2013年03月22日
Elderly Concept Phone
The whole stay aging trend is worsening the lives of the elderly are more concerned about. In response to this phenomenon, the designer Anurag Sarda specifically designed for the elderly this concept phone Edd Mobile Phone.
We can see Edd Mobile Phone has a very simple body design, the candy bar design to provide a better grasp of sense for those hands powerless elderly. Age growth will decline due to the vision of the elderly, the phone LED screen is compressed to one-third of the entire phone, the most notable feature of the fuselage is that a very large number of keys, to facilitate the elderly to enter a phone number operation. In addition there is a smiley face on top of it, it can be better to help the elderly positioning ear position, so do not close the phone can clearly hear the sound, while avoiding the damage caused by the phone fever on the face.
Edd Mobile Phone using electromagnetic induction charging, and the level of radiation generated by the phone to geographical phone for the elderly, how much forgetfulness, so this phone is set away from the sensor, forgotten when the phone is 1015 feet away from your body. tone, it will be issued. Entire phone emits light and can see clearly in low-light situations. Edd Mobile Phone smartphone does not belong in the traditional sense, but any course has some of the characteristics of the smart phone, one of which is voice dialing.
We can see Edd Mobile Phone has a very simple body design, the candy bar design to provide a better grasp of sense for those hands powerless elderly. Age growth will decline due to the vision of the elderly, the phone LED screen is compressed to one-third of the entire phone, the most notable feature of the fuselage is that a very large number of keys, to facilitate the elderly to enter a phone number operation. In addition there is a smiley face on top of it, it can be better to help the elderly positioning ear position, so do not close the phone can clearly hear the sound, while avoiding the damage caused by the phone fever on the face.
Edd Mobile Phone using electromagnetic induction charging, and the level of radiation generated by the phone to geographical phone for the elderly, how much forgetfulness, so this phone is set away from the sensor, forgotten when the phone is 1015 feet away from your body. tone, it will be issued. Entire phone emits light and can see clearly in low-light situations. Edd Mobile Phone smartphone does not belong in the traditional sense, but any course has some of the characteristics of the smart phone, one of which is voice dialing.
Posted by novaking at
10:45
│Comments(0)
2013年03月16日
Sensor into Security Industry
As security awareness is deeply rooted in the hearts of the people, and now more and more people began to focus on security surveillance industry, security monitoring market is another combination of sensor industry development space, many of security surveillance products are inseparable the support of the sensor, and therefore is in the period of development, and has a broad market space security monitoring market more market opportunities will be provided for the sensor industry.
The sensor gradually into the security industry
The security industry products mostly related to real-time information included in video surveillance, sound admission, but if a long time to open the device involved in the problems of storage capacity, the more time recording, you need a larger storage space. To solve this problem, some products using infrared sensors and other equipment needed before start, saves space, and now the entry of the gas sensor, will make more rational application of these devices, more scientific
The combined sensor is formed by different combinations of products in a single sensor package added accelerometers, gyroscopes or electronic compass, so that through the integration in each single package can be increased more applications, and as much as possible to save space and cost. This sensor is more used in electronic products which price pressures or limited board space, mobile consumer electronics products such as mobile phones and tablet PCs in the next few years, the separation of the various sensor devices will be gradually integrated into the 6-axis inertial sensor measurement unit (IMU), become the dominant application form, will be more widely applied to mobile phone and tablet PC market.
In addition, as some mandatory use of certain technology products, the cost on to become a key factor, for example, is now becoming more common off from the automotive sector, in order to reduce production costs, a combination of sensors has become the first choice for many automobile production businesses. The past two years in a these applications increasingly wide range of areas to promote, the combined sensor market sales has been in a rising state.
Smart phones, tablet PCs, security industry, and automotive applications market is the fastest growing market, and there is a huge market space is still hidden in the future vacancies, so the market potential is still considerable, and this is in the period of development of the combination sensor The industry has brought more new development opportunities.
Security sensors development of a new dynamic
Sensors and detection technology has been widely development in the past year, while also showing a lot of new features and trends. Detection technology transfer gradually from indoor to outdoor, the electronic pulse fence, cable leak detectors perimeter devices emerge gradually replaced the traditional infrared shooting and other outdoor detection equipment. Security monitoring market for sensors market opportunity to explore most of the security industry products related to video surveillance, sound admission and immediate information included, but if a long time to open the device, it will involve the issue of storage capacity, the more time recording, you need the greater storage space.
To solve this problem, some products using infrared sensors and other equipment when start, saves space, and now the entry of the sensor will make the application of these devices is more reasonable, more scientific. The combined sensor is formed by different combinations of products in a single sensor package added accelerometers, gyroscopes or electronic compass, so that through the integration in each single package can be increased more applications, and as much as possible to save space and cost.
This sensor is more used in electronic components which price pressures or limited board space, mobile consumer electronics products such as mobile phones and tablet PCs in the next few years, the separation of the various sensor devices will be gradually integrated into the 6-axis inertial sensor measurement unit (IMU), become the dominant application form, will be more widely applied to mobile phone and tablet PC market.
The sensor industry development trend
In the sensor market, there will always continue to extend the application. Today, the development of the sensor space extended to security monitoring market. Because a lot of security surveillance products have a close relationship, and sensors, the sensors have many problems in the security industry have been a good solution. In the development during the period due to the security, and the security market in the future there is a lot of space, so also will bring a lot of opportunities for sensor manufacturer.
Sensor in the security industry contributed, for example, even if the inclusion of data such as video monitoring and voice recording, long recording time of storage devices, the greater the amount of storage needed on this issue, some security products to see infrared sensors for startup and other sensor, this sensor applications saves a lot of space, making the application of the device is more scientific.
Is very popular combination of sensors, is also very popular in the security, acceleration sensor in the sensor package, gyro or electronic compass formed by different combinations of products can increase more application functionality, integrated in a single package, and as much as possible to save the space and cost. Similar to the automotive industry, in order to reduce production costs, the combined sensor has become the first choice for many automobile production businesses. In a these applications increasingly wide range of areas to promote the two years combined sensor market sales has been in a state of rising costs on to become a key factor. The combination of sensors in the future so will be application of the trend, the market potential is great, because there are a lot of market vacancies waiting for the sensor to make up.
