Instructions
To build
Fresnel
lens yourself you need to have a significant understanding of optics.
So, unlike conventional lenses, fresnel does not consist of solid glass, but of concentric rings with a special prism shape in cross-section. Make calculations and determine the boundaries of the Fresnel
. They are determined by the intersection of the wavefront of the original wave with a sequence of wavefronts of the “projected wave” shifted relative to each other by l/2.
Make transparent rings that will cover the odd Fresnel
. Their thickness must correspond to the additional phase shift l/2. For convenience, use the drawing.
To achieve the greatest effect, coat the ends of each prism with a coating, for example, aluminum. Articulate the structure by checking the position of the prisms using the equation.
There are two types of Fresnel
– ring and belt.
Unlike ring lenses, which direct the light flux in a strictly defined direction, waist lenses distribute light from the source in all directions. Fresnel
lenses have very diverse applications: from marine lighthouses and photographic lenses to a special film that is applied to the rear window of a car to reduce the blind spot behind the car when using the rear-view mirror.
Simultaneously with the creation of the lens O.Zh. Fresnel developed the most complex technology for its production. In a nutshell, we are talking about making a lens consisting of a set of several prisms in the form of thin rings. In modern conditions, such production is possible only with the use of modern high-precision processing, vacuum-spraying and control-measuring equipment.
In the production of Fresnel
HOTLENS technology uses holography, thanks to which infrared radiation is more accurately focused and the ingress of, for example, visible light is reduced.
Such lenses make it possible to create a more accurate detection zone in space. The set of technological equipment for the production of Fresnel
includes precision lathes, on which trimming and preliminary rounding of workpieces is carried out. Sphero-lathes machine the outer and inner surfaces of lenses.
The most important step is grinding the surface of the lens. It is carried out on polishing machines. The polishing process simultaneously removes roughness and improves the cleanliness of the spherical surfaces of the lenses. The edges of the lenses are polished on special machines, and special diamond cutters are used to process the concave and convex surfaces of the lenses. In addition, all necessary technological equipment is manufactured at such enterprises.
A lens is a transparent device, mostly made of special glass, designed to magnify an image. The lens is the main part of any optical system. The principle of its operation is based on the refraction of light rays. Make a glass lens
It’s very difficult to do it in a homemade way, especially since you can’t do it without the necessary equipment.
But based on the effect of light refraction, it is possible to make
liquid-based lens
You will need
- Plastic bottle, plasticine, glycerin or water, syringe with needle, plastic bag.
Instructions
Take a one and a half liter plastic bottle. From the top of this bottle, cut out two identical, convex circles (for convenience, cut out one circle first, and then cut the second one according to its diameter).
Then, take ordinary plasticine or some other sticky material. Use this plasticine to glue both halves of the lens so that it is convex on both sides.
After this, make holes in two places between the halves of the lens. Fill one of these holes with a syringe using a syringe (you can fill it with ordinary water, but it is better to use a liquid with a high refractive index, try filling the lens
glycerin, the effect will be better), fill it to the brim and there should be no air bubbles in it. The second hole is designed to allow air to escape so that pressure does not build up. After filling the lens with liquid, seal the holes.
In extreme conditions, for example, being in the taiga in winter, without matches, you can make a lens
for making a fire. To do this, take an ordinary plastic bag and fill it with water. Shape the bag into a ball and let the water freeze. Once frozen, tear off the bag to create a lens. The lens can also be cut out of frozen ice.
Good light in a car is the most important safety parameter. Modern technologies are developing at the speed of a spaceship, and the solutions used 5 years ago today already look hopelessly outdated. It is not profitable for automakers to update old products, but third-party developers actively support this topic. To improve the design and luminous flux, it is proposed to install a lens
into the reflective design of the headlight.
You will need
- - lenses;
- - industrial dryer;
- - Screwdriver Set;
- - gloves;
- - plastic and soldering iron
Instructions
First remove and completely disassemble the headlight
on your car. When removing headlights, follow the repair instructions. To disassemble the headlight, warm it up with an industrial low heat.
The Fresnel lens is almost the very first, according to historical chronology, device, the basis of which is the principle of light diffraction. Despite the age of this invention, it has not lost its relevance today and has found application in many areas.
DIY games “Noise boxes”, “Colored magnifying glasses”
Marina Nurtinova
Do-it-yourself games “Noise boxes”, “Colored magnifying glasses”
Do-it-yourself games: “Noise boxes”, “Colored magnifying glasses”
Didactic game “Noise boxes”
Purpose of the game:
development of auditory memory, ability to distinguish and differentiate noises, logic, training of concentration.
Materials:
noise boxes with various fillings that make different sounds (paired, colored cards with images of what is in the boxes).
For this game, noise boxes were made from Kinder Surprise containers. They are all paired. The following fillers were used:
• Two boxes are empty.
Also for the game you need cards - pictures depicting what is in each of the boxes.
