公开(公告)号：JPH04217079A

公开(公告)日：1992-08-07

申请号：JP3041491

申请日：1991-02-25

Applicant: SYMBOL TECHNOLOGIES INC

Inventor： JIYOSEFU KATSUTSU ,  EMANIYUERU MAROOMU ,  GUREN SUPITSUTSU ,  NEIMU KONFUOOTEI

IPC: G02B5/00 ,  G02B26/10 ,  G06K7/10

Abstract: PURPOSE: To obtain a bar code scanner which has a wide operation range by arranging an optical element in the optical path between a laser light source and a scanning mirror. CONSTITUTION: This laser scanner is provided with the laser light source 20, e.g. a gas laser or semiconductor laser diode, an optical means which forms a diffraction pattern 25 having a center beam spot 26 with a specific diameter, and a scanning means which makes a scan with a modulated laser beam 14 across a symbol 15. The barrel part 11 of a housing has an exit window 13. The laser beam 14 exits through the window 13 to impinge on the symbol 15 placed outside the housing and scan it. The laser beam 14 moves across the symbol 15 to draw a scanning line 16. The scanning motion of this laser beam 14 is caused by an oscillatory mirror 17 driven by a stepping motor 18. Consequently, the wide operation range, i.e. depth of focus is obtained.