HANDSET
The present invention relates to a handset and in particular to a handset which is suitable for use in a telephone incorporating dialling keys in the handset.
Telephone equipment is often required to display information to the user. Telephone equipment often comprises a handset which normally rests on a cradle but is lifted from the cradle by the user either to answer an incoming call or to initiate an outgoing call. It is now conventional practice for telephone equipment to display for example a number the user has dialled, a list of stored numbers that the user can make selections from, or the number of a calling party. When an incoming call is detected, the number of the calling party must be visible to the user when the handset is resting on the cradle. In contrast, when a user is making a telephone call, the numbers the user has dialled must be visible when the handset has been lifted from the cradle.
In one known form of telephone equipment, the cradle incorporates dialling keys and a display device which is visible whether or not the handset is placed on the cradle. Thus all the required messages regarding for example numbers dialled or calling party numbers can be readily displayed on a single display device mounted on the cradle. Telephone equipment is now widely available however in which the handset incorporates the dialling keys. In some such equipment, the cradle is no more than a passive receptacle for receiving the handset and interacting with the handset so as to enable the telephone equipment to distinguish between an idle mode (handset on the cradle) and an in-use mode (handset lifted from the cradle). There are economies available if all active components of the telephone equipment can be mounted in the handset, but this presents problems in units where it is necessary to display information to the user whether or not the handset is mounted on the cradle.
It is possible to arrange a handset with a single message display device which is visible from the side of the handset from which access to the dialling keys is available. With such an arrangement however the handset must be mounted in a cradle with the side on which the dialling keys and the display device are provided facing the user. Such arrangements are not popular however as all of the active components of the device must be on the side which is exposed when the handset is mounted in the cradle, including the mouthpiece and earpiece. Visually this is
unappealing and practically it means that those parts of the handset which come into contact with the user's ear and mouth are exposed to dust and other contamination even when the handset is mounted on the cradle.
The above problems could be overcome if two display devices were provided, either one on the cradle and one on the same side of the handset as the dialling keys, or one on both sides of the handset. Neither of these possibilities is attractive however as both involve additional cost and complexity.
It is an object of the present invention to obviate or mitigate the problems outlined above.
According to the present invention there is provided a handset having a body supporting a display device which is visible from opposed first and second sides of the body, the display device being controllable such that messages can be displayed by selectively adjusting visually apparent characteristics of regions of the display device to generate patterns which are visible from both the first and second sides of the body, wherein the handset is designed either to be mounted on a cradle such that the first side of the body is presented to a user or to be lifted from the cradle and held in a predetermined orientation so that the second side of the body is presented to a user, means being provided for reversing a generated pattern when the handset is lifted from or returned to the cradle such that a message to be displayed is presented as a pattern in a format suitable for reading from the first side of the body when the handset is mounted on the cradle and as a pattern in a format suitable for reading from the second side of the body when the handset is lifted from the cradle.
The display device may be a liquid crystal device which is located in a window provided in the handset body between an earpiece and mouthpiece. The liquid crystal device may have regions which may be selectively rendered either transparent or opaque such that the patterns are generated as a result of the visual contrast between adjacent transparent and opaque regions.
Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 is a view of a handset in accordance with the present invention as it would appear when positioned in an orientation in which it would normally be received on a cradle;
Figure 2 shows the handset of Figure 1 as it would appear to a user holding it in one hand and controlling dialling keys of the handset with the other hand;
Figure 3 illustrates a message as it would appear on the uppermost side of the handset shown in Figure 1 if the handset was placed on a support cradle and on the uppermost side of the handset as shown in Figure 2;
Figure 4 shows the message of Figure 3 as displayed on the underside of the display device of the handset shown in Figure 1 and Figure 2; and
Figures 5, 6, 7, 8 and 9 show five different views of a second embodiment of the invention.
Referring to Figure 1, the illustrated handset comprises a body 1 defining a window in which a liquid crystal display device 2 is visible. The handset when idle would be placed in a cradle (not shown) in the orientation shown in Figure 1. When in use, the user would pick the handset up from the cradle and hold it so that the side which is lowermost when the handset is in the cradle is presented to the user, thereby enabling access to dialling keys 3. When in use, the user would be presented with the handset as shown in Figure 2. It will be seen that the display device 2 is visible from both sides of the handset.
Figure 3 shows the message 1236 which it may be desired to display on the display device of the handset of Figures 1 and 2. Figure 4 shows the reversal of the message represented in Figure 3. Assuming that the message of Figure 3 is to be displayed to a user, when the handset is in its cradle the message is displayed so that it appears as the message of Figure 3 if viewed from the side of the handset which is uppermost and as the message of Figure 4 on the side which faces the cradle. When the handset is lifted from the cradle, this is detected and the pattern displayed by the display device is reversed such that the message of Figure 3 is presented to the side of the handset on which the dialling keys 3 are provided and the pattern as shown in Figure 4 is presented on the opposite side of the handset.
With the described embodiment of the invention, all that is required is circuitry to detect whether or not the handset is in the cradle and to control the reversal of the displayed message when the handset is lifted from or returned to the cradle. Thus when a user approaches the handset as it rests on the cradle the message presented on the side of the display device facing the user will be easily read.
Similarly if the handset is then lifted from the cradle and turned around to give access to the dialling keys, reversal of the pattern means that the same message can be read from the dialling key side of the handset which is presented to the user.
The display device 2 could be a liquid crystal device regions of which can be selectively switched so as to be either transparent or opaque. Alternative arrangements are possible however. All that is required is the ability to present a pattern of visually apparent contrast differences in a format which can be easily read by the intended user.
In the embodiment of the invention shown in Figures 1 and 2, the display device 2 is located in a relatively thick portion of the handset between recesses defined on the two opposed faces of the handset. A second embodiment of the invention is shown in Figures 5 to 9 in which the display device is substantially flush with the side of the handset which is uppermost when the handset is placed on a cradle. Figure 9 shows the handset placed on a cradle, Figure 5 is a front view of the side of the handset which supports the dialling keys, Figure 6 is a side view of the handset from which it is apparent that the display device is located in a relatively thin position of the handset, Figure 7 is a front view of the side of the handset which is uppermost when it is placed on the cradle, and Figure 8 is a perspective view of the handset.