Stylish became a word synonymous with Canon`s range of scanners following the introduction of LiDE technology by Canon. The introduction of LiDE technology has resulted in a range of home scanners that combine sleek design, operational speed and superb quality.
In the past flatbed scanners used CCD imaging sensors exclusively and because these sensors were not able to record information at the edges of the document, this necessitated the use of a series of lenses and mirrors to allow for the entire document to be scanned. The result was a large scanning head that was both heavy and complex, which in turn affected the physical size of the scanning unit.
In the search for a simpler method of recording scanned images, Canon`s researchers began experimenting with LED (light-emitting diodes) and the company`s own CMOS sensors. These diodes have the advantage of being very small and consistent in the quality of their output and by producing LEDs in red, green and blue (RGB) and placing them close to the document and the sensor, Canon discovered they could successfully be used.
However, to make use of these diodes a new head needed to be designed to allow for a shorter light path from document to sensor. To eliminate the requirement for an optical reduction system and its associated distortion potential, Canon created a sensor that stretches the full width of the scanner platen, resulting in a drastically shortened light path.
Consequently Canon engineers developed a new lens system to bring everything much closer together. This new system comprises a chain of rod lenses that could be placed right next to the LED light source and channel the reflected light directly to the pixels of the sensor below. The benefit of controlling the light path means that the sensor and the light source can be placed very close to each other and the light therefore has less distance to travel.
Efficient lenses combined with diminished light loss due to the shorter scanning path proved powerful enough to be recorded efficiently by the CMOS sensor. Despite initial scepticism, LEDs have proved to be an excellent source of light for reflective scanning and have also enabled scanning heads to be made very much smaller. In fact, they can be reduced in size to as little as 5% of the size of the standard CCD unit.
Apart from allowing for a smaller, sleeker design, the smaller and lighter scanning head requires less power to drive it. An LED scanner consumes only 2.5 Watts while in use and this level can be easily supplied by the computer via a USB cable connection. This also means that the scanner needs none of the usual transformers and converters which mains powered devices needed to handle and regulate a power supply, resulting in further savings in size and part costs.
Despite the less powerful light source Canon`s LiDE scanners are just as fast at getting the job done as standard CCD type machines and a further advantage of using LEDs is that they take no time to warm up, unlike the cold cathode tubes in CCD scanners.
Even though LiDE technology presents a wide range of benefits to both manufacturer and user, Canon has no intentions of discontinuing its CCD range. LEDs are ideal for reflective scanning for the home and photo enthusiast markets, but at this time professional resolutions still require the CCD system.
"Canon will continue to drive a greater wedge between Canon scanners and the rest of the market and LiDE is now paving the way for the development of new products, such as ultra small faxes and mobile scanners and it will no doubt facilitate the development of a new breed of miniature devices for handling digital images," comments Ashley Botha, Product Manager for Printers and Scanners at Canon South Africa.
Share
Editorial contacts