DESCRIPTION OF THE RELATED ART Many current mobile telephones make use of a hinged cover, or"flip", to enable the size of the telephone to be kept desirably small and to protect the display and keypad of the telephone when not in use.

Similarly, portable computers/electronic organisers make use of hinged cases to enable a small size of device to be produced, as well as to provide protection for display and keypad components.

However, previously considered hinge assembly designs do not readily allow a mobile telephone to include portable computer/electronic organiser functions, whilst retaining the small size and ability to protect components of current separate mobile telephones and organisers.

SUMMARY OF THE PRESENT INVENTION According to a first aspect of the present invention, there is provided an electronic device comprising a first housing and a second housing which is mounted on the first housing by way of a hinge assembly, wherein the hinge assembly comprises: first and second cooperating parts attached to the first and second housings respectively, the second part being rotatably and slidably engaged with the first part, such that the second housing is rotatable with respect to the first part, about an axis from the closed position to a first open position of the device, and such that the second

housing is linearly movable, with respect to the first housing, in a direction parallel to the axis, with respect to the first housing, from a closed position of the device to a second open position of the device.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a mobile telephone including a hinge assembly embodying one aspect of the present invention, in a closed position; Figure 2 shows the mobile telephone of Figure 1 in a first open position; Figure 3 shows the mobile telephone of Figure 1 in a second open position; Figures 4 and 5 show perspective and end views respectively of a first housing of the telephone of Figure 1; Figures 6 and 7 show perspective and end views respectively of a second housing of the telephone of Figure 1; Figure 8 shows a side elevation of the housing of Figures 6 and 7; Figure 9 shows a partial end cross-sectional view of the housings of the telephone of Figure 1.

DETAILS OF THE DESCRIPTION OF THE PREFERRED EMBODIMENT A mobile telephone 1 is shown in Figure 1 in a closed position, and comprises first and second housings 2 and 4 which are movably attached to one another by way of a hinge assembly 12.

In this example, the first housing 2 carries a battery 10 and an antenna 14. The second housing member carries a keypad 6 for user input, and a microphone 8.

In the closed position shown in Figure 1, the second housing 4 covers the whole of an upper face of the first housing 2, and is held in place by way of a

clip 16. In this condition, the telephone is sealed, and the internal components of the telephone are protected from damage.

A first open position of the telephone is shown in Figure 2, in which the telephone has the usual functions of a mobile telephone, ie. sending and receiving telephone calls. To enable such use, the second housing, or cover, 4 is moved along the housing 2, so that a telephone display 9, and a loudspeaker 7 are revealed for use in conventional manner by the user of the telephone. In one embodiment of the invention, the movement of the cover 4 can automatically cause the telephone to answer an incoming call, or to be put into a dialling mode (ie. an"off-hook"condition).

Figure 3 shows a second open position of the telephone, in which the cover 4 has been opened, from the closed position of Figure 1, about the hinge assembly 12, to reveal fully the display 9 carried by the main housing 2. The cover 4 can carry on its inner surface an input device, for example a touch sensitive scribble pad, to enable a user of the device to input data. In the example shown, speakers 18 and 19 are provided in the main housing 1 for relaying audio information to the user. In this second open position, the mobile telephone can be used as a portable computer/electronic organiser. For example, the input device can be used to input text for downloading to an office computer, or the device could be used to send facsimile message by making use of the mobile telephone functions.

The hinge assembly 12 is shown in greater detail in Figures 4 to 9.

Referring to Figure 4 and 5, the first housing 2 of the telephone carries a first part 121 of the hinge assembly 12. This first part 121 extends along at least part of one side edge region of the housing 2 by

way of a connecting portion 124. The first part 121 curves from the front edge region towards the rear edge region of one side of the telephone, thereby defining a <BR> <BR> <BR> <BR> curved internal surface 125. The curved surface 125 is for engagement with a second part of the hinge as will be described below.

The curved surface 125 carries a number of contacts 241 for providing power and function control for the telephone. The contacts are intended to connect with corresponding contacts on the second part of the hinge assembly 12.

Figure 6 shows a perspective view of the second housing 4, and Figure 7 shows an end view thereof. The second housing 4 carries a substantially cylindrical elongate second part 122 which forms the hinge pin of the hinge assembly 12. The second part 122 extends along on edge region of the second housing 4, and defines a curved external surface for engagement with the curved internal surface of the first part 121. The second part 122 carries, on the outer surface thereof, contacts 242 which are for connecting with the contacts 241 carried by the first part 121. The second part is also provided with a stop 28 for preventing excessive rotation between the two housings, The electrical connections made by the contacts 241 and 242 are dependent upon the relative positions of the first and second housings 2 and 4, and are preferably used to determine the function of the device (ie. a mobile telephone, or portable computer). The contacts 241 and 242 can also be used for power transfer between the two housings 2 and 4 in the two open positions. In addition, a contact can be specifically provided to initiate changes in function of the telephone when the housings 2 and 4 are moved between the two open positions. The contacts can also be used for the transfer of data between components in

the two housings 2 and 4.

In order to hold the two housings 2 and 4 in place in the various positions, the first housing 2 is provided with a clip arrangement 16, and the second housing 4 is provided with two stop members 31 and 32.

These stop members are shown in Figures 8 and 9.

As shown in Figure 9, a first stop member 31 is engaged with the clip 16. The clip 16 is biased to engage with the stop member concerned by way of a spring device 161. In order to release the second housing 4 from the closed position of the device, the clip 16 is pressed into the first housing 2, thereby releasing the stop member 31. The second housing 4 can then be moved along the first housing 2 until the second stop member 32 engages with the clip 16. The device is then held in the first open position.

Similarly, the clip 16 must be depressed so that the second housing 4 can be rotated about the hinge 12 in order to provide the second open position of the device.