Ams introduces highly sensitive optical sensors that eliminate flicker artifacts

     Ams has introduced a new sensor solution, the TCS3408, to help mobile phone rear cameras with rolling shutter image sensors eliminate effects such as banding and other image artifacts caused by blinking artificial light sources.

     With the widespread use of leds, mobile phone photography is increasingly plagued by flickering light sources. ams' new TCS3408 color sensor offers increased accuracy and sensitivity to measure not only the color temperature and light intensity of ambient light, but also the physical flicker of the optics, enabling the mobile phone camera image enhancement system to eliminate defect artifacts caused by artificial light sources. It offers the industry's highest level of on-chip light scintillation detection sensitivity three times higher than the previous generation TCS3707.

     Dave Moon, Senior product Marketing Manager, AMS Semi-Conductor Integrated Optical Sensors Business Line, said: "Today, high-resolution smartphone cameras have an ever-increasing number of pixels that can capture images with extraordinary detail and clarity. However, pictures and videos are often ruined by unsightly streaks and distorted effects caused by the flickering of artificial light sources. Thanks to the TCS3408 highly sensitive light source flicker sensor, smartphones will be able to capture detailed images free from light source flickers and artifacts in all light source conditions."

     Today's cell phone cameras generally use a basic three-channel red/green/blue (RGB) sensor to estimate color balance in an image enhancement system and do not implement Flicker detection. The TCS3408 supports Flicker detection on chip and concurrently reads five ambient light sensing channels (in addition to RGB channels, additional wide-band channels and full-band channels for reference) to accurately measure light color and intensity. The TCS3408 also offers the option to store a range of flicker measurements in internal memory, allowing the smartphone camera's video processor to detect higher-order flicker frequencies (up to 2kHz). These flicker frequencies are ubiquitous in modern pulse-width modulation (PWM) -based LED light sources, and will become more and more popular in the visible future.

     During the rolling shutter operation of the camera, if the visible light modulation caused by the flickering light source is captured, the image or video taken will have banding artifacts that cause distortion. The TCS3408 device contains a Flicker detection engine for detecting 50Hz or 60Hz light source flickers typically produced by incandescent or fluorescent lamps. When the light source flicker is detected, it is captured and reported by the internal status register of the device, and the digital I2C interface quickly reports the output information through external processing. Knowing that the light source flicker is present, the camera's video processor synchronizes the shutter with the "on" portion of the scene relative to the ambient light output. Using the additional information provided by the TCS3408, the video processor can eliminate distorted banding artifacts and truly recreate the image as seen by the user.

     The TCS3408 is the latest in AMS 'family of smart optical sensors for managing the color and intensity of mobile phone displays and enhancing the image processing capabilities of cameras. It offers superior color detection sensitivity, 10 times ALS sensitivity and only half the power consumption of competing products. Ams is trusted by smartphone manufacturers for developing color sensors with Flicker on-chip detection that can detect flickers present in modern light sources. Ams provides the industry's best-performing optical sensing solutions that set their products apart from the competition.