What changes have taken place in the telephone style?

Bell, the famous inventor of the telephone, applied for a telephone patent in the US Patent Office on February 1876. In fact, just two hours after his application, a man named e? Gray's people also applied for a telephone patent.

Before the two of them, many people in Europe were already doing ideas and research in this field. As early as 1854, the telephone principle was conceived by the Frenchman Bausal, and the idea was repeated by the German rice six years later. The principle is that two thin metal sheets are connected by wires. When one side makes a sound, the metal plate vibrates and becomes electricity, and the electricity is transmitted to the other side. But this is just an idea. The problem is the structure of microphone and receiver, and how to convert the mechanical energy of sound into electrical energy and transmit it.

At first, Bell used electromagnetic switches to form on-off pulse signals, but this method obviously didn't work for such high-frequency sound waves. The final success came from an accidental discovery. 1June 2, 875, in an experiment, he connected a metal plate to an electromagnetic switch. Unexpectedly, in this state, the sound becomes a wonderful current. According to the analysis principle, the original metal sheet induces current in the connected electromagnetic switch coil due to sound vibration. Now it seems that this principle is known to all students who have studied junior high school physics, but it is undoubtedly a very important discovery for Bell at that time.

Gray's design principle is different from Bell's, which uses the resistance change of the liquid inside the microphone, while the receiver is exactly the same as Bell's. 1877, Edison obtained the invention patent of carbon particle microphone. At the same time, many people have made various improvements to the way the telephone works. The patent dispute is complicated, and it didn't come to an end until 1892. One of the reasons for this situation was that the largest Western Union telegraph company in the United States bought the patents of Gray and Edison at that time and confronted Bell's telephone company. Due to the long-term patent dispute, the two sides reached an agreement. Western Union Telegraph Company fully recognized Bell's patent right and never set foot in the telephone industry again. In exchange, it shared 20% of Bell's income in 17.

technological development

In the decades after the invention of the telephone, a large number of patents were applied around the operation and technology of the telephone. Strowger's "automatic dialing system" reduces the problems caused by manual wiring, the application of dry battery reduces the size of the phone, and the application of loading coil reduces the signal loss of long-distance transmission. 1906, Li De invented the electronic test tube, and its amplification function led the direction of telephone service. Later, Bell Telephone Laboratory made an electronic triode based on this, and this research is of great significance. 1915 65438+1On October 25th, the first cross-regional telephone line was opened between new york and San Francisco. It uses 2500 tons of copper wire, 6.5438+0.3 million telephone poles and numerous load coils, and also uses three vacuum tube amplifiers along the way to strengthen the signal. On July 1948, scientists at Bell Laboratories invented the transistor. This is not only of great significance to the development of telephone, but also has great influence on all aspects of human life. In the following decades, a large number of new technologies appeared, such as the production of integrated circuits and the application of optical fibers, which played a very important role in the development of communication systems.

The mobile phone is in China.

After the Opium War, while western powers plundered land and wealth in China, they also brought modern postal services and telecommunications to China. 1900, the first local telephone in China came out in Nanjing; 1904 to 1905, the Russian side set up a radio station from Yantai to Niuzhuang. The ancient postal system and non-governmental communication institutions in China have been gradually replaced by advanced postal services and telecommunications.

During the Republic of China, China's post and telecommunications were still under the control of western powers. Coupled with years of war, communication facilities are often destroyed. During the War of Resistance against Japanese Aggression period, the Japanese imperialists reformed and expanded the telecommunication network system for the need of war and the purpose of trying to rule China for a long time. They took advantage of China's backward economy and technology and the corruption of the political system at that time to control the telecommunications industry in China from the aspects of technology, equipment, maintenance and management.

Before 1949, China's telecommunications system developed slowly. By 1949, the telephone penetration rate in China was only 0.05%, and there were only 260,000 telephone users.

After 1949, the central people's government quickly resumed and developed communications. The Beijing Telegraph Building, completed in 1958, became an important milestone in the development history of new China communication. Ten years of "Cultural Revolution", post and telecommunications suffered another blow, and business development stagnated. By 1978, the national telephone penetration rate was only 0.38%, which was lower than the world level of110. The total number of telephones owned by China15 population is less than 1% of the total number of telephones in the world, and there is less than one telephone for every 200 people, which is 75 years behind the United States! The automation rate of switches is low, most counties and rural areas still use "crank", and long-distance transmission mainly depends on open wire and analog microwave. Even in Beijing, 20% of long-distance calls can't be connected every day, and 15% of long-distance calls can't be connected until 1 hour. Visitors to the telegraph building must take lunch to the queue.

