Changes in the function of mobile phones
Just for talking entertainment and office
Can be both
The birth of a telephone
The phone is probably the most frequently used tool we have today ，And we can hardly leave it 。
1973 mobile phone has been registered patents, but until 1985 was born in the first modern mobile phone. It is the power and antenna placed in a box, the weight of 3 kg, very heavy and inconvenient, the user should carry it like a backpack to carry it to walk, so it is called the shoulder back phone".
Modern cell phone appearance was born in 1987. Compared with the shoulder, it is much lighter and easier to carry. Nevertheless, its weight is still about 750 grams, compared to today's weighs only 60 grams’s mobile phone , it like a big brick. Since then, the development of mobile phones has become more and more rapid. 1991, the phone weighs about 250 grams or so; at the fall of 1996, a volume of 100 cubic centimeters, weight 100 grams of mobile phones appeared. Since then further miniaturization, lightweight, In 1999 there was a weight of 60 grams or less of a cell phone.That is to say, a cell phone is not much more heavy than an egg.
