Toshiba 3511, 4511 manual CCD board

3

(3) Data reading (scanning)

Data reading is a process of illuminating the original with light and converting the reflected light into electrical signals.

The light reflected from the original is directed to the Charge Coupled Device (CCD) and this optical image information is converted to electrical signals (image signals), which are then transmitted to the image processing section via the scanner control PC board.

The CCD for color processing has RGB filters provided over its surface, which allow the CCD to read the light amount in the respective ranges of wavelength. The image data corresponding to the respective RGB colors is then transmitted to the image processing section.

(4) Data writing

Data writing is a process of converting the image signals transmitted from the image processing section into light signals and exposing the drum surface with the light signal.

Namely, the image signals transmitted from the image processing section are converted into optical signals (laser emission) by the semiconductor laser element, which are then used to expose the drum surface, thus forming an electrostatic latent image there.

CCD board

		Scanning section
		control PC board
		Image processing
			section
	Fig. 3-304
(Example)
CCD light	Value of image
receiving	signals to be
amount	output
Light	255		
				Difference between
				"light " and "dark" is
			 divided into 256 steps.
			
Dark	0

Image	Laser driving
processing	PC board
section

Semiconductor laser element

Polygonal mirror

Drum

Fig. 3-305

e-STUDIO3511/4511 COPY PROCESS 3 - 4 November 2003 © TOSHIBA TEC