TECHNICAL FIELD

The present invention relates to an arrangement in a device comprising a free fall detection arrangement and a power source and a method of preventing power failure

BACKGROUND

Communication devices, such as cellular telephones, have become increasingly versatile For example, cellular telephones today often include applications that allow users to do more than just make and receive telephone calls, such as send/receive text messages, play music, play video games, take pictures, etc As a result, cellular telephones have become an increasingly common part of every day life for a large number of users

Due to the mobility, it is easy to drop the device

One essential problem is on-off problem (software (SW) freezing), which occurs when the device is dropped and the connection between the battery and the device electronics is lost The problem occurs, mainly because of glitches between the battery connectors and the electrical connectors of the device connecting the electronics to the battery The time that the connection between the battery and device electronic is lost, may be assumed to a range of , e g 1 - 10 ms

Normally, when the device is in "sleep mode" the current consumption is around, e g 1 - 2 mA

In sleep mode the voltage can drop to, e g 3 OV before the device intelligence shuts down the device The software shutdown at e g 3 2V is too slow to react at times described above

Recently, mobile handsets with motion sensing MEMS (Micro-electro-mechanical systems) devices, such as accelerometers, have been introduced on the market Accelerometers are being integrated into some mobile handsets to enable such applications as intelligent user interfaces that that let users input commands through gestures, indoor GPS functionality, which calculates the movement and direction of the device after contact is broken with a GPS satellite, game controls, and intelligent power consumption, which automatically shuts off circuitry when it is not needed

Fig 1 illustrates a device 100, such as a mobile phone, comprising a housing 101 , a power source such as a battery 110, an accelerometer 120, and controlling electronics 130

Of course the device comprises other electrical circuits, e g transceiver and interface circuits in case of a mobile phone, well known to a skilled person, which are not described herein

SUMMARY

The present invention introduces a novel solution for a power interruption control, e g due drops and/or unwanted acceleration, which eliminates the problems with on/off problems and software freezing

This solution according to present invention may use already existing hardware It may improve the robustness and quality of the mobile devices from a user point of view and may reduce the return rate

Thus, a method is provided in a device comprising at least one electrical component configured to be supplied with power from a power source, said device comprising a motion sensor to provide a motion profile of said device and a processing unit The method comprises the steps of sensing a motion of said device by said motion sensor to provide a first motion profile of said device, generating a signal corresponding to said sensed first motion profile, and providing a signal to said at least one of said electrical component to resume a first operational mode if said first motion profile differs from a predetermined motion profile Most preferably, the first operational mode is a shut off state

The method may further comprise sensing a motion of said device corresponding to a second predetermined motion profile, generating a signal corresponding to said second predetermined motion profile, and providing a signal to said at least one electrical components t resume a second operational mode Thus, the second operational mode is a normal operational mode Preferably, the predetermined motion profile is substantially zero (0) g motion the first motion profile is a free fall motion and the second motion profile is a substantially zero (0) g motion

The invention also relates to a device comprising an electrical component configured to be supplied with power, a power source for supplying said components, a motion sensor, a processing unit, The motion sensor is configured to sense a motion of said device corresponding to a first motion profile, the processing unit is configured to receive a signal from said motion sensor corresponding to said first motion profile, and the processing unit is further configured to compare said signal corresponding to said first motion profile with a predetermined motion profile and generate a signal supplied to said electrical component to resume a first operational mode The first operational mode is shut off state

The device may further comprise a capacitive element for maintaining power during said first operational mode Preferably, the power supply is a battery

Advantageously, the electrical component comprises radio receiver and/or transmitter The device may further comprise a communication portion for communication with a communication network Preferably, the device may further comprise a housing, a display, control buttons and a keypad

In one advantages embodiment, the motion sensor is further configured to sense a motion of said device corresponding to a second motion profile, the processing unit is configured to receive a signal from said motion sensor corresponding to said second motion profile, and said processing unit is further configured to compare said signal corresponding to said second motion profile with a predetermined motion profile and generate a signal supplied to said electrical component to resume a second operational mode The second operational mode is thus a normal operational mode

Preferably, the device may be one of a radiotelephone, a personal communications system (PCS) terminal combining a cellular radiotelephone with data processing, a facsimile, and data communications capabilities, a personal digital assistant (PDA), a camera, a sound recorder and/or global positioning system (GPS) receiver, a laptop, or a GPS device

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention In the drawings

Fig 1 illustrates schematically a state of the art solution,

Fig 2 illustrates schematically an embodiment of a device according to the present invention, and

