A scanner guide for attachment to a pre-existing bar code scanner wand to enable such a wand to read bar coded labels disposed on a cylindrical surface of a relatively small diameter such as containers used for the collection of medical specimens. The scanner guide includes a cylindrical pin having a...http://www.google.com.tw/patents/US5902990?utm_source=gb-gplus-share專利 US5902990 - Bar code scanner guide
