Patent ID: 7142334

Claim:
Reading unit for a document having a control and/or evaluation device incorporating a scanner device for reading a document, with a guide mechanism for the document and with a conveyor device to effect a relative displacement between document and scanner device, in which the control and/or evaluation device has a compensating device containing corrective values to correct the image signals emitted by an optoelectric transducer of the scanner device in real time and the individual corrective values for each optoelectric transducer are determined at least by comparing desired values of a reference document with the actual values of the image signals of the reference document emitted by the optoelectric transducer and permanently stored in a first memory device, characterised in that the first memory device ( 42 ) for the corrective values is arranged directly on a scanner head ( 117 ) of the scanner device ( 25 ) and/or on the optoelectric transducer ( 34 ) and forms a single-piece unit therewith having predefined interfaces to the peripheral electronic components, and the control and/or evaluation device ( 44 ) is programmed to transfer the corrective data from the first non-volatile memory device ( 42 ) into another memory device ( 46 ) of the control and/or evaluation device ( 44 ) at least during every power-up phase, this other memory device ( 46 ) offering the possibility of a relatively faster access and a faster data transfer rate.