code dataform to be read. Finally, a photodetector compo- operator of the "gun"-type dataform reader must bend or his
nent such as a photodiode is provided to receive reflected or her hand, wrist and/or arm into an awkward and uncom
light from the bar code dataform being read and to generate 30 fortable position to "aim" and actuate the reader to read a bar
an electrical signal representative of an intensity of the code dataform, fatigue will result if a large number of bar
reflected light codes are to be read. Repetitive motion injuries resulting
At least one of the mirror, the focusing lens and the light from continual straining of the hand, wrist and arm have source reciprocates to oscillate or "play" the emitted light been is well recognized in the medical field, beam back and forth across the bar code dataform to be read. The proposed hand held bar code dataform reader disThe oscillating optical path of the light beam defines a bar closed in U.S. Pat. No. 5367,152 to Krichever et al. procode dataform reading plane. The light beam emitted by the vides for repositioning a structure supporting an exit winlight source exits the housing through an exit window which dow. The support structure is removably attachable to a is transparent or semi-transparent. The light reflected from housing in a selected one of two possible positions. This the bar code dataform enters the housing and strikes the proposed reader thereby provides for bar code reading in photodetector. Depending on the design of the reader, the two directions or reading planes. While providing greater photodetector may be positioned adjacent the exit window flexibility in reading orientation with respect to the housing or a separate light return window. than a "gun"-type reader, this proposal has significant dis
A typical one dimensional (ID) bar code dataform con- 45 advantages. Repositioning the exit window requires remov
tains coded data or information in a single row of varying ing the exit window support structure from its attached
width adjacent bars and spaces. The coded information is position on the top of the housing. Removal of the support
encompassed in a particular pattern bars and spaces. Start structure is both time consuming and additionally exposes
and stop patterns are provided at the beginning and end of the reading assembly and other electronic components dis
the bar code dataform to indicate the boundaries of the actual 50 posed in the housing to environmental contaminants. Yet
coding area. The bars and the spaces of a bar code dataform another disadvantage of the aforementioned dataform reader
have differing coefficients of light reflectivity. The magni- is that only two reading orientations are possible, the posi
tude of the electrical signal generated by the photodetector tions being angularly displaced by 180°.
varies with the intensity of the light received by the photo- OSTTRF OF THF TNVFNTTON
detector. The intensity of the reflected light changes over 55 DISCLOSURE OF THE INVENTION
time as the light beam oscillates across and is reflected by A bar code dataform reader for reading a bar code
the sequence of bars and spaces comprising the bar code dataform is disclosed. The reader includes a bar code
dataform. dataform reading assembly mounted on a rotatable support
A decoder electrically coupled to the photodetector is also within a housing interior region. The support is rotatable disposed within the housing. The time varying electric signal go with respect to the housing and can be indexed to a selected
generated by the photodetector is processed and converted one of a plurality of positions. Each indexing position
by the decoder to generate machine-readable data corre- corresponds to a different bar code reading orientation. The
spending to the data or information encoded in the read bar housing includes one or more exit windows through which
code dataform. a beam of light generated by the bar code reading assembly
Previously proposed bar code dataform readers have 65 exits the housing and through which reflected light returns,
included a bar code reading assembly and an exit window in The bar code dataform reader further includes structure
a fixed orientation with respect to the housing. That is, the coupled to the support and accessible from an exterior of the
