US 6631845

US 6,631,845 B2 — Two Window Optical Scanner

Title: Two window optical scanner
Patent number: US 6,631,845 B2
Application number: US 09/824,961
Inventor: Edward Barkan
Original assignee / current assignee (as listed): Symbol Technologies LLC
Priority / filing date: 2001-04-03
Publication date: 2003-10-14
Status (as listed): Expired – Lifetime; adjusted expiration 2021-10-28

Purpose. The text describes the invention as relating to optical scanners, and particularly to a scanner with at least two windows for scanning objects from different angles. Two-window slot scanners typically have a horizontal window and a vertical (or generally vertical) window on two surfaces of a generally L-shaped housing, projecting respective light beams that create two sets of scan lines, for reading bar codes on items such as at a supermarket checkout counter.

Plain-language scope (from the excerpt). The described scanner has a housing with a horizontal window and a vertical window. Each window has its own associated light source and its own polygon mirror rotated by a motor, plus a separate collection system detecting light reflected off a bar code. The collection systems send electrical signals to a decoder that generates a digital signal corresponding to the bar code, and the decoder is capable of reading a bar code even if part is scanned by one window and another part by the other window. In the described arrangement the polygon for the horizontal window is preferably mounted with its axis of rotation vertical, and the motor/polygon for the vertical window horizontally oriented; both polygons have four reflective sides, and the sides are preferably tilted differently with respect to the two axes. The two lasers may be focused differently and/or operate at different powers. A four-mirror array is described for the vertical-window pattern.

Source: https://patents.google.com/patent/US6631845/en

What the excerpt does not establish. The supplied text is expressly an excerpt and notes that omitted text follows ("The scan pattern can also be generated by inve…"). It therefore does not establish the full claim language, the complete written description, the number or scope of claims, the drawings' contents, or the specific prior-art references cited (the excerpt names only U.S. Pat. No. 5,717,195 as incorporated by reference).