光电传感器中英文对照版.docx

1、光电传感器中英文对照版Photoelectric sensor Key word: photoelectric effect photoelectric element photoelectric sensor classification sensor application characteristics .Abstract: in the rapid development of science and technology in the modern society, mankind has into the rapidly changing information era, peop

2、le in daily life, the production process, rely mainly on the detection of information technology by acquiring, screening and transmission, to achieve the brake control, automatic adjustment, at present our country has put detection techniques listed in one of the priority to the development of scien

3、ce and technology. Because of microelectronics technology, photoelectric semiconductor technology, optical fiber technology and grating technical development makes the application of the photoelectric sensor is growing. The sensor has simple structure, non-contact, high reliability, high precision,

4、measurable parameters and quick response and more simple structure, form etc, and flexible in automatic detection technology, it has been widely applied in photoelectric effect as the theoretical basis, the device by photoelectric material composition. Text: First, theoretical foundation - photoelec

5、tric effect Photoelectric effect generally have the photoelectric effect, optical effect, light born volts effect. The light shines in photoelectric material, according to the electronic absorption material surface energy, if absorbed energy large enough electronic electronic will overcome bound fro

6、m material surface and enter the outside space, which changes photoelectron materials, this kind of phenomenon become the conductivity of the photoelectric effect According to Einsteins photoelectron effect, photon is moving particles, each photon energy for hv (v for light frequency, h for Plancks

7、constant, h = 6.63 * 10-34 J/HZ), thus different frequency of photons have different energy, light, the higher the frequency, the photon energy is bigger. Assuming all the energy photons to photons, electronic energy will increase, increased energy part of the fetter, positive ions used to overcome

8、another part of converted into electronic energy. According to the law of conservation of energy: Type, m for electronic quality, v for electronic escaping the velocity, A microelectronics the work done. From the type that will make the optoelectronic cathode surface escape the necessary conditions

9、are h A. Due to the different materials have different escaping, so reactive to each kind of cathode materials, incident light has a certain frequency is restricted, when the frequency of incident light under this frequency limit, no matter how the light intensity, wont produce photoelectron launch,

10、 this frequency limit called red limit. The corresponding wavelength for type, c for the speed of light, A reactive for escaping. When is the sun, its electronic energy, absorb the resistivity reduce conductive phenomenon called optical effects. It belongs to the photoelectric effect within. When li

11、ght is, if in semiconductor electronic energy big with semiconductor of forbidden band width, the electronic energy from the valence band jump into the conduction band, form, and at the same time, the valence band electronic left the corresponding cavities. Electronics, cavitation remained in semico

12、nductor, and participate in electric conductive outside formed under the current role. In addition to metal outer, most insulators and semiconductor have photoelectric effect, particularly remarkable, semiconductor optical effect according to the optoelectronics manufacturing incident light inherent

13、 frequency, when light resistance in light, its conductivity increases, resistance drops. The light intensity is strong, its value, if the smaller, its resistance to stop light back to the original value. Semiconductor produced by light illuminate the phenomenon is called light emf, born volts effec

14、t on the effect of photoelectric devices have made si-based ones, photoelectric diode, control thyristor and optical couplers, etc. Second, optoelectronic components and characteristics According to the outside optoelectronics manufacturing optoelectronic devices have photoelectron, inflatable photo

15、tubes and photoelectric times once tube. 1. Phototubes phototubes are various and typical products are vacuum phototubes and inflatable phototubes, light its appearance and structure as shown in figure 1 shows, made of cylindrical metal half cathodic K and is located in the wires cathodic axis of an

16、ode in A package of smoke into the vacuum, when incident light within glass shell in the cathode, illuminate A single photon took all of its energy transfer to the cathode materials A free electrons, so as to make the freedom electronic energy increase h. When electrons gain energy more than escape

17、of cathode materials, it reactive A metal surface constraints can overcome escape, form electron emission. This kind of electronic called optoelectronics, optoelectronic escaping the metal surface for after initial kinetic energy Phototubes normal work, anode potential than the cathode, shown in fig

