Toshiba FC-22 manual Transfer belt, Place the Patch chart for gamma adjustment produced in step

1. 7 Automatic Adjustment of Gamma Correction

(1)At the time of unpacking:

When the reproduction of gradation is not appropriate, the gradation reproducibility of all colors Y, M, C and K can be corrected by performing this automatic adjustment of gamma correction. Check the image, and if the gradation reproduction is not satisfactory, make this adjustment as described below.

(2)When any of the following parts has been replaced, be sure to make this adjustment:

• Laser optical unit • Drum • Developer material

(3)When any of the following parts are replaced or adjusted, make a copy and check the image to

determine if the adjustment is necessary:

• Main charger • Transfer belt

Note: Be sure that this adjustment be made after performing the copy image adjustment in “1.5 Auto- matic Initialization of Image Quality Control” and "1.6 Copy Image Dimensional Adjustment".

Code	Adjustment item		Content
643	Automatic adjustment	<Procedure>
	of gamma correction	Adjustment of Text or Map mode
		(1)	While pressing [0] and [5] simultaneously, turn the power ON.
			n Adjustment mode
		(2)	Press [4] n [SETTINGS] and output a “Patch chart for gamma
			adjustment”.
		(3)	Place the “Patch chart for gamma adjustment” produced in step
			(2), face down onto the original glass, with the side, on which a
			black band is present, precisely against the original scale.
		(4)	Input code [643] with digital keys and press [START].
		(5)	Input [2] with digital keys, and press [START] and then [INTER-
			RUPT] n The scanner reads the original automatically and
			performs automatic gamma adjustment calculation (approx. 30
			sec.).
		(6)	When the adjustment ends normally, “SCAN COMPLETE” is
			shown. Press [START] to have the adjustment results reflected.
			(To cancel the reflection of adjustment results, press [STOP].)
			When “COMPLETE” is shown, press [STOP] to return to the
			standby state.
			In the case of an abnormal ending, “ADJUSTMENT ERROR”
			is shown. Press [STOP] to clear the error display. When it is
			cleared, the control panel display will return to the standby state.
			Then, check if the gradation pattern image on the original glass
			is oriented in the wrong direction or if it is placed inclined on the
			original glass, and then repeat step (3) and afterward.

FC-22 ADJUSTMENT 1 - 66 January 2000 © TOSHIBA TEC