Integrated opto-mechanical-thermal analysis of infrared lens

20161028

In the design of infrared optical system, the impact of thermal effect on optical performance should be taken into account so as to achieve a good temperature performance and the integrated opto-mechanical-thermal analysis should be conducted.

The method and flow chart of integrated optomechanical-thermal analysis were discussed. An infrared lens with a focal length of 200 mm was designed, which matched with cold shield and could operate at a wide temperature range. The finite element model of the infrared lens was established and the thermodynamic analysis was accomplished, each lens interval and surface figure changes were obtained by using processed analysis data.

The interval changes, Zernike coefficients and refractive index at ambient temperature were substituted into optical design software, and the temperature effect on image quality was obtained.

The analysis results show that the modulation transfer functions of infrared lens with 16 line pairs in all field of views are larger than 0.5 from -40℃ to +60℃. The design of infrared lens is easy to be implemented and meets the requirements.

This article comes from yygx website edit released

Usage of Thermal Imaging Camera

Since thermal imaging cameras can “see” through darkness or smoke, they allow firefighters to quickly find the seat of a structure fire, or see the heat signature of visually obscured victims. They can be used to search for victims outdoors on a cool night, spot smoldering fires inside a wall, or detect overheating electrical wiring. Thermal imaging cameras were credited with saving multiple lives per year through victim identification and removal from low visibility conditions as early as 1999.

In addition to the ability to see through dense smoke, thermal imaging cameras also can see materials involved in spontaneous, low level combustion. In one documented instance, a TIC was used to isolate a smoldering hot spot in a grain storage facility; by isolating and removing only the affected grain, 75% of the stored crop was saved.

In another, Tennessee firefighters used a thermal imaging camera to detect a hidden fire inside a cinder railroad bed, resulting in an estimated $500,000 cost avoidance. Thermal imaging cameras have also been reported to be particularly useful for fighting fires in cellulose insulation, and for ascertaining that a structure is safe to reenter after a fire has been put out. Ventura County, California firefighters used their TIC to find a cat which had become sealed inside a walkway during construction.

Prototypes of helmet-mounted thermal imaging cameras were first publicized in 1992, but a detailed evaluation of their performance in real world situations was not published until 2007. The model evaluated in 2007 weighed approximately 1.5 lbs, substantially increasing weight over an unadorned helmet. However, the ability to “use the devices while they were also pulling hose and carrying tools” was favorably received by firefighters evaluating the product.

Benefits of helmet mounted TICs included that multiple firefighters each observed different aspects of a fire, while drawbacks included firefighters relaxing safety discipline. In timed testing, teams of firefighters with helmet-mounted cameras completed search tasks substantially faster, were less disoriented, and used less air than teams with a single handheld camera, who in turn fared better than teams with no TIC at all.

A limitation of these and similar devices has been their poor depth perception (the user has a hard time judging how far away objects are). This increases the likelihood that the user will trip over or run into obstacles, or have other distance-related problems. An additional limitation of infrared technology is that since materials at the same temperature are shown as the same color, the display will not depict many details normally viewable in visible light.

This article comes from wikipedia edit released

Adds to Its Line of Thermal Network Cameras

20161025We launched Thermal Network Camera, which increases fixed thermal network cameras for outdoor surveillance.

Thermal Network Camera is a bullet-style Internet protocol camera that arrives ready for outdoor installation in harsh environments and tough climates. The Thermal Network Camera is designed for dimgeployment at locations where early detection of an intrusion. The camera can provide images from areas covered by complete darkness and during challenging conditions.

The Thermal Network Camera offers high-contrast 384 x 288 resolution thermal images with four available lens options to provide maximum flexibility for different detection ranges and fields of view, which extend from 240 yards to 1970 yards. The Thermal Network Camera is also the first thermal camera to support “Corridor Format,” which is designed to monitor long fences, shorelines and tunnels by delivering a vertically oriented, portrait field of view.

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Binocular Hand Held Thermal Imager

Thermal Binocular Imager is a light weight binocular eyepiece model thermal imager suitable for comfortable viewing and observation by the user. This model of Thermal Binocular Imager replaced the existing monocular eyepiece based thermal imager Observation through dust, fog and through bushes. Thermal Binocular Imager are used while Day and Night patrolling and surveillance.

  • Integral miniature video monitor
  • External standard video output
  • Battery Powered
  • Strain free viewing with binoculars
  • Miniature closed cycle cooler
  • Advanced DDC [Detector Dewar Cooler] module with on chip signal processing
  • Provision for Inter Pupillary Distance adjustment

Technical Data

Spectral Band 8-10.5 mm Entrance Aperture 94mm Weight 3.4Kg [w/o batteries] Communication port RS422 FOV 4.0° X 2.5° [Narrow] 13.6° X 8.5° [Wide] Detector MCT-PV with on chip pre-Processing Cooler Miniature closed cycle, integral with Dewar Display Integral Miniature Monochrome CRT Power Sources Disposable LiSo2 battery Rechargeable NiMh battery External DC source [via adapter] Environmental Designed and tested to MIL-STD-810 Operating Temperature -30℃ to +55℃.

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Thermal Night Vision Riflescopes

Never miss a shot in the dark by making sure to outfit your firearm with a thermal night vision scope! Planning to do some night hunting? You’re going to need thermal night vision! A thermal night vision riflescope needs to do more than simply give you a great image; it also has to be tough as nails so as to stand up to the shock of recoil.

Fortunately, we offer a great selection of thermal night vision riflescopes that have both outstanding tech and reliable construction! Ranging from the more cost efficient 1st Generation Thermal Night Vision scope to the best-in-class thermal night vision, we have the perfect option for you.