Sensor is a detecting means, can feel the information to be measured, and can detect the feel of the information, is converted into an electrical signal according to certain rules, or other desired forms of information output to meet information transmission, processing, storage, display, record and control requirements. It is the most important part of the automatic detection and automatic control.
The sensor gradually into the security industry
The security industry products mostly related to real-time information included in video surveillance, sound admission, but if a long time to open the device involved in the problems of storage capacity, the more time recording, you need a larger storage space. To solve this problem, some products using infrared sensors and other equipment needed before start, saves space, and now the entry of the gas sensor, will make more rational application of these devices, more scientific
The combined sensor is formed by different combinations of products in a single sensor package added accelerometers, gyroscopes or electronic compass, so that through the integration in each single package can be increased more applications, and as much as possible to save space and cost. This sensor is more used in electronic products which price pressures or limited board space, mobile consumer electronics products such as mobile phones and tablet PCs in the next few years, the separation of the various sensor devices will be gradually integrated into the 6-axis inertial sensor measurement unit (IMU), become the dominant application form, will be more widely applied to mobile phone and tablet PC market.
In addition, as some mandatory use of certain technology products, the cost on to become a key factor, for example, is now becoming more common off from the automotive sector, in order to reduce production costs, a combination of sensors has become the first choice for many automobile production businesses. The past two years in a these applications increasingly wide range of areas to promote, the combined sensor market sales has been in a rising state.
Smart phones, tablet PCs, security industry, and automotive applications market is the fastest growing market, and there is a huge market space is still hidden in the future vacancies, so the market potential is still considerable, and this is in the period of development of the combination sensor The industry has brought more new development opportunities.
Security sensors development of a new dynamic
Sensors and detection technology has been widely development in the past year, while also showing a lot of new features and trends. Detection technology transfer gradually from indoor to outdoor, the electronic pulse fence, cable leak detectors perimeter devices emerge gradually replaced the traditional infrared shooting and other outdoor detection equipment. Security monitoring market for sensors market opportunity to explore most of the security industry products related to video surveillance, sound admission and immediate information included, but if a long time to open the device, it will involve the issue of storage capacity, the more time recording, you need the greater storage space.
To solve this problem, some products using infrared sensors and other equipment when start, saves space, and now the entry of the sensor will make the application of these devices is more reasonable, more scientific. The combined sensor is formed by different combinations of products in a single sensor package added accelerometers, gyroscopes or electronic compass, so that through the integration in each single package can be increased more applications, and as much as possible to save space and cost.
This sensor is more used in electronic components which price pressures or limited board space, mobile consumer electronics products such as mobile phones and tablet PCs in the next few years, the separation of the various sensor devices will be gradually integrated into the 6-axis inertial sensor measurement unit (IMU), become the dominant application form, will be more widely applied to mobile phone and tablet PC market.
The sensor industry development trend
In the sensor market, there will always continue to extend the application. Today, the development of the sensor space extended to security monitoring market. Because a lot of security surveillance products have a close relationship, and sensors, the sensors have many problems in the security industry have been a good solution. In the development during the period due to the security, and the security market in the future there is a lot of space, so also will bring a lot of opportunities for sensor manufacturer.
Sensor in the security industry contributed, for example, even if the inclusion of data such as video monitoring and voice recording, long recording time of storage devices, the greater the amount of storage needed on this issue, some security products to see infrared sensors for startup and other sensor, this sensor applications saves a lot of space, making the application of the device is more scientific.
Is very popular combination of sensors, is also very popular in the security, acceleration sensor in the sensor package, gyro or electronic compass formed by different combinations of products can increase more application functionality, integrated in a single package, and as much as possible to save the space and cost. Similar to the automotive industry, in order to reduce production costs, the combined sensor has become the first choice for many automobile production businesses. In a these applications increasingly wide range of areas to promote the two years combined sensor market sales has been in a state of rising costs on to become a key factor. The combination of sensors in the future so will be application of the trend, the market potential is great, because there are a lot of market vacancies waiting for the sensor to make up.
Sensor is a detecting means, can feel the information to be measured, and can detect the feel of the information, is converted into an electrical signal according to certain rules, or other desired forms of information output to meet information transmission, processing, storage, display, record and control requirements. It is the most important part of the automatic detection and automatic control.
Posted by novaking at
10:51
│Comments(0)
2013年03月06日
White LED Road Lighting 2
White LED operation up to 20% energy form of photon radiation, and the remaining 80% of the energy is transformed into heat can make chips and phosphor coating heating. For low-power LEDs, the 80% of the input power of the heating effect does not rise too much so that the chip temperature, little effect of the LED luminous efficiency, life and operational state. But 0.5W or more high-power white LED, more than 80% of its power concentrated in a very small pn junction area, and will make the chip and phosphor coating substantial warming, which affects not only the luminous efficiency, but will also cause rapid light failure and shortened life expectancy.
50000 or 10-hour long-life judge is estimated monochromatic LED small power LED early stage of development, the power LED, the white light LED chip and phosphor baked at a high temperature for a long time, will make the life of a substantial decline. This is the poor design of the LED lighting engineering operation in three to four months after the sharp decline of the light enables designers often had to replace the light source.
The Ⅲ LED road lighting the the white LED huge investment and excessive publicity, to make this area part of the personnel sent to the high expectations of the white LED, white LED eager to push conventional functional lighting, a lot of personnel in this area and the direct promotion of road lighting, over the years the country completed the LED road lighting and LED photovoltaic road lighting model works dozens (authors examine the excessive road lighting using LED as the light source) and has made enough experience and lessons to be summarized. I think that this test should be a temporary slowdown, the conditions are ripe and then restart.
