GB2379576A

GB2379576A - Backlighting arrangement for a communication unit

Info

Publication number: GB2379576A
Application number: GB0121879A
Authority: GB
Inventors: Michael John Roper
Original assignee: Sendo International Ltd
Current assignee: Sendo International Ltd
Priority date: 2001-09-11
Filing date: 2001-09-11
Publication date: 2003-03-12
Anticipated expiration: 2021-09-11
Also published as: GB2379576B; GB0121879D0

Abstract

The backlighting light source 32 or illumination means of a communication unit is located in a detachable, decorative cover part 16 of the communication unit. The cover part 16 is attachable to a core part 14 of the communication unit to provide a completed communication unit 10. The communication unit 10 may, for example, be a mobile telephone, mobile radio or portable radio. The light source 32 is arranged to illuminate one or more items, for example a display 12 and/or keypad, in the core part 14 of the communication unit 10.

Description

COMMUNICATION UNIT Field of the Invention This invention relates to communication units with light sources for illuminating one or more items of the communication units.

Background of the Invention In the field of this invention it is known for communication units or devices, such as mobile telephones, mobile radios and portable radios, to require illumination means in order to improve the visibility of, for example, displays, such as liquid crystal displays (LCDs), and/or keypads.

It is also known for such illumination means to be embedded within the device and mounted on a printed circuit board (PCB) of the device. The PCB may be the main PCB of the device or an ancillary PCB that may or may not be dedicated to the illumination means.

However, this known prior art has the disadvantage that during manufacture of the device, the illumination means is incorporated at a relatively early stage, when the respective PCB is produced. It is therefore difficult for the illumination means to be altered at a later stage.

A further disadvantage of this known prior art is that once the device has reached the customer, it is not susceptible to the customer changing the illumination means to suit their own requirements and/or preferences.

A need therefore exists for a more flexible way of providing illumination means.

Statement of Invention The present invention provides or locates the light source or illumination means of a communication unit in a cover part of the communication unit. The cover part is attachable to a core part of the communication unit to provide a completed communication unit.

In a first aspect, the present invention provides a communication unit as claimed in claim 1.

In a second aspect, the present invention provides a cover for a core part of a communication unit, as claimed in claim 23.

In a third aspect, the present invention provides a set of covers, as claimed in claim 31.

In a fourth aspect, the present invention provides a set of covers, as claimed in claim 32.

In a fifth aspect, the present invention provides a core part of a communication unit, as claimed in claim 39.

Further aspects are as claimed in the dependent claims.

The expression"cover part"encompasses or extends to "cover","casing","enclosure"etc. The expression"core part"encompasses or extends to"module part","main part","primary function part"etc.

Brief Description of the Drawings Exemplary embodiments of the present invention will now be described, with reference to the accompanying drawings, in which: Figure 1 shows a mobile telephone ; Figure 2 shows a core part and a two-part cover part from which the mobile telephone of Figure 1 is constituted ; Figure 3 shows a prior art arrangement for illuminating a display of a mobile telephone; Figure 4 shows an arrangement for illuminating a display of a mobile telephone where a light source is in a cover part of the mobile telephone; Figure 5 shows the arrangement of Figure 4 with the cover part attached to the core part of the mobile telephone;

Figure 6 schematically illustrates a keypad of a mobile telephone ; Figures 7 and 8 show an arrangement for illuminating a keypad of a mobile telephone; and Figures 9 and 10 show another arrangement for illuminating a keypad of a mobile telephone.

Description of Preferred Embodiments The invention will be described in terms of exemplary embodiments in which the invention is embodied in a mobile telephone. However, it will be appreciated that the invention may be embodied in other types of communication units, for example mobile radios and portable radios.

Figures 1 and 2 illustrate a mobile telephone 10. Figure 2 is an illustration of the mobile telephone 10 in a partially disassembled condition.

The mobile telephone 10 has a module part (i. e. core part) 14 and a front cover 16, which is preferably a detachable cosmetic cover. For the illustrated embodiment it can be seen in Figure 2 that the mobile telephone also has a detachable rear cover 18. The front and rear covers together can be considered as a two-part cover part.

When the telephone is assembled, the front and rear covers 16,18 substantially enclose the module part 14 of the mobile telephone 10. Preferably the front and rear covers 16,18 have means to cooperate with one another in order to detachably retain the two covers 16,18 in position relative to one another when the mobile telephone is assembled.

