Seeing is Believing 20301

April 4, 2005

8 Min Read
Seeing is Believing

Semiconductor-based imaging sensors are coming on strong today, thanks to new advanced features, reduced power consumption, and lower costs. Design engineers are increasingly finding ways to apply the technology in a whole range of products, including cell phones, digital still cameras, PC cameras, cars, security and surveillance systems, bar code readers, medical devices, and even toys.

Image sensors are based on either CCD (charge-coupled device) or CMOS technology. High-performance imaging sensors (with resolutions of 5 megapixels or more) rely on CCD semiconductor technology, while low-cost imaging has historically been associated with CMOS technology.

However, the lines have begun to blur now that advancements in CMOS have extended its capability to up to 5 megapixels.

High and ultra-high performance applications continue to rely on CCD technology. Omron's F160-S2 double-speed camera, for example, can perform measurements as fast as 3 msec. Likewise, Keyence's CV-2600 Series camera provides ultra-high accuracy detection with a 2 million pixel CCD. Sub-pixel processing and image digitization offers repeatability down to ±0.05 pixels.

Advancements include increased integration at both the silicon and package level. For example, Phillips Semiconductor integrates a Video Graphics Array camera, a TFT display and driver, and its Nexperia mobile image processor into a single unit.

A typical imaging application requires three critical elements: the imaging sensor, an image processor, and an application processor. Some suppliers, such as STMicroelectronics make both the image sensor and the image processor—a chipset for mobile imaging. ST's STV0976 digital image processor supports its 1 megapixel Standard Mobile Imaging Architecture (SMIA) camera module at up to 15 frames per second (fps), or up to 30 fps with its Super Video Graphic Adapter (SVGA) unit.

Other suppliers provide dedicated image processing chips. For digital still cameras, TMS320DM270 processor from Texas Instruments integrates an 80 MHz ARM7 32-bit processor, a 90MHz TI C54x digital signal processor, and a 180 MHz single instruction, multiple data (SIMD) image processing engine for programmable image processing to support both CCD and CMOS image sensors. The engineer designing a vision system has several choices—what works best for a particular application will depend on the system performance and cost objectives.

The acompanying table compares some of the latest offerings in vision sensors and systems.

Vision Sensors and Systems

Supplier

Product

Part Number

Description

Target Applications

Resolution

Size

Module Size

Integrated Features

Power Consumption

Operating Temp Range

Other Key Specifications

Main Differentiating Factor(s)

Price

Micron http://rbi.ims.ca/4389-565

CMOS image sensor

MT9V022

System-on-a-chip (SOC) that combines both the image photoplane and the image processing of a video camera

Automotive lane departure warning, driver drowsiness detection systems, occupant sensing, blind spot detection, and general security

361,000-pixel VGA

752 × 480 array

9 mm × 9 mm 52-pin IBGA Package

On-chip timing, two-wire serial programmable interface, automatic gain and exposure control and auto black level calibration global shutter

&200 mW at maximum data rate

-40 to +85C

Enhanced near-IR sensitivity (greater than 40 percent QE at 850 nm), 26.6 MPS/26.6 MHz, optical format 1/3-inch, frame rate 60 fps

Designed for automotive applications, wide-VGA format, and a higher than normal dynamic range (>110dB)

$12 for 100K+ units

OmniVision Technologies Inc. http://rbi.ims.ca/4389-566

CMOS image sensor

OV5610

Color CMOS QSXGA (5.17 Megapixel) CAMERACHIP with OmniPixel Technology

Digital still cameras, PC camera/dual mode, video conference, machine vision, security cameras, biometrics, bar code scanners

5 megapixels

2,592 × 1,944 image array

14.22 mm × 14.22 mm

On-chip 10-bit A/D converter, can perform continuous digital zoom and in VGA resolution is capable of operating at 30 frames per sec (fps)

3.3V dc / 1.8V dc: Active 40 mA, Standby 10 µA

0 to +40C

Pixel Size 2.775 µm × 2.775 µm; 10-bit digital RGB raw data; max image transfer rate 4 fps