Road lighting the main light source in China and developed countries is still high pressure sodium lamp, a small number of metal halide lamps, the former 100-120lm / W luminous efficiency, color rendering index of only 20 or less, the luminous efficiency of the latter 80 ~ 100lm / W, color rendering index of 80 or so, taking into account the energy consumption of electrical accessories, such light source system light efficiency 75lm / W ~ 90lm / W between. The road lighting the lighting device is not high optical reflectance, and is often below 60%. About 40% of the use of such lamps direct light to the ground, and the remaining 60% of the light is fired at the ground require the approval of the lamps reflected. Rough estimate to remove a variety of loss does not exceed 76% total light utilization of conventional road lighting, and thereby estimate the ultimate effect of light is about 60lm / W to 70lm / W. In addition, due to unreasonable as well as high-pressure sodium lamp lighting design a special slender columnar luminous body caused by the uneven distribution of light for the dark area between the road centerline and two lights meet lighting standards, the design had to use more power, more high luminous flux of the light source to meet the dark area of the illumination requirements, and thus more caused a waste of energy.
Based on the above, LED road lighting designers that the use of the LED directional radiation performance road lighting design, can significantly reduce energy waste, they believe that the white LED is more energy efficient than high pressure sodium lamps. They designed a number of use of high power LED (1W, 3W) road lighting program and made a model project. However, most of these model projects has not been carefully tested and certified. One lighting design is 120 1W white LED matrix distribution 200 × 250mm rectangular planar circuit board, board wiring, then the overall installed in conventional street lamps. This design is very unscientific, the program selected LED single light-emitting no more than 40lm estimated to 40lm theory, taking into account the the supporting electrical loss (10%) and 90% light utilization, light use of the actual system rate of less than 32 lm / W, 120 LED's total luminous flux approximately 4300lm. If the LED light emission angle of 120 °, press this design 4300lm of light will be the emission angle of 120 ° toward the bottom. Conceivable that such a design will enable ground light is very unevenly distributed between the middle of the street and the light poles completely dark. Did not consider them these facilities to take effective measures to cool the LED substrate, so the LED is concentrated in such a small space, more than 80 watts of power consumption the continued accumulation will make the chip temperature is too high, blocking pressure drop decreased the fat Blu-ray to the long direction of the drift, which will inevitably lead to a serious decline of its light efficiency. Investigated the outskirts of Beijing in a photovoltaic lighting model road (the total power of the light source to 105W) lamp illumination of only 3.5 lux, It is said that the previous two and a half, the completion of the project, the lamp illumination of 7 lux. Lamp diameter of 15 meters away from the place, there is no lighting effects. Those engineering samples in Jiangsu, Zhejiang, Shandong, Guangdong, Guangdong Shunde somewhere, and somewhere in Shenzhen LED road lighting demonstration Street dimly lit, and the light source must be replaced every 3-5 months.
LED road lighting tests must be under the guidance of experts, after strict certification and design to implementation.
Guangdong enterprise specializing in LED road lighting engineering from access to the lessons, they take measures to make the 1W LED work in 0.5 ~ 0.6W or 3W LED design 1W use, so although the cost is high, light low efficiency, poor lighting effects, but basically solved the light fades and life issues.
Hot in view of China's white LED, developed specifically for the Chinese for road lighting white LED 1W LED front-end packaging materials designed for the specific structure of the convex lens, and the alleged use of such LED without a multinational twice, three times optical design can get a uniform illumination of the road, and easy to use. The company claims that such LED cold light efficiency 70lm / W, compared to 50lm / W in normal use.
Zhejiang, a company designed for road lighting, the integrated-type white LED, the plurality of blue LED chips assembled on the same substrate, using a specially designed larger convex lens for the output window, the coated phosphor in the inner wall of the output window, so that all the LED chips jointly excited the same phosphor coating. This modular LED light-emitting characteristics transformed similar with conventional spherical light source, is more convenient to use, but this structure LED substrate cooling problem persists.
Note that together the plurality of LED road lighting design, in addition to a sufficient luminous flux and a reasonable optical design in order to ensure reasonable light distribution and, more importantly, the heat problem. As mentioned above, approximately 80% of the energy consumption of the LED transformed into heat, high temperature semiconductor devices, if you can not heat generated instant guide to walk you will cause serious consequences.
Road with led lighting conditions are not yet mature, and both need to be LED light efficiency improvement and power increase, more remains to be effective LED cooling solution and measures to solve, of course, the more reasonable optical design is very important.
Of Ⅳ DOE's assessment of the effectiveness of commercial LED products (CALiPER)
LED luminous efficiency and life expectancy indicators, there is a big disagreement, one of the important reasons is that there is no uniform standards and test methods, such as the lighting industry has always been as parameters of the stable operation of the luminous flux output and optical efficiency, while LED industry in general to the initial (cold), the maximum luminous flux and luminous efficiency as the standard, there are many differences in the color rendering index measuring methods and standards of life standards and measurement methods are different, the data falls far short , the evaluation is also very different.
This problem is not only our country, in a foreign country is equally serious, the U.S. Department of Energy had discovered seven market product survey, they were carried out from December 2006 to September 2008, in 2008 alone on continuous January three spot checks were carried out in May and September, and was released in September of the assessment and reporting of the effectiveness of the "commercial LED products CALiPER (Commercially Available LED Product Evaluation & Reporting), they released the data and conclusions are negative in the detect 24 types of products, only two categories (ejection downlight) data and product specifications consistent few LED luminous efficiency of 62lm / W, an average of only 32lm / W the low lack 10lm / W, far from being able to achieve energy Star of the standard. Chaos and data exaggerated propaganda made a very harsh and negative conclusions, including the luminous efficiency, color temperature, color quality, light distribution, as well as the power factor of the lighting system. Optical efficiency, in particular, tend to exaggerate the propaganda they found 2 to 3 times higher than the general users do not understand this. The conclusion of the U.S. Department of Energy is required to establish uniform standards to regulate product quality and indicators, the above problems in our country is more prominent and important.