Everyone needs a little advice from time to time, and when you consider the highly technical and specialized nature of a thermal night vision scope, it’s best to seek answers from the experts. Your first stop for information should be our helpful and informative How to Buy Thermal Night Vision Guide, we give you the service necessary to make sure you make the smart choice when picking up a great new scope.

This article comes from opticsplanet edit released

High Performance Thermal Imaging Core

Next generation thermal imaging engine platform is especially designed for better, smaller, cheaper integration by OEM clients who gain VGA resolution. With an advanced, DSP-based platform, the engine supports a 17μm 640 x 480 detector. Software and firmware modules can be easily developed and modified to any specifications. Due to the engine’s user friendly interface and attractive size, it can be integrated cost-effectively into small-size applications, a key marketing advantage for dual use applications. The Thermal Imaging Core supports the most advanced motorized lenses based on continuous zoom or dual FOV and equipped with automatic focus algorithms.

Features

  • Easy integration
  • High performance
  • Low power consumption
  • Rugged military grade design

Why Thermal Imaging Core?

With easy system integration and rugged design, this high performance uncooled thermal engine is best-in-class for image processing and can be integrated cost effectively into small applications.

This article comes from opgal edit released

Why does it happen? – Infrared lens

our webcam has a sensor behind the lens which is sensitive to most colours of light and IR (and also ultra violet). It has a infrared lens on the front which stops the IR, and then a series of filters on the sensor chip itself to only allow one colour through to each sensor on the chip so they can detect different colours.

1

Camera working normally

Our camera

In a webcam the IR is stopped by the infrared lens, and then there are coloured filters in front of each pixel so the camera can determine colour.

If we put a visible light filter on the camera only the IR can get through which goes through all the coloured filters.

When we just let IR into the camera by putting our infrared lens on the front it will pass through all the coloured filters to slightly varying degrees, as these infrared lens are not designed to stop it.

Why is my webcam sensitive to IR anyway?

Webcams detect light by having lots of small sensors on a piece of silicon. Each of these sensors is a small diode – a one way valve for electricity, and the electronics is trying to push electricity the wrong way through this diode.

This normally doesn’t work because a diode is designed so that there are no free electrons to carry an electric current when you try and push electricity the wrong way. But if a photon of light with enough energy hits the middle of the diode it will knock an electron off a silicon atom which can now move and carry electric current. The electronics then measures this current and so how much light has hit the sensor.

2

A sensor

Light on Photodiode

Most webcams use photodiodes as sensors, these have an area in the centre with no fee electrons to carry current.

If light hits the photodiode it knocks an electron off an atom, which can now move carrying electric current

Any colour of light above the mid infra red (so near IR, visible, UV etc) will have enough energy to do this, so your camera is sensitive to infra red light. More expensive CCD chips found in real digital cameras work slightly differently but on the same principle, so they are also sensitive to IR.

This article comes from thenakedscientists edit released

Thermal network camera for challenging conditions

20161012The thermal network camera is said to be a robust, affordable and solid bullet-style camera designed for outdoor surveillance in complete darkness and challenging conditions. It offers high contrast 384×288 resolution thermal images and is the first thermal camera offering its corridor format, which allows the camera to deliver a vertical field of view, perfect for situations such as the monitoring of long fences and other perimeters.

With four lens alternatives, 384×288 resolution and advanced image processor, the cameras also support key IP-Surveillance features such as H.264 and Motion JPEG, two-way audio, local storage and Power over Ethernet.

In addition, it provides intelligent video, tampering alarm, motion detection and support for the camera application platform. The camera is quick to install and can easily be integrated with existing security systems and with other products.

This article comes from itsinternational edit released

The Best Thermal Binocular

If you are looking for cutting edge thermal optics technology than check out our Thermal Multipurpose Viewers, Goggles, Thermal Binoculars, and Cameras. We arae offering the latest and greatest in thermal night vision for law enforcement, fire and search & rescue teams, military, hunting, and wildlife observation. These optics see heat so they are effective in total darkness or daylight and can see through obstructions such as smoke and fog.

Remember that these optics are newer technology and the cheap thermal Multipurpose Viewers you may see will have limited range and resolution. Photos of these cheaper devices are often taken in “ideal” conditions or are simply photo shopped. A basic analogy would be that a $3000 thermal device will give you the resolution of a $300 night vision device (which isn’t very good), however a $3000 night vision unit will give you outstanding resolution and performance. One of the main factors that determines performance is the FPA format or number of pixels. The more pixels the better the resolution will be. We would recommend at least a 320 x 240 FPA in a high quality device for minimum efficient use.

The Thermal Binocular is a very impressive viewing system that we would highly recommend as it has exceptional performance and is very rugged. The new ATN Mini Thor thermal Multipurpose Viewer is now available and offer unmatched value and cutting edge features in the 320 x 240 models.

This article comes from nightvision4less edit released

How Thermal Night Vision Works

Here’s how thermal night vision works:

  1. A special lens focuses the infrared light emitted by all of the objects in view.
  2. The focused light is scanned by a phased array of infrared-detector elements. The detector elements create a very detailed temperature pattern called a thermogram. It only takes about one-thirtieth of a second for the detector array to obtain the temperature information to make the thermogram. This information is obtained from several thousand points in the field of view of the detector array.
  3. The thermogram created by the detector elements is translated into electric impulses.
  4. The impulses are sent to a signal-processing unit, a circuit board with a dedicated chip that translates the information from the elements into data for the display.
  5. The signal-processing unit sends the information to the display, where it appears as various colors depending on the intensity of the infrared emission. The combination of all the impulses from all of the elements creates the image.

This article comes from howstuffworks edit released