2. The principle of the energy-saving lamp: the two poles of the energy-saving lamp are ordinary tungsten wires. After the tungsten wire is energized and heated, the electrons can be emitted. A relatively high voltage is applied to both sides of the lamp to form an electric field. The tube is accelerated to form a stream of electrons with a certain speed and energy. The tube is vacuumed and filled with mercury, which is what we call mercury. In the case where the lamp is energized and heated, the mercury is evaporated from the liquid state to a gaseous state, and a mercury atom in a free state is formed. The electrons in the electron flow hit the mercury atom at a certain speed, causing the mercury atom to be excited and become an excited state. It is called a step, and the excited state of mercury spontaneously falls back after a short time. In the original state, ultraviolet light is released at the same time, and ultraviolet light cannot be used for illumination . Therefore, we apply some fluorescent substances on the inner wall of the tube. Under the bombardment of ultraviolet light, the fluorescent substance is excited to emit a relatively natural light. Can be used for our lighting. The more common energy-saving lamps on the market have general ordinary lamps and three-primary lamps that are gradually becoming mainstream. Compared with incandescent bulbs, they have the advantage of saving electricity. The difference is that the color rendering of ordinary lamps is low, while the lamps of the three primary colors show a natural sunlight color, and the color rendering and light efficiency are better than ordinary ordinary lamps. From the above we can know that mercury plays a mediating role in energy-saving lamps, and no mercury energy-saving lamps will not emit light. There is very little mercury in each tube.

According to the investigation: a thick tube diameter fluorescent lamp with a diameter of 36 mm contains 25 to 45 mg of mercury, and a small diameter tube with a diameter of 26 mm contains 20 mg of mercury and a diameter of 10 mm. The compact fluorescent lamp contains 10 mg of mercury. Mercury is liquid at room temperature and is a flowable silver-white liquid metal. Mercury exists as a gas discharge medium in fluorescent tubes, which not only improves the light efficiency of the lamp, but also enriches the type of light source. Therefore, current energy-saving lamp sources contain mercury. Since the boiling point of mercury is very low, it can be evaporated at normal temperature. Immediately after the broken fluorescent tube is broken, mercury vapor is emitted to the surroundings, and the concentration of mercury in the surrounding air can be instantaneously 10 to 20 mg per cubic meter. The maximum allowable concentration in air is 0.01 mg per cubic meter. It can also flow with the air. Once the mercury entering the body exceeds a certain threshold, it will destroy the central nervous system of the human body, causing great harm to the body. Mercury is difficult to remove after entering the human body.

In fact, there is generally no pollution in the use of mercury-containing lamps. The pollution is mainly caused by the electric light source being discarded after being scrapped. The rupture causes mercury to diffuse into the air, endangering human health and polluting the environment. Due to the difficulty of recycling and the low value of recycling, and its many other ills, the only way is to eliminate it.

What are the disadvantages of energy-saving lamps?

A. Mercury pollution in the production process and after the use of waste. At present, Western countries pay considerable attention to mercury pollution. The people of the country are also increasingly aware of the harmfulness of mercury pollution.

B, because it is a glass product, easy to break, not easy to transport, not easy to install.

C, its power consumption is still too big.

D, easy to damage, short life, energy saving does not save money, this sentence is its best portrayal.

3, LED lights

Led is made of a III-IV compound, such as GaAs (gallium arsenide), GaP (gallium phosphide), GaAsP (phosphorus gallium arsenide) and other semiconductors, the core of which is the PN junction. Therefore, it has the IN characteristic of a general PN junction, that is, forward conduction, reverse cutoff, and breakdown characteristics. In addition, it has luminescent properties under certain conditions. At the forward voltage, electrons are injected into the P region from the N region, and holes are injected into the N region from the P region. A part of the minority carriers (small children) entering the other area is combined with the majority carriers (multiple sub-) to emit light.

Assuming that luminescence occurs in the P region, the injected electrons directly composite with the valence band holes to emit light, or are first captured by the luminescent center and then condensed with the holes. In addition to this luminescent composite, some electrons are trapped by the non-luminous center (this center is near the middle of the conduction band and the intermediate band), and then recombined with the holes, and the energy released each time is not large, and visible light cannot be formed. The greater the ratio of the composite amount of luminescence to the non-luminous composite amount, the higher the photon efficiency. Since the recombination emits light in the minority carrier diffusion region, light is generated only within a few μm of the PN junction surface.