The Ⅴ conclusions LED is an excellent light source of the future, the specific luminescence mechanism to give it a range of features and characteristics. Because of its small luminous body, the density of the medium, the light emitting very concentrated, high brightness. Even if the power is very small, little luminous flux of LED also give the human eye in a clear, bright the correct optical signal, to indicate, show no superiority than with the theory, its application has an extremely broad in the display area, everywhere. Low-power color LED also decorative lighting and art lighting display unique features and charm, and the 2008 Beijing Olympics, give full play to the LED such functions.
The white LED is an outstanding member of the LED family has a lot of features and characteristics. One of the important purpose of the development of white LED is used to replace the conventional electric light sources such as incandescent, fluorescent, high intensity discharge lamps, etc., however it seems its development as expected rapid. Actual market white LED luminous efficiency of about 40lm / W, up more than 50lm / W for functional lighting, these parameters are to be increased. Even more important for the promotion of the white LED is a cheap and efficient development of the cooling system.
As is known, other than the addition to the LED, all the light emitting body of the light source are to work at high temperatures, a high temperature of several thousand degrees, is to ensure its efficient light-emitting conditions, but the temperature rise of the semiconductor light emitting device such as an LED, a light emitting center is extremely harmful, if this problem can not be solved, the LED light efficiency improvement, power increase is limited.
Small power white LED (1W and below) in a wide range of applications shows tremendous advantages, such as very widely in the small space for local lighting, garden lights, close small power flashlight, lamps and emergency lighting room for growth. White LED does not require, nor conditions and in high-power conventional lighting sources compete for road lighting market.
Not reflective objects, the wide open spaces around the road lighting indoor lighting, road lighting requirements of the luminous flux, which is most of the road lighting 250W 400W high luminous flux high pressure sodium reason, this lamp luminous flux 28000lm to 48000lm range terms 1W, 3W white LED replaces the requirement of the LEDs is too large, the high cost and difficulty of design, and the effect is difficult ideal. In recent years LED road lighting has made a lot of lessons to be white LED light efficiency is not high, life is not long, and I think that should be put off for road lighting with LED test, to be successfully developed higher efficiency, more power white LED and a cheap and efficient cooling system before advancing.
Road lighting consumption for huge energy has great potential to be tapped, the transformation imperative, Philips and Fudan University in cooperation recently, this a very useful study [5], they concluded that the ceramic metal halide lamps is a very good replacement products in the high-pressure sodium lamps.
50000 or 10-hour long-life judge is estimated monochromatic LED small power LED early stage of development, the power LED, the white light LED chip and phosphor baked at a high temperature for a long time, will make the life of a substantial decline. This is the poor design of the LED lighting engineering operation in three to four months after the sharp decline of the light enables designers often had to replace the light source.
The Ⅲ LED road lighting the the white LED huge investment and excessive publicity, to make this area part of the personnel sent to the high expectations of the white LED, white LED eager to push conventional functional lighting, a lot of personnel in this area and the direct promotion of road lighting, over the years the country completed the LED road lighting and LED photovoltaic road lighting model works dozens (authors examine the excessive road lighting using LED as the light source) and has made enough experience and lessons to be summarized. I think that this test should be a temporary slowdown, the conditions are ripe and then restart.
Road lighting the main light source in China and developed countries is still high pressure sodium lamp, a small number of metal halide lamps, the former 100-120lm / W luminous efficiency, color rendering index of only 20 or less, the luminous efficiency of the latter 80 ~ 100lm / W, color rendering index of 80 or so, taking into account the energy consumption of electrical accessories, such light source system light efficiency 75lm / W ~ 90lm / W between. The road lighting the lighting device is not high optical reflectance, and is often below 60%. About 40% of the use of such lamps direct light to the ground, and the remaining 60% of the light is fired at the ground require the approval of the lamps reflected. Rough estimate to remove a variety of loss does not exceed 76% total light utilization of conventional road lighting, and thereby estimate the ultimate effect of light is about 60lm / W to 70lm / W. In addition, due to unreasonable as well as high-pressure sodium lamp lighting design a special slender columnar luminous body caused by the uneven distribution of light for the dark area between the road centerline and two lights meet lighting standards, the design had to use more power, more high luminous flux of the light source to meet the dark area of the illumination requirements, and thus more caused a waste of energy.
Based on the above, LED road lighting designers that the use of the LED directional radiation performance road lighting design, can significantly reduce energy waste, they believe that the white LED is more energy efficient than high pressure sodium lamps. They designed a number of use of high power LED (1W, 3W) road lighting program and made a model project. However, most of these model projects has not been carefully tested and certified. One lighting design is 120 1W white LED matrix distribution 200 × 250mm rectangular planar circuit board, board wiring, then the overall installed in conventional street lamps. This design is very unscientific, the program selected LED single light-emitting no more than 40lm estimated to 40lm theory, taking into account the the supporting electrical loss (10%) and 90% light utilization, light use of the actual system rate of less than 32 lm / W, 120 LED's total luminous flux approximately 4300lm. If the LED light emission angle of 120 °, press this design 4300lm of light will be the emission angle of 120 ° toward the bottom. Conceivable that such a design will enable ground light is very unevenly distributed between the middle of the street and the light poles completely dark. Did not consider them these facilities to take effective measures to cool the LED substrate, so the LED is concentrated in such a small space, more than 80 watts of power consumption the continued accumulation will make the chip temperature is too high, blocking pressure drop decreased the fat Blu-ray to the long direction of the drift, which will inevitably lead to a serious decline of its light efficiency. Investigated the outskirts of Beijing in a photovoltaic lighting model road (the total power of the light source to 105W) lamp illumination of only 3.5 lux, It is said that the previous two and a half, the completion of the project, the lamp illumination of 7 lux. Lamp diameter of 15 meters away from the place, there is no lighting effects. Those engineering samples in Jiangsu, Zhejiang, Shandong, Guangdong, Guangdong Shunde somewhere, and somewhere in Shenzhen LED road lighting demonstration Street dimly lit, and the light source must be replaced every 3-5 months.
