If the basic lighting conditions are similar in terms of illumination, color temperature, illumination height, and amplitude, what is the basis for the choice of table lamp source? Incandescent lamps, halogen lamps, fluorescent lamps, energy-saving lamps, LED lamps, which one is best for children’s eyes?
I have watched a lot of discussions before buying the lights. The general idea is:
- incandescent light is best, but the light bulb is difficult to buy;
- The halogen lamp is an upgraded version of the incandescent lamp, and the halogen lamp is the best;
- with energy-saving light bulbs, as long as the color temperature can reach the standard, but it seems to have radiation;
- Use your mobile phone to take a photo of the LED light, as long as there is no flicker on the screen of the mobile phone.
When I was going to buy a lamp for my baby, I spent a lot of time searching for various science articles and technical stickers. I found that the above points related to the principle of illumination, national policy, strobe, color temperature, … counted once and said no. Finish, I think I want to share all of it, I really want to write a series. Of course, I am not a professional. I am just a mother who likes to be true and loving. If there are any mistakes in the learning experience and experience, please feel free to point out at any time.
Let me introduce these different kinds of electric light sources first.
- incandescent lamp
An incandescent lamp is an electric light source that energizes a filament to an incandescent state and emits visible light using thermal radiation.
The kind of light that we used when we were young will be very hot, and we often call out the light bulb that burned the filament, which is the incandescent bulb.
There is a household story: Edison failed to invent 480 times in order to invent the light bulb. People laughed at him. He said, I know at least 999 ways is not enough.
If Edison hears this story, he might respond like this: I have not said this.
Because – as early as Edison, British electrical engineer J. Swan began research on electric lights in the late 1940s. After nearly 30 years of hard work, Swan finally found a carbon wire suitable for filaments. On December 18, 1878, Swan successfully produced the first incandescent bubble.
In 1879, Edison also began to invest in the study of electric lights. He believes that the key to extending the life of incandescent lamps is to increase the vacuum of the bulbs and to use less heat-consuming, light-emitting, and cheaper heat-resistant materials for filaments. Edison has tried 1600. A variety of heat resistant materials, the results are not ideal. On the evening of October 21, 1879, Edison made a carbon fiber (ie carbon filament) incandescent lamp, which was the first to send electric light to the home. Edison used a carbonized cotton thread as a filament, put it into a glass ball, and then started the air machine to evacuate the ball. As a result, the light from the carbonized cotton filaments was bright and stable, and it illuminate for more than 10 hours (45 hours). In this way, carbonized cotton incandescent lamps were born, and Edison obtained a patent for this.
Edison has also been working on the improvement of incandescent lamps and large-scale commercial use. Later inventors continued to improve the materials and processes of incandescent lamps, and the history of the entire incandescent lamp was a history of improving the luminous efficiency of light bulbs.
However, in the past 100 years, this kind of effort has not achieved the desired effect. The incandescent lamp can never solve its original defect: less than 10% of the energy it consumes can be converted into light energy (ordinary incandescent lamp) Only 2%), and the rest are lost in the form of heat. At the same time, the higher the filament temperature, the faster the tungsten filament evaporates, making most incandescent lamps have a shorter life.
So although incandescent lamps have many advantages – the color is closest to the sun, the color is good, the spectrum is uniform and not abrupt – but the waste of energy is huge, since the beginning of 2007, the Australian government took the lead in declaring the full elimination of incandescent lamps in legislation. At the beginning, more than a dozen countries and regions have successively released the incandescent lamp elimination plan. China has gradually implemented the phase-out plan from 2011. From October 1, 2016, it is forbidden to sell and import incandescent lamps for general lighting of 15 watts and above.
- halogen lamp
Halogen lamps can be seen as an upgraded version of incandescent lamps.
A halogen lamp, referred to as a halogen bubble or a halogen lamp, also known as a tungsten halogen bulb or a quartz bulb, is a variant of an incandescent lamp. The principle is to inject halogen gas such as iodine or bromine into the bulb. At high temperature, the sublimated tungsten wire and the halogen chemically act, and the cooled tungsten will re-solidify on the tungsten wire to form a balanced cycle to avoid premature rupture of the tungsten wire. . Halogen bulbs therefore last longer than incandescent bulbs (almost four times that of incandescent bulbs), while filaments can operate at higher temperatures, resulting in higher brightness, higher color temperatures and higher luminous efficiency.
As an upgraded version of incandescent lamps, halogen lamps have all the advantages of incandescent lamps: the color of light is closest to the color of the sun, the color rendering is good, the spectrum is uniform and not abrupt. However, halogen lamps also inherit the disadvantages of incandescent lamps: short life (although longer than incandescent lamps), low luminous efficiency (although already higher than incandescent lamps), and halogen lamps are also heat radiation sources, in or after lighting Because the bulb temperature is still very high, never touch it by hand.
