Common Technology
of Image Sensors

Types of image sensors: CCD and CMOS image sensors

There are two major types of image sensors: CCD, or charge coupled device and CMOS, or complementary metal oxide semiconductor. The CMOS image sensor has advantages over the CCD image sensor in terms of speed and power consumption, and for this reason, it is becoming a preferred choice in many areas, such as smartphones and digital cameras.

Sony Semiconductor Solutions Corporation (SSS) had a major business shift in 2004 from CCD image sensors, of which the company had the largest market share at the time, to CMOS image sensors despite being a late-comer in this field. Leveraging the years of expertise and know-how in CCD image sensors, SSS devoted much resources to the development and production of CMOS image sensors. Today, SSS has come to enjoy the top market share in this type of image sensor.

Structural comparison between CCD and CMOS image sensors

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Light is turned into electricity by each photodiode, which relays the electricity. The amplifier located at the exit amplifies the electricity and turn it into a signal.

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Each photodiode is equipped with an amplifier, so that the converted electricity is amplified on the spot and turned into a signal. All these signals are transmitted straightaway.

Light is turned into electricity by each photodiode, which relays the electricity. The amplifier located at the exit amplifies the electricity and turn it into a signal.

Each photodiode is equipped with an amplifier, so that the converted electricity is amplified on the spot and turned into a signal. All these signals are transmitted straightaway.

Characteristic features of CMOS image sensor

A CMOS image sensor is faster and consumes less power than a CCD image sensor. On top of these, it is compatible with the system integration arrangement, meaning that both an analog and digital circuits can be mounted onto a single chip.
Early models of CMOS image sensors were inferior to CCD image sensors in terms of image quality for being more susceptible to noise and less sensitive. However, technological innovations made it possible to capture high-quality moving and still images, exceeding that of CCD image sensors. Adding improved image quality to its advantages of high speed and low power consumption, the CMOS image sensor supports the advancement of various cameras.

Features of SSS's CMOS image sensors

In 2007, SSS launched a CMOS image sensor with its original Column-Parallel A/D Conversion Circuit, realizing high speed and low noise performance. Then in 2009, we brought to the market a back-illuminated CMOS image sensor which doubled the sensitivity on conventional models. It surpassed the performance of CCD image sensors. In 2012, a stacked CMOS image sensor was commercialized thanks to the stacked structure of the pixel and logic sections, achieving high image quality, multi-function, and smaller size. Further in 2015, we succeeded in realizing an applied Cu-Cu (copper-copper) connection, the first of its kind in the world, which enabled a smaller size, high performance, and improved productivity. SSS continues to lead the industry through its perpetual innovations in technology.

Image sensor Advance in key technology

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Image sensor Advance in key technology