LED road lighting tests must be under the guidance of experts, after strict certification and design to implementation.
Guangdong enterprise specializing in LED road lighting engineering from access to the lessons, they take measures to make the 1W LED work in 0.5 ~ 0.6W or 3W LED design 1W use, so although the cost is high, light low efficiency, poor lighting effects, but basically solved the light fades and life issues.
Hot in view of China's white LED, developed specifically for the Chinese for road lighting white LED 1W LED front-end packaging materials designed for the specific structure of the convex lens, and the alleged use of such LED without a multinational twice, three times optical design can get a uniform illumination of the road, and easy to use. The company claims that such LED cold light efficiency 70lm / W, compared to 50lm / W in normal use.
Zhejiang, a company designed for road lighting, the integrated-type white LED, the plurality of blue LED chips assembled on the same substrate, using a specially designed larger convex lens for the output window, the coated phosphor in the inner wall of the output window, so that all the LED chips jointly excited the same phosphor coating. This modular LED light-emitting characteristics transformed similar with conventional spherical light source, is more convenient to use, but this structure LED substrate cooling problem persists.
Note that together the plurality of LED road lighting design, in addition to a sufficient luminous flux and a reasonable optical design in order to ensure reasonable light distribution and, more importantly, the heat problem. As mentioned above, approximately 80% of the energy consumption of the LED transformed into heat, high temperature semiconductor devices, if you can not heat generated instant guide to walk you will cause serious consequences.
Road with led lighting conditions are not yet mature, and both need to be LED light efficiency improvement and power increase, more remains to be effective LED cooling solution and measures to solve, of course, the more reasonable optical design is very important.
Of Ⅳ DOE's assessment of the effectiveness of commercial LED products (CALiPER)
LED luminous efficiency and life expectancy indicators, there is a big disagreement, one of the important reasons is that there is no uniform standards and test methods, such as the lighting industry has always been as parameters of the stable operation of the luminous flux output and optical efficiency, while LED industry in general to the initial (cold), the maximum luminous flux and luminous efficiency as the standard, there are many differences in the color rendering index measuring methods and standards of life standards and measurement methods are different, the data falls far short , the evaluation is also very different.
This problem is not only our country, in a foreign country is equally serious, the U.S. Department of Energy had discovered seven market product survey, they were carried out from December 2006 to September 2008, in 2008 alone on continuous January three spot checks were carried out in May and September, and was released in September of the assessment and reporting of the effectiveness of the "commercial LED products CALiPER (Commercially Available LED Product Evaluation & Reporting), they released the data and conclusions are negative in the detect 24 types of products, only two categories (ejection downlight) data and product specifications consistent few LED luminous efficiency of 62lm / W, an average of only 32lm / W the low lack 10lm / W, far from being able to achieve energy Star of the standard. Chaos and data exaggerated propaganda made a very harsh and negative conclusions, including the luminous efficiency, color temperature, color quality, light distribution, as well as the power factor of the lighting system. Optical efficiency, in particular, tend to exaggerate the propaganda they found 2 to 3 times higher than the general users do not understand this. The conclusion of the U.S. Department of Energy is required to establish uniform standards to regulate product quality and indicators, the above problems in our country is more prominent and important.
The Ⅴ conclusions LED is an excellent light source of the future, the specific luminescence mechanism to give it a range of features and characteristics. Because of its small luminous body, the density of the medium, the light emitting very concentrated, high brightness. Even if the power is very small, little luminous flux of LED also give the human eye in a clear, bright the correct optical signal, to indicate, show no superiority than with the theory, its application has an extremely broad in the display area, everywhere. Low-power color LED also decorative lighting and art lighting display unique features and charm, and the 2008 Beijing Olympics, give full play to the LED such functions.
The white LED is an outstanding member of the LED family has a lot of features and characteristics. One of the important purpose of the development of white LED is used to replace the conventional electric light sources such as incandescent, fluorescent, high intensity discharge lamps, etc., however it seems its development as expected rapid. Actual market white LED luminous efficiency of about 40lm / W, up more than 50lm / W for functional lighting, these parameters are to be increased. Even more important for the promotion of the white LED is a cheap and efficient development of the cooling system.
As is known, other than the addition to the LED, all the light emitting body of the light source are to work at high temperatures, a high temperature of several thousand degrees, is to ensure its efficient light-emitting conditions, but the temperature rise of the semiconductor light emitting device such as an LED, a light emitting center is extremely harmful, if this problem can not be solved, the LED light efficiency improvement, power increase is limited.
Small power white LED (1W and below) in a wide range of applications shows tremendous advantages, such as very widely in the small space for local lighting, garden lights, close small power flashlight, lamps and emergency lighting room for growth. White LED does not require, nor conditions and in high-power conventional lighting sources compete for road lighting market.
Not reflective objects, the wide open spaces around the road lighting indoor lighting, road lighting requirements of the luminous flux, which is most of the road lighting 250W 400W high luminous flux high pressure sodium reason, this lamp luminous flux 28000lm to 48000lm range terms 1W, 3W white LED replaces the requirement of the LEDs is too large, the high cost and difficulty of design, and the effect is difficult ideal. In recent years LED road lighting has made a lot of lessons to be white LED light efficiency is not high, life is not long, and I think that should be put off for road lighting with LED test, to be successfully developed higher efficiency, more power white LED and a cheap and efficient cooling system before advancing.
Road lighting consumption for huge energy has great potential to be tapped, the transformation imperative, Philips and Fudan University in cooperation recently, this a very useful study [5], they concluded that the ceramic metal halide lamps is a very good replacement products in the high-pressure sodium lamps.
