The development of semiconductor lighting technology and industry is much faster than people expected. Some characteristics of LED light source are unmatched by any artificial light source, such as rich color, high color saturation, concentrated beam, solid state light, fast response, and brightness. And color can be digital, intelligent, networked control and adjustment, and so on. The wide application of these new features will change the experience and habits of people's traditional lighting, trigger the transformation of lighting concepts and light culture, and promote the development of lighting products to people-oriented and more humane. The Ministry of Science and Technology launched the “Ten Cities and Ten Thousand†semiconductor lighting demonstration project. Will push the LED to a broader market, and promote the LED industry to become bigger and stronger.
Lighting is a comprehensive engineering technology involving a variety of disciplines and a variety of technical fields. Human visual characteristics and visual cognition determine the quantity and quality of lighting, not only considering integrated innovation in semiconductor technology and other scientific and technological fields. It is also necessary to consider and pay attention to scientific issues in the fields of aesthetics, art, philosophy, ergonomics, physiology and psychology, and integrate them to meet people's growing pursuit of quality of life. The current situation is that no authority, a university, a scientific research institution or a company can fully understand the connotation of lighting technology. Therefore, lighting is a science and technology field that should be more people-oriented, implement the scientific development concept, and integrate technological innovation. From the perspective of ours, we only list some controversial, vague concepts and issues that need to be studied and discussed for your discussion.
Is urban road lighting the main application direction of “Ten Cities and Ten Thousand Cities�
High-pressure sodium lamp has been a mature high-efficiency light source in the development of urban road lighting for more than 30 years. The improved high-color sodium lamp with high color rendering, in addition to LED, PHILIPS low color temperature ceramic metal halide lamp and electrodeless lamp. Most professional opinions and experiments show that LED is not as good as the above light source in terms of luminous efficiency, stability, reliability, heat resistance, color temperature, light distribution, maintainability, and cost performance. At present, the overall level of LED street lamps is not up to the backbone. “Urban Road Lighting Design Standards†for road lighting. The main problems in the transformation of main roads or branch roads with LED street lamps are: first, poor stability, high maintenance and replacement frequency; second, insufficient total luminous flux, which does not meet the requirements of “urban road lighting design standardsâ€; It is a big reflection from the suburbs or farmers. They said that the street lights in the city have changed one after another. From bright to non-light, when can we install street lights.
According to the current technical level of LED street lamps, it is mainly used for branch roads, auxiliary roads, walking paths and residential roads below 8 meters. It is used for rural urbanization, new roads in urban suburbs, solar photovoltaic or wind-solar hybrid power generation and LED combination. The street lighting system, in this way, uses the taxpayer's money to do social harmony, and can save energy and reduce consumption.
Is the evaluation of the illumination index for LED road lighting evaluated with the brightness index?
Nowadays, there are thousands of papers or lectures on LED road lighting every year. The conferences are frequent and overwhelming. There are many big-name experts or chief engineers of large enterprises. They have little knowledge of the driver's visual operation characteristics, human visual function and visual information. Most papers or speeches use LED illuminance, road illuminance, and illuminance uniformity to evaluate LED street lighting or LED road lighting design. Developed countries have adopted "brightness standard" since the 1980s. China Academy of Building Research Researcher Li Tienan emphasized in his book "Urban Road Lighting Design" and many speeches that "the lighting standard is selected according to visual work"; "the evaluation index of road lighting (including visual functionality and comfort): pavement average Brightness, total uniformity of road surface brightness, longitudinal uniformity of road surface brightness, disability glare (threshold increment), environmental ratio, inductivity, etc. These indicators have been included in the “City Road Lighting Design Standard CJJ45-2006†The aim is to provide the lightest possible road surface, to see the silhouette of the object or to the high against a relatively bright background. The reflected light of the incident object can only be used in some special cases when the brightness indicator cannot be used to evaluate the illumination of the road. Zou Jiping and Li Li of Tongji University's School of Architecture and Urban Planning, in the article "Importance of the relationship between brightness and illuminance in road and tunnel lighting" (Journal of Lighting Engineering 08, 2009), the comparison of tunnel lights at home and abroad, the illumination is the same, The brightness of imported tunnel lights is 80% higher than that of domestic lamps. Some of our experts who engage in "ten cities and cities" can't tell which of the concepts of luminous intensity, brightness, illuminance, and luminous flux are objective quantities, which are subjective quantities related to the human eye; 90% of professional books and magazines define luminous intensity. It is: “the luminous flux emitted by the light source in a solid angle in a given directionâ€; the brightness and illuminance are simply converted by proportional relationship, and even the brightness is mistaken for illuminance. In the standard, the uniformity of the road surface illumination is also used to characterize the LED street light. light intensity. These unscientific problems are also one of the reasons for the immature LED street lights. Scientific development of LED street lights has a long way to go, and there is a long way to go.
Is road lighting corrected with the visual spectrum optical efficiency function?
