Arrangement for reducing interference in an electronic shelf label

• US 9,559,414 B2
• Filed: 05/31/2011
• Issued: 01/31/2017
• Est. Priority Date: 06/01/2010
• Status: Active Grant

• Current Assignee: MariSense Oy (MariCap Oy)
• Original Assignee: MariSense Oy (MariCap Oy)
• Inventors: Karhuketo, Hannu, Wright, Gregory
• Primary Examiner(s): Levi, Dameon E
• Assistant Examiner(s): Baltzell, Andrea Lindgren
• Application Number:
  US13/698,392
• Publication Number:
  US 20130076586A1
• Time in Patent Office: 2,072 Days
• Field of Search: 343/841
• US Class Current: 1/1
• CPC Class Codes: G09F 3/208 Electronic labels, Labels integrating electronic displays
• CPC Class Codes: H01Q 1/085 Flexible aerials; Whip aerials with a resilient base
• CPC Class Codes: H01Q 1/2225 used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials
• CPC Class Codes: H01Q 19/021 Means for reducing undesirable effects

Abstract

An arrangement for reducing interference in a wireless electronic shelf label (ESL) (100) having a layered structure the ESL comprising: a display layer (101) comprising display material, a circuit board (203) with a backplane material structure and an antenna (202), and a circuit board arrangement with control electronics for controlling the operation of the label, such as the display and the radio communication, and a resilient layer having a space for a rigid component, such as a battery, wherein said resilient layer is arranged to provide a substantially even total thickness of said label (100), wherein the radio communication control further comprises means for radio frequency communication via modulated backscatter, wherein the arrangement is ring resonator arrangement isolating the ESL from the electrically conducting shelf arranged on the antenna circuit board, the ring resonator arrangement comprising a plurality of ring resonators (204) that are electrically isolated from the antenna and arranged at least on the side nearest the shelf when the ESL is attached to the shelf.

Claims

1. A wireless electronic shelf label (ESL) having a layered structure comprising:

a display layer comprising display material,

an antenna circuit board with a backplane material structure,

a far field antenna disposed on the antenna circuit board,

a circuit board arrangement with control electronics for controlling the operation of the label, including the display and radio communication control, and

a resilient layer having a space for a rigid component, such as a battery, wherein said resilient layer is arranged to provide a substantially even total thickness of said label,

wherein the radio communication control further comprises means for radio frequency communication via modulated backscatter,

wherein the ESL further includes an arrangement for reducing interference which comprises a split ring resonator arrangement, arranged on the antenna circuit board to isolate the ESL from an electrically conducting shelf to which the ESL is attached, and

wherein the split ring resonator arrangement comprises a plurality of ring resonators, as separate structures that are electrically isolated from the antenna but are printed on the same layer of the antenna circuit board and arranged at least on a side nearest the shelf to which the ESL is attached.

2. The wireless electronic shelf label according to claim 1, wherein the ring resonators are arranged at least on a common centre line that is parallel with an edge of the circuit board that is nearest the shelf.

3. The wireless electronic shelf label according to claim 1, wherein the ring resonators have all the same diameter which is essentially smaller than the width of the ESL.

4. The wireless electronic shelf label according to claim 1, wherein the ring resonators may additionally be arranged on another side of the board.

5. The wireless electronic shelf label according to claim 1, wherein the split ring resonators comprise a ring and an opening in the ring, whereby the ring operates as an inductor and the opening as a capacitor.

6. The wireless electronic shelf label according to claim 1, having an arrangement for reducing the interference.

7. The wireless electronic shelf label according to claim 6, wherein the antenna and the split ring resonators are arranged on separate sides of a circuit board or on separate circuit boards arranged onto each other.

8. The wireless electronic shelf label according to claim 6, wherein the circuit board for said antenna and control electronics is flexible.

9. A wireless electronic shelf label according to claim 2, having an arrangement for reducing the interference.

10. A wireless electronic shelf label according to claim 3, having an arrangement for reducing the interference.

11. A wireless electronic shelf label according to claim 4, having an arrangement for reducing the interference.

12. The wireless electronic shelf label according to claim 7, wherein the circuit board for said antenna and control electronics is flexible.

13. The wireless electronic shelf label of claim 3, wherein the split ring resonators have a diameter which is less than 20% of the width or length of the circuit board.