Posted by novaking at
17:53
│Comments(0)
2013年03月06日
White LED Road Lighting 1
LED the development so far, nearly 30-year history, has made great progress, and white LED calendar for more than ten years of rehearsals, the rapid development. LED came into being in the era of severe energy shortages, pollution, and has attracted significant attention. To ease the energy shortage, the mid-1990s, the Japanese government took the lead, following the U.S. government from the financial support of the country's technology and industry to promote the development of solid-state lighting. Our government (Ministry of Science and Technology, led by, including the Department of Energy, Economic and Trade Commission, Ministry of Information Industry, as well as local government) is also strongly supported and funded the research and development of LED and set up a National Semiconductor Industry Association advancing solid-state lighting (China termed 2010 white LED luminous efficiency can be increased to 100 lm / W for semiconductor lighting) plan, and expected , and can be used to a large number of alternative light efficiency of about 90 lm / W fluorescent lamps are widely used in the field of general lighting.
A large number of our businesses, investors, researchers and technical staff have to intervene in this situation, and the large-scale investment to develop LED R & D and production so far is estimated to have invested a total of RMB billions of dollars, in less than a decade achieved outstanding results, and the formation of large-scale industrial chain.
World especially LED white LED so emphasis on their underlying causes, this huge amount of energy consumption and the resulting energy shortages, rising prices, especially caused by the environment has become a very urgent task to make energy savings. A large part of the national energy consumption for lighting. In China and developed countries, electricity for lighting accounts for about total power generation capacity of 12 to 13%, which is a very substantial loss of energy. The light source is still used worldwide inefficient incandescent light source mainly from tapping the potential is very promising.
LED focuses many talents, brilliant achievements, some of the research department announced that they have developed LED reached 120lm / W or even 150 lm / W luminous efficiency under certain conditions. Thus most enterprises have also claimed the luminous efficiency of their product has reached 70lm / W, 90lm / W or higher, the light utilization than the radiation output of each LED optical radiation is directed, even ordinary light source alone directional reflection of the lamps lighting efficiency is higher, and therefore finds that LED is the best functional lighting source, and vigorously promoted to various areas of lighting, a few years ago has been declared the LED will largely replaced by compact fluorescent lamps in 2010, a large scale into the family lighting, and asserted that white LED is the best road illumination light source.
There is no doubt that after 20 years of development, the LED in the display area has been made entirely successful, without than with the theory and has become irreplaceable display devices. Fully display its features decorative lighting, made half of LED outstanding performance in the 2008 Olympic Games opening ceremony to shake the world. But must address the fact that greater limitations in terms of functional lighting white LED persists. China is already the world's largest LED production base and consumer market, LED application fields, but due to the restrictions of the current level of technology and performance, such devices are used for functional lighting is not to use their skills. So-called high power LED, currently on the market can find the most high-power devices, but 3W, even 10W devices in R & D to large-scale production, but for conventional lighting, especially the hundreds of watts of light sources used in road lighting single The granulocyte power err too small. White LED design a lighting project amount must be great, whether it is difficult to design or cost will be worth the wait.
Common evaluation Ⅱ LED light efficiency of LED high light efficiency and long life, and many manufacturers claim their products luminous efficiency of up to 90lm / W or higher, but these data are just some laboratory in the the test initial stage when the LED is still in the highest measured in the cold state data. The so-called 50,000 hours or 100,000 hours life just early estimate of the low-power color LED.
Its theoretical light efficiency can be estimated from the LED light-emitting mechanism. As known LED is the use of carrier recombination and light emission, all of its potential energy in the carrier recombination when transformed into light energy, its internal quantum efficiency of 100% of the purposes of this process alone. Carrier collision with the crystal lattice and the loss of energy in the medium when the composite contained the kinetic energy carried by the carrier, and the electricity is consumed to overcome the resistance of the external circuit are not converted into light. Taking into account the variety of additional energy, the actual carrier recombination within the quantum efficiency does not exceed 90%.
Photons generated when the carrier recombination, has a 50% chance for outgoing radiation, part of the 50% of the photons collide with the lattice and lattice absorption is converted into heat. Portion photon propagation in the different media at the interface will be reflected back to the original medium and is absorbed, addition, as the metal the omentum or transparent conductive film of the output window of the outer electrode also allow a portion of the photons reflected by absorption, these processes will reduce the LED quantum extraction rate, the extraction rate of 80% is located in this part of the photon quantum.
Of photons generated in the carrier recombination, a 50% chance of the incoming radiation, this part of the photons reach the underlying conductive film serves as a reflective mirror, a partially reflective converted to outward output optical photons in this section, however, the inwardly or outwardly The transmission during the collision with the crystal lattice and is partially absorbed, through different media interface will also be part of the reflected or refracted back to the original medium eventually be absorbed. Substrate mirror reflection efficiency and the above process limitations such inward radiation photons into the output light quantum extraction rate does not exceed 40%.
According to the above analysis can estimate the total LED electro-optical conversion efficiency of approximately 54%, which is the ideal case where the estimated result. Any omissions, any defects in the material in the manufacturing process will cause a decrease in the efficiency of energy conversion. Less than 5% of visible light conversion efficiency than incandescent, even compared with the current highest conversion efficiency of high-pressure sodium lamps, ceramic metal halide (electro-optical conversion efficiency of about 30%) is also very high, this is the LED very luring. person prospects reason.
As is known, the 1W energy is completely converted to 555nm wavelength of the yellow light produced when the light flux up to 683lm / W (683lm / W optical power equivalents) approximately 360lm / W, if all is converted to white. As estimated earlier in this article, in the ideal case 555nm yellow LEDs may reach up to about the highest luminous efficiency of 300lm / W, the above estimates are also far from being achieved. Reported the highest light efficiency LED actually only half of the ideal value, and in fact less than 1/4, this is what people On the LED there is great potential to be tapped on the high hopes reason.
The key is to improve the LED luminous efficiency to improve quantum extraction rate, which is to minimize the internal absorption of photons, this is slimline LED reasons. Highest luminous efficiency of ultra-thin (thickness of tens of nanometers) GaN LEDs under conductive film with a high reflective mirror membrane and the inner surface of the output window is made of rough structure, in order to reduce the photon inward reflection, however even so reported the highest light efficiency, but 150lm / W.
