Document-sheet conveyance device and image forming apparatus

An image forming apparatus including a document-sheet conveyance device, wherein

• the document-sheet conveyance device comprises:
• a reader configured to read a document-sheet passing through on a contact glass plate;
• a white plate configured to be placed opposed to the contact glass;
• a first conveyance roller and a first driven roller placed upstream of the reader in a sheet conveying direction, and configured to nip and convey the document-sheet to the reader;
• a second conveyance roller and a second driven roller placed downstream of the reader in the sheet conveying direction, and configured to nip and convey the document-sheet having been read by the reader to a subsequent stage;
• a holding member configured to hold rotatably the first and second driven roller;
• and
• a spacer configured to support the holding member and include one or more of support planes different in height;
• wherein
• a support plane selected from among the one or more support planes of the spacer in accordance with a thickness of the document-sheet is moved manually to support the holding member, and
• the white plate is configured to lift upward from the contact glass plate by a forehead of the sheet passing through the contact glass plate.