Riso HC5500

1. Overview of automatic image adjustment

Automatic image adjustment for the printer involves scanning of the test pattern printed by the printer using the image adjustment software and a scanner, and adjustment of parameters based on the results of automatic measurement of the images. Through this process, the printer determines and sets the optimum parameters automatically. Of the image adjustment items, only the head angles need to be set manually. Except for the following two items, image adjustment items are automatically set by the printer by exchange of information with the image adjustment software. When print heads are replaced during maintenance, the parameters for the recommended head drive voltage and head drive AL must be changed before head angle adjustment. These two items must be set manually on the Control panel and saved.

* For information on the image adjustment method, refer to [Adjustment after print head replacement] in [Ink supply passages].

2. Overview of test patterns for image adjustment

Use the following test patterns for automatic measurement and setting of parameters.

1. Scanner calibration test chart
   •Compensating for geometrical distortion of the scanner
2. Coarse adjustment pattern
   •Head angle parameter
   •Print timing of two heads in each print head
3. Density adjustment pattern
   •Recommended drive voltage correction
4. Fine adjustment pattern
   •Print timing of print head
   •Overlap amount
   •Top edge registration
   •Execution of fine adjustment of relative positions of colors and other settings

3. Parameters and image quality

Described below are the characteristics of image affected by parameter settings. If the image defects described in a later section appear, the parameter settings may be unsuitable for the printer conditions. If so, repeating automatic image adjustment will correct the problem. The original device conditions will tend to drift over time, and automatic image adjustment may need to be repeated. If the characteristics of the actual image differs from those described, image quality will not improve even if automatic adjustment is performed. This is because such defective image conditions arise from the mechanical instability of the paper transport system or other factors rather than parameter settings. In these cases, you must locate and correct the cause of the problem.

Image defects caused by defective parameter settings are characterized by uniform deviation of dots. On the other hand, mechanical defects result in irregular and uneven deviations. The occurrence of the defect will also be unpredictable.