WO2002017600A2

WO2002017600A2 - Shield for mobile phones

Info

Publication number: WO2002017600A2
Application number: PCT/DK2001/000487
Authority: WO
Inventors: Ulf Nilsson; Frank Sørensen
Original assignee: Individual
Current assignee: Individual
Priority date: 2000-08-24
Filing date: 2001-07-12
Publication date: 2002-02-28
Anticipated expiration: 2003-02-24
Also published as: WO2002017600A3; AU2001278414A1

Abstract

A shield for protection against harmful radiation transmitted towards or emitted from a mobile phone (15) or a wireless telephone is configured as a laminate (3a, 3b, 3c, 3d), which consists of at least one plastic layer (3a), such as a layer of ABS plastic, PVC or resin plastic. On the outside of the plastic layer there is at least one layer of metal (3a, 3b, 3c), preferably three layers which are cu, zn and cr. The shield (1, 11) can be mounted on the antenna (14) of the mobile phone (15) or a wireless telephone. It can be configured in two parts (2, 3), where the one part (2) consists of a plate part (2) with a snap-lock (4) for clipping on to a mobile phone (15), in that the outwardly-extending plate part has longitudinal grooves (7a, 7b) which are arranged to co-operate with the edge parts (8a, 8b) of a second plate part (3). In a preferred embodiment, the shield is configured as one part (11) which consists of a plate part (12) with arcuate dimensions, corresponding to the outer dimensions of an antenna (14) on a mobile phone (15) or wireless telephone, in that from the one end of the plate part, two projecting lobes (13a, 13b) are provided which can grip around the antenna (14). With the invention, a shield is provided, which gives a reduction in the GSM 900 band, expressed in SAR (specific absorption rate), of approx. 97 % compared with the radiation, which is measured without a shield according to the invention.

Description

Shield for mobile phones

The invention concerns the shielding of radiation from mobile phones or wireless telephones, and of the kind where the shield is placed in the proximity of the mobile phone's antenna, so that the strength of the radiation which comes to and from the mobile phone's antenna is reduced towards the head of the user.

Over the last decade, the use of mobile phones has become so widespread that today they must be considered to be owned by everyone, understood in the way that mobile phones to a wide extent are possessed by individual persons, as opposed to traditional fixed-net phones where several people share the same telephone. Among other things, this means that the amount of communication which is transferred via mobile phones is constantly increasing, partly because of the increased number of phones which are in operation, and partly because it is possible for the phones to be used from any conceivable place and at any conceivable time.

Among researchers, the very great prevalence of mobile phones has resulted in focus being placed on whether the use of the phones over longer periods can involve a health risk for the users, in that the phones emit and receive radio waves which unavoidably come quite close to the user's head when communication is taking place.

Some researchers are of the opinion that the radio waves, which stem from the mobile phones can, after long-time use, cause injury to the users' DNA and perhaps even cause cancer ailments.

Therefore, it is quite natural that research is conducted into the reduction of this radio radiation, which stems from mobile phones, but such that their ability to receive and transmit is not influenced hereby. US patent no. 5,826,201 describes a shield for a mobile phone of the kind disclosed in the preamble to claim 1.

According to the US patent, the shield is produced as a thin plate, which can be of metal or an electrically-conductive plastic, i.e. a plastic containing metal.

It is now an object of the invention to construct a shield, which is easy to configure while maintaining effective shielding characteristics.

The object of the invention is achieved by a shield of the type disclosed in the preamble to claim 1 , which is characterised in that the shield is configured as a laminate, where at least one layer consists of plastic which is coated with at least one layer of metal.

In this way, it becomes relatively easy to configure the shield with subsequent application of one or several metals.

It is expedient for use to be made of plastic materials as disclosed in more detail in the claims 2 and 3, i.e. ABS plastic, PVC or resin plastic.

As disclosed in the claims 3 and 4, two or three layers can be applied to the plastic layer for additional strengthening of the effect of the shield and, as disclosed in claim 6, if the three layers consist of cu copper, zn zinc and of cr chrome, tests have shown that a shield is achieved which provides a distinct reduction of radio radiation in the GSM 900 band.

Expressed in SAR (specific absorption rate), the reduction is approx. 97% in relation to that radiation which is measured without the shield according to the invention. Other metals can naturally also form part as lamination layers for the shield according to the invention, of which, as disclosed in claim 7, gold au is a possibility.

The plastic layer can expediently be formed by injection moulding as disclosed in claim 8.

Expedient configurations of the shield are disclosed in claim 9, i.e. that it is configured with a snap-lock for clipping on to the mobile phone or the antenna of the wireless telephone, and where the snap-lock extends from a first plate part which has grooves which are arranged to co-operate with edge parts on a second plate part.

It is preferably configured as in claim 10, in that it is configured as a plate part which has rounded-off dimensions which correspond to the outer dimensions of the antenna of a mobile phone or wireless telephone, and where in its one end the plate part has two outwardly-projecting lobes which are arranged to grip around the antenna of the mobile phone or wireless telephone.

In this way an extremely effective and, from the point of view of production, an extremely advantageous shield is provided.

In the following, the invention will be explained in more detail with reference to the embodiments shown in the drawing, in which

fig. 1 shows the shield in a first embodiment,

fig. 1 a shows on a larger scale how a part of the shield is built up,

fig. 2 shows the shield in fig. 1 separated, fig. 3 shows the shield in a second embodiment,

fig. 4 shows the shield in a third embodiment,

fig. 5 shows the shield according to fig. 4 mounted on the antenna of a mobile phone, seen from the front of the mobile phone, and

fig. 6 shows the shield according to fig. 4 mounted on the antenna of a mobile phone, seen from the rear of the mobile phone.

