Printer Gamma; Adjustment Overview; Adjustment Procedure - Ricoh J-P2 Service Manual

IMAGE ADJUSTMENT

3.2.3 PRINTER GAMMA

NOTE: Normally, the printer gamma is enough to adjust the color balance to
achieve the optimum print output. The gamma correction is only required
for fine-tuning to meet the user requirements.

Adjustment Overview

Make the gradation scales on the printout smooth from the highlight to the shadow
density. Adjust the CMY gradation scale at the top of the chart by balancing the
density of the C, M, and Y gradation scales – the CMY gray scale should change
smoothly from minimum to maximum, and there should be no coloration.
For each color, you can adjust 15 points between 0 (lowest density) and 255
(highest density).
The gradation scales marked "Default Value" are printed according to the default
gamma settings. The gamma adjustment changes the densities at the adjustable
points in the gradation scale. The gradation scale marked "Current Value" shows
the current settings.
During the adjustment procedure, compare the "Current Value" gradation scale
with the "Default Value" Select the density for each of the 15 adjustable points,
excluding points 0 and 255, from the "Default Value" gradation scale.
The NVRAM holds three printer gamma settings, those saved this time (Current),
those saved in the preceding adjustment (Previous), and the factory settings
(Factory).

Adjustment Procedure

1. Enter SP mode.
2. Select "1. Service"
3. Select "Data Recall" and load the settings that will serve as the base for the
adjustment.
4. Select "Mode Selection", and select the print mode that you are going to adjust.
5. To review the image quality for these settings, choose "Test Page" to print out a
color calibration test sheet.
6. Select "Gamma Adj."
7. Adjust the color density at each of the 15 points for a color (CMY and K).
8. When the density setting is complete for all colors, print out a color calibration
test sheet again and make sure that the gradation scale for each printed color
is smooth and that the CMY gradation scale is gray. Repeat the adjustment if
there is an anomaly.
9. If the adjustment results prove satisfactory, execute "Data Save."
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17 January, 2003