The module part 14 of the mobile telephone may be capable of being detachably retained in position relative to the front cover 16 and/or the rear cover 18 when the mobile telephone 10 is assembled.

The module part 14 comprises a display 12, for example a liquid crystal display (LCD), an antenna 20, transceiver means (not shown), electronic circuitry (not shown) for controlling the functionality of the mobile telephone 10, the LCD 12, user interaction means in the form of a keypad 22, and other means necessary for the mobile telephone 10 to function.

The front cover 16 comprises protection means 24 as known in the art, which can be in the form of a transparent material that extends over the LCD 12 when the mobile telephone 10 is assembled, protecting the LCD 12 from being damaged, whilst allowing a user to view the LCD 12.

Figure 3 illustrates a prior art method of illuminating an LCD 12 that is mounted on a PCB 26. One or more light emitting diodes (LEDs) 28, also mounted on the PCB 26 are used to provide light when the LCD 12 requires

illumination. A light guide 30 redirects light from the LEDs 28, under the LCD 12 and allows it to pass through the LCD 12 in the direction A so that a user can more easily discern the image being displayed by the LCD 12.

A disadvantage of this method of illuminating the LCD 12 is that during manufacture of the device, the LEDs 28 are incorporated at a relatively early stage, when the PCB 26 is produced. It is therefore difficult for the LEDs to be altered at a later stage.

A further disadvantage of this known prior art is that once the mobile telephone has reached the customer, it is not susceptible to the customer changing the type of illumination to suit his or her own requirements and/or preferences.

Figure 4 illustrates a method of illuminating the LCD 12 according to the present invention. As with the prior art illustrated in Figure 3, the LCD 12 is mounted on the PCB 26. The PCB 26 is preferably the main PCB for the mobile telephone 10. However, it could alternatively be an ancillary PCB that may or may not be dedicated to the LCD 12.

A light source serving as illumination means is mounted in the front cover 16 of the mobile telephone 10. The illumination means may be of any type known in the art, for example one or more LEDs. For the purposes of the illustrated embodiment, the illumination means will be

described with reference to LEDs 32 providing the illumination means.

Preferably any electrical circuitry 34 required to drive the LEDs 32 is also provided in the front cover 16. In this way the illumination means is self-contained in the cover, requiring only power and where necessary control signals. However, such circuitry could alternatively be provided within the module part 14.

The illumination means and/or driver circuitry is connected to contacts 36, which make contact with respective opposing contacts 38 mounted on the PCB 26 within the module part 14. The opposing contacts 38 could alternatively be mounted on a PCB separate to that on which the LCD is mounted, however it is preferred that the two be mounted on the same PCB 26.

Alternatively still, it will be appreciated that the opposing contacts 28 need not be mounted directly onto a PCB, but rather may be mounted on any part of the module part 14 of the mobile telephone 10 and connected by any known means to the PCB 26.

The LEDs 32 are located in the front cover 16 such that light from the LEDs is guided by light guide means 40 to illuminate the LCD 12. The light guide means 40 is preferably mounted within the module part 14. However, they may alternatively be provided in part or in whole in the front cover 16. The light guide means 40 may comprise any form of light guide known in the art, such as a

diffuser or light pipe with a coupling aperture, a prism or a combination thereof.

Figure 5 is an illustration of the regions of the module part 14 and front cover 16 adjacent to the LCD 12 when the mobile telephone 10 is in the assembled condition.

As can be seen, the respective contacts 36,38 make contact with one another to provide power and where necessary control signals to the driver circuitry 34. The LEDs 32 are located substantially adjacent the light guide 40, which guides the light behind the LCD 12 and then through the LCD 12 in the direction A.

Thus, a user is able to view the image displayed by the LCD 12 through the protection means 24.

An advantage of this aspect of the present invention is that the module part 14 of the mobile telephone 10 can be manufactured in its entirety, with the front and rear covers 16,18 being manufactured separately. This allows a variety of front covers to be produced, each having different characteristics, such as different illumination means, which may differ in the amount of light they produce, the colour of light they produce etc. The type of illumination means may also differ.

Thus, during the manufacture of the mobile telephone 10, the illumination means can be chosen at a late stage, simply by selecting a front cover 16 with the required

illumination means, without affecting the manufacturing of the module part 14.

A further advantage is that once the mobile telephone 10 reaches the customer, the customer can easily change the illumination means to suit their own requirements/preferences by buying a front cover 16 that has the appropriate illumination means.

