Image forming apparatus

An image forming apparatus comprising:

• an attachment part;
• and
• a sheet feeding cassette which is attached to the attachment part in a predetermined attachment direction, wherein
• the attachment part includes a sheet feeding device which feeds a sheet from the sheet feeding cassette, and
• the sheet feeding cassette includes:
• a cassette main body in which the sheet is stored;
• a lift plate supported by the cassette main body in a turnable manner between a lowered position where the sheet can be placed and a lifted position where a downstream end portion of the placed sheet in the attachment direction can be fed by the sheet feeding device;
• a lock member movable between a lock position where a turning of the lift plate with respect to the cassette main body is restricted and a release position where the turning of the lift plate is permitted;
• and
• a biasing member which biases the lock member to the lock position, wherein
• in a state where the sheet feeding cassette is not attached to the attachment part, the lock member is biased by the biasing member to be positioned at the lock position, and
• in a state where the sheet feeding cassette is attached to the attachment part, the lock member is movable either to the lock position or the release position by hand,
• the attachment part has a pin protruding in an opposite direction to the attachment direction, and
• the pin is movable to a first position where the lock member is positioned in the release position in the state where the sheet feeding cassette is attached to the attachment part and a second position where the lock member is positioned in the lock position in the state where the sheet feeding cassette is attached to the attachment part.

An image forming apparatus comprising:

• an attachment part;
• and
• a sheet feeding cassette which is attached to the attachment part in a predetermined attachment direction, wherein
• the attachment part includes a sheet feeding device which feeds a sheet from the sheet feeding cassette, and
• the sheet feeding cassette includes:
• a cassette main body in which the sheet is stored;
• a lift plate supported by the cassette main body in a turnable manner between a lowered position where the sheet can be placed and a lifted position where a downstream end portion of the placed sheet in the attachment direction can be fed by the sheet feeding device;
• a lock member movable between a lock position where a turning of the lift plate with respect to the cassette main body is restricted and a release position where the turning of the lift plate is permitted;
• and
• a biasing member which biases the lock member to the lock position, wherein
• in a state where the sheet feeding cassette is not attached to the attachment part, the lock member is biased by the biasing member to be positioned at the lock position, and
• in a state where the sheet feeding cassette is attached to the attachment part, the lock member is movable either to the lock position or the release position by hand,
• the attachment part includes an attachment detection part switchable from a cassette non-detection state to a cassette detection state by an attachment of the sheet feeding cassette to the attachment part, and
• when the sheet feeding cassette is attached to the attachment part, the lock member acts on the attachment detection part to switch the attachment detection part from the cassette non-detection state to the cassette detection state.