CMOS image sensor technology advances and market analysis (1)

1. Introduction to the image sensor is the sensor technology in an important branch, is the PC multimedia world indispensable peripherals in the future, and also the security monitoring industry's core components.

In the knowledge economy and information society has come of this, it's in our social life more and more applications. Solid state image sensors into charge-coupled device (CCD), MOS-and CMOS-three categories, early because of the integrated circuit design and technological level of restriction, MOS type camera devices could not overcome its sensitivity to low and anti-jamming ability small shortcomings, which are not widely used, along with the development of television technology and semiconductor manufacturing technology of the quicker, MOS-camera device faults be overcome to a certain extent. To the late 1980s, Edinburgh University successfully trial-the world first single-chip CMOS image sensors, thereby opening the way for practical use. CMOS-camera device is part of the image sensor and a control circuit integrated on one chip, which not only significantly reduce the volume and power consumption is significantly reduced. Low price make it in the address and other related applications have great potential, so that the CMOS image sensor and gradually become the focus of research and development. CMOS image sensor and CCD camera device in almost 20 years ago is also underway. Because CCD device with illumination high sensitivity, low noise, the advantages of small pixels, resulting in the past 15 years it has been dominated image sensor market. In contrast, CMOS image sensors in the past there was a pixel, the SNR of small, low resolution, the dark current is large (this is determined by the sub-micron methods need caused by high silicon; larger dark current lead to larger image noise), and so on shortcomings, it has been unable to compete with CCD technology. But as LSI technology continues to develop, past CMOS image sensor manufacturing process is not easy to solve technical problems, now can find the appropriate solution, which greatly improved CMOS image sensor image quality. Current CMOS cell area the number of pixels in the CCD unit with the area of the pixel is equivalent to the CMOS image sensors can achieve a higher resolution. If you cannot use a black and white and color CMOS image sensor-to-noise ratio and increased sensitivity to light 10dB, 4 ~ 5 times increase, then replace the CMOS image sensor CCD devices soon. If the CMOS image sensor with small size, light weight, low power consumption, high reliability, high integration, low cost, wide dynamic range, anti-radiation and almost no trailing, and so the past has not been fully exploit the advantages into full play, CMOS image sensor will put us into a new era of image technology. This shows that the CMOS image sensor of the above benefits will be replaced in many areas of the market occupied by CCD, and open up a wider market, thereby significantly extending the application of video technology. Although the current CMOS image sensor image quality is still slightly inferior to the CCD devices, however, it is estimated that one year later the image quality is high, then all CCD image sensor applications may use CMOS devices. CCD device due to the high power consumption, large, and so has the range of difficult to access, CMOS camera devices will occupy. In this way, CMOS image sensors in the security monitoring, doorbell (such as security cameras to monitor the situation of stealth), embedded mobile phones, laptops and PDA digital camera, rearview, consumer electronics, toys, P videoconferencing, video phone, video e-mail, closed circuit television systems, medical devices, computer input, digital still cameras, supermarket anti-theft, elevator control, PC multimedia needs high-quality, low-cost black-and-white and color images, and other applications will play a very important role.

2.CMOS image sensor market prospects according to United States Omni Vision company predicts that global imaging products in the market from 1998 8.8 million increase to 16 billion in 2002, the whole to double.

In addition, according to market research firm forecasts, Cahners In-stat Group 2002, based on CMOS image sensor imaging products will reach 50 per cent, that is, when the CMOS image sensor CCD and will replace the market mainstream. Omni Vision forecast of United States domestic and global development of CMOS camera market conditions as listed in table 1. Visible, CMOS camera market prospects are very broad. The next few years, global sales of CMOS image sensors, the rapidly increasing and in many areas of digital imaging applications to traditional CCD launched impact. It is expected that by 2002, sales will reach 60 million tablets. This is because the CMOS image sensor parts have two advantages: first, lower prices than CCD devices 15 ~ 25%; the second is the chip structure can be easily integrated with other silicon-based components, which can effectively reduce overall system cost. Despite past CMOS image sensor CCD image quality is poor and low resolution, but after a quick approximation has been continuously improved, CCD's technical level, this sensor has been widely used in the resolution requirements lower digital cameras, electronic toys, video conferencing and security system camera structure. Japan Nintendo Co., Ltd. has recently launched a CMOS image sensor for low resolution digital camera, listing the first two months, sales reached US $ 100 million units. Mitsubishi, Motorola, HP, Toshiba and Intel Corporation will soon launch this kind of product. According to statistics, global annual sales of CMOS image sensors for 1997, 1998, 5400 million $ 2.18 billion, projected to 2002, the product sales will increase to $ 48.87. In 1997 the United Kingdom VLSI vision company monthly sales of 10 million block CMOS image sensor chip. The company is the world's production CMOS image sensorFor chip and CMOS camera one of the biggest manufacturers. Table 2 lists the global CMOS image sensor sales and sales forecasts.

United States Omni Vision company launched OV series CMOS image sensor to 1000 tablets for units from sales, prices are as follows: black and white analog output OV7000 series (628 × 528CCIR/508 × Δ 92 E I A) price of $ 17 per piece; black and white digital output OV7100 series (640 × 480CCIR) of us $ 17 per tablet, color analog output OV7500 series (628 × 582PAL/508 × 492VTSC) $ 19 per tablet, color digital output OV7600 series (640 × 480CCIR) $ 19 per tablet.

Toshiba Corporation in 2001 sale of 55 million block imaging chip in half is the latest CMOS image sensor. Now, North America, Japan, Europe and other parts of the production of black and white and color image sensor has been used PC camera, table 3 shows the use of CMOS image sensor manufacturing PC camera market forecasts.