The invention is related to operations of a cellular phone in a vehicle.
Due to the wide spread use of cellular phones, they have become very important electronic products to the human life. However, due to the potential for users to become distracted while using the phones, advocates for cell phone safety dominate the swirling safety controversy. Most safety specialists argue that the cell phone safety issue is a multi-pronged problem. Cell phones pose a risk in two basic ways: 1) cell phones introduce conversation into the driving equation; and 2) use of a cell phone is a distraction, not unlike changing the radio station. Human behavior then may be construed to be the number one danger, an attachment to cell phone use.
As noted in U.S. Pat. No. 7,505,730, a cellular phone jammer, claiming to effectively obstruct cellular phone signals within a specific range so as to disable the cellular phone's communication function, is available on the market. U.S. Pat. No. 6,301,475 granted to Saarela, et al. for a “Procedure for limiting the mobility area of a terminal device in a wireless local loop” defines a mobility area (MOA) to perform inhibiting communications in accordance with geographical locations. However, in critical conditions such as a fire accident in a theater, it would cause a tragedy if the cellular phone cannot be used for emergency calls. This is the main reason why the cellular phone jammer is not legal yet in many countries. Therefore, it is desirable to provide a cellular phone jammer to be used ordinarily to effectively inhibit the communication function of the cellular phones, yet to be automatically turned off to allow the communication when there is an emergency within the area.
U.S. Pat. No. 7,505,730 discloses a cellular phone jammer permitting cellular phones to be used in an emergency, and includes a cellular phone signal-obstructing apparatus and an alarm apparatus. The cellular phone signal-obstructing apparatus further has a cellular phone signal-blocking unit, a power supply unit, and a trigger unit. The cellular phone signal-blocking unit sends out a blocking-signal to disconnect the communication between cellular phones and cellular tower within the effective range. The trigger unit connects to the power supply unit and cellular phone signal-blocking unit in series. The invention effectively disconnect the communication between the cellular phones and cellular tower within a range, yet automatically turns off the jammer when there is an emergency in the designated area to resume normal communication between cellular phones and cellular tower so that the users can call for help.