The word "eye protection" of eye protection desk lamp basically has no blue light and glare.
The bigger the blue light, the more dazzling it is. Blue light refers to a high color temperature. The higher the color temperature, the higher the light frequency and the shorter the light wave. The shorter the light wave, the stronger the penetration ability.
Well, we can do two experiments to verify whether there is no blue light and glare.
Low brightness Two lamps with the same brightness, one is the eye protection desk lamp you bought, and the other is the tungsten lamp. Look straight at the two lamps with your eyes (not too bright, not too dazzling, not to mention dazzling, the friendliest sun can be dazzling at noon)
Ordinary LED lights will have dazzling symptoms and slight headaches.
Another experiment
High brightness Two lamps with the same brightness, one is the eye protection desk lamp you bought, and the other is the tungsten lamp. Shake the foot cloth dry, bounce the nails, tear the toilet paper, and look in the mirror under the lamp. If you can see tiny dust, flying fibers in the air or dust fibers on the mirror, you can be sure it is an eye-protection desk lamp. If you can't see it or it's not obvious, it's not an eye lamp. So is the dust flying in the sun. The reason is that the light of the desk lamp without eye protection is too strong to directly penetrate the dust and form reflection, which is invisible to the human eye. It is normal for human eyes to read books in this penetrating light for a long time.
In fact, electromagnetic waves, sound waves and light waves are all the same. The higher the frequency, the stronger the penetration. Just like the wireless router at home, 2GHZ. The higher the frequency, the thicker the wall. When the frequency of sound waves exceeds a certain level, the eardrum can't receive sound, and when it reaches a certain frequency, it can also shatter glass, kidney calculi and so on. When the light wave reaches a certain frequency, it can't be reflected by dust, so it can't be seen by human eyes.
The above two methods are indirect methods to test whether the light of desk lamp is blue and dazzling.
The second factor: don't make your eyes tired.
The mains frequency is 50HZ, and there will be stroboscopic when directly connected to the light source. Although the eyes can't look straight, it will also make the human eye easily tired. Strobe can be found with the camera of the mobile phone. Turn on the camera, turn off the anti-flicker function and watch it at close range. If the light does not flash, it is basically proved to be DC, but high frequency flash (several thousand hertz) is not excluded. If it is high-frequency flash, hehe ~ danger, high-frequency flash means high-frequency electromagnetic radiation. Like this kind of desk lamp with local illumination, people study at close range, read books at close range for a long time, and high-frequency electromagnetic radiation is harmful to their health, especially primary school students. Although ordinary family members do not have special equipment to detect, they can buy a hand-held radiation detector to detect, and the price is not expensive. If I can't buy this equipment or don't want to buy it, I can also teach my family how to distinguish eyes.
Methods: Observe the type of light source. If it is tubular (whether it is long or block), it can be proved that this light source is a fluorescent lamp (energy-saving lamp, fluorescent lamp). The luminous principle of this light source: arc glow effect (arc glow of fluorescent lamp: glow effect of free electrons colliding with fluorescent wall; If you still don't understand what it means, you can imagine that there are thousands of lightning in the lamp. This principle will produce very strong high-frequency electromagnetic radiation (no video flash). Indoor lighting is no problem, after all, the radiation distance is very short, but if it is short-distance long-term lighting such as table lamps. In order not to mutate flowers in the future, it is best not to use this kind of desk lamp. Close-range high-frequency electromagnetic radiation hurts the body, which is more terrible than blue light hurting the eyes.
At present, the best hundred-dollar LED is not the worst eye protector in tungsten lamp.
There are fluorescent lamps, and I won't choose them. Close-range high-frequency electromagnetic radiation harms the body. If you want to mutate, then use it to accelerate your transformation into Altman!
There are many things to consider when choosing tungsten lamp as the light source (incandescent halogen lamp).
1 Like many tungsten filament lamps on the market, DC and dimming can't be saved.
Why do you need DC? The above is mentioned by the classics, so I won't go into details.