Because human eye vertebrate cells and rod cells have different sensitivity to different brightness and spectrum, the average human eye has a brightness of more than 3 cd/w, and the vertebral cells act as bright vision. The human eye's vertebral cells are at 555 nm wavelength. Light efficiency can reach 683lm/w. When the brightness is less than 0.001 cd/, the rod cells act, which is called dark vision. The human eye rod cells are most sensitive to the wavelength of 507 nm, and the luminous efficiency is up to 1725 lm/w, while the brightness range is between 0.001 and 3 cd/. Intermediate vision. In China's urban road lighting design standards, the average brightness of motor vehicles is specified to be between 0.5 cd/-2 cd/. In the middle vision range, many people have suggested that the LED has more blue light components and the sensitivity of the human eye is improved. The luminous efficacy of the Led street light is multiplied by 1.6 times, while the sodium light is yellow, the human eye is not sensitive, and the sodium light is effective. Multiply by 0.64, the luminous efficiency of the calculated effect-corrected LED is higher than that of the sodium-light. The measured result is that the illumination of the main roads of most cities in China exceeds the national standard, both in the visual range, plus the brightness of the lights. The superposition is greater than 3cd/, even if it is 0.1cd/, which is equivalent to the streetlight without street lighting, and the difference of 3cd/only one order of magnitude, the spectral light visual efficiency function curve moves very little, so even if there are many discussions about intermediate vision every year in the world. The paper also did not conclude that the intermediate vision spectral light efficiency function should be used to correct the luminous efficiency of the road illumination source. Even under the darker illumination conditions, the color rendering of the light source is improved, and the subjective perceived luminance of the person can only be improved. 20% - 30%, it is impossible to increase exponentially.
Can LED street lights drive the local LED industry to become bigger and stronger?
Now all local governments are relying on high-tech and emerging industries; changing the mode of growth and adjusting the direction of industrial structure; in the name of energy saving and emission reduction, environmental protection and carbon reduction, etc., LED street lights, enterprises fooling the government, the government flickers enterprises, and thinks that several roads are given. Doing LED demonstration projects can support an industry.
Just as Xiamen's LED nightscape project was launched in 2005, 24 enterprises participated in the Xiamen nightscape project from 2005 to 2007, and later promoted to the whole province. The main backbone enterprises in Xiamen also participated, in addition to beautifying the city and prospering the economy. In addition, mainly through the night scene project to support the local industry, bigger and stronger, after nearly five years of development, there are still a few companies left to do LED landscape lights, no one company has a value of more than 100 million yuan, as a guide, many cities It is too ideal to support an industry by doing LED engineering for several street lamps. LED street lamps have been speculated as a high-risk industry with excessive investment and excessive competition. Now most of the companies that do LED street lamps are likely to become martyrs.
For a long time now and in the future, LED backlights are still the main field of LED applications, making full use of and playing the characteristics of LEDs. According to the current state of the art, LEDs in commercial lighting, office lighting, special lighting, garages, cold storage, clean rooms, The diversified applications of chain stores, jewelry stores and other fields have broad prospects. We believe that it is possible to correctly guide the application direction and scientific development of LEDs.
LED technology is developing at a rapid pace, and problems are inevitable. The physiological optics and mental optical effects of LED-induced illumination are at the forefront of contemporary cognitive science. We should face these problems squarely, discuss these issues extensively, and propose innovative solutions to promote China's semiconductor lighting industry is developing healthily. China is the largest producer and user of lighting appliances. LED is triggering the revision of a new round of standards by the International Standards Committees such as CIE and IEC. Scientific development of semiconductor lighting applications, we are on the same starting line with countries, and lighting is involved. For the subject group, we hope to open up a column discussion on the science and technology newspapers for some controversies in the "Ten Cities and Ten Thousand Cities" semiconductor lighting demonstration project or the issues to be studied and discussed. There are hundreds of flowers, hundreds of schools of thought, from different technical fields and different perspectives. Publish different opinions, brainstorm and promote the scientific development of China in the field of lighting, from making a difference to being promising.
(Editor: Happy)
What`s the main features appear into your mind when you look yoga laptop? Lightweight, super thinner, touch screen, 360 rotating, smaller size, like as notebook? You are right, that`s the main reasons why some people also called it as laptop yoga slim or yoga notebook. To OS, just same as Education Laptop-windows operating system, so you can see many windows yoga laptop at the market around the world. In fact, this intel yoga laptop usually is designed for normal jobs, like basic WPS, Photoshop, video or music editing, online learning, shopping, presentation when on a business trip, etc. At our store, you can see 11.6 inch n5100 360 Laptop in metal, 13.3 inch 360 flip laptop, and 14 inch 360 degree rotating laptop, etc. The people who take business trips often or prefer fashion design should like this type device.
There are education laptop also, like 14.1 inch Student Laptop for Hope or government Projects, 15.6 inch competitive celeron business laptop for normal business works, 15 inch 10th or 11th Gaming Laptop for heavier tasks, like teachers, high or university students, etc, 16.1 inch i7 16gb ram 4gb graphics laptop for engineering student, etc
Any other question or other requirements, just contact us freely.
Yoga Laptop,Laptop Yoga Slim,Yoga Notebook,Intel Yoga Laptop,Windows Yoga Laptop
Henan Shuyi Electronics Co., Ltd. , https://www.shuyiaiopc.com