The beam of the flashlight is inserted into the convex lens ―― so that the original light is converged and then spread.
Question 2: What phenomena in life can explain that light travels in a straight line? 1. Lighting with a flashlight in a dark place at night;
2. Sunlight penetrates through the pores between leaves, and countless dots appear on the ground;
3. In shooting and archery, use the straight-line propagation of light-aim at three points on a straight line;
4. The carpenter planed out the batten with a planer, and after twice planed, checked whether it was straight or not. He used the straight-line propagation of light to judge.
When waiting in line, if you only see the back of the head of the person in front, the line is straight.
Question 3: What are the advantages of strong flashlight? The advantages of strong flashlight can't be said, but felt, and only felt at night. Last time I compared the flashlight with Longxing's flashlight, I felt that the flashlight was more powerful.
Question 4: What kind of jade has a perfect phenomenon with flashlight notes? Bai Yushi, jade and so on. You can look at tank007.
1.J6 is a special flashlight for jade identification. The light source is CREE LED (yellow light and white light optional) imported from the United States, with strong penetration. It is a powerful tool to identify jade and antiques, and also a good helper for experts, jewelry shopkeepers and antique lovers to identify.
2. The pen container is designed to be portable.
3. The fuselage is made of aviation grade aluminum alloy, and the head and tail are made of 304 stainless steel, which shows noble quality with harmonious color matching and is more wear-resistant and difficult to change color.
4. The button switch at the back is convenient and practical, with handstand function.
5. Using orange peel aluminum alloy reflective cup, the light beam is softer and the light spot is more uniform.
6. Constant current circuit chip/constant brightness, two-step dimming, brightness can be adjusted as needed.
7. Anti-reverse connection protection circuit design, don't worry about reverse connection of the battery to the product.
Question 5: What is the function of fluorescent flashlight? Is fluorescence harmful? Fluorescent flashlight can detect fluorescent agent. If we are exposed to a lot of fluorescent agents for a long time, it will affect our health and hemolysis will occur. However, the light of fluorescent flashlight, that is, purple flashlight, can't illuminate people, especially the eyes, which is particularly harmful to the eyes.
Question 6: What is the reason for the phenomenon of camera flashlight in security monitoring?
The night vision function of infrared camera is to use infrared lamp as light source to obtain image information in dark conditions.
The light source of an infrared camera is generally made into a circular lamp board with many infrared lamps on it, which are installed at the front end of the camera for lighting.
Flash phenomenon: in a certain part of the camera screen, the light shines strongly, just like a beam of light, which makes people feel that the beam of the picture is uneven, so some people call it flash phenomenon; The reason is that the emission angle of the infrared lamp is too narrow, that is, it is much smaller than the lens angle of the camera, and the beam line irradiation occurs in the light entering range of the camera under infrared light irradiation. The solution is to increase the infrared lamp angle or decrease the lens angle;
Dark corner phenomenon: the feet around the picture are dim, as if the light is blocked. The reason is that the reflection of infrared light leads to poor focusing of the lens. The solution is to separate the lens from the infrared light source with double glass.
Infrared night vision means that in low light environment, infrared components will emit infrared rays invisible to human eyes to illuminate the subject. Without the infrared filter, the infrared ray will no longer be blocked from entering the CCD, and the infrared ray will enter the lens for imaging after being reflected by the object. At this time, what we see is an image reflected by infrared rays, not an image reflected by visible light, that is, an image that can't be seen by the naked eye in a dark environment. At this time, we can shoot it. Because the CCD used in ordinary color cameras can only sense visible light, the images taken at night are very unclear or invisible. In order to solve this problem, many companies that produce infrared night vision cameras have adopted the technology of "infrared LED+ infrared color CCD". Although these products partially meet the requirements of night monitoring, the night monitoring function of night vision cameras is hindered by the following reasons:
1, the quality of infrared LED light-emitting tube is average, the service life is only 2000-3000 hours, and the camera can only be used for less than one year, or the night vision camera has a short irradiation distance because of the small power of a single infrared LED light-emitting tube.
2. Due to the common optical lens, the infrared light reflected by the LED lamp can not be effectively focused on the CCD target surface during night monitoring, and the infrared night vision effect is greatly reduced.
In order to have a wide range of products and show the strength of the company, many companies have made more products on night vision cameras, from 1/4 to 1/3, from Sony to Sharp, from 10 m to 150 m, from 420 lines to 480 lines, with illumination of 0LUX and infrared.
① Size:1/4cd cannot be used for infrared night vision cameras with an effective distance greater than15m, because the luminous flux of1/4cd is only 50% of that of1/3cd, and it is large in size, large in receiving luminous flux and small in size, so it cannot effectively capture infrared light.
② Number of lines (resolution): The CCD of 420 lines is about 260,000 pixels, and the CCD of 480 lines is about 390,000 images. Imagine that there are 260,000 or 390,000 dots on a chip with the same area (1/3 "or 1/4"). Of course, the light receiving area of each point of 260,000 points is relatively large, so the illumination is relatively low (that is, the sensitivity is relatively high).
(3) Illuminance: The minimum illuminance of CCD is ≤0.02LUX when the night vision camera does not require infrared light, but some camera manufacturers falsely report the minimum illuminance, which greatly reduces the effective distance of night vision. Customers are also the easiest to ignore this point: the infrared camera targets are all 0LUX.
④ Infrared lamp: The general concern is not the quality of infrared lamp, but the quantity. In fact, this is a very big misunderstanding. A good infrared LED chip optical system should have reasonable design, high power, good consistency, high luminous efficiency, uniform luminous and low calorific value. A high-grade LED is dozens of times that of an ordinary LED, and a low-end infrared camera will definitely not choose this infrared lamp, because the price is much more expensive than that of an ordinary infrared lamp.
⑤ Chip: Sony's heat resistance is better than Sharp's, so for the time being, if the infrared reaches more than 80 meters, the power will definitely be higher and the calorific value will definitely be high, so it is best to use Sony's chip at a long distance. You can also use Sharp, but some people may go back to their hometown. )
⑥ Night vision distance: It is related to the chip above. Occasionally, I hear customers ask: How many meters can infrared rays reach? He pouted when he said 100 meter ... >>
Question 7: What is the reason why the flashlight shines on the jade after the light absorption is turned off? It is mainly because there are materials with similar fluorescent components that similar phenomena will occur. This is mainly fluorite, and the specific analysis will tell.
I do titanium lighting for flashlights. At present, the flashlight with strong irradiation effect is mainly the jade-appreciating flashlight with 800 lumen single chip CREE XML T6 LED. They are small and super bright, and we can communicate.