Viewfinder: Image Sensor

The image sensor is the heart of the camcorder. Video cameras originally used vacuum tubes, but today camcorders include either a charge-coupled device (CCD) or a metal-oxide semiconductor (CMOS) image sensor to convert light into an electric signal. Both of these are types of integrated circuits. ICs, semiconductors or silicon chips also cover a wide range of purposes. The most popular may be the microprocessors used in personal computers, mobile phones and portable media players. Collectively these devices have revolutionized how we live our lives. While most tend to think of Silicon Valley in California as the epicenter for ICs, some consider Kumamoto, Japan to be the most important region for image sensors because it is the home of Sony’s Semiconductor Kyushu Corporation’s Kumamoto Technology Center (Kumamoto TEC). I had the chance to visit this facility where one of the Sony folks told me that “this is where the magic happens.”

Image sensors are used in camcorders, digital still cameras, medical products, security equipment and mobile phones. Kumamoto TEC is one of the largest producers of image sensors in the world. I learned more about image sensors while visiting Kumamoto TEC in a few hours than many will learn in a lifetime. Image sensors come in many sizes, from the tiny sensors in endoscopes used by the medical industry to the large CMOS chips used in 4k motion picture cameras. Image sensors capture images which will display with the greatest accuracy while keeping both the digital file size and the cost as low as possible. This is why you can capture stunning video on your inexpensive cell phone.

The process of manufacturing image sensors is highly complex and the development of higher quality CMOS sensors continues at a rapid pace. The tiniest particle of dust can ruin an IC, so a clean environment is a necessity. The engineers working behind the scenes at image sensor plants don’t get enough credit for their amazing efforts that has enabled the common person to become a video producer. The people at YouTube somehow get more glory because their brand logo appears alongside every video being displayed, but it is also the hard work of the image sensor engineers that make the democratization of video possible. These folks are changing the world from their pleasant location in southern Japan and few people appreciate their contribution.

The quality just keeps on improving. Imagine the video from 10 years ago. Today, nearly all camcorders produce video with a quality that greatly exceeds this. Soon, we can expect to see affordable camcorders capturing video suitable for projection in your local movie theater. When that day comes, you can be sure that the engineers will be working on the next generation of video, which we can barely imagine.

Matthew York is Videomaker‘s Publisher/Editor.