The above analysis is monochromatic LED is the monochromatic transformed into the white must then go through a quantum conversion, mostly by emission center wavelength of about 470nm blue LED excitation radiation spectrum center wavelength to 560nm broadband yellow phosphor, which made the blue-yellow mixed white LED, but this led lights efficiency will further reduce required. Photon efficiency can be estimated as follows:
If retained approximately 20% of the Blu-ray LED radiation output, with the remaining 80% of the Blu-ray excited yellow phosphor, in the best case, about 20% of the 80% of the Blu-ray photon absorption for phosphor, and the rest 80% transfer to the center wavelength of 560nm for broadband yellow radiation, this process resulted in an average of 16.1% of the quantum energy loss. Combine the previous data can be estimated that the total energy efficiency does not exceed 40%, and converted to white when the total light efficiency white LED white LED but up 150lm / W. If there is no other breakthroughs, this current white LED may be the highest light efficiency, this luminous efficiency HID lamps, high pressure sodium lamp or ceramic metal halide light sources, such as the current highest light efficiency is also high compared to some. Luminous efficiency has not yet actually achieved, and this half.
We have this experimental study, we use a company's production 1W high brightness blue LED, the center of the spectral radiation wavelength of 470nm see Fig.3 go except SMD LED Package were coated with different thickness of the center wavelength of the radiation is 560nm yellow phosphor coating, after treatment, to measure the emission spectrum thereof. Four typical case is selected from the 24 kinds of samples of different thickness, and its results are shown in Fig.4 a, b, c, d and Schedule. Lumen output in the best case (Fig.4 c) of 38lm (initial cold 50lm), color rendering index of 78.
A well-known multinational companies and technical personnel initial introduced their 1W white LED luminous efficiency reached 70lm / W, the normal operation of the pn junction temperature rise, 50lm / W luminous efficiency reduced.
The results obtained by the Japanese Institute of Materials Science, 2007 nano ceramic center is the highest, they used a center wavelength of 450nm InGaN blue LED and the photon conversion efficiency is high, and has a strong absorption peak at 450nm blue range, low temperature coefficient of the three kinds of phosphors test, the three phosphor were: α-sialon: Yb2 + α-sialon: Eu2 + and Sr2Si5, N8: Eu2 +. The characteristics of these phosphors is the luminous efficiency of the thermal decay is small, 85% of the initial value is still maintained at 150 ℃.
Made InGaN blue LED and phosphor white LED emission spectrum is shown as Fig.6, its luminous efficiency of 55lm / W, color temperature 4500K. This is the highest white LED luminous efficiency reports (I know, according to most of the testing domestic 1W white LED luminous flux 40lm below). No. 2 and No. 3, White LED emission spectrum is shown, such as mixed phosphor preproduction Fig.7, its color rendering index to 82, a color temperature of 4200K, the light efficiency is indeed reduced to 20lm / W.
As described above, the light emitting of the LED is on the load of the carriers (electrons) in the n-type semiconductor in the foreign potential role to overcome the electric potential of the barrier layer into the p-type semiconductor, and to generate a composite light-emitting hole-trapping. Usually the temperature coefficient of the semiconductor, its resistivity decreases as the temperature rises, the barrier potential will also drop to the bottom, at the same time the center wavelength of the radiation will be the longwave direction of drift the leaving luminous efficiency of the phosphor of the (redshift) decreased.
A large number of our businesses, investors, researchers and technical staff have to intervene in this situation, and the large-scale investment to develop LED R & D and production so far is estimated to have invested a total of RMB billions of dollars, in less than a decade achieved outstanding results, and the formation of large-scale industrial chain.
World especially LED white LED so emphasis on their underlying causes, this huge amount of energy consumption and the resulting energy shortages, rising prices, especially caused by the environment has become a very urgent task to make energy savings. A large part of the national energy consumption for lighting. In China and developed countries, electricity for lighting accounts for about total power generation capacity of 12 to 13%, which is a very substantial loss of energy. The light source is still used worldwide inefficient incandescent light source mainly from tapping the potential is very promising.
LED focuses many talents, brilliant achievements, some of the research department announced that they have developed LED reached 120lm / W or even 150 lm / W luminous efficiency under certain conditions. Thus most enterprises have also claimed the luminous efficiency of their product has reached 70lm / W, 90lm / W or higher, the light utilization than the radiation output of each LED optical radiation is directed, even ordinary light source alone directional reflection of the lamps lighting efficiency is higher, and therefore finds that LED is the best functional lighting source, and vigorously promoted to various areas of lighting, a few years ago has been declared the LED will largely replaced by compact fluorescent lamps in 2010, a large scale into the family lighting, and asserted that white LED is the best road illumination light source.
There is no doubt that after 20 years of development, the LED in the display area has been made entirely successful, without than with the theory and has become irreplaceable display devices. Fully display its features decorative lighting, made half of LED outstanding performance in the 2008 Olympic Games opening ceremony to shake the world. But must address the fact that greater limitations in terms of functional lighting white LED persists. China is already the world's largest LED production base and consumer market, LED application fields, but due to the restrictions of the current level of technology and performance, such devices are used for functional lighting is not to use their skills. So-called high power LED, currently on the market can find the most high-power devices, but 3W, even 10W devices in R & D to large-scale production, but for conventional lighting, especially the hundreds of watts of light sources used in road lighting single The granulocyte power err too small. White LED design a lighting project amount must be great, whether it is difficult to design or cost will be worth the wait.
Common evaluation Ⅱ LED light efficiency of LED high light efficiency and long life, and many manufacturers claim their products luminous efficiency of up to 90lm / W or higher, but these data are just some laboratory in the the test initial stage when the LED is still in the highest measured in the cold state data. The so-called 50,000 hours or 100,000 hours life just early estimate of the low-power color LED.