Theoretically and practically, the peak wavelength λ of light is related to the forbidden band width Eg of the semiconductor material in the light-emitting region, that is, the unit of Eg in the formula λ≈1240/Eg(mm) is electron volt (eV). If visible light (wavelength between 380 nm and 780 nm red) is produced, the Eg of the semiconductor material should be between 3.26 and 1.63 eV. Light longer than the wavelength of red light is infrared light. There are now infrared, red, yellow, green and blue light - emitting diodes , but the blue light diodes are expensive and expensive, and are not commonly used.

LED lighting features:

A. The meaning of the limit parameters

(1) Allowable power consumption Pm: The maximum value of the product of the forward DC voltage applied to the LED and the current flowing through it. Above this value, the LED is hot and damaged.

(2) Maximum forward DC current IFm: The maximum forward DC current allowed to be applied. Exceeding this value can damage the diode.

(3) Maximum reverse voltage VRm: The maximum reverse voltage allowed to be applied. Above this value, the LED may be damaged by breakdown.

(4) Working environment topm: The ambient temperature range in which the LED can work normally. Below or above this temperature range, the LED will not work properly and the efficiency will be greatly reduced.

B. Status of development:

In the context of the current global energy shortages, the energy conservation is an important issue for us in the future. In the field of lighting, the application of LED lighting products is attracting the attention of the world. LED is a new type of green light source. It is bound to be the trend of future development. In the 21st century, it will enter the era of new lighting sources represented by LED.

The Chinese LED industry started in the 1970s. After more than 30 years of development, China's LED industry has initially formed a relatively complete industrial chain including LED epitaxial wafer production, LED chip preparation, LED chip packaging and LED product application. Under the impetus of “National Semiconductor Lighting Project”, seven national semiconductor lighting engineering industrialization bases in Shanghai, Dalian, Nanchang, Xiamen, Shenzhen, Yangzhou and Shijiazhuang were formed. The Yangtze River Delta, the Pearl River Delta, the Triangle and the North have become the gathering places for the development of China's LED industry.

At present, the development of China's semiconductor lighting industry is improving, the development of epitaxial chip companies is particularly rapid, the scale of packaging enterprises continues to grow rapidly, and lighting applications have made great progress. In 2007, the output value of China's LED application products has exceeded 30 billion yuan. It has become the world's largest producer and exporter of LED full-color display, solar LED, landscape lighting and other applications. The emerging semiconductor lighting industry is taking shape. Domestically, it has formed certain characteristics in the field of lighting. Among them, outdoor lighting has the fastest development. There are hundreds of LED street lamp companies and dozens of demonstration roads have been built. However, domestic large-size LCD backlights and automobile headlights still lag behind.

The concentrated display of LED lighting in the 2008 Beijing Olympic Games gave people a new understanding of LEDs and effectively promoted the development of China's semiconductor lighting industry. At present, China's semiconductor industry is large and not strong, and its core competitiveness still needs to be further improved. For domestic enterprises, it is the primary task to strengthen the product quality and technology level, improve the ability to obtain the price of the patent in the future, or gradually break through the core patent through research and development.

C. Development trends:

LED is called the fourth generation of illumination source or green light source. It has the characteristics of energy saving, environmental protection, long life and small size. It can be widely used in various fields such as indication, display, decoration, backlight , general illumination and urban night scene. In recent years, some economically developed countries in the world have launched a fierce technical competition around the development of LED. The United States has invested $500 million since 2000 to implement the National Semiconductor Lighting Program. The European Union also announced the launch of a similar "Rainbow Program" in July 2000. With the support of the “863” program, the Ministry of Science and Technology of China first proposed the development of semiconductor lighting plans in June 2003.

D. Advantages:

High energy saving: Energy-saving energy is environmentally friendly without pollution. DC drive, ultra-low power consumption (single tube 0.03-0.06 watts) electro-optical power conversion is close to 100%, the same lighting effect is more than 80% energy saving than traditional light sources.