Then why do you need to adjust the brightness? Tell a short story before answering this question.
Many people ask me, how many lumens is appropriate for a desk lamp? How many lumens does a desk lamp have to protect the eyes?
It always reminds me of children asking me why there is a sun in the sky, and what is the sun in the sky made of? Does it taste good？
Let me deeply understand that the ability of businessmen to fool and the stupidity of fools are so powerful that adults are fooled into three-year-old children. Don't think that you don't believe what I said. I'll explain to you why I should scold you for being stupid with things that accompany you from getting up to going to bed at night!
At noon, the light intensity in the sun is tens of thousands to hundreds of thousands of lumens, and the light intensity lumens in the morning and evening, cloudy and sunny days are all tens of thousands of lumens. And people can see things clearly, so they won't make your eyes uncomfortable and unprotected because of how many lumens have changed. Why? Because people's eyeballs contract muscles, when the light intensity is weak, the contraction muscles tighten to make the light weak into the eyes, and when the light is weak, the contraction muscles relax and enlarge to make the light strong into the eyes. Therefore, the human eye can see clearly under the light intensity of hundreds to hundreds of thousands of lumens, and it does not hurt the eyes. Then, you asked me how many lumens is the most suitable for a desk lamp?
Ok, let's go back to the above question. Why do you need a desk lamp with adjustable brightness?
A: The difference between local brightness and ambient brightness should not be too big. If the desk lamp is too bright and the room is too dark, people will turn to look at the room, relax their eye muscles, dilate their pupils for one second to adapt to the dark light, and then turn their heads back to the desk lamp. The strong light of the desk lamp stimulates the retina through the enlarged pupil, and then the eye muscles contract the pupil to adapt to the strong light in a second or two. In this one or two seconds, the retina is stimulated by strong light, which deepens the cataract. The indoor environment brightness changes at any time (there are two or three factors, such as turning on the headlights and turning off the lights in the afternoon and evening, changing the indoor brightness at any time). But if the desk lamp is not dimmed, it is easy to accelerate cataract.
So how much difference between local brightness and ambient brightness is appropriate and the above situation will not occur? Reminds me of a hundred thousand whys of children. Stupid, just adjust the brightness of the desk lamp until you turn your head under the lamp and there will be no more dazzling. It's as simple as that. Don't ask. I think I have a baby.
All right, keep talking. I'm worried about these stupid questions.
Infinite dimming can adjust the brightness, but it is 50HZ strobe. Test the stroboscope as I taught you above.
There are also some low-voltage DC incandescent lamps. Although there is direct current, it can't be dimmed, and the power supply it carries is very hot (power supply heat means a lot of power consumption). The high power consumption means that this power box is corrupt: the left hand inputs 100 taels of silver, and the left hand only gives 90 taels to the people. Such a corrupt official will not live long (fever accelerates life aging)
Therefore, when you choose the DC power supply of incandescent lamp, it is required not only to be DC, but also to have the function of adjusting brightness and low power consumption. Then such a power supply can't be cheap.
So I would like to remind all the guys who want to buy eye protection lamps: prepare more money and store more knowledge. Be careful when you are a big head, you will hurt your eyes and your health after spending money.
Many people have also asked me that incandescent lamps consume a lot of electricity, with ultraviolet rays, extreme heat and radiation, and the state prohibits the use of incandescent lamps. . . .
Hearing these questions, I really want to pull you out and beat you a hundred times. Your confused brain can't limp any more, because of unscrupulous businessmen. Can't you figure it out for yourself or find some facts from real life? Don't be dissatisfied when I scold you. I will talk about the above questions one by one. Why do you say that you have been cheated and are lame?
1: high power consumption
60W incandescent lamp, 1 kWh. How long does it take?
1 kwh = 1 kw/h (1 kwh)
1 kWh =60W*H, and the result is H= 16.6 hours.
Then, I do my homework with a desk lamp for 3 hours every day on average, which is 16.6/3=5.5 days.
