I recently unpacked a new Canon CanoScan LiDE 70 scanner, followed the included directions, and plugged it into my mac to start moving towards a paperless — or at least, less paper — office. I put a document on the scanner bed, clicked the preview button in the “ScanGear” software, and it started to calibrate the scanner:

As it was “processing calibration data from a scanner”, I could hear the scanner buzzing briefly, and then got an error message: “Cannot communicate with scanner. Cable may be disconnected or scanner may be turned off. Check status. Scanner driver will be closed.”
Crappy drivers, I thought. The documentation kept mentioning OSX 10.3, which is ancient. So I went to Canon’s driver download site and discovered that new drivers for OSX were released this month. I installed those, repeated the process, and met with the same results.

Cannot communicate with scanner. Scanner driver will be closed.
I was about to repack the scanner and send it back. Before I did, I thought I’d open the cover and watch what was going on during the failed calibration. The light came on, and to my surprise, the calibration worked this time. The preview scan, however, was completely overexposed. Probably because it calibrated with no light reflecting back, since the cover was wide open. Then I took a closer look at the scanning surface, and realized my folly.
Most of the photocopiers and scanners that I’ve used align to the top-right corner; this one is bottom left. The calibration was failing because the document wasn’t at the “top” (bottom) of the scanning bed to reflect light back. Doh. After recalibrating (advanced tab of ScanGear) with a document in the correct position, it works like a charm.
By the way, to start ScanGear, click the Photo1 button in CanoScan Toolbox, then select the “Display the Scanner Driver” option, and click the Scan button.






Pingback: Mac Info » Blog Archive » Skenování s CanoScan LiDE 70 v MacOS X