Video: IR-SF641

Video transcript

A thermal imaging core of 640 × 512 pixels, small enough to build into a drone or an instrument, what it contains, what it leaves to the integrator, and how it is connected. Whoever builds a drone payload, a fixed sensor, or an embedded instrument does not want a finished camera inside it. A camera brings its own housing, its own power, and its own controls. What the designer needs is the thermal core, the detector, the processing, and a clean interface, in as little volume and power as possible.

In figures, an uncooled vanadium oxide detector of 640 × 512 with a 12 µm pixel pitch, a sensitivity of 30 mK or better, 50 images a second in the 8 to 14 µm band, and a single 5-volt supply. Without its lens, the module measures 26 × 26 mm and weighs 22 g. The lens in front is fixed and athermalized, so the focus holds when the temperature around it changes, with no motor and no refocusing. The small pixel keeps both the detector and the lens compact. The lens sets the compromise between field and detail.

9 mm gives the widest view for close work or a broad scene. 75 mm gives the narrowest, to resolve a small target far away. The IR-SF641 offers 6 focal lengths. The IR-SF641 keeps the compact set of 9, 13, and 25. So there are two variants. They share the detector, the processing, and the interfaces. They differ in the lenses available and in the working temperature, from minus 40 to 70 degrees for the IR-SF641, and from minus 20 to 60 for the R.

Everything passes through the module interface. 5 volts in. The analog video out, PAL or NTSC, to a monitor, a recorder, or a video link. The 16-bit digital video for an image processor. The UART line at 3.3 volt TTL for the controller that sends commands. And reserved user inputs and outputs for the application. Over the UART, the host controls the image, brightness and gain, the detail enhancement, the polarity, the zoom, and the calibration.

The module answers with its video, analog, or digital, already processed and ready to display or record. The processing is done inside the module. Digital detail enhancement brings out edges in a scene with a wide temperature span. Noise reduction cleans the image. Polarity switches between white-hot and black-hot. The digital zoom goes from one to eight times, and brightness and gain can be manual, partly automatic or fully automatic.

An uncooled detector needs its image calibrated, so that every pixel responds the same. The module does it by itself at power-on. After that, a manual calibration can be requested whenever the image needs it. Integrating it follows a clear order. Choose the variant and the lens for the field of view you need. Design the mounting and the housing around it. Give it a clean 5-volt supply.

Connect the video to the recorder or the link. Connect the UART to the controller and set the image parameters. Where it goes. Drones and other aerial platforms. Industrial temperature measurement systems. Security and outdoor observation. And high-volume products where size and consumption are tight. Thermal imaging from Amperis.