So five and a half days need 1 kwh, 1 kwh = 50 cents. Five and a half days in 0.5 yuan, this money is not enough to wipe your ass. It's silly not to buy incandescent eye protection lamps to save that 50 cents. Are you convinced to scold you like this? Not satisfied? Ok, back to the following question.
2: Ultraviolet rays
Incandescent lamps do have ultraviolet rays. After all, it is close to the sun, and of course there are ultraviolet rays. But this is really a good thing. The intensity of ultraviolet rays emitted by incandescent lamps under 60W is equivalent to that in the evening, which is not strong and harmless to the skin, but more beneficial. 1 can sterilize and enhance the body's immunity. 2 Children who take calcium supplements often bask in the sun, grow taller and taller. 3 Improve the quality of sleep, and so on. As the old saying goes: get out! Don't always stay at home, go out and get some sunshine. Ok, let's buy an incandescent lamp. What? You think I'm fooling you, well, I'll give you a few more examples to prove your stupidity.
The sun that rises at sunrise and returns at sunset; Light a candle, which will drain the wick every night; Firewood for the bonfire party; Kerosene lamp for household lighting, incandescent lamp, gas lamp for cooking, briquette fire, lighter, etc. All burning and glowing. Ultraviolet rod. It is said that people who live under ultraviolet rays are shit. Why are you so scared? You weren't shot to death on the wall. Are you a moldy creature living in darkness and humidity? Furthermore, tungsten lamp has a round glass cover, which filters out high-frequency ultraviolet rays, which is better than sunlight. So don't worry about these useless things at all. If this is the reason why you don't buy incandescent lamps, then you are really fooled by the merchants.
Some people say that incandescent lamps are too hot for you to learn. There is a truth of energy conservation in the world. I don't know if you have heard of it. Never mind if you haven't heard of it. Use a daily life to instill some truth in your stupid and confused brain. I believe you all know the Yuba used in the bathroom. This is about 4000W in tungsten lamp. It emits 66 times as much heat as a 60W incandescent lamp and 100 times as much as a 40W incandescent lamp. I still don't understand. When you go to the bathroom, the heat you feel is divided by 66 times, 100 times, which is the heat given to your body by incandescent lamps. Although its fever is not very great, the temperature near the incandescent lamp mouth is still very high. It's best not to use hand mould for lampshade, it's very hot, and it's best not to use plastic for lampshade at lamp mouth. Plastic is easy to produce chemical toxic gases at high temperature, so you must buy good quality desk lamps, metal lampshades and ceramic lampholders.
4: There is radiation. I don't know if I saw radiation and thought of nuclear leakage. Please use your confused brain and think about it. Does incandescent lamp have such a tall function? If there were, then mankind would have been extinct long ago. You didn't come to see me scold you. The radiation of incandescent lamp refers to thermal radiation: it is warm just like the sun shining on the body. This is the most basic characteristic of warm light source, and neither LED nor fluorescent lamp can emit warm light.
5. Why does the policy prohibit incandescent lamps?
This is because incandescent lamps consume more electricity than LED fluorescent lamps, and the lighting in construction sites and factories is mostly kilowatt-level, which puts great pressure on power plants and should be banned. But, I want to say but. Household local low-power lighting desk lamp. It is better to choose between eye injury and power consumption. You can't save 1 day of 10 yuan, give your child thick eyes, get cataracts, and worry about the impact of electromagnetic radiation on the body. It's easy to say that you picked up sesame seeds and threw watermelons, but throwing them on the earth is nothing but dung.
The above summarizes five elements:
1 Non-LED light (blue light is dazzling)
Non-fluorescence (high frequency electromagnetic radiation)
3 Choose tungsten lamp (eye protection is closest to the sun, no blue light, no glare, comfortable and warm).
There should be a low-power DC dimmable desk lamp power supply (preferably with protection function)
5 table lamp metal lampshade ceramic lamp holder