Shielding device for a hand-held radiophone

• US 20020148625A1
• Filed: 04/12/2002
• Published: 10/17/2002
• Est. Priority Date: 08/14/2000
• Status: Abandoned Application

• Current Assignee: ConcepTech, Inc.
• Original Assignee: ConcepTech, Inc.
• Inventors: Madsen, Henrik, Wedel, Flemming, Darling, Keld Emlington
• Application Number:
  US10/110,402
• Publication Number:
  US 20020148625A1
• Time in Patent Office: Days
• US Class Current: 174/35R
• CPC Class Codes: H01Q 1/245 with means for shaping the antenna pattern, e.g. in order to protect user against rf exposure
• 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: H04B 1/3838 Arrangements for reducing RF exposure to the user, e.g. by changing the shape of the transceiver while in use
• CPC Class Codes: H04M 1/03 Constructional features of telephone transmitters or receivers, e.g. telephone hand-sets

Abstract

The invention relates to a shielding device to be fixedly arranged on a hand-held mobil radio transmission means (1), such as a mobile phone, and which protects a user against electromagnetic radiation from said radio transmission means (1) when said radio transmission means is used. The shielding device (10) comprises at least on substantially plane shielding member (12) of metal, where the metal is a nickel alloy, especially mu-metal. The shielding member (12) defines at least partially an acoustic resonance chamber (18) communicating with the air surrounding the shielding device through at least one sound channel (19). According to the invention, a shielding device (10) is obtained, which protects the user very efficiently against electromagnetic radiation transmitted by the radio transmission means (1) when it has been fixedly arranged on said radio transmission meams opposite the loudspeaker while it simultaneously allows sound from the loudspeaker to pass without causing a noticeably deterioration of the sound quality. The invention relates furthermore to a hand-held mobile radio transmission means (1), such as a mobile phone, and which has been provided with a shielding device (10).

Claims

1. A shielding device to be fixedly arranged on a hand-held mobile radio transmission means (1), such as a mobile phone, and which protects a user against electromagnetic radiation from said radio transmission means (1) when said radio transmission means is used, and where said shielding device (10) comprises at least one substantially plane shielding member (12) made of metal, characterised in that the metal is a nickel alloy, especially mu-metal, and that the shielding member (12) at least partially defines an acoustic resonance chamber (18) communicating with the air surrounding the shielding device through at least one sound channel (19).

2. A shielding device as claimed in claim 1, characterised in that the sound channel (19) extends substantially at least approximately parallel to a substantially plane wall in the shielding member (12).

3. A shielding device as claimed in claim 1 or 2, characterised in that the side of the shielding member (12) of nickel alloy facing the radio transmission means (1) is coated with at least one layer of electromagnetically absorbing foam material (13), which at least partially forms defining walls for the resonance chamber (18) as well as for the sound channel (19).

4. A shielding device as claimed in claim 3, characterised in that the electromagnetically absorbing foam is polyurethane foam.

5. A shielding devices claimed in claim 3 or 4, characterised in that the electromagnetically shielding foam layer (13) is secured to the shielding member (12) of nickel alloy by means of an adhesive, such as a modified acrylic adhesive, whereas the opposite side of said foam layer (13) is coated with a layer of auxiliary adhesive which in turn is covered by a detachable cover layer (14), such as silicone paper.

6. A shielding device as claimed in one or more of the preceding claims 1 to 5, characterised in that the resonance chamber (18) is of a substantially elliptical shape according to a sectional view in a direction parallel to the shielding member (12) made of nickel alloy, preferably in a ratio b/a less than 0.5, especially less than 0.3, a representing the major axis of the ellipse and b representing the minor axis of said ellipse.

7. A shielding device s claimed in one or more of the preceding claims, characterised in that the shielding member (12) of nickel has been subjected to a surface treatment with an alkyd-based metal lacquer.

8. A shielding device as claimed in one or more of the preceding claims, characterised in that the plate-shaped shielding member (12) of nickel alloy is elliptic and coated with a layer of plastics (11), such as resin, on the side facing the user.

9. A shielding device as claimed in claim 8, characterised in that a metal foil is embedded in the plastic layer (11).

10. A hand-held mobile radio transmission means (1), such as a mobile phone, and which is provided with the shielding device (10) as claimed in one or more of the claims 1 to 9, and where said shielding device (10) is fixedly mounted opposite a loudspeaker (4) built into the radio transmission means.

11. A radio transmission means as claimed in claim 10, characterised in that the shielding device (10) is secured, preferably by way of sticking, to the outer side of the cabinet (2) of said radio transmission means.

12. A radio transmission means as claimed in claim 10, characterised in that the shielding device (10) is secured inside the cabinet (2) of the radio transmission means.

13. A radio transmission means as claimed in claim 11, characterised in that the outer side of the cabinet (2) of the radio transmission means represents a defining wall of the resonance chamber (18).