Its theoretical light efficiency can be estimated from the LED light-emitting mechanism. As known LED is the use of carrier recombination and light emission, all of its potential energy in the carrier recombination when transformed into light energy, its internal quantum efficiency of 100% of the purposes of this process alone. Carrier collision with the crystal lattice and the loss of energy in the medium when the composite contained the kinetic energy carried by the carrier, and the electricity is consumed to overcome the resistance of the external circuit are not converted into light. Taking into account the variety of additional energy, the actual carrier recombination within the quantum efficiency does not exceed 90%.
Photons generated when the carrier recombination, has a 50% chance for outgoing radiation, part of the 50% of the photons collide with the lattice and lattice absorption is converted into heat. Portion photon propagation in the different media at the interface will be reflected back to the original medium and is absorbed, addition, as the metal the omentum or transparent conductive film of the output window of the outer electrode also allow a portion of the photons reflected by absorption, these processes will reduce the LED quantum extraction rate, the extraction rate of 80% is located in this part of the photon quantum.
Of photons generated in the carrier recombination, a 50% chance of the incoming radiation, this part of the photons reach the underlying conductive film serves as a reflective mirror, a partially reflective converted to outward output optical photons in this section, however, the inwardly or outwardly The transmission during the collision with the crystal lattice and is partially absorbed, through different media interface will also be part of the reflected or refracted back to the original medium eventually be absorbed. Substrate mirror reflection efficiency and the above process limitations such inward radiation photons into the output light quantum extraction rate does not exceed 40%.
According to the above analysis can estimate the total LED electro-optical conversion efficiency of approximately 54%, which is the ideal case where the estimated result. Any omissions, any defects in the material in the manufacturing process will cause a decrease in the efficiency of energy conversion. Less than 5% of visible light conversion efficiency than incandescent, even compared with the current highest conversion efficiency of high-pressure sodium lamps, ceramic metal halide (electro-optical conversion efficiency of about 30%) is also very high, this is the LED very luring. person prospects reason.
As is known, the 1W energy is completely converted to 555nm wavelength of the yellow light produced when the light flux up to 683lm / W (683lm / W optical power equivalents) approximately 360lm / W, if all is converted to white. As estimated earlier in this article, in the ideal case 555nm yellow LEDs may reach up to about the highest luminous efficiency of 300lm / W, the above estimates are also far from being achieved. Reported the highest light efficiency LED actually only half of the ideal value, and in fact less than 1/4, this is what people On the LED there is great potential to be tapped on the high hopes reason.
The key is to improve the LED luminous efficiency to improve quantum extraction rate, which is to minimize the internal absorption of photons, this is slimline LED reasons. Highest luminous efficiency of ultra-thin (thickness of tens of nanometers) GaN LEDs under conductive film with a high reflective mirror membrane and the inner surface of the output window is made of rough structure, in order to reduce the photon inward reflection, however even so reported the highest light efficiency, but 150lm / W.
The above analysis is monochromatic LED is the monochromatic transformed into the white must then go through a quantum conversion, mostly by emission center wavelength of about 470nm blue LED excitation radiation spectrum center wavelength to 560nm broadband yellow phosphor, which made the blue-yellow mixed white LED, but this led lights efficiency will further reduce required. Photon efficiency can be estimated as follows:
If retained approximately 20% of the Blu-ray LED radiation output, with the remaining 80% of the Blu-ray excited yellow phosphor, in the best case, about 20% of the 80% of the Blu-ray photon absorption for phosphor, and the rest 80% transfer to the center wavelength of 560nm for broadband yellow radiation, this process resulted in an average of 16.1% of the quantum energy loss. Combine the previous data can be estimated that the total energy efficiency does not exceed 40%, and converted to white when the total light efficiency white LED white LED but up 150lm / W. If there is no other breakthroughs, this current white LED may be the highest light efficiency, this luminous efficiency HID lamps, high pressure sodium lamp or ceramic metal halide light sources, such as the current highest light efficiency is also high compared to some. Luminous efficiency has not yet actually achieved, and this half.
We have this experimental study, we use a company's production 1W high brightness blue LED, the center of the spectral radiation wavelength of 470nm see Fig.3 go except SMD LED Package were coated with different thickness of the center wavelength of the radiation is 560nm yellow phosphor coating, after treatment, to measure the emission spectrum thereof. Four typical case is selected from the 24 kinds of samples of different thickness, and its results are shown in Fig.4 a, b, c, d and Schedule. Lumen output in the best case (Fig.4 c) of 38lm (initial cold 50lm), color rendering index of 78.
A well-known multinational companies and technical personnel initial introduced their 1W white LED luminous efficiency reached 70lm / W, the normal operation of the pn junction temperature rise, 50lm / W luminous efficiency reduced.
The results obtained by the Japanese Institute of Materials Science, 2007 nano ceramic center is the highest, they used a center wavelength of 450nm InGaN blue LED and the photon conversion efficiency is high, and has a strong absorption peak at 450nm blue range, low temperature coefficient of the three kinds of phosphors test, the three phosphor were: α-sialon: Yb2 + α-sialon: Eu2 + and Sr2Si5, N8: Eu2 +. The characteristics of these phosphors is the luminous efficiency of the thermal decay is small, 85% of the initial value is still maintained at 150 ℃.
Made InGaN blue LED and phosphor white LED emission spectrum is shown as Fig.6, its luminous efficiency of 55lm / W, color temperature 4500K. This is the highest white LED luminous efficiency reports (I know, according to most of the testing domestic 1W white LED luminous flux 40lm below). No. 2 and No. 3, White LED emission spectrum is shown, such as mixed phosphor preproduction Fig.7, its color rendering index to 82, a color temperature of 4200K, the light efficiency is indeed reduced to 20lm / W.
As described above, the light emitting of the LED is on the load of the carriers (electrons) in the n-type semiconductor in the foreign potential role to overcome the electric potential of the barrier layer into the p-type semiconductor, and to generate a composite light-emitting hole-trapping. Usually the temperature coefficient of the semiconductor, its resistivity decreases as the temperature rises, the barrier potential will also drop to the bottom, at the same time the center wavelength of the radiation will be the longwave direction of drift the leaving luminous efficiency of the phosphor of the (redshift) decreased.
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