In figs. 1 and 2, the reference figure 1 indicates a shield for mounting on an antenna of a not-shown mobile phone or similar communication arrangement such as a wireless telephone, a walkie-talkie, a wireless headset etc.

As will be seen, it consists of two plate parts 2, 3, where the first 2 plate part is arranged to be fastened to the second 3 plate part, in that the first plate part 2 has grooves 7a, 7b along its outer edge in which edge parts 8a, 8b on the second plate part 3 can engage.

On the side of the first plate part 2 which faces towards the second plate part 3 when they are locked together, there is a locking element which consists of two straight pieces 6a, 6b which extend out from the first plate part 2 and end in two arcuate parts 5a, 5b, which in turn form a slot 16 between them.

The shield in figs. 1 and 2 is used on a mobile phone in the following manner: The arcuate parts 7a, 7b are pushed down over the antenna of a mobile phone, where the shield is held fast due to the spring effect from the arcuate parts 5a, 5b with the slot 16.

The shield is mounted on the antenna of the mobile phone so that the outer side of the second plate 3 comes to face towards the ear of the user when the mobile phone is used.

Hereafter, the construction of the plate part 3 will be explained in more detail.

As will be seen in section in fig. 1a, the second plate part 3 is built up as a laminate 3a, 3b, 3c and 3d, which consists of the following layers:

Innermost, indicated at 3a, there is a plastic layer, which, e.g., can be ABS plastic, a PVC or a resin plastic or other plastic, which is applicable for the purpose. On all surfaces on the outside of the plastic layer a metal layer 3b is applied, which e.g. can be a layer of copper.

Around this copper layer a further layer of metal 3c is applied, which can e.g. consist of a layer of zinc.

Finally, around the zinc layer a layer of chrome 3d can be applied.

With this building-up of layers, a shield is provided, which can suppress radiation in the microwave range, e.g. at approx. 0.930 GHz, from a mobile phone's antenna towards a user's head by up to approx. 97% as compared to that when no shield is mounted on the mobile phone's antenna. Although it is specifically explained above which layers are preferably desired to be used, there is nothing to prevent use being made of other layer compositions, both with regard to number and type.

The decisive aspect is that at least one plastic layer is used, on which one or more metal layers are applied.

In fig. 3 a second embodiment of the shield according to the invention is seen. In this figure, the shield is indicated in its entirety by the reference number 11.

As will be seen, this shield also consists of a plate part 3 which can have the same configuration as the plate part according to figs. 1 and 2.

On its internal arcuate side, a locking part 9 is provided, which is configured as a plate with an arcuate part 10.

The shield according to this embodiment is mounted on a mobile phone's antenna simply by sliding it down over the mobile phone's antenna so that it comes to lie in the arcuate part 10, which exercises a certain force against the antenna.

In fig. 4 a third embodiment is seen, which, like the embodiment according to fig. 3, is configured in one piece, and which is indicated in its entirety at 11. As will be seen, it consists of a plate part 12, which at its lowermost end has projecting lobes 13a, 13b, which are terminated by a slot 16.

The plate part 12 and the lobes 13a, 13b are internally arcuate so that the parts fit the antenna of a mobile phone. The mounting of this shield part is effected either by sliding the shield part down over the mobile phone's antenna, or by pressing the shield part against the antenna so that the lobes, due to their spring effect, are spread and then exercise a pressure against the antenna when the shield is mounted.

Finally, in figs. 5 and 6 a mobile phone 15 is seen with a shield arrangement as shown in fig. 4 mounted on its antenna.

Although the invention is explained in connection with mobile phones, within the framework of the patent claims, there is nothing to prevent the use of the invention in other connections where protection against radiation from the antennae of transmission and/or receiving equipment is desired.

Claims

C L A I M S

1. Shielding of radiation from mobile phones or wireless telephones, and of the kind where the shield (1 , 11 ) is placed in the proximity of the mobile phone's antenna (14), so that the strength of radiation which is received by or emitted from the mobile phone's antenna is reduced towards a user's head, characterized in that the shield is configured as a laminate (3a, 3b, 3c, 3d), where at least one layer (3a) consists of plastic to which at least one layer of metal (3b, 3c, 3d) is applied.

2. Shield according to claim 1 , characterized in that the plastic layer (3a) consists of ABS plastic.

3. Shield according to claim 1 , characterized in that the plastic layer (3a) is PVC or a resin plastic.

4. Shield according to claim 1 - 3, characterized in that on the outside of the plastic layer, two layers of metal (3a, 3b) are laminated.

5. Shield according to claim 1 - 3, characterized in that on the outside of the plastic layer, three layers of metal (3a, 3b, 3c) are laminated.

6. Shield according to claim 5, characterized in that the three metal layers (3a, 3b, 3c) are cu, zn and cr.

7. Shield according to claim 1 - 5, characterized in that one of the metal layers (3a, 3b, 3c) is gold.

8. Shield according to claim 1 - 6, characterized in that the plastic layer (3a) is produced by injection moulding.

9. Shield according to claim 1 - 8, characterized in that it is configured with a snap-lock (4) for clipping on to a mobile phone or the wireless telephone, and where the snap-lock (4) extends from a first plate part (2) which has grooves (7a, 7b) which are arranged to co-operate with edge parts (8a, 8b) on a second plate part (3).

10. Shield according to claim 1 - 8, characterized in that it is configured as a plate part (12) which has arcuate dimensions which correspond to the outer dimensions of the antenna of a mobile phone or wireless telephone, and where at its one end the plate part (12) has two projecting lobes (13a, 13b) which are arranged to grip around the antenna (14) of the mobile phone (15) or the wireless telephone.