A second embodiment of the present invention is to provide a method of illuminating the keypad 22 of the mobile telephone 10.

Figure 6 illustrates a layout of key contacts 42 and illumination means such as LEDs 44 mounted on a PCB 46 (Figure 7). Also illustrated are keys 48, shown as broken lines, which in use are located generally above the key contacts 42.

Figure 7 is a cross-sectional illustration between points A and B in Figure 6 of a prior art method of illuminating a keypad. The keys 48 form part of a key mat 50, which is capable of elastic deformation at least in the regions of the keys 48, or the regions adjacent the keys 48.

In use, the keys 48 extend through apertures 62 in a cover 60 of the device of which the keypad forms a part.

Protrusions 52 depend from the keys 48 substantially to domes 54 located over the key contacts 42, such that when one of the keys 48 is depressed, the respective

protrusion 52 push down on the respective dome 54, which is made of a conductive material. As the dome 54 is pushed down, it creates a conductive path between the contacts 54, creating a circuit.

A light guide 56 is located between the PCB 46 and the key mat 50. The light guide comprises a recess located over the LED 44, and partially receives the LED 44 therein. Apertures 58 in the light guide 56 accommodate the protrusions 52, and allow them to pass there through.

The light guide 56 may be made from any suitable known material, for example glass or plastic, and in use receives light from the LED 44 and guides it to the apertures 58.

The protrusions 52 are at least partially transparent, such that at least part of the light from the light guide 56 is redirected along the protrusion 52. At least a part of each key 48 is at least partially transparent such that some of the light directed along the protrusion 52 radiates from the at least partially transparent part of the key 48. Thus the keypad is illuminated.

An alternative prior art method of illuminating a keypad is illustrated in Figure 8. Where this method differs from the previous method illustrated in Figure 7 is that instead of using a light guide of the type described above and shown in Figure 7, the LED 44 and contacts 42 are located within a light guide formed by a substantial chamber 64. Preferably the inner surface 68 of the upper

wall 66 of the chamber 64 is at least partially reflective, such that light from the LED 44 is reflected around the chamber 64.

In this way, when the light from the LED 44 reaches the protrusions 52, which extend through apertures 70 in the upper wall 66 of the chamber 64, some of the light is redirected along the protrusions 52 in the same way as for the example illustrated in Figure 7.

Figure 9 illustrates the present invention being applied to the method illustrated in Figure 7. Relating Figure 9 to the mobile telephone 10 of Figure 1, an LED 72 is provided within the front cover 16, which extends through an aperture 78 in the key mat 50. A light guide 74, similar to that of Figure 7, is provided between the key mat 50 and the PCB 46. A recess 76 is provided in the top of the light guide 74, in which at least a part of the LED 72 is received.

As for the prior art method illustrated in Figure 7, light from the LED 72 is guided from the LED 72 by the light guide 74 towards the protrusions 52.

Figure 10 illustrates the present invention being applied to the method illustrated in Figure 8. As for Figure 9, the LED 72 is provided within the front cover 16 of the mobile telephone 10. A light guide comprising a substantial chamber 80, similar to that of Figure 8, comprises an aperture 86 through which the LED extends in use. Light from the LED is reflected off an inner surface

84 of an upper wall 82 of the chamber, towards the protrusions 52.

Contacts (not shown) for the LED 72 and respective opposing contacts (not shown) provided on the module part 14 of the telephone 10 may be located at any convenient position. Driver circuitry for the LED may also be provided in the front cover 16 if required.

It will be appreciated that the variations for the first embodiment of the present invention apply to this second embodiment, and that the advantages provided by the first embodiment of the present invention are also provided by the second embodiment.

The general concept behind the present invention may be applied to illumination means for any communication unit or device where there is a removable cover.

In the illustrated embodiment, the mobile telephone 10 comprises both a front and a rear cover 16,18. The present invention may be implemented on devices that only have a front cover.

Alternatively, the illumination means could be provided on the rear cover 18, with the light guide means 40 guiding the light from the rear of the module part 14 to the required location. Under such circumstances, it will be appreciated that only a rear cover 18 would be required.

For the fist and second aspects of the present invention, a single illumination means could be provided on the cover, with light guide means guiding the light from the illumination means to both the LCD and the keypad.

