Transfer device and image forming apparatus having the same

An image forming apparatus comprising:

• a plurality of photoconductors;
• a transfer belt to which images formed on the plurality of photoconductors are transferred;
• a plurality of transfer rollers corresponding to the plurality of photoconductors, and being movable between transfer positions where the images are transferred to the transfer belt and ready positions separated from the transfer positions;
• first slider members moving one of the plurality of transfer rollers between the transfer position and the ready position;
• second slider members moving the remaining transfer rollers between the transfer positions and the ready positions;
• a driving unit moving the first slider members and the second slider members;
• a motor rotating a cam rotating shaft to which the first cam members and the second cam members are connected;
• a sensing unit connected to the cam rotating shaft rotating the first cam members and the second cam members, and including an indicating member with a plurality of indicating parts;
• and
• a controller recognizing the rotating position of the indicating member based on change of a signal generated when the plurality of indicating parts of the indicating member passes through the sensing unit,
• wherein:
• the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members;
• and
• when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different in accordance the first cam members and the second cam members.

A transfer device of an image forming apparatus comprising:

• a transfer belt to which images formed on a plurality of photoconductors are transferred;
• a plurality of transfer rollers corresponding to the plurality of photoconductors, and being movable between transfer positions where the images are transferred to the transfer belt and ready positions separated from the transfer positions;
• first members moving one of the plurality of transfer rollers between the transfer position and the ready position;
• second slider members moving the remaining transfer rollers between the transfer positions and the ready positions;
• and
• a driving unit moving the first slider members and the second slider members,
• wherein:
• the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members;
• and
• when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different in accordance with the first cam members and the second cam members,
• wherein:
• the first cam members and the second cam members are connected to a cam rotating shaft passing through both the first slider members and the second slider members;
• the first cam member includes a first cam profile pressing a pressed part of the first slider member according to a rotating angle of the first cam member, and the second cam member includes a second cam profile pressing a pressed part of the second slider member according to a rotating angle of the second cam member;
• and
• a phase of the top dead center of the first cam profile and a phase of the top dead center of the second cam profile are different so that the time when movement of the first slider members is completed and the time when movement of the second slider members is completed are different.

An image forming apparatus comprising:

• a plurality of photoconductors;
• a transfer belt to which images formed on the plurality of photoconductors are transferred;
• a plurality of transfer rollers corresponding to the plurality of photoconductors, and being movable between respective transfer positions where the images are transferred to the transfer belt and respective ready positions separated from the transfer positions;
• first slider members moving one of the plurality of transfer rollers between the transfer position and the respective ready position;
• second slider members moving the remaining transfer rollers between the respective transfer positions and the respective ready positions;
• and
• a driving unit moving the first slider members and the second slider members,
• wherein:
• the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members;
• and
• when the plurality of transfer rollers moves from the respective transfer positions to the respective ready positions, the first slider members and the second slider members move simultaneously during a first time, and only one of either the first slider members and the second slider members move during a second time after the first time in accordance the first cam members and the second cam members.

An image forming apparatus comprising:

• a plurality of photoconductors;
• a transfer belt to which images formed on the plurality of photoconductors are transferred;
• a plurality of transfer rollers corresponding to the plurality of photoconductors, and being movable between transfer positions where the images are transferred to the transfer belt and ready positions separated from the transfer positions;
• first slider members moving one of the plurality of transfer rollers between the transfer position and the ready position;
• second slider members moving the remaining transfer rollers between the transfer positions and the ready positions;
• and
• a driving unit moving the first slider members and the second slider members,
• wherein:
• the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members;
• and
• when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different in accordance the first cam members and the second cam members, and
• wherein the time when movement of the first slider members is completed is earlier than the time when movement of the second slider members is completed.

A transfer device of an image forming apparatus comprising:

• a transfer belt to which images formed on a plurality of photoconductors are transferred;
• a plurality of transfer rollers corresponding to the plurality of photoconductors, and being movable between respective transfer positions where the images are transferred to the transfer belt and respective ready positions separated from the respective transfer positions;
• first slider members moving one of the plurality of transfer rollers between the transfer position and the ready position;