18、ure 2. In one shot more than red light frequency is premise, escape from the optoelectronic cathode surface by positive potential attracted the anode in photoelectric tube forming space, called the current stream. Then if light intensity increases, the number of photons bombarded the cathode multipl

19、ied, unit of time to launch photoelectron number are also increasing, photo-current greatens. In figure 2 shows circuit, current and resistance is the voltage drop across the only a function of light intensity relations, so as to achieve a photoelectric conversion. When the LTT optoelectronic cathod

20、e K, electronic escape from the cathode surface, and was the photoelectric anode is an electric current, power plants absorb deoxidization device in the load resistance - I, the voltage Phototubes photoelectric characteristics fig.03 shows, from the graph in flux knowable, not too big, photoelectric

21、 basic characteristics is a straight line. 2. Photoelectric times had the sensitivity of vacuum tube due to low, so with people developed has magnified the photomultiplier tubes photo-current ability. Figure 4 is photomultiplier tube structure schematic drawing. 图4光电倍增结构示意图From the graph can see pho

22、tomultiplier tubes also have A cathode K and an anode A, and phototubes different is in its between anode and cathode set up several secondary emission electrodes, D1, D2 and D3. They called the first multiply electrode, the second multiply electrode,. Usually, double electrode for 10 15 levels. Pho

23、tomultiplier tubes work between adjacent electrode, keeping a certain minimum, including the cathode potential potentials, each multiply electrode potential filtering increases, the anode potential supreme. When the incident light irradiation, cathodic K escape from the optoelectronic cathode multip

24、lied by first accelerated, by high speed electrode D1 bombarded caused secondary electron emission, D1, an incident can generate multiple secondary electron photonics, D1 emit of secondary electron was D1, D2 asked electric field acceleration, converged on D2 and again produce secondary electron emi

25、ssion. So gradually produce secondary electron emission, make electronic increased rapidly, these electronic finally arrived at the anode, form a larger anode current. If a n level, multiply electrodes at all levels for sigma, the multiplication of rate is the multiplication of photomultiplier tubes

26、 can be considered sigma n rate, therefore, photomultiplier tube has high sensitivity. In the output current is less than 1mA circumstances, it in a very wide photoelectric properties within the scope of the linear relationship with good. Photomultiplier tubes this characteristic, make it more for l

27、ight measurement. 3 and photoconductive resistance photoconductive resistance within the working principle is based on the photoelectric effect. In semiconductor photosensitive material ends of mount electrode lead, it contains transparent window sealed in the tube and shell element photoconductive

28、resistance. Photoconductive resistance properties and parameters are: 1) dark resistance photoconductive resistance at room temperature, total dark conditions stable resistance called dark resistance, at the current flow resistance is called dark current. 2) light resistance photoconductive resistan

29、ce at room temperature and certain lighting conditions stable resistance measured, right now is called light resistance of current flow resistance is called light current. 4, volt-ampere characteristics of both ends photoconductive resistance added voltage and current flows through photoconductive r

30、esistance of the relationship between called volt-ampere characteristics shown, as shown in figure 5. From the graph, the approximate linear volt-ampere characteristics that use should be limited, but when the voltage ends photoconductive resistance, lest than shown dotted lines of power consumption

31、 area 5, photoelectric characteristics photoconductive resistance between the poles, light when voltage fixed the relationship between with bright current photoelectric characteristics. Called Photoconductive resistance photoelectric characteristics is nonlinear, this is one of the major drawback of

32、 photoconductive resistance. 6, spectral characteristics is not the same incident wavelength, the sensitivity of photoconductive resistance is different also. Incidence wavelength and photodetector the relationship between relative sensitivity called spectral characteristics. When used according to

33、the wavelength range by metering, choose different material photoconductive resistance. 7, response time by photoconductive resistance after photo-current need light, over a period of time (time) rise to reach its steady value. Similarly, in stop light photo-current also need, over a period of time (down time) t