In the above embodiments the communication unit is a mobile telephone, with a core part, plus detachable covers, more particularly a front cover and a back cover, which in the examples described may be considered as a two-part cover part. The covers are preferably intended for and adapted to be easily attached or removed from the core part, allowing end-users to replace or select covers. In this case the invention advantageously allows the end-user to include a choice of one or more light source characteristics in his considerations when choosing or selecting between particular covers, for example according to the user's mood or activity to be engaged upon (e. g. business or leisure).

Furthermore, this allows a supplier at any level in the commercial supply chain of the communication unit to endusers to select light source characteristics according to any reason. By way of example, particular possibilities include co-coordinating or in some other way associating the colour of output light from the light source with either or both of: (i) The colour, visual design or appearance of the cover, e. g. a red light with a red-based cover design, and (ii) Some association or co-ordination with a supplier, or network provider, who is to provide for

example cellular communication service to a particular mobile telephone or end-user (e. g. mobile telephones to be used on the Orange network may be provided with light sources providing orange coloured output light).

However, the present invention may also be implemented for communication units where cover parts are fitted during manufacture or before supply to end-users, as this allows the manufacturing or assembly process to be more flexible in that common core parts of the communication units may be manufactured for assembly with different light output types of covers.

In the above description, a mobile telephone or other communication unit is described as comprising a core part and a cover part (and the cover part may itself comprise two or more parts). However, due to the large number and types of mobile telephones and other communication units currently available, different terminology may be encountered for the items referred to as core parts and cover parts in the above description. Merely by way of example, cover parts may also be referred to as a casing or casing part, an enclosure, and so on, and a core part may also be referred to as a module part, a main module, a main part, a primary function part, a main body, and so on.

Moreover, the exact criterion for determining what is or is not a cover part of a communication unit will depend on the exact nature of a particular communication unit,

and as such cannot be defined simply in an absolute sense for all situations.

Nevertheless, it will be appreciated that for any particular communication unit, characteristics of an external attachable part that tend to support the considering of that external part as a cover part include one or any combination of the following: (i) The external attachable part is required to complete the communication unit, at least in the eyes of the end-user ; (ii) When the cover part is attached to the core part, the cover part provides substantial physical support and/or protection for at least some of the core part; (iii) When the cover part is attached to the core part, the cover part provides substantial physical support and/or protection to substantially all of the core part; and (iv) When the cover part is attached to the core part, the cover part substantially surrounds the core part.

For the sake of clarity, it is noted that, in contrast, an item that primarily functions or is intended as an external light for shining light on to the external surface of a communication unit is not to be considered

as a cover part in the sense of this specification or invention, even if it may be attached to a communication unit, particularly if it does not substantially display any of the characteristics (i) to (iv) listed in the preceding paragraph.

Claims

Claims 1. A communication unit, comprising: a core part comprising one or more items to be illuminated; a cover part for attaching to the core part ; a light source ; a light guide; the light source and the light guide being arranged such that, in operation with the cover part attached to the core part, light from the light source is substantially guided by the light guide to the one or more items to be illuminated ; wherein the light source is located in the cover part.
2. A communication unit according to claim 1, wherein, when the cover part is attached to the core part, the cover part provides substantial physical support and/or protection for at least some of the core part.
3. A communication unit according to claim 2, wherein, when the cover part is attached to the core part, the cover part provides substantial physical support and/or protection to substantially all of the core part.
4. A communication unit according to any preceding claim, wherein, when the cover part is attached to the core part, the cover part substantially surrounds the core part.

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5. A communication unit according to any preceding claim, wherein the cover part is a front cover.
6. A communication unit according to any of claims 1 to 4, wherein the cover part is a back cover.
7. A communication unit according to any of claims 1 to 4, wherein the cover part comprises two parts separably attachable to the core part.
8. A communication unit according to claim 7, wherein the two parts are a front cover and a back cover respectively.
9. A communication unit according to any preceding claim, wherein the cover is adapted to be readily removed and attached to the core part by an end-user of the communication unit.
10. A communication unit according to any preceding claim, wherein the light guide is such as to substantially re-distribute the light from the light source compared to if the light guide was not included.
11. A communication unit according to any preceding claim, wherein the light guide is any one or any combination of: (i) a diffuser ; (ii) a light pipe with a coupling aperture ; (iii) a prism;

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(iv) a light chamber.
12. A communication unit according to any preceding claim, wherein the light guide is located in the core part.
13. A communication unit according to claim 12, wherein the light guide is located internally in the core part.
14. A communication unit according to any preceding claim, wherein the light guide comprises a first part located in the core part and a second part located in the cover part.
15. A communication unit according to claim 14, wherein the first part of the light guide is located internally in the core part.
16. A communication unit according to any preceding claim, wherein the light guide is located in the cover part.
17. A communication unit according to any preceding claim, wherein the light source comprises one or more light emitting diodes.
18. A communication unit according to any preceding claim, further comprising circuitry for driving the light source, the circuitry being located in the cover part.

