# Patent

## Title
System and method for conserving battery power in a mobile station

## Abstract

A mobile station and a method of conserving battery power consumed thereby. In one embodiment, the mobile station includes: (1) a chassis having a display and (2) a proximity sensor coupled to the chassis and adapted to cause a power consumption of the display to be reduced when the display is within a predetermined range of an external object.

## Background
TECHNICAL FIELD OF THE INVENTION
The present invention is directed, in general, to mobile stations and, more specifically, to a mobile station of mobile radio system having a reduced power consumption under certain operating conditions.
BACKGROUND OF THE INVENTION
Mobile stations have found many uses in today's world. When paired with a single base station located at a user's own premises, they are called “cordless telephones.” When they interact with various, geographically distributed cellular base stations, they are called “cellular telephones” or simply “cell phones.”
Usually the stand-by time, as well as the talk-time, of a mobile station depend on the lifetime of a (rechargeable) battery inserted within the mobile station and hence, on the load and/or on the capacity of the battery.
Increasing of the capacity of the battery would increase the lifetime of the mobile station, but batteries having increased capacities are often larger, heavier or more expensive, none of which are desirable attributes for a portable, affordable mobile station. Accordingly, what is needed in the art is a way to prolong the lifetime of a mobile station without having to use a battery with an increased capacity.
SUMMARY OF THE INVENTION
To address the above-discussed deficiencies of the prior art, the present invention provides a mobile station, including: (1) a chassis having a display and (2) a proximity sensor coupled to the chassis and adapted to cause a power consumption of the display to be reduced when the display is within a predetermined range of an external object.
Thus, by reducing the power consumption of the display of an activated telephone set in case the display is not needed, i.e., in particular during a telephone call, current is saved instead of needlessly consumed from the (rechargeable) battery. Accordingly, the spared available battery power may be significant, especially for color displays, resulting in an overall increasement of the stand-by and/or talk time of the telephone set.
According to preferred embodiments the means are adapted to switch-off the display in response to a detection that the set, preferably the display of the set, is attached near to an object, in particular to the ear.
As a consequence, if a call for example is incoming for example, possibly the user wants to see by means of the display the number and/or the stored name of the calling party. However, if the user wants to accept the call and hence is attaching the telephone set to the ear, the invention enables that the display is switched off. In a similar way, in case the user is trying to call a third party he may want to have a look at the display for verifying the entered number, but when the call is established he is likewise attaching the set and accordingly the display to his ear for performing the call. On the other hand, as long as the telephone set is inside a pocket, for example, it is not necessary to keep the display in an on-condition or to indicate the number and/or the name of a calling party.
Moreover, the means may be further adapted to switch-on the display in response to a detection that the set, preferably the display of the set, is moved away from any object, in particular from the ear.
As an alternative or in addition, the triggering event for current saving purposes may also be selectable by the user, for example via a menu list. According to further preferred refinements, the proximity sensor is proposed to be a heat flow or temperature sensor, an optical or infrared sensor, or a load sensor. However, as a further advantage, basically any kind of proximity sensor which is capable of observing a close range or small distance may be used.
Correspondingly, the invention proposes a method for saving available battery power of a mobile station, in particular of a mobile station comprising the steps of detecting an attachment of the set, in particular of the display of said set near to an object, in particular to the ear, and switching off the display in response to such a detection in case the display is in an on-condition.
The foregoing has outlined, rather broadly, preferred and alternative features of the present invention so that those skilled in the art may better understand the detailed description of the invention that follows. Additional features of the invention will be described hereinafter that form the subject of the claims of the invention. Those skilled in the art should appreciate that they can readily use the disclosed conception and specific embodiment as a basis for designing or modifying other structures for carrying out the same purposes of the present invention. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the invention in its broadest form.



BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
FIG. 1 schematically depicts a preferred embodiment of a mobile station having the inventive detection functionality; and
FIG. 2 schematically depicts a block diagram showing essential components of the invention.