In addition, incandescent and halogen lamps have a small amount of ultraviolet (UV) and infrared (IR) radiation problems. If you want to achieve the ideal eye color, you must use a high-power bulb, so that the infrared heat is large and long-term use, it is easy to cause facial skin problems, plus ultraviolet radiation, and may even lead to extreme conditions such as sun dermatitis. . Therefore, if a halogen lamp is to be used as a light source for a desk lamp, at least a UV protection process is required – in other words, it is preferable that the portion from which the lamp is exposed has a frosted or partially frosted and UV-resistant glass panel.
- ordinary fluorescent lights
The long tube that we used when we were young was a fluorescent lamp, also called a fluorescent lamp. The conventional fluorescent lamp, that is, the low-pressure mercury lamp, is a low-pressure arc discharge source that utilizes a low-pressure mercury vapor to emit ultraviolet light after being energized, thereby causing the phosphor to emit visible light.
Ordinary fluorescent tubes are coated with halogen phosphors and filled with argon and helium-argon mixed gases. The light color is: cool white daylight fluorescent tube, warm white daylight fluorescent tube. Although the fluorescent lamp is not hot compared to the incandescent lamp, the luminous efficiency is much higher, but the two color fluorescent tubes have lower color rendering performance and the color rendering index R value is less than 40. Far less than the sun, the color rendering index R = 100 standard value. View the color of the surface of a colored object and produce a color shift. The color is greenish and grayish, and the color is dim and not bright. These two kinds of fluorescent lamps are not high-efficiency energy-saving electric light sources and do not meet the requirements of green lighting technology.
Generally, the light source for table lamps seldom uses ordinary fluorescent lamps, so it is simply skipped.
4. energy-saving lamps (CFL lamps)
The name “energy-saving lamps” is widely abused on electric light sources other than incandescent halogen lamps, such as the word “LED energy-saving lamps” that can be seen everywhere. The energy-saving lamp mentioned here is a compact three-primary electronic fluorescent lamp (referred to as CFL lamp in foreign countries), which is a compact fluorescent lamp with a ballast.
In detail, the CFL lamp is a single-ended compact energy-saving fluorescent lamp. The fluorescent tube, the ballast and the lamp head are closely integrated (the ballast is placed in the lamp cap), and they cannot be disassembled except for the destructive blow, so it is called a “compact” fluorescent lamp. Since there is no need to add a ballast and the drive circuit is also in the ballast, the fluorescent lamp is also a self-ballasted fluorescent lamp and an internal starting fluorescent lamp. The entire lamp is directly connected to the power supply network through the lamp head such as E27, which can easily replace the incandescent lamp directly. Most of these fluorescent lamps use a rare earth element trichromatic phosp
hor and thus have an energy saving function, so they are called “energy saving lamps”.
Energy-saving lamps are small in size, save energy compared to incandescent lamps, and have a longer life than incandescent lamps. However, the shortcomings are also obvious: as a kind of fluorescent lamp, mercury is added to the lamp tube, and the environmental pollution caused by the current lack of a good recycling mechanism cannot be ignored. In addition, the ballast used in the energy-saving lamp generates a certain amount of electromagnetic radiation when an instantaneous high voltage is generated.
As a light source for table lamps, the most critical problems of CFL lamps are color temperature and color rendering. This will be covered in a later series.
5. LED lights
The LED is an abbreviation for English light emitting diode. A light-emitting diode is a solid-state semiconductor device that converts electrical energy into visible light, which directly converts electricity into light.
The heart of the LED is a semiconductor wafer with one end attached to a holder, one end being the negative pole and the other end connected to the positive pole of the power supply, so that the entire wafer is encapsulated by epoxy. The semiconductor wafer consists of two parts, one part is a P-type semiconductor, in which the hole dominates, and the other end is an N-type semiconductor, which is mainly electrons here. But when the two semiconductors are connected, they form a P-N junction. When a current is applied to the wafer through the wire, the electrons are pushed toward the P region. In the P region, the electrons recombine with the holes, and then the energy is emitted in the form of photons. This is the principle of LED illumination.
Because LED lamps do not generate high heat, and convert electrical energy into light energy as much as possible, LEDs are often referred to as “LED energy-saving lamps.” When buying energy-saving lamps, it is important to distinguish between LEDs and CFLs, which are completely different sources.
Also known as energy-saving lamps, compared to CFL lamps, LED lamps are environmentally friendly and contain no mercury, which can be recycled and reused. This is probably a major driving force for countries to develop LED lamps.
LED lights have many advantages, mainly on the table lamp source:
- Green and environmental protection: glare is small, no radiation, no harmful substances are produced during use.
- long life, stable performance, there are no shortcomings such as filament light-emitting, heat deposition, light decay and so on.
- multi-transformation: LED light source can use the three primary colors of red, green and blue, and produce different colors, intensity and color temperature under the control of computer technology. But LED lights also have well-known shortcomings: blue light, stroboscopic problems, which is also a place where many eye-protection lamps make a big fuss.
Original Article From: luxonshop.com