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Sensors for IoT, Robotics, and Mobile: ams Optical Imaging Sensors Roundup

January 20, 2019 by Mark Hughes

An update on some new ams optical imaging sensors coming down the pipe in 2019.

Optical imaging sensors are a staple of many modern designs across industries. Here's an update on some new ams sensors coming down the pipe in 2019.

While ams has been in business for almost 40 years, three years ago the company went through a transformation and recentered its focus on the sensor market. In rapid order, the company acquired various pieces of sensor-related intellectual property and grew in size from 2500 employees to 10,000 employees. Their portfolio focuses largely on audio, optical, and full spectral sensors for mobile and automotive solutions. 

In this article, we'll take a look at some examples of ams optical image sensors. At the vehicle’s door, 3D sensors can positively identify a driver approaching a vehicle and unlock a door. Inside the vehicle, additional 3D sensors can detect distracted driving.

3D Sensing

ams offers three industry standards in their 3D sensing portfolio: structured light illumination (PARSENN), stereoscopic imaging (BELICE), and time-of-flight (PMSON).

Each solution is small enough to incorporate in the next generation of smartphones or as standalone modules for 3D face detection and authentication.

 

The BELICE-SD dot-pattern infrared illuminator for 3D stereoscopic imaging. Image from ams

 

  • Structured Light Illumination: PARSENN (pre-production)
    • 30,000 random dot patterns for facial recognition (@940nm)
  • Stereoscopic Imaging: BELICE 
    • Infrared 10,000 dot-pattern illuminator (@850nm)
  • Time-of-Flight: PMSON (pre-production)
    • Infrared illumination for mobile, IoT and robotics (@940nm)

The current state-of-technology allows no more than one error in 50,000 readings. For reference, your car key has about a one in 3500 chance of opening someone else’s car. To prevent unauthorized access, 3D facial recognition could be combined with voice-recognition to create an almost bulletproof security solution.

NanEye Miniature CMOS Image Sensor

This 1mm x 1mm microminiature camera has just four connections: two for power and two for data in a miniature 4-pad BGA connector. The full package (sensor + lens) is the size of a grain of sand.

 

Miniature image sensors. Image from ams

 

The NanEye is a CMOS sensor that offers 249x250 pixel resolution in either a single or dual-sensor (stereoscopic) configuration. The pixels on this sensor are necessarily tiny, so additional light is often needed to illuminate a target. This can be accomplished with fiber-optic (along the connector path) or external illumination.

 

Block diagram for the NanEye 2D CMOS image sensor.

 

Cameras this small have multiple medical applications, ranging from a swallowable endoscopic pill to arterial catheterization. In an industrial setting, these devices can fit into inspection spaces that other cameras simply cannot.

Spectral Sensors: Measuring Color

Full spectral color sensors provide detailed color information for visible, near infrared (NIR), and ultraviolet light. These sensors can be used during manufacturing to ensure product purity or in laboratories for spectroscopy. They might also find use in consumer smartphones and cameras to bring accurate color reproduction in a variety of lighting situations. These sensors have a variety of narrow-band optical filters that allow light of a particular wavelength to travel through.

 

An example application of a spectrum color sensor. Image from ams

 

Here's an overview of ams's spectral sensors portfolio:

  • XYZ + NIR (near IR) sensors
    • AS7261 White color sensor plus NIR (near IR); color identification, measurement, and matching
      • AS7261N (pre-production) Color analysis and color calibration
    • AS7262 
    • AS7264N (new) (440/490nm blue sensor) 
  • 6-channel visible spectral sensor
  • Smart 18-channel VIS + NIR sensor
  • 11-channel spectral color sensor
    • AS7341 (pre-production)

Optical sensors, used with an appropriate light source, can be turned into mobile Fabry-Perot interferometers smaller than the size of a pack of playing cards. All chemicals and materials have a unique spectrum associated with them. By recording the spectrum of a target object and comparing it to the known spectrum of pure substances, users can determine what substances are present in the target and in what proportions. For example, these devices can be used to determine the sugar content of a cookie, find contaminants in milk, or gluten in a supposedly gluten-free pastry.


 

What optical sensor applications are you most interested in? Share your thoughts in the comments below.

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