3D image sensor

The 3D Image Sensor from ifm efector evaluates size, shape and volume in material handling applications. An integrated 64 x 48 pixel array - in which each pixel represents a time of flight measurement - defines the field of view for the sensor.

The 3D sensor technology provides critical information in applications such as palletising and de-palletising, material handling, bulk level of materials and intelligent routing and sorting.

The 3D image sensor’s receiver element is a system-on-chip design, with the complete sensor element and electronics built on a 0.25 mm² chip. This miniature chip enables 3D imaging, and reduces the size of the sensor and its cost.

The photonic mixing device (PMD) principle is based on time-of-flight distance measurement. Each of the 3072 pixels within the array has two gates that are controlled by an oscillator that oscillates at a frequency of 20 MHz. Light is emitted from the sensor and reflected by the target and received back into the PMD chip. Relating the phase difference measured by each pixel to the speed of light gives the distance travelled by light falling onto the detector. The phase shift of the light is then compared to the reference signal and sent from the chip as the representative distance for that pixel. Information from all the pixels is then brought together to create a 3D image.

The sensor also includes technology for suppression of background illumination (SBI). This allows the sensor to eliminate the effects of external lighting such as sunlight and high-powered internal lighting so that the sensor can be used in almost any indoor or outdoor application.