Single-chip Ambient Light Sensing and Proximity Detection sensors provide improved digital ambient light sensing and proximity detection technology for touchscreen and LCD display control of tablets, notebook PCs, LCD monitors, flat-panel televisions, and cell phones. Ambient light sensors are designed for use in mobiles and other portable display controllers. Ambient light sensors will operate in environments over 60,000 lux (sunlight). The sensors produce accurate ALS and proximity detection results when operating behind spectrally distorting glass regardless of the lighting sources (e.g. sunlight, fluorescent) and intensity.

Ambient Light Sensing and Proximity Detection devices provides both ambient light sensing (ALS) and proximity detection. The ALS approximates human eye response to light intensity under a variety of lighting conditions and through a variety of attenuation materials. The proximity detection feature allows a large dynamic range of operation for use in short distance detection behind dark glass such as in a cell phone or for longer distance measurements for applications such as presence detection for monitors or laptops. The programmable proximity detection enables continuous measurements across the entire range. In addition, an internal state machine provides the ability to put the device into a low power mode in between ALS and proximity measurements providing very low average power consumption.

Ambient Light Sensing is particularly useful for display management with the purpose of extending battery life and providing optimum viewing in diverse lighting conditions. Display panel and keyboard backlighting can account for up to 30 to 40 percent of total platform power. The ALS features are ideal for use in tablets, notebook PCs, LCD monitors, flat-panel televisions, and cell phones.

In cell phones, the proximity detection can detect when the user positions the phone close to their ear, and provide proximity information at a high repetition rate needed when answering a phone call. It can also detect both close and far distances so the application can implement more complex algorithms to provide a more robust interface. In laptop or monitor applications, the proximity detection determines whether a user is in front of the laptop using the keyboard or away from the desk. This provides both improved green power saving capability and the added security to lock the computer when the user is not present.

Applications of Ambient Light Sensing and Proximity Detection Sensors

  • Cell Phone Backlight Dimming
  • Cell Phone Touch Screen Disable
  • Laptop/Monitor Security
  • Automatic Speakerphone Enable in smartphones
  • Automatic Menu Popup
  • Kiosks, Toys, and Gaming systems
  • Industrial display interface and Instrumentation panels
  • Home Security systems and Smoke detectors
  • Residential HVAC and other Home appliances
  • Fax/printer/scanner front panels