Automatic Temperature Calibration (ATC) Circuit

NAC Image Technology Revolutionizes the High-Speed Imaging Industry, implementing the ATC Circuit in all its Memrecam digital high-speed camera systems….

ATC Benefits - The Automatic Temperature Calibration (ATC) Circuit samples the sensor temperature at different temperature points and adjusts the camera’s images to eliminate Fixed Pattern Noise (FPN). As the name implies, this process is completed automatically and requires no user intervention for the setting of black level and/or white balancing.

Application Environment - A major military range user faces difficulty in high-speed image acquisition using digital high-speed camera systems in part due to rapidly changing temperatures. High-speed cameras must be activated, set up and operated remotely and cameras cannot be physically accessed after set up. Temperatures during setup can be below 0°C. Cameras may be left in the “On” position for several hours before testing occurs and temperatures at test time can be greater than 40°C. Capturing images without correcting for the change in the camera’s sensor temperature introduces FPN into the image with the result being images of poor quality.

Challenge - The FPN for each digital sensor is unique and it also changes with variations in sensor temperature. The digital high-speed camera must be “re-balanced” to take into account the change in the screen noise patterns due to sensor temperature. This camera “re-balance” is critical in that it eliminates the FPN effect resulting in higher quality images. The “re-balance” must be accomplished without physically accessing the camera.

Solution - Having implemented an Automatic Temperature Calibration (ATC) Circuit in all its Memrecam digital high-speed camera systems manufactured since 1994, NAC Image Technology provided its Memrecam fx K4 Digital High-Speed Camera System with Gigabit Ethernet for this application. Most digital high-speed cameras require manual re-balancing of whites and blacks to eliminate FPN. NAC’s ATC Circuit continuously samples the camera sensor’s temperature and allows for FPN correction remotely without any manual intervention on the part of the user.

The ATC Circuit has been incorporated into all NAC’s digital high-speed camera systems since the introduction of the Memrecam Ci in 1994 (the world’s first digital high-speed camera system). NAC’s current lineup of Memrecam fx digital high-speed camera systems continues to employ the ATC Circuit helping to make the Memrecam fx family of cameras the most user-friendly, easy-to-use digital high-speed camera systems in the world.

Utilizing the ATC Circuit

The Memrecam fx series features ATC Circuit technology to address screen noise patterns that can become apparent due to rising sensor temperature. Once the system is activated, the sensor temperature rises.

At the time the system is set to ARM mode, the ATC Circuit polls the sensor to determine the sensor’s temperature. Based upon the sensor temperature, the Memrecam fx automatically performs black balancing and white balancing, calibrating the camera system, eliminating fixed pattern noise (FPN) from the image.

For best results of the ATC circuit the user should go from stand by to Arm mode as near to test time as is feasible. This may be accomplished by sending the commands to the camera from a remote location shortly before the test.

Following these guidelines allows the user of the Memrecam fx digital high-speed camera systems to optimize image quality without having to perform manual black balancing and white balancing. The Memrecam fx ATC Circuit makes it possible for the user to employ the digital high-speed camera system and record images over an extended period of time without having to stop and perform cumbersome re-balancing procedures common in other digital high-speed camera systems.