Image Sensor Innovations Push Machine Vision Forward

Just as machine vision innovations drive automation forward, advances in image sensors drive machine vision forward. And make no mistake: image sensing has lately witnessed many significant developments, in areas such as 3D imaging, event-based sensing, and nonvisible image sensing. This blog takes a snapshot look at some of the latest advancements.

Capturing 3D  

Image sensor companies continue to make 3D imaging applications more accessible to camera makers by releasing innovative new offerings. For example, a few years back Sony released its DepthSense line of back-illuminated 3D Time of Flight (ToF) CMOS sensors. Soon thereafter, major machine vision camera companies, including LUCID Vision Labs and Basler, released 3D ToF cameras based on the sensors.

More recently, Teledyne e2v introduced the Hydra3D ToF CMOS image sensor, which offers a 10 µm three-tap pixel that captures more phases simultaneously and minimizes motion artifacts. This 832 x 600 sensor achieves a frame rate of 416.7 fps and uses a single train of pulses to capture all phases.

Teledyne e2v also recently released its Flash series of image sensors for 3D laser triangulation. Available in 2 MPixel and 4 MPixel models, the global shutter CMOS image sensors reach up to 1800 fps. They offer up to 100 decibel real-time and single-frame HDR features, embedded on-chip for simultaneous inspection of high- and low-reflective materials. Both the Hydra3D and the Flash series received 2021 Innovators Awards from Vision Systems Design magazine.

Event-Based Sensing

Another company making waves in the world of image sensors is Prophesee, recipient of the 2021 Vision Award. Prophesee developed an event-based neuromorphic image sensor inspired by the human retina. Each pixel in the company’s Metavision sensors features embedded intelligence, so pixels can activate themselves independently when luminance changes are detected in a scene and can output the changed data, at the same time eliminating unnecessary event data such as LED flickering.

This capability is combined with XY coordinate information on pixel position, as well as time information, which enables high-speed, low-latency data output for machine vision applications. In fact, these sensors capture up to 1,000 times less data than a traditional image sensor and offer a 10,000 fps time-resolution equivalent. Prophesee recently partnered with Sony Semiconductor Solutions to integrate event-based capabilities into Sony’s IMX636 and IMX637 sensors.

IMAGO Technologies integrates Prophesee event-based image sensors into its Vision Cam EB smart camera — a programmable embedded vision system that delivers high sampling rates for the detection of high-speed processes.

Beyond the Visible

Nonvisible imaging technologies also continue to progress. Sony Semiconductor Solutions has been busy here as well; the company recently announced commercialization of its IMX487 ultraviolet-compatible CMOS image sensor. Featuring a global shutter design, the 8.13 MPixel sensor offers a high level of ultraviolet (UV) sensitivity with minimal noise and targets several applications, including semiconductor defect inspection.

Many know that not long ago, Sony released its SenSWIR line of shortwave infrared (SWIR) sensors. Their novel copper-to-copper bonding process enables the capture of SWIR and visible light on a single chip. In another example of SWIR image sensor developments, SWIR Vision Systems recently received $5 million in funding to expand its business. The company is known for an innovative colloidal quantum dot (CQD) SWIR sensor integrated directly onto a CMOS readout integrated circuit, thereby offering smaller pixel pitch, higher resolution, lower costs, and ease of global export, according to the company. SWIR Vision Systems offers the Acuros SWIR line (400 to 1700 nm wavelength) and the Acuros eSWIR line (350 to 2000 nm wavelength).

Elsewhere, Emberion recently released the VS20 SWIR camera, which features a 400 to 2000 nm wavelength. The VS20’s image sensor is a detector array monolithically built on a tailor-made CMOS readout integrated circuit. The new camera offers Camera Link, USB, and GigE interfaces and targets a wide range of applications.

Toward New Heights

Other notable examples include the ultra-high-resolution Gpixel GMAX32103 CMOS image sensor, which can be found in the HZ-100-G camera from Emergent Vision Technologies. This camera — the only Platinum Award winner in Vision Systems Design’s 2021 Innovators Awards competition — reaches 24 fps at 103.7 MPixels through a 100GigE interface.

Ultimately, advancements in machine vision are driven by the availability of new, high-quality image sensors, which are in turn advanced by ever-evolving machine vision application requirements. Those discussed here represent just a snapshot of the latest developments in image sensing. Of course image sensor companies will continue to release notable products, pushing the capabilities of machine vision applications to new heights.