Technology Used in Scanners
Canon, which has worked to develop high-precision scanning technology, has combined many of its unique advanced optical, electronics, and software technologies to create scanners that enable the conversion of camera film, photo prints, and text documents into high-grade digital data.
White LED Light Guiding
Enhancing Work Efficiency and Conserving Energy
With conventional CCD scanners that employ fluorescent lamps, about 30 seconds of warm-up time is required after startup or re-activation from sleep mode. While using an LED*1 as the light source eliminates warm-up time, because it is a point light source, technology is needed to convert it into a linear light source with uniform light intensity.
By applying the LED light guide technology Canon developed for its CIS scanners and researching LED installation and light guide formats, the company was able to develop a high-brightness white LED light source for scanners. This technology ensures stable light intensity immediately upon starting up the scanner, reducing warm-up time to zero. In addition, it is no longer necessary to keep the light on after scanning, which helps save energy.
- *1 LED (Light Emitting Diode)
A semiconductor diode that emits light when an electric current is applied. While LEDs are smaller and lighter than fluorescent lamps, have a longer lifespan, and require less electricity to run, lower light intensity has been cited as a drawback. Recently, as LED brightness has improved, they have been adopted for a wide range of applications.
Image Correction Technology
A Full Array of Image Correction Features for a Variety of Documents
The scanning mechanism is not the only factor that determines scanner performance. The driver that processes data from the scanner and reproduces images is equally important. Canon's ScanGear scanner driver is designed not only to enable exceptional ease of use but also to deliver a wide range of image-processing features. This image-processing technology is based on platform technology used in other Canon digital imaging devices, but has been specially customized for use in scanners.
Dust and Scratch Removal
When scanning photographic film using a high-resolution scanner, minute dust particles and scratches that are invisible to the naked eye are picked up. The dust and scratch removal function first detects dust and scratches with infrared light from an infrared LED, and then determines the size andshape of the dust and scratches along with the characteristics of the surrounding image. Next, the dust and scratches are automatically removed through a high-level integration of hardware and software processing to create a beautiful reproduction.
The backlight correction function analyzes backlit images and automatically adjusts the overall image brightness and contrast according to the darkness levels in the areas that need correction.
The discoloration correction function restores vivid colors to film or photo prints that have faded or display color bleeding. The histogram of the scanned image is analyzed and hue, color balance, contrast, and saturation are automatically adjusted to appropriate levels.
Book-Binding Shadow Correction
This corrective function reduces the shadow that occurs when an open book or magazine is scanned. The shadow created by the book's spine is detected using a shape recognition density table, and the brightness is adjusted accordingly.
CCD and CIS Systems
Canon offers two types of flatbed scanner: CCD and CIS. CCD models incorporate high-precision optics and high-density CCD line sensors that illuminate the document with a light source such as white LED to deliver sharp, high-resolution images. CIS scanners are slim-bodied, energy-efficient models that utilize a three-color RGB LED as the light source and read documents with a CIS (Contact Image Sensor) of the same width as document originals.