1978 The national telephone capacity was 3.59 million, with 2140,000 users, with a penetration rate of 0.43%.

After the reform and opening up, the backward communication network has become the bottleneck of economic development. Since the mid-1980s, the government of China has accelerated the construction of basic telecommunication facilities. By March 2003, the number of fixed telephone users had reached 2,256.26 billion, and the number of mobile telephone users had reached 2,265.438+0.498+0 billion.

At all times, many people are trying to transmit information faster and better. During the telecom development of 100 years, people have tried various communication methods: the original telegrams used expressions similar to "numbers" to convey information; So there appeared a telephone that used analog signals to transmit information; With the development of science and technology, the digital model has been paid attention to again with its obvious advantages. The historical wheels of digital program-controlled switching, digital mobile phone and optical fiber digital transmission are still advancing.

A phone call a hundred years ago.

Since the invention of the telephone, there have been great changes from the working principle to the shape design. Please follow us through the century-long road of telephone development. These telephones are the collections of antique telephone collectors all over the world.

1878, handheld phone

This telephone was made in 1878 by Werner Siemens of Germany. Its receiver and microphone are the same, and they are used alternately when listening and speaking.

1879, boxed mobile phone

This mobile phone is equipped with a magnetic generator made of mahogany by viaduct manufacturing company and a cylindrical receiver.

1880, Bell Telephone

This is the first telephone used in Europe. It replaces the telegraph and is more advanced than the magnetophone with handle.

188 1, 1882, wall-mounted telephone with magnetic generator.

The phone on the left is American Bell model, 188 1 produced and used by Bell International Telephone Company in Copenhagen. Made by L.M.Ericsson. This mobile phone was very popular at the end of last century.

1885, "Eiffel Tower" magnetic generator telephone

This mobile phone was made by L.M. Ericsson at 1885. At that time, this was the first telephone on the desktop. The microphone is installed on the rotating arm, and the crank is used to connect the switch.

1885, 1902, wall-mounted telephone with magnetic generator.

Ferdinand E. Stensen was made in Copenhagen on 1885, which was the earliest telephone made by Danes. This model is made by Emile Deleuse Telephone Company of Hawthorne.

1885, wooden stand desk phone

The manufacturer and place of origin are unknown.

1892, electric folding counter mobile phone

This kind of telephone is mostly used in homes, hotels and telephone booths.

1892, "Eiffel Tower" telephone with receiver

This is a real classic telephone, 1892, made by L.M. Ericsson. This mobile phone has spread all over the world and produced nearly one million sets.

1893, "coffee pot" phone

This mobile phone has only a few samples in Denmark, which is the most attractive and valuable for collectors. 1899, digital mechanical wall phone

There are two kinds of digital mechanical phones: wall-mounted and desktop.

1900, vertical desk phone

This round-bellied desk phone is plated with bronze nickel. There is a strong bakelite under the hanging rod. It also has a peripheral phone to show off.

1900, Vertical Cone Desk Phone

This mobile phone has a nickname "oil pan" because of its shape.

1900, 20-line separated telephone

This section is the so-called 20-line separated telephone. It can only be used for the internal telephone of Swedish company L. M. Ericsson.

190 1 year, desk phone with magnetic generator.

This model was manufactured by Ferdinand E. Stensens Telefon Fabrick in Copenhagen in 190 1 year. Pay attention to its receiver and hang it on the hook alone. It may be because the quality of telephone access was not high at that time, and sometimes two ears were needed to listen.

1902, Kellogg corner desk phone

This kind of corner desk phone is mostly used in homes, offices and telephone booths. It is made by American hardwood telephone company. I bought it from farmers in a small town in California.

1902, public battery wall telephone

This kind of phone doesn't need to turn the handle, so it can pick up the receiver and talk directly to the operator. It was bought from an antique shop in San Francisco.

1904, magnetic generator * * * line telephone

This mobile phone is produced by L.M.Ericssom company, and the phone number is 1904. This phone can be shared by four users. 1753, 17 In February, the idea of current communication was first put forward in a magazine named Scotsman, and the article was signed by C.M.

1August 78415th, a visual communication method called "Yuanwang" was first used between Lille and Paris.

1796, an Englishman named Hughes proposed a method of transmitting sound by microphone relay, and named it telephone, which has been in use ever since.

1832, Russian diplomat Schilling made a telegram that used galvanometer pointer to deflect the received information.

1835, American Morse invented the telegraph which used electromagnetic principle to transmit telegrams.

1in June, 837, an Englishman, Cook, obtained the first patent for the invention of the telegraph, and his telegraph machine was used on the railway for the first time.

From 1837 to 1838, Morse invented Morse code to encode numbers and letters by "turning on" and "turning off" current.

1843, Morse built a telegraph line from Washington to Baltimore, with a total length of 64.4 kilometers.

1844 On May 24th, Morse sent the first telegram in human history to Baltimore at the Capitol: "What a miracle God has created!" .