DETAILED DESCRIPTION
FIG. 1 illustrates a mobile station 110 of a mobile radio telecommunication system having a loudspeaker 120 and a microphone 130. A proximity sensor 140 is located near a display 150 toward a side of the loudspeaker 120. A keypad 160 allows a user (not shown) to establish an outgoing call, accept an incoming call and/or terminate an active call. However, it should be apparent to one skilled in the pertinent art, that these functionalities can be also performed by other control means, for example by speech control. The proximity sensor 140 is integrated within the mobile station 110 to enable a functionality as described in more detail with regard to FIG. 2.
As can be seen from FIG. 2, an incoming call may be managed by a central processing unit 220, for example for further specific processing. For example, the number or the name of the calling party stored within a storage (not referenced) implemented within the mobile station 110 can be depicted at the display 150.
If the user of the mobile station 110 wants to accept the incoming call 210, he may press a key on the keypad 160 or issue a voice command. Alternatively, an incoming call may directly activate the proximity sensor 140 without the necessity of pressing a key on the keypad 160 to accept the call.
In response to the acceptance of the incoming call 210 or automatically, the proximity sensor 140 is activated to monitor a proximity 230 to an external object (not shown), for example a range of about five centimeters. This is preferably done by a standard low-cost proximity sensor, for example a thermal sensor. However, other proximity sensors, such as conventional mechanical proximity (load) sensors, optical sensors or range detecting sensors, fall within the broad scope of the present invention. If the proximity sensor 140 detects an external object (such as the user's ear) within the monitored range, the power consumption of the display 150 is reduced, most preferably by switching the display 150 completely off, as indicated by an arrow 240, to spare battery power during the telephone call.
When the telephone call 210 is finished, the user of the mobile station 110 typically moves the mobile station 110 away from his ear. This causes the proximity sensor 140 to move out of range of the external object (in this case the user's ear). Accordingly, in response thereto, the display 150 is switched back on, enabling the user to look at information on the display 150.
Correspondingly, for an outgoing call, the proximity sensor 140 is activated by pressing a key on the keypad 160 to establish the outgoing call to a third party. As long as the outgoing call remains in effect and the proximity sensor 140 detects proximity to an external object, e.g., the ear of the user, the display 150 remains in a state of reduced power consumption, or off, as the case may be.
The function of switching the display off or on or otherwise reducing the amount of power the display consumes may comprise hardware and/or software components. For example, electronically readable instructions executable in the central processing unit 220 may be stored on a memory chip located in the mobile station 110 and adapted to cooperate with the proximity sensor 140 to perform the function.
Moreover, if the proximity sensor 140 is directly activated by an incoming call or automatically activated, the display can be kept in a switched-off condition as long as the mobile station 110 is, for example, within a pocket (not referenced) or the like and is only switched on when the user retrieves the mobile station 110 from the pocket to enable the user to look on the display 150 for an information about the calling party. If the user then wants to accept the call and thence places the mobile station 110 proximate an external object, such as his ear, the proximity sensor 140 again detects an object, causing the display again to be switched off.
Although the present invention has been described in detail, those skilled in the art should understand that they can make various changes, substitutions and alterations herein without departing from the spirit and scope of the invention in its broadest form.

## Claims

1. A mobile station, comprising:
a chassis having a display;
a power reducer configured to control power consumption of said display;
a proximity sensor coupled to said chassis and configured to cause said power consumption to be reduced when said display is within a predetermined range of an external object, and
a microprocessor coupled to said proximity sensor through a keypad of said mobile station and directly coupled to said display, said microprocessor configured to automatically activate said proximity sensor based on said mobile station receiving an incoming wireless telephone call.

2. The mobile station as recited in claim 1 wherein said proximity sensor causes said display to be turned off.

3. The mobile station as recited in claim 1 wherein said proximity sensor causes said power consumption to be reduced when said display is within said predetermined range during said telephone call.

4. The mobile station as recited in claim 1 wherein said proximity sensor is selected from the group consisting of:
a mechanical proximity sensor,
an optical sensor, and
a range detecting sensor.

5. The mobile station as recited in claim 1 wherein said proximity sensor is located proximate said display.

6. The mobile station as recited in claim 1 wherein said proximity sensor is activated manually when said mobile station initiates an outgoing wireless telephone call.

7. The mobile station as recited in claim 1 wherein said predetermined range is about five centimeters and said external object is selected from the group consisting of:
the ear of a user, and
a pocket.

8. A method of conserving battery power in a mobile station, comprising:
employing a microprocessor of said mobile station to automatically activate a proximity sensor when said mobile station receives an incoming wireless telephone call, said microprocessor coupled to said proximity sensor through a keypad of said mobile station and directly coupled to a display of said mobile station;
sensing with said proximity sensor when said display of said mobile station is within a predetermined distance of an external object; and
causing, in response thereto, a power consumption of said display to be reduced.

9. The method as recited in claim 8 wherein said causing comprises causing said display to be turned off.

10. The method as recited in claim 8 wherein said causing comprises causing said power consumption to be reduced when said display is within said predetermined range during said telephone call.

11. The method as recited in claim 8 wherein said proximity sensor is selected from the group consisting of:
a mechanical proximity sensor,
an optical sensor, and
a range detecting sensor.

12. The method as recited in claim 8 further comprising manually activating said proximity sensor based on user interaction with a keypad of said mobile station when said mobile station initiates an outgoing telephone call.

13. The method as recited in claim 8 wherein said causing comprises causing said power consumption to be reduced independent of whether said mobile station is being used during said telephone call.

14. The method as recited in claim 8 wherein said predetermined range is about five centimeters and said external object is selected from the group consisting of:
the ear of a user, and
a pocket.

15. A mobile station, comprising:
a chassis having a display;
a power reducer configured to control power consumption of said display; a proximity sensor coupled to said chassis and configured to cause said display to be turned off when said display is within a predetermined range of an external object during an incoming wireless telephone call, and
a microprocessor coupled to said proximity sensor through a keypad of said mobile station and directly coupled to said display, said microprocessor configured to automatically activate said proximity sensor based on said mobile station receiving said incoming wireless telephone call.

16. The mobile station as recited in claim 15 wherein said proximity sensor is selected from the group consisting of:
a mechanical proximity sensor,
an optical sensor, and
a range detecting sensor.

17. The mobile station as recited in claim 15 wherein said proximity sensor is located proximate said display.

18. The mobile station as recited in claim 15 wherein said proximity sensor is located on a speaker side of said chassis.

19. The mobile station as recited in claim 15 wherein said predetermined range is about five centimeters and said external object is selected from the group consisting of:
the ear of a user, and
a pocket.

20. The mobile station as recited in claim 15 wherein said proximity sensor is activated manually when said mobile station initiates an outgoing wireless telephone call.