Small and Inexpensive 3D Image Sensor

Image sensors are becoming one of the key components for use in various application areas including such sectors as automation, gaming, automobiles, medical, and many others. Due to intense development of each of the above mentioned sectors, there is an ongoing need for more advanced solutions such as three-dimensional (3D) cameras that would enable on one hand more functionalities, and on the other--will be smaller and cheap.

PMDTechnologies GmbH (PMDtec), a fab-less integrated circuit (IC) manufacturer located in Siegen (Germany), is working on the 3D CMOS-based digital imaging. The company provides solutions for 3D imaging developed based on the photonic mixer device (PMD) technology.

The technology is based on the time-of-flight approach. The A light source transmits the a signal, which is intensity modulated. The PMD sensor detects the light that is reflected from the scene. Based on the reflected signal the distance in each pixel can be calculated determined due to the time-of-flight in the light that is usedof the transmitted light signal. To their customers the company provides PMD chips together with or without (as the customers wish) the needed electronics on a printed circuit board (PCB) board. The company is involved in the chip design of the chipsand offers also engineering support in all aspects of the product development of a PMD-based solution. The fabrication of the chips is done externally at the company partners, andfollowed by than the quality insurance, that is done again at PMDTecchnologies GmbH itself. So the company delivers tested and qualified imagers to its customers in high numbers.

The biggest advantage of the technology is the possibility to build 3D cameras, which are very small and very cheap. "3D image sensing is nothing completely new," comments Thorsten Ringbeck, director business development of PMDTechnologies GmbH. "Before we started to establish our technology, there were also other approaches to do 3D imaging, like for example the stereo-vision systems. The main advantage of using PMD technology is that you do not need two cameras but only one camera. So the technology that you need for the 3D information detection is integrated within the image sensor itself." When using the PMD technology, the 3D information is provided in real time, and is stable and very robust against external interferences.

Moreover, due to additional features incorporated in the solution, such as a suppression of background illumination (SBI), the sensor is stable for thein case of varying background illumination for example. As the solution is developed based on one providing the 3D information directly, it is also more efficient from the calculation side or the computing power that is needed. And this is an important advantage in consuming, automotive or other applications.

The solution could be beneficial for 3D information detection in multiple application areas, including automation, automotive, medical, security, gaming, and many others.

According to Ringbeck, future developments will include integration of more functionalities on the image sensor itself. "We are working on 0.18-micrometer CMOS technology integration, so what we will have is a camera on a chip where everything will be done on a chip (that is, raw data calculation, application calculation, and so on) and you just apply this to you system and give power supply, and what comes out of the chip is directly distance information or even the application (the decision - for example, if there is a pedestrian in front of the car: yes or no)," comments Ringbeck.

The company has been founded in 2002 as the spin-off from the Center for Sensor Systems (ZESS) at the University of Siegen, Germany. The basic PMD technology has been initially developed at the University of Siegen, however further improvements as well as the industrialization have been done by the company itself. Currently, PMDTechnologies GmbH owns all the patents (about 35 to 40 patents worldwide) concerning PMD-based applications, the PMD principle and the its realization of the principle. The company is open for collaboration and looks for new application areas, but itby focuses focusing mainly on key players in each application sector. "Because we do not have the know-how to design a specific product for a specific market, but we have the know-how to develop the 3D camera for it. So we need aare searching partner that haspartners that have the market access and the experience to make the product more successful," adds Ringbeck.


Thorsten Ringbeck

Director Business Development at PMDTechnologies GmbH

Am Eichenhang 50

D-57076 Siegen


Phone: + 49-271-238-538-801

Fax: + 49-271-238-538-809



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