Option 1. Find a pair by sound
To begin with, we introduce the children to all the noise boxes. Together we explore the sound of each of them. We draw children's attention to the fact that all boxes sound differently. After the children become familiar with the sound of each of the noise boxes, you can begin the educational game itself - ring one of the boxes and invite the children to find a box with exactly the same sound. Among all the noise boxes, the child should try to find boxes with the same sound, that is, find pairs by sound. During the game, the child learns to concentrate his attention on sounds (which is very important for the development of hearing and speech). In addition, to find a box that sounds similar, you also need to use logical thinking.
Option 2. Drawing up rows
You need to arrange the noise boxes in rows. First of all, find the loudest, then the quietest noise and determine the average one, comparing it with the first two noises. You should start with three boxes. If the child has learned to classify three boxes, then you can introduce all the others one after the other. Each new box is compared with all the already familiar boxes and ordered in relation to them. The number of boxes for classification is determined depending on the child’s abilities and interest.
Option 3. Sound lotto
Listen with your children to how different containers sound. Then draw the children’s attention to the picture and say what is shown on it. Then invite the children to guess what is in the containers and place them on the corresponding picture.
Didactic manual “Colored magnifying glasses”
"The World Changes Color"
Task:
show children that surrounding objects change color if you look at them through colored glasses.
Description.
The teacher invites the children to look around them and name what color objects they see. Everyone together counts how many colors the children named. Do you believe that the turtle sees everything only in green? This is true. Would you like to look at everything around you through the eyes of a turtle? How can I do that? The teacher hands out green glasses to the children. What do you see? How else would you like to see the world? Children look at objects. How to get colors if we don't have the right pieces of glass? Children get new shades by placing glasses - one on top of the other.
"Mysterious Pictures"
- examining colored pictures through glasses of different colors and observing which images in the picture become invisible.
What is a Fresnel Lens
A Fresnel lens is a complex compound lens. Unlike ordinary lenses, it does not consist of a single ground piece of glass with a spherical surface, but of individual concentric rings. They are tightly adjacent to each other and have a small thickness. In cross-section they are prisms of a special profile. This type of lens got its name from the French physicist Augustin Fresnel, who proposed it, who worked in the field of physical optics.
Thanks to its unique design, this lens model is lightweight and thin. The sections of its rings are constructed in such a way that its spherical aberration is extremely small, as a result of which the rays refracted by it emerge as a single parallel beam. The diameter of the Fresnel lens varies from a couple of centimeters to several meters.
Fresnel lenses are usually divided into ring and belt. The first direct a beam of light in one predetermined direction. The latter send light from the source in all directions in one plane.
Master class “Colored magnifying glasses for experimentation”
Oksana Nikolaevna Molchanova
Master class “Colored magnifying glasses for experimentation”
Master class “Colored magnifying glasses for experimentation“
Dear colleagues!
Childhood is a joyful time of discovery. Knowledge of the environment should take place in the child’s direct interaction with the natural world and unfold like an exciting journey, so that he receives joy from it.
Children's experimentation is a wonderful means of intellectual and cognitive development of preschool children. In the process of experimentation , the preschooler gets the opportunity to satisfy his inherent curiosity, to feel like a scientist, researcher, discoverer. Therefore, in my work I use elements of children's experimentation .
For the master class we will need:
- plastic bottles of different colors (brown, transparent, green, blue,
— colored cardboard.
What to do:
Draw a magnifying glass in duplicate on colored
Glasses for small work
If you do handicrafts or jewelry, you have probably thought more than once about purchasing magnifying glasses for small jobs. There are a lot of offers, but be careful, when buying cheap optics, there is a real chance of damaging your vision.
I would like to warn you right away that I do not pursue any advertising goals, and, moreover, I am not a representative of jewelry store chains. I won’t invent or assume anything, I’ll just give a couple of examples of using magnifying glasses from my own experience.
The problem arose when making Tiffany stained glass with your own hands. If I could make medium-sized Tiffany stained glass windows with ordinary glasses without straining my eyes, then when wrapping in foil and turning the details of small stained glass crafts, certain difficulties arose. Especially when the foil merged with the glass.
At first I considered stationary illuminated magnifiers, but they are more suitable for soldering radio circuits. I had to settle on magnifying glasses (binocular). The first binocular glasses for small work (if you can call them that) with foam padding under the forehead
and additional lenses on hinges I purchased on the radio market at a fairly modest price.
Understanding perfectly well that the seller is an interested person, he believed that the quality was super, and that this was exactly what I needed for comfortable work. Problems started from the very first days. Even after a short period of work, my eyes became very tired, and the headband put pressure on my head. In general, I used the glasses for a couple of days.
Relatively recently, I happened to be in a jewelry store, where glasses for small work (USA) caught my eye. The price is 4 times higher than the previous copy. But, as I was convinced, the quality corresponds to the price.
glasses for small work
I do not recommend purchasing OPTIVISOR binocular glasses without trying them on. The fact is that I tried on several numbers until I decided on those that suit me personally. Here are the main numbers for information:
In conclusion, a few main differences between No. 1 (untitled) and No. 2 (“Optivisor”).
