Polaroid SprintScan SS35, Repair Manual

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Slide Scanner Repair Manual Scanner Overview
Calibration
For SS35/SS35 ES slide scanners, the first calibration is performed at the first requested scan.
It is also performed when the slide scanner detects a specified amount of drift in the lamp or
front end during subsequent scans. The SS35 PLUS performs a full calibration before each
scan.
Refer to Figure 1-8 for a simplified flow diagram of the SS35/SS35 ES slide scanner calibration
routine and to Figure 1-9 for a simplified flow diagram of the SS35 PLUS slide scanner
calibration routine.
Upon completion (passed calibration), the Ready LED indicator lights steady to indicate that the
slide scanner is ready to operate.
Note: The Ready LED indicator continually blinks while the slide scanner cycles through its
calibration.
The following types of adjustments occur during the first calibration:
• Base line integration time to ensure a minimum signal and mitigation of saturation
• Analog gain and offset for base line neutral settings
• Digital uniformity offset calibration
• Digital uniformity gain calibration
• Bad pixel identification
Subsequent scans may require additional analog gain and offset and/or integration time
adjustments to accommodate white points requested by the host or film tables, as a function of
the specific calibration algorithms.
A drift check is also performed with each scan to verify the stability of the front end. Each
calibration that requires a significant change in the front end settings necessitates a
recalculation of the digital uniformity offset correction during the actual scan.
Causes of calibration failure are usually due to a defective lamp, obstructions in the optical path,
a defective sensor (CCD) PC board, a defective main controller PC board, a defective filter, or
a misaligned filter wheel (Original SS35 only).
Refer to Section 5 in this Repair Manual for a detailed list and definition of all calibration type
errors.