Image Sensor

A CCD image sensor of the type for providing charge multiplication by impact ionisation has an image area and a plurality of pixels. A separate multiplication register has a plurality of multiplication elements arranged to receive charge from the pixels of the image area. Each multiplication element comprises a sequence of electrodes operable to cause multiplication, the electrodes of each multiplication element being adjacent one another and non-overlapping. The non-overlapping arrangement may be manufactured by a CMOS process thereby providing a CCD image sensor with the advantages of CCD multiplication but using a CMOS manufacturing process

Selecting source image sensor nodes based on 2-hop information to improve image transmissions to mobile robot sinks in search \& rescue operations

We consider Robot-assisted Search $\&$ Rescue operations enhanced with some fixed image sensor nodes capable of capturing and sending visual information to a robot sink. In order to increase the performance of image transfer from image sensor nodes to the robot sinks we propose a 2-hop neighborhood information-based cover set selection to determine the most relevant image sensor nodes to activate. Then, in order to be consistent with our proposed approach, a multi-path extension of Greedy Perimeter Stateless Routing (called T-GPSR) wherein routing decisions are also based on 2-hop neighborhood information is proposed. Simulation results show that our proposal reduces packet losses, enabling fast packet delivery and higher visual quality of received images at the robot sink

Custom transistor layout design techniques for random telegraph signal noise reduction in CMOS image sensors

Interface and near oxide traps in small gate area MOS transistors (gate area ,1 mm2) lead to RTS noise which implies the emergence of noisy pixels in CMOS image sensors. To reduce this noise, two simple and efficient layout techniques of custom transistors have been imagined. These techniques have been successfully implemented in an image sensor test chip fabricated in a 0.35 mm CMOS image sensor process. Experimental results demonstrate a significant reduction of the noisy pixels for the two different techniques

Poster Abstract: Practical issues in image acquisition and transmission over wireless sensor network

Multimedia data have become an important objective in wireless sensor networks. Due to the node resource constraints (energy consumption, memory capacity, network latency and throughput) the incorporation of image sensor at the nodes is currently a challenge. In this paper, we study different node architectures, evaluating processing time, energy consumption, image quality and data delivery issues. The study shows that a specialized image co-processor is an optimal solutionJUnta de Andalucía P07-TIC-0247

Image Sensor

An image sensor of the type for providing charge multiplication by impact ionisation has plurality of multiplication elements. Each element is arranged to receive charge from photosensitive elements of an image area and each element comprises a sequence of electrodes to move charge along a transport path. Each of the electrodes has an edge defining a boundary with a first electrode, a maximum width across the charge transport path and a leading edge that defines a boundary with a second electrode, the leading edge having one or more changes of direction so that the length of the edge is greater than the maximum width of the charge multiplication electrode across the charge transport path. Various arrangements with such changes of direction are provided including a zigzag saw-tooth arrangement, a castellated arrangement and a triangular arrangement

A high dynamic range digital LinLog CMOS image sensor architecture based on Event Readout of pixels and suitable for low voltage operation

Several approaches have been developed to extend the dynamic range of image sensor in order to keep all the information content of natural scenes covering a very broad range of illumination. Digital CMOS image sensor are especially well suited to wide dynamic range imaging by implementing dual sampling, multiple exposure methods using either column or in pixel ADC, or Address Event Representation. A new architecture of digital high dynamic range CMOS image sensor, suitable for low voltage operation, has been developed that implements a built-in dynamic compression function targeted to LinLog behavior, by combining an event based readout of pixels, the use of multiple integrations per frame and the coding of pixel values using the mantissa-exponent principle, to achieve the dynamic range extension