HP 1175C - Manual (Page 17)

HP OfficeJet Pro User’s Guide 2-7
Step 3 — Unlock Your HP OfficeJet Pro
The scanner lock is under the front panel.
Unlock the scanner by twisting the green knob (lever) under the front
panel, toward the back of your HP OfficeJet Pro, until it stops. The
knob (lever) only turns one way.
NOTE Leave the scanner unlocked unless you need to move your HP OfficeJet Pro.
Locking the scanner protects it during moving. Refer to “Prepare Your
HP OfficeJet Pro for Shipment” on 14-3 for locking instructions.