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19. A communication unit according to any of claims 1 to 17, further comprising circuitry for driving the light source, the circuitry being located in the core part.
20. A communication unit according to any preceding claim, wherein the one or more items to be illuminated comprises a display.
21. A communication unit according to any preceding claim, wherein the one or more items to be illuminated comprises a keypad.
22. A communication unit according to any preceding claim, wherein the communication unit is one of a mobile telephone, a portable radio, or a mobile radio.

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23. A cover for attaching to a core part of a communication unit, comprising a light source arranged to provide light to an item of the core part of the communication unit when the cover is attached to the core part of the communication unit.
24. A cover according to claim 23, wherein the cover is a front cover for the communication unit.
25. A cover according to claim 23, wherein the cover is a back cover for the communication unit.
26. A cover according to any of claims 23 to 25, adapted to be readily removed and attached to the core part of the communication unit by an end-user.
27. A cover according to any of claims 23 to 26, further comprising a light guide arranged to guide light from the light source to the core part of the communication unit.
28. A cover according to any preceding of claims 23 to 27, wherein the light source comprises one or more light emitting diodes.
29. A cover according to any of claims 23 to 28, further comprising circuitry for driving the light source.
30. A cover according to any of claims 23 to 29, wherein the cover is adapted for attaching to one of the

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following: a mobile telephone, a portable radio, or a mobile radio.
31. A set of covers, each according to any of claims 23 to 30, wherein each cover of the set of covers is visually different.
32. A set of covers, each according to any of claims 23 to 30, wherein each cover of the set of covers has a different light source characteristic.
33. A set of covers according to claim 32, wherein the different light source characteristic comprises a different type of light source.
34. A set of covers according to claim 32 or 33, wherein the different light source characteristic comprises a different brightness level of output light.
35. A set of covers according to any of claims 32 to 34, wherein the different light source characteristic comprises a different colour of output light.
36. A set of covers according to any of claims 32 to 35, wherein each cover of the set of covers is visually different.
37. A set of covers according to claim 36, wherein the visual difference between each cover comprises colour design differences.

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38. A set of covers according to claim 37 when dependent from claim 35, wherein the output light colour of the light source of each cover of the set of covers is selected in association with the colour design of the respective cover.
39. A core part of a communication unit, comprising: one or more items to be illuminated; wherein the core part adapted for the one or more items to be illuminated by light from a light source located in a cover part attachable to the core part.
40. A core part of a communication unit according to claim 39, wherein the communication unit is adapted such that the cover is readily removed and attached to the core part of the communication unit by an end-user.
41. A core part of a communication unit according to claim 39 or 40, further comprising a light guide for guiding, when the cover part is attached to the core part, light from the light source of the cover part to the one or more items to be illuminated.
42. A core part of a communication unit according to claim 41, wherein the light guide is such as to substantially re-distribute the light from the light source compared to if the light guide was not included.
43. A core part of a communication unit according to claim 41 or 42, wherein the light guide is any one or any combination of:

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(i) a diffuser; (ii) a light pipe with a coupling aperture; (iii) a prism ; (iv) a light chamber.
44. A core part of a communication unit according to any of claims 39 to 43, further comprising circuitry for driving the light source.
45. A core part of a communication unit according to any of claims 39 to 44, wherein the one or more items to be illuminated comprises a display.
46. A core part of a communication unit according to any of claims 39 to 45, wherein the one or more items to be illuminated comprises a keypad.
47. A core part of a communication unit according to any of claims 39 to 46, wherein the communication unit is one of a mobile telephone, a portable radio, or a mobile radio.
48. A communication unit substantially as hereinbefore described with reference to the accompanying drawings.
49. A cover for attaching to a communication unit substantially as hereinbefore described with reference to the accompanying drawings.

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50. A core part of a communication unit substantially as hereinbefore described with reference to the accompanying drawings.