Fresnel lens in the role of many daily consumption areas:
The role of the first ˎ Fresnel lens in the human body infrared sensor:
The Fresnel lens utilizes the special optical principle of the lens to produce an alternating "dead zone" and "high sensitive area" in front of the detector to improve its detection reception sensitivity. When someone walked from the front of the lens, the infrared emitted by the human body constantly alternately from the "blind spot" into the "high sensitive area", so that the received infrared signal to suddenly weak weak pulse input, and thus its energy amplitude The Fresnel lens has two roles: one is the focus, that is, pyroelectric infrared signal refraction (reflection) in the PIR, the second role is to detect the area is divided into a number of bright and dark areas, so that into the detection area Of the moving object can change in the form of temperature on the PIR to produce changes in pyroelectric infrared signal. Fresnel lens, simply said that the side of the lens is an equidistant tooth pattern, through these teeth, you can achieve the specified spectral range of light band pass (reflection or refraction) role. Conventional polished optical instruments are expensive to wear optical filters. Fresnel lens can greatly reduce the cost. A typical example is PIR. PIR is widely used on alarms. If you take a look, you will find a plastic hat on every PIR. This is the Fresnel lens. The inside of the little hat is engraved with a tooth pattern.
This Fresnel lens limits the frequency of the incident light to about 10 microns (the peak of human infrared radiation). Fresnel lens can be through the narrowband interference filter light focused on the silicon photoelectric secondary detector on the photosensitive surface, Fresnel lens can not use any organic solution (such as alcohol, etc.) wipe, dust can be used first distilled water Or ordinary water rinse, then wipe with absorbent cotton.
The second ˎ Fresnel lens in the camera focus screen role:
Now the camera focus screen is matte glass Fresnel lens, its advantage is bright and uniform brightness. When the focus is not on time, the imaging on the focusing screen is not clear. In order to match the more precise focus, generally in the center of the focusing screen with a crack and micro-prism device. When the focus is not allowed, the subject in the center of the focus screen is split into two images, when the two split images together, indicating that the focus is accurate. AF SLR standard focusing screen generally do not have a crack device, but engraved with a small rectangular box to represent the AF area, some focus screen is also engraved with local metering or spot metering area. Early AF SLR machine in the dark light when the focus is often difficult to see the focus frame, it is difficult to determine which point the camera as a focus point, a new generation of SLR focus on the focus screen will light, or focus sound Prompt for easy focusing in complex environments. Different types of focusing screen have different uses, shooting portraits may be better, such as a split screen, with a horizontal screen or scale of the focus screen for building photography and file remake; the middle part of the crack without the edge and only micro-focus Screen for a small aperture lens, it will not crack the side of the black side of the shortcomings. Many SLR camera focal lengths can be replaced by the user. Also known as thread lens.
The effect of the third ˎ Fresnel lens in the LED spotlight:
Fresnel lens for LED light source, play an increase in light efficiency, improve the brightness of the effect. Relative to the same lens and LED lights, different focal length, different distance, how to set the light angle, single light or multi-array LED lights can be designed according to demand. Applicable to LED flood light, colorful flood light, lighting, landscape lights, lights, all kinds of lamps.
Features: Fresnel lens ultra-thin structure, large size, arbitrary shape of the cutting, excellent light transmittance than traditional convex lens advantages, its weight is less than convex lens, a variety of occasions apply.
The effect of the fourth ˎ Fresnel lens in the rear view of the wide-angle lens:
Fresnel lens wide-angle lens for trucks, home two boxes of cars, buses, four-wheel drive off-road vehicles and other vehicles without "tail", often do not know after the car "possession" something. This lens uses a unique FRESNEL lens technology, it only affixed to the inside of the rear window, you can drive
Members to provide a large angle of vision, see the original blind area can not see the obstacles, increase the scope of the rear view.
The fifth ˎ Fresnel lens concentrates the role of photovoltaic solar cells:
Spotlight Photovoltaic lens is one of the core components of the third generation of high-concentrating photovoltaic solar power generation. As a precision optical device, the solar panel can increase the power generation several times. Yu Ying can be based on the customer's condenser ratio and the size of solar panels designed different specifications of the Fresnel lens, to achieve the best condenser effect.
The sixth ˎ Fresnel lens magnifying mirror effect:
Fresnel magnifying glass, which is an ultra-thin magnifying glass. With transparent plexiglass (of course, can also use more material) made. The Fresnel magnifier made of PVC, the smallest thickness can be between 0.45mm and 0.90mm, unlike the general magnifying glass, its surface is covered with tiny stripes, in its vortex-like stripes contains many convex lenses ( Referred to as a circular ring), so that through its light bending that is generated diffraction phenomenon, thus forming an enlarged image. Fresnel lens is characterized by higher brightness than ordinary lenses and surface smooth, radiation area is also large. General ordinary convex lens its diameter is very limited, and Fresnel in the magnifying glass in this field played a very good role, to achieve the general ordinary lens can not achieve the effect. And now made out of the Fresnel magnifying glass thickness of only 0.45mm, then carry, in fact, the main role is to reduce the traditional magnifying glass to create ordinary plexiglass, glass magnifying glass weight and volume.
Seventh ˎ Fresnel lens used in traffic lights:
As the popularity of high-power LED, the use of single or several LED light source, Fresnel lens with micro-array lens to do more light to replace the LED light source composition traffic signal has become the industry development trend. Has been put into use in many countries around the world.
The eighth ˎ Fresnel lens used in 3D glasses:
For 3D lenses to be thinner and lighter, some 3D glasses use Fresnel lenses. This lens is consistent with the curvature of ordinary lenses, but one side burned the size of the thread. Because the beam is from different angles on the lens, so it will feel the distance between the eyes and things far away, and in fact the distance is not so far.
Using Fresnel Lens 3D glasses means you need to make some sacrifices. You can make a multi-threaded lens, so you can see a clearer image.
In addition, you can also use less thread Fresnel lens, helps the beam to concentrate and improve the contrast, but the image clarity will be damaged, more on the VR lens principle design effect.