Proprietary pixel structure diminishes dark current to unnoticeable levels, a key factor in bringing CMOS image quality to CCD levels

$15 for 10K+ units

Philips Semiconductors http://rbi.ims.ca/4389-567

Nexperia mobile display module

n/a

Complete imaging and display solution for consumer camera phones: CMOS VGA camera, TFT display, display driver, and image processor

Mobile phone camera

5 megapixels

2,592 × 1,944 array of pixels

36.0 × 41.0 × 5.4 mm

CMOS VGA camera, Si TFT display (65k), color display driver (PCF8881), Philips Nexperia RAM-less Mobile Image Processor (PNX4000)

85 mA for backlight

-20 to +70C

n/a

Optimized design for cellular phones with reduced overall power consumption in standby mode

$20 to $30 depending on volume

Samsung Electronics Co. http://rbi.ims.ca/4389-568

CMOS image sensor

S5K3B1FX

2-megapixel CMOS image sensor features the industry's smallest 2.8 mm2 pixel size with a 1/3.2-inch optical format

Camera function in next-generation smart phones

2 megapixels

1,600 × 1,200 pixels

n/a

n/a

80 mW @ 15fps

-20 to +60C

Chip can realize a minimum illumination rating of 2 lux

Utilizes 0.13 micron process technology; Small lens size of 1/3.2 inches

$7 per unit in the second half of 2005

SMaL Camera Technologies http://rbi.ims.ca/4389-569

Ultra-Pocket 5 Rapid Development Kit

UP5

The first megapixel mobile-camera chipset compliant with the Standard Mobile Imaging Architecture (SMIA)

Digital still camera

3 megapixels

2,000 × 1,500 pixels active array

6.75 mm × 5.08 mm sensor area

Autobrite 120 dB wide dynamic range for adapting to varying light conditions, electronic rolling shutter, on-chip 12-bit column parallel analog to digital converter

140 mW; Standby mode, &0.5 mW

-10 to +50C

1× to 16× digital gain, 8 or 12-bit digital output

High level of integration in ASIC and sensor, and autobrite wide dynamic range and longevity low power design

Available by customer request

STMicroelectronics http://rbi.ims.ca/4389-570

Megapixel SMIA camera module

VS6650

The first megapixel mobile-camera chipset, compliant with the Standard Mobile Imaging Architecture (SMIA)

Surveillance, PDAs, industrial, mobile phones

1 megapixel

1,152 × 864 array of pixels

9.5 × 9.5 × 7.6 mm

Three element 50-degree horizontal field of view lens, 10 bit A/D converter

85 mW operating, 30 µW standby

-25 to +55C

SMIA 1.0 profile 1 compliant imager, up to 30 frames per sec

Includes lens

$16 for the 1-megapixel kit

Toshiba America Electronic Components Inc. http://rbi.ims.ca/4389-571

CMOS image sensor camera module

TCM8230MD

Very small, thin VGA camera modules designed for camera-enabled compact cell phones. Unit incorporates a double lens and a single chip integrating a CMOS image sensor and a digital signal processor.

Cellular telephones, PDAs, and other portable equipment

330,000-pixel VGA

660 × 492 array of pixels with 1/6 of an inch optical format

6 mm (W) × 6 mm (D) × 4.5 mm (H)

Double lens and a single chip integrating a CMOS image sensor and a digital signal processor

40 mW at 30fps

-20 to +60C

Digital outputs: YUV = 4:2:2 or RGB Scanning: Progressive-scanning Frame rate: Maximum 30 frames per sec

Individual 3.75-microns pixels allows approximately 330,000 signal pixels on a single chip with a 1/6 of an inch optical format

$20 in 10K quantities

Web Resources

//Check out the links below for additional imaging resources//

CV-2600 Series vision system from Keyence: http://rbi.ims.ca/4389-559

Imaging ICs from Atmel Corp.: http://rbi.ims.ca/4389-562

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