And the most important difference: when working with glasses No. 1, the eyes get tired after short work; With glasses No. 2 you can work for hours without straining your eyesight.
I think they can be useful not only for making Tiffany stained glass windows with your own hands, but also for embroidery, watch repair and other small work.
Source
Cheap or expensive watch magnifier?
There are products on the market that have different prices. Therefore, watchmakers do not know which option should be preferred. The conclusion is clear: you don’t need to pay attention to cheap goods. They are not highly functional and do not correspond to current trends.
A watch magnifying glass from a well-known brand is a high-quality product developed by leading experts. Manufacturers are introducing innovative ideas. Therefore, their products have improved technical characteristics. Devices for enlarging the mechanisms in question have a stylish design and good ergonomic characteristics. They meet the expectations of watchmakers and are widely used.
How to make a magnifying glass with LED light
An illuminated magnifying glass will help you easily read the instructions for any medicine, the inscription on any package, or the intentionally small print of a credit or insurance agreement. It allows you to read small but necessary text in any conditions, for example, in a dimly lit store or in a gateway.
The good thing about backlit text is that it is perceived as having more contrast, so your eyesight doesn’t strain or get tired when reading for a long time.
An illuminated magnifying glass helps men with soldering and repair work with small parts, women with searching for small pieces of jewelry that have fallen out of a dark entrance, and children with studying insects, philately, and working with microcircuits.
That’s why we suggest you make such a backlit lamp with your own hands.
– 8 white SMD PLCC LEDs; – 8 SMD resistors (size 0805 or 1206) 100 Ohm each; – an ordinary magnifying glass; – a printed circuit board cut in the shape of a ring from a foil blank (according to the size of a magnifying glass); – battery compartment for AA batteries (for 4 places); – 4 batteries; – Moment glue; – connecting stranded wires of two insulation colors – one meter of wire of each color;
– wire cutters; – soldering iron and solder; – Dremel with cutting wheel; – a drilling machine with large diameter drills.
Do It Yourself (Knowledge) 2008-01, page 99
lenses ((X2 > a^). Such a simple lens, used for viewing small objects, mounted in a frame and equipped with a handle, is called a magnifying glass (Fig. 1 shows the designs of several such magnifying glasses). Magnifiers with higher magnification usually consist of a system of lenses ( Fig. 17).
In Fig. 9, a shows the path of light rays in the lens and inside the eye when viewing an object AB. First, the rays are refracted in the lens, then pass into the eye through the lens and are reflected on its retina in the form of APVP images. If the object under study were in place AjBj and had its magnitude, then it would be reflected on the retina of the eye with the magnitude ApBc at an angle. As a result of the appearance of light excitation on the retina of the eye, an image of the object AB is created in our consciousness and we clearly see it.
The magnification of a magnifying glass is determined by the formula K = -, in which L is the distance of best vision, it is equal to 250 mm, and is the distance between the object and the lens, in magnifying glasses a = f, then the approximate magnification of the magnifying glass is:
/
Let's solve some practical examples.
Example 4. The focal length of the magnifying glass is f = 50 mm. Determine the magnification factor.
Example 5. What magnification does a magnifying glass provide, the optical power of which is D = 16 dp.
K=- = L-— = LD = 0.25-16 = 4. / /
It would seem that with the help of a magnifying glass you can obtain very large magnifications - you just need to reduce its focal length, for example, with / = 0.5 mm, the magnification should be K = 500. However, the use of magnifying glasses with a very short focal length and, accordingly, with a small diameter , almost impossible. Usually one-
framed lens; 2 - handle
Lens magnifiers are made with a magnification factor of no more than 6.
Making magnifying glasses. Based on lenses released from old, deteriorating optical devices (photo enlargers, filmoscopes, etc.), and magnifiers that have failed for various reasons, it is possible, with diligence and desire, to make excellent magnifiers (Fig. 10). It is advisable to choose stainless steel as the material for their parts. The manufactured base of the magnifying glass (frame and handle) must be cleaned with sandpaper, sanded and polished, and then the lens must be mounted into the frame and the magnifying glass is ready.
As an example, we will show the manufacture of a magnifying glass based on a double-convex lens with dimensions: diameter 90, thickness in the center 15 and at the ends 5 mm. In Fig. Figure 11 shows the structural design of such a magnifying glass, which consists of a frame (a lens with epoxy glue is inserted into it), a base for the handle and a handle embedded in the base, also with epoxy glue. The magnifier's handle is long (-180 mm) so that it can be used for mounting on a tripod.
The sequence of making a magnifying glass is as follows:
— for the frame of the magnifying glass we take a strip of stainless steel with a thickness of 0.9 - 1, a width of 22 and a length of 3.14-90 = 283 mm. Along the entire length of the strip, with a width of 5 mm along the center line, we make holes with a depth of 0.4-0.5 mm using a drill 0 1 mm on a drilling machine (Fig. 12, a).
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