Shrinking Vision Sensors

Vision sensors or cameras that pack a lot of performance into very little space, find new applications in many industrial situations. With an increasing amount of integration and capability to operate without a PC, some are even called smart. In fact, the key to these small vision systems is the specific functionality they provide in a limited amount of space. Both charge coupled device (CCD) and CMOS cameras continue to provide users technology choices. Other capabilities to attract users include special interfaces, the availability of a specific format for progressive and interlaced scans and the ability to handle low-light or high-speed measurements.

COMPACT ICCD

The camera head of Hamamatsu's newest compact Intensified CCD (ICCD) camera, the C10054, is approximately half the volume of its previous ICCD version. The ICCD integrates an image intensifier with a high-speed gate circuit and a remote controller to produce a high-sensitivity imaging unit for observing low-light or high-speed phenomena. The electronic shutter of the C10054 is as short as 5 nsec and its spectral response is from UV to visible or near-infrared for capturing still images or continuous video. Three different types of photocathodes provide spectral response from 280 to 720 nm, 370 to 920 nm or 185 to 900 nm and can be combined with either a one-stage or two-stage microchannel plate (MCP) for image intensification. The two-stage MCP models provide a minimum photocathode illuminance as low as 4 x 10e-7 lux. Ideal applications for the ICCD cameras include analysis of high-speed events such as combustion process or turbine blade and low-light-level measurements of bio- or chemiluminescence.

SMALL IEEE-1394 CAMERA

Allied Vision Technologies' Guppy family use either CCD or CMOS technology, but all interface with the industry standard IEEE 1394 or FireWire protocol.

Available in black/white as well as in color versions, the cameras operate in an 8-bit mode and target cost-sensitive, entry-level vision applications. IEEE 1394 provides easy computer connectivity and bi-directional data transfer at 800 Mbits/sec today with 1,600 Mbits/sec and even 3.2 Gbits/sec in the future. Each of the units in the compact family addresses different resolutions and formats including VGA, WideVGA, SVGA and XGA. For interlaced-based applications, the family has six digital interlaced sensor versions. The newest Guppy F-036B/C, a type 1/3 micron, progressive scan, wide-VGA (752 x 480 pixel) CMOS camera, provides up to 64 fps at full resolution.

SMALL SMART CAMERA

Measuring 65 x 45 x 45 mm, Vision Components' VisiCube camera weighs 170 gm and comes with measuring lights and an integrated lens. The image processing systems have a ¼-inch CCD sensor with a 640 x 480 pixel resolution and a frame rate of 32 fps. A 400 MHz (3,200 MIPS) image processor from Texas Instruments provides 32 MB DRAM and 4 MB Flash EPROM for program and data storage. Using the company's VCRT operating system that is similar to Linux, the cameras are easily programmed and execute all image processing routines without an additional PC. RS422 or Ethernet connections allow interfacing to an existing automation network. The compact vision sensor targets industrial applications where PC-based image processing systems are too costly or too complicated to implement.

2X PERFORMANCE IN SAME SIZE

If the package does not shrink but the performance increases, the net results are still more in the same form factor. For Cognex Corp., the In-Sight 5600 vision sensor provides twice the processing speed and memory to perform inspections compared to its In-Sight 5400 series. Delivering reliable performance in high-speed applications, the In-Sight 5600 product line includes 640 x 480 pixel resolution as standard and two-megapixel (1,600 x 1,200) models. Similar to other models in the series, the units have an IP67 (NEMA 4) rating to withstand dust and washdown without requiring an additional enclosure. Support tools for the camera include a library of advanced vision software for inspection, identification, measurement and alignment tasks. For reviewing inspection results without a PC, In-Sight Explorer software release 3.4 provides enhanced optical character reading and verification tools, as well as onboard image storage capability.