Fig 3 is a flow diagram of the steps of the method according to the present invention, and

Fig 4 is graphical test results from an embodiment according to the invention

DETAILED DESCRIPTION

A "device," as the term is used herein, is to be broadly interpreted to include a radiotelephone, a personal communications system (PCS) terminal that may combine a cellular radiotelephone with data processing, a facsimile, and data communications capabilities, a personal digital assistant (PDA) that can include a radiotelephone, pager, Internet/intranet access, web browser, organizer, calendar, a camera (e g , video and/or still image camera), a sound recorder (e g , a microphone), and/or global positioning system (GPS) receiver, a laptop, a GPS device, a camera (e g , video and/or still image camera), a sound recorder (e g , a microphone), and any other computation or communication device capable of displaying media, such as a personal computer, a home entertainment system, a television, etc

An "on/off" as the term is used herein, is to be broadly interpreted to include power supply failure or reduction

As shown in Fig 2, an exemplary device 200 may include a housing 210, a display 21 1 , control buttons 212, a keypad 213, communication portion 214, a battery 215, a micro processor 216 (or data processing unit), a memory unit 217 and a motion detecting sensor 220, such as an accelerometer. The housing 210 may protect the components of device 200 from outside elements. Display 211 may provide visual information to the user. For example, display 21 1 may provide information regarding incoming or outgoing calls, media, games, phone books, the current time, etc. Control buttons 212 may permit the user to interact with device to cause device to perform one or more operations. Keypad 213 may include a standard telephone keypad. The motion detecting sensor 220 enables applications such as commands input through gestures, indoor GPS functionality, game controls; and intelligent power consumption.

The communication portion comprises parts (not shown) such as receiver, transmitter, antenna etc., for establishing and performing communication with one or several communication networks.

When a free falling condition (e.g. substantially zero g) is detected by the motion detecting sensor 220, i.e. the accelerometer, a signal is sent to the processing unit 216, which is configured to generate an interrupt signal according to the instruction stored in the memory unit 217.

Then the processing unit 216 instructs the running applications (programs) to shut down at this interrupt, e.g. transmitters, LEDs, memory access, etc., and go to "sleep mode" with its low current consumption.

After the phone has stopped its motion, e.g. hit the ground, the processor receives a signal from the accelerometer and thus can restore the applications to the previous state, e.g. restore connections (transmitters), switch on LEDs, access memory, etc.

Calculations and simulations revile that it is possible to maintain a voltage not dropping below, e.g. 3.0 V and thereby keep the phone running with a capacitance 230 normally used in the electronic design. Fig. 3 illustrates a chart over the simulation result. This capacitance may be a part of normal design and is used for decoupling mainly at voltage regulators and DC/DC converters.

Thus, fig. 3 illustrates the steps of the method of the invention: the motion sensor 220 senses (301) the motion of the device, and transmits (302) a signal to the processing unit 216. The signal may correspond to the sensed sensor value and/or a difference (303) between a predetermined stored (threshold) value. If the signal corresponds to a sensed value the processing unit may compare (303) the value with a predetermined value stored in the memory 217 If it is determined that the sensed motion is a free falling motion, the some or all of the electrical components are instructed (304) to shot off The motion sensor 220 may continue to sense (301) the motion of the device, and transmit (302) the signal to the processing unit 216 The signal may correspond to the sensed sensor value and/or a difference (303) between a predetermined stored (threshold) value If the signal corresponds to a sensed value the processing unit may compare (303) the value with a predetermined value stored in the memory 217 If it is determined that the sensed motion is not free falling, e g rest, the electrical components are instructed (304) to resume functionality

The simulations result given as an example in Fig 4 shows the battery disconnected at 100ms and connected again at 109 ms (9 ms disconnection), the voltage drop at phone electronic (on top, starting point = 3 7 V, drops to 3 15 V), the current to the phone electronic (at the bottom, starting point = 2 0 mA) A 30 uF capacitor was used This capacitance is equal to what normally may be used connected to the battery on the electronic side

By doing so, the effect of the power failure is eliminated and the circuits needing power for their operation are maintained operating

It should be noted that the word "comprising" does not exclude the presence of other elements or steps than those listed and the words "a" or "an" preceding an element do not exclude the presence of a plurality of such elements It should further be noted that any reference signs do not limit the scope of the claims, that the invention may be implemented at least in part by means of both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware

The above mentioned and described embodiments are only given as examples and should not be limiting to the present invention Other solutions, uses, objectives, and functions within the scope of the invention as claimed in the below described patent claims should be apparent for the person skilled in the art