1850 On August 28th, the first submarine cable was built by John and Jacob. The Brett brothers laid cables on the high seas between Cape Grace-Naiz in France and Cape Richland in England, but they were interrupted only by sending a few telegrams. It turned out that a fisherman hooked a rope with a trawl and cut off a piece to brag about this rare "seaweed" specimen, and was surprised to say that it was full of gold.

1March, 876 10, the British Bell invented the telephone. "Mr Watson, come and help me" became the first voice on the phone. At that time, Bell spilled acid from the microphone on his leg.

1879, a telegraph line was set up between Tianjin and Dagu Beitangbao.

1882 February 2 1 day, Gaodan Gaobei Telegraph Company set up a telephone exchange on the Bund in Shanghai.

1895, Russian popov and Italian Marconi invented the wireless telegraph respectively.

On May 6th, 2008, Marconi successfully conducted radio communication in Bristol Strait.

1900, Shanghai Nanjing telegraph office opened the local telephone, and there was only 16 telephone at that time.

190 1 year, Marconi realized radio communication across the Atlantic.

1903, the wireless phone test was successful.

1907165438+1October 8, French inventor Edward? Belan showed his research results-photo fax in the building of the French Photography Association.

19 19, Pahlm and Behlander invented the "crossbar connector". 10 years later, the world's first large-scale vertical and horizontal telephone exchange was built in Sonzwar, Sweden.

In July, 1920, Chunghwa Post started postal telegraph service.

1937, British Reeves proposed a method of transmitting voice information through all combinations of pulses (pulse code modulation).

1945 10 month, English A? c？ Clark put forward the idea of geostationary satellite communication.

1946, eckert and mochiri built the world's first electronic computer.

1947, Bell Laboratories put forward the concept of cellular communication, which divided the service area of mobile phones into several cells, and each cell was equipped with a base station to form a cellular mobile communication system.

1950 65438+February, the international trunk line project of China Northeast Long-distance Open Line was completed, and the Beijing-Moscow cable carrier circuit was opened.

1In July, 954, the US Navy made use of the reflection of radio waves on the surface of the moon to conduct a telephone transmission test between the two places on the earth. At 1956, communication service was established between Washington and Hawaii.

1956, a telephone cable was laid under the Atlantic Ocean between Britain and Canada, making long-distance telephone communication between continents a reality.

1957, 10 year 10. On October 4th, the former Soviet Union successfully launched the first artificial satellite "1 satellite".

1958 In August, the first domestic 12 carrier telephone equipment was successfully developed in Shanghai Post and Telecommunications Equipment Factory.

1960 65438+ 10, the first set of 65438+ 10,000-door automatic telephone exchange in China was put into use in Shanghai Wusong telephone office.

1960, American physicist Mayman irradiated artificial gem with powerful ordinary light, and produced a laser with a light intensity of 0/00000 times that of the sun.

1962, the United States successfully developed a pulse code modulation device for telephone multiplex communication.

1965, the first program-controlled telephone exchange controlled by computer came out in America, marking the beginning of a new telephone era.

1966, Gao Kun, a British Chinese, put forward the idea of long-distance laser communication with glass fiber.

1969, Beijing Long-distance Telecommunication Bureau successfully installed the first fully automatic long-distance telephone equipment in China.

1969, the Advanced Research Projects Agency (ARPA) of the US Department of Defense put forward a plan to develop ARPA network, which was completed and put into operation in 1969, marking the development of computer communication has entered a new era.

1970, the world's first program-controlled PBX was opened in Paris, marking the comprehensive application of digital telephone and the arrival of a new era of digital communication.

In 1972, CCITT first proposed the concept of-—ISDN.

1974, the Sino-Japanese submarine cable started construction, which was the first international submarine cable that China participated in.

1975, the crossbar automatic telephone exchange equipment developed and designed by our country passed the national appraisal and began mass production.

1976 in March, China's first large-capacity transmission system-1800 coaxial cable carrier system was completed and put into operation in Beijing, Shanghai and Hangzhou, with a total length of 1700 km.

1982, GSM was established in Europe, with the task of formulating roaming standards for pan-European mobile communication.

1982, the first batch of coin-operated public telephones in China appeared in busy streets such as East and West Chang 'an Avenue, with a total of ***22 coin-operated public telephone booths.

1982 65438+February, the first domestic ten thousand-door program-controlled local telephone exchange system imported from Japan was put into operation in Fuzhou Telecommunications Bureau, and the first imported program-controlled telephone office was built in China.

1983, the AMPS cellular system was opened in Chicago, USA.

1904, "spider" civil band telephone

Length m Ericsson's first civil band telephone. 1905, tree desk phone in Chicago

This desktop mobile phone is called "paunchy", which is named after the bulge in the middle of its handle.

