The Plessey Company plc (also known as The Plessey Company Ltd) was a British electronics, defence and telecommunications company. It originated in 1917, growing and diversifying into electronics. It expanded after World War II by acquisition of companies and formed overseas companies. It was listed on the London Stock Exchange and was a constituent of the FTSE 100 Index. In 1951, the Electronics Division started at Ilford and in 1955 the Electronics and Equipment Group was established. Around circa 1961, The Plessey Company set up four other businesses: Telecommunications Division, Plessey Avionics and Communications, Plessey Radar (Weybridge) and Plessey Marine. In 1988, Plessey and The General Electric Company (GEC) merged their telecom units to form GEC-Plessey Telecommunications (GPT), with the ownership then split with Siemens AG in 1989.

In 1966, Peter J. W. Noble created the world's first solid state image sensor, later known as the 'active pixel' sensor. This invention laid the groundwork for image sensors used in digital cameras and bridged the gap between analogue and digital technology. The creation led to the development of almost all sensors in digital cameras, mobile phones, web applications, web cameras as well as in broadcast television. Peter was born on 13th November 1940. During his time at school, he enjoyed making model aircraft and experimenting with control systems. In his own words, he “…sailed through all the maths and science subjects and was dismal at most of the others.” He joined the school's Air Training Corps Squadron, which centered on aircraft, technology and related topics. In 1956, when almost sixteen years old, he started an apprenticeship at Aldermaston Court, a research facility operated by Associated Electrical Industries (AEI). The apprenticeship consisted of four days at the research laboratory and one day at the local technical college. Peter earned both the Ordinary National Certificate and the Higher National Certificate whilst there. When he was eighteen, Peter attended the Northampton Polytechnic (now the City University) in London where he gained a degree in both Physics and Electronics. During this time, he had been moved into the electron microscope group, a small team which used the device for investigations of various processes. He worked in the research laboratory where he created automated alignment systems, combining optical systems with electronic detectors and electronics. At eighteen, he created his first scientific patent with Dr. James Dyson – a modification to a Mach-Zehnder microscope. During this time, he also taught mathematics at the Technical College for two years. He later became a chartered physicist and chartered electrical engineer. In 1963, it was announced the site at Aldermaston Court was to close and Peter was transferred to a new facility based in Rugby and then to another facility in Lincoln. Peter’s work involved the process of transferring the manufacture of thyristors from GEC in the United States to AEI so that the company could make them under license. Bored by the repetitive nature of the work, he sought out new employment and moved to Texas Instruments at Manton Lane, Bedford. Peter worked in the research department where he was tasked with trying to develop an optical detector for very high modulation frequency, near visible wavelength, optical signals. Peter joined the Plessey Company on 1st May 1966 at twenty-five where he worked at the Allen Clarke Research Centre at Caswell. Plessey had been developing a machine to automate the processing of bank cheques and the machine required a camera to read the cheque numbers. This required a new way of sensing images to allow the machine to ‘read’ numbers and letters automatically and very quickly in a way that it could understood. Peter and his team were tasked with developing a new electronic device which would be the first of its kind, specifically for use in Optical Character Recognition (OCR) applications. They experimented with ideas and processes until the team developed a series of test sensors and presented papers on the topic in Washington DC. In the early sensors the tiny amount of light hitting each pixel was too weak to make a strong electrical signal. Peter Noble’s team's breakthrough was to invent the active pixel. Each pixel on the sensor was loaded up with electricity so that when light struck it, it allowed the electricity already there to flow.  In 1967, Peter presented a sole authorship paper called ‘Light sensitive arrays based on photodiodes combined with MOS devices’ at a conference on Integrated Circuits in Eastbourne, UK. The paper outlined his work on his latest experimental project, a 10 x 10 array of sensors which would have one hundred pixels. In 1967, the word ‘pixel’ (derived from picture element) was not yet a widely used term. The paper was reported by correspondent John Davy in The Observer newspaper. He stated in his article that the technology was the dawn of a new era and said he looked forward to the ‘arrays’ being used in place of film and in television cameras. Peter and some of his old colleagues established Integrated Photomatrix Ltd in September 1968 with its premises in Dorchester, Dorset. Peter J. W. Noble was the founding Managing Director of the company. The first devices, created in May 1969, included switching devices for street lighting control with built in hysteresis, simple on/off sensors all based on the MOS process and linear arrays made for use in measuring apparatus, such as gauging, ranging and the determination of the thickness/size of manufactured products. The company successfully applied for government research funding to continue the development of two-dimensional arrays to further the understanding, design and technology of the product. The result was the 64 x 64 array which had a sufficiently high pixel density (4096) and was used in a camera to produce a recognisable black and white moving image of a woman’s face. At the time, digital storage did not exist, so the image could only be shown in real time on a television. Integrated Photomatrix Ltd continued to research and develop sensor devices and the company received the Queen’s Award for Technology in 1974 for their work creating the first solid state image sensor that produced an image of a recognisable face – a technology that was the become the founding system for almost all image sensors in mobile phones and cameras. The same year, Peter Noble wrote ‘Light Sense: A Handbook of Integrated Optoelectronic Devices and Systems,’ which was published by Integrated Photomatrix Ltd. During this time, part owners of Integrated Photomatrix Ltd steered the company into engineering existing products and therefore moved away from creating new sensor arrays and developing the technology forwards. Near the end of 1974, Peter decided to leave the company he created and took on a chief executive role at Tekflo. Peter spent many years as a consultant whilst simultaneously working on one off projects and producing reports for other companies. In 1989, he produced another book ‘Printed Circuit Board Assembly’ which was published by Oxford University Press. In 2003, Peter was awarded the Paul Harris Fellowship Award by the Rotary Club of Dorchester and in 2015 he was awarded the Pioneering Achievement Award by the International Image Sensor Society for seminal contributions to the early years of MOS image sensors. In 2018, Peter was made a Member of the British Empire (MBE) for his services to photography and charity, and he published another book ‘My Imageination: My Life +50 Years’. In 2022, he won an Emmy Award for the Pioneering Development of early MOS based Image Sensors.