Long life: LED light source lamp some people call long, which means light never goes out. Solid cold light source, epoxy resin package, there is no loose part in the lamp body, there are no shortcomings such as filament light-emitting, heat deposition, light decay, etc. The service life can reach 60,000 to 100,000 hours, which is 10 times longer than the traditional light source. the above.

Multi-variable: LED light source can use the principle of red, green and basket. Under the control of computer technology, the three colors have 256 levels of gray and can be mixed arbitrarily, which can produce 256×256×256=16777216 colors to form different lights. The combination of colors is varied, enabling a variety of dynamic changes and various images.

Environmental protection: better environmental protection, no ultraviolet and infrared rays in the spectrum, no heat, no radiation, little glare, and waste can be recycled, no pollution, no mercury, cold light source, safe touch, typical green Lighting source.

High-tech tip: Compared with the monotonous lighting effect of traditional light sources, LED light source is a low-voltage microelectronic product, which successfully combines computer technology, network communication technology, image processing technology, embedded control technology, etc., so it is also a digital information product. Semiconductor optoelectronic device "high-tech" technology, with online programming, unlimited upgrades, flexible and changeable features.

E. Terminology:

Wavelength: The change in color intensity of light can be described by data. This data is called wavelength. The wavelength of light we can see ranges from 380 to 780 nm. Unit: nanometer (nm)

Brightness: Brightness refers to the degree of light and darkness of an object, defined as the luminous intensity per unit area. Unit: Nit (nit)

Light intensity: refers to the brightness of the light source. That is, it means the physical quantity of the visible light radiation emitted by the light source in a certain direction and range.

Unit: Candlelight (cd)

Luminous flux: The sum of the amount of visible light emitted by the source per second. Unit: Lumens (Lm)

Light effect: The luminous flux emitted by the light source divided by the power of the light source. It is an important indicator of energy saving in light sources. Unit: lumens per watt (Lm/w).

Color rendering: The degree to which a light source is presented to an object, that is, the degree to which the color is realistic. Usually called the "color rendering index" unit: Ra.

Color temperature: When the color of the light emitted by the light source is the same as the color of the black body at a certain temperature, the temperature of the black body is called the color temperature of the light source.

Unit: Kelvin (k).

Glare: There is a very bright object in the field of view or a strong contrast of brightness. The visual discomfort caused by it is called glare. Glare is an important factor affecting the quality of lighting.

Synchronization: Two or more LED lights can be operated normally according to the program in a specified time. Generally speaking, the LED lighting of the internal control mode is the basic requirement for the coordinated change of the LED lights.

Protection level: IP protection level is to classify the lamp according to its dustproof and moisture-proof characteristics. It consists of two numbers. The first number represents the level of dustproof and prevent foreign objects from invading the lamp (0-6 ), the second number represents the degree of sealing of the luminaire against moisture and water intrusion (0-8). The higher the number, the higher the protection level.

A consumer group now features LED lighting products, already have a stable of three consumer groups: the first major consumer group is the engineering company that provides personalized lighting engineering design and production and processing; second largest consumer groups, industrial enterprises, industrial Specially-designed LEDs are used for product development; the third is domestic lighting brand enterprises that carry out OEM processing. Of course, it also includes OEM processing for international lighting and lighting brands. According to the analysis of relevant institutions, in 2010, the output value of China's LED industry will exceed 150 billion yuan; double the total output value in 2008, the total output value in 2008 is about 70 billion yuan.

2. Market share China is the world's largest producer of lighting sources and lamps, but mainly produces low-end products, accounting for about 18% of the global market. In the industrial chain, LED epitaxial wafers and LED wafers account for about 70% of the industry's profits, LED applications account for about 10%-20%; LED packaging is less than 10%.

III. Market competition environment In the lighting market, the penetration rate of LED lighting has expanded rapidly, and the market price war is brewing in 2010. However, it is worth noting that because LED lighting subverts the traditional sales mode of lamps and light sources, and the degree of customization is high, under the pressure of LED lighting manufacturers, if the pockets are not deep enough, they will not be able to balance product quality and price competitiveness. And fear of falling into the fate of being merged or eliminated by the market.