Tilted antenna

• US 5,274,392 A
• Filed: 01/08/1992
• Issued: 12/28/1993
• Est. Priority Date: 01/09/1991
• Status: Expired due to Fees

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Schuermann, Josef H., D'Hont, Loek
• Primary Examiner(s): Wimer, Michael C.
• Assistant Examiner(s): Ho, Tan
• Application Number:
  US07/818,002
• Time in Patent Office: 720 Days
• Field of Search: 340/505, 340/572, 343/866, 343/788, 343/741, 343/742, 343/745, 343/868, 343/869
• US Class Current: 343/866
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer
• CPC Class Codes: G06K 7/10316 using at least one antenna particularly designed for interrogating the wireless record carriers antennas in general H01Q1/22
• CPC Class Codes: G06K 7/10336 the antenna being of the near field type, inductive coil

Abstract

A novel antenna system disposed around a conveyor belt for the interrogation of objects passing through the antenna which overcomes centralized dead zone problems is disclosed. A frame antenna is disposed around a conveyor belt and is tilted to form, for example, a 30 deg. angle with the vertical longitudinal plane of the conveyor belt, which is perpendicular to the horizontal plane within which the conveyor belt lies, and a 30 deg. angle with the transverse axis of the conveyor belt. In this way, a "dead-zone" free read area is formed to facilitate the read of a transponder oriented in any manner as it moves along the conveyor belt.

Claims

1. The antenna system for interrogation and identification of a transponder, wherein the transponder moves along an interrogation path comprising:

a frame antenna disposed around the interrogation path for interrogating a transponder moving along said interrogation path, said frame antenna defining a plane intersecting said interrogation path and oriented such that said plane forms an angle with the vertical longitudinal plane of the interrogation path and simultaneously said plane forms an accute angle with the transverse axis of said interrogation path.

2. The antenna system of claim 1, wherein said acute angle is 30°

.