1905, porch intercom

This is a 32-door porch intercom from Connecticut Telecom.

1905, 1 1 digital dial desk phone

It uses the number 1 1 to dial.

1907, "German mode" radio band telephone

1907 in Germany by e.zwuetsch &; Co manufacturing, the emergence of this mobile phone can solve the problem of long call waiting time to a certain extent.

1907, magnetic generator telephone

This phone 1907 was made by L.M. Ericsson. It is worth noting that the receiver should be hung on a separate hook when answering the phone. This was the unified standard of telephone manufacturers at that time.

1908, CH-08 hands-free phone

Introduced by KTAS.

19 10 year, VoIP.

This is a vertical desk phone made by S.H. Couch Company, which is used for communication between offices.

19 12, Office Finisher

This mobile phone can have 17 extensions at the same time through the host, each extension can be dialed out, and the extensions can also be connected to each other.

19 12, CH-08 wall phone

This telephone was made in 19 12, and made by Danes in Copenhagen. It can automatically send and receive telegrams.

19 12, telephone number of magnetic generator.

Telegrams and fax telephones produced by Ericsson are often used in remote areas or small islands.

19 14, Magnavox anti-noise desk phone

The unique design of this mobile phone is that when talking into the microphone, the sound passes through the small hole on the top of the mobile phone, which makes the vibrating plate in the mobile phone vibrate. Noise will be eliminated when it enters the microphone. Its dual rotating headphones help prevent useless noise.

19 14, Magnavox anti-noise desk phone B 1.

It also has the function of eliminating noise.

19 14, telephone number of magnetic generator.

19 14 is made in HORWENS and can be used for telegrams and faxes.

19 15, Veau desk phone

The information is unknown.

19 15, self-made wall phone.

This mobile phone was found in an abandoned farm in East Oregon. There are nearly 20 abandoned farms in the local area, with traces of telephones hanging on the walls.

1920, wall-mounted telephone of magnetic generator

This mobile phone is made by 1904 and updated by 1920, and it is equipped with an audible rotary red button.

1927, D-08 semi-automatic telephone

The first dial-up telephone, its appearance will replace the manual call system of the switch. The dialer was installed in 1927 and actually used in 1978.

1927, ringing telephone for AC power generation

It was made by Kristian Kirks Telefonfabrikker in Hohense, Denmark, and is still in use in the 1970s.

1929, automatic wall-mounted telephone

The information is unknown.

1930, D-30 semi-automatic gold-plated telephone

This mobile phone was produced by a Danish company at 1930, and its special feature is that its surface is gold plated. At that time, most telephones were black, and this telephone had a dialing device.

1930, FL-30 automatic telephone

It was made in Denmark in the 1930s, and it can dial letters. Similar mobile phones have been used for about 48 years.

1935, automatic telephone

This kind of telephone is used to communicate with telecommunication exchanges in remote areas, and its design was influenced by the American telephone industry in the 1930s.

1943, CB-43 telephone

This mobile phone is made by Kristian Kirks Telefonfabrikker in Denmark, and there are two kinds of ringtones designed inside to distinguish the incoming calls from those outside the city.

195 1 year, F-5 1 automatic dial-up telephone.

This telephone was made by Kristian Kirks Telefonfabrikker after World War II.

1952, F-52 automatic dialing telephone

1952, which is different from the previous black bakelite material. It is made of ivory and later plastic materials.

1956, "Ericofon" automatic dialing telephone.

This mobile phone is designed and manufactured by L.M. Ericsson of Sweden and named Ericofon. It is made of new material, which is much lighter than the receiver of traditional telephone.

1968, F-68 automatic dialing telephone

This telephone was the most common telephone in the 1970s. It was originally designed in 1960s and widely produced in Denmark.

1970, F-68 button dial phone

The first touch-tone telephone used in Denmark, which uses numeric keys instead of the original dialing method.

1976,76e/dk80 push-button dial phone

Originally produced by Jutland Telephone Company, the telephone number is 1972.

1979, F-79 push-button dial toll phone

This telephone is between the ordinary telephone and the public telephone. Mainly used in service places, hotels and other similar places, which can prevent theft and make phone calls. 1980, DA-80 push-button dial phone

The design of this phone marks that the electronics theory has really entered the telephone industry.

1982, portable telegraph telephone

This phone is made by Ericsson Wireless Systems. It was only available in Denmark, Finland, Norway and Sweden. Its appearance has opened up a new world for the future GSM mobile phone system.

1983, Danish 2-key mobile phone

DanMark2 is made in 1983, which is the embodiment of the most advanced technology in 1980s. It has many functions, such as telephone number memory function, redial function, monitoring function and 24 kinds of ringtones.