The system creates "lock-out mechanisms" to disable cell phones from performing certain functions, such as texting, while one is driving.
The patent describes how sensors in a mobile phone could tell how quickly a person was moving and would be sensitive enough to work out whether a person was in the driving seat or in a safe operating area of a vehicle, allowing passengers to text as normal.
"A handheld computing device can provide a lock-out mechanism without requiring any modifications or additions to a vehicle," the patent said.
"The device can comprise a motion analyser, a scenery analyser and a lock-out mechanism. The motion analyser can detect whether the handheld computing device is in motion beyond a predetermined threshold level.
"The scenery analyser can determine whether a holder of handheld computing device is located within a safe operating area of a vehicle.
"And the lock-out mechanism can disable one or more functions of the handheld computing device based on output of the motion analyser, and enable the one or more functions based on output of the scenery analyser," it said.
The patent further develops the idea and says the vehicle itself could contain technology that could effectively block the signal to a phone inside a moving car.
It is not clear how this could ensure that passengers' phones would not be affected, 'The Times' reported.

The patent application, which was filed in 2008, but only published and granted recently, also said that police report that their ability to catch drivers texting is limited "because the texting device can be used out of sight (eg on the driver's lap), thus making texting even more dangerous.
"Texting while driving has become so widespread it is doubtful that law enforcement will have any significant effect on stopping the practice," the patent said.
Earlier this month, it was reported that Apple has filed a patent for 'transparent texting' technology to make texting while walking safer by replacing the text background with a live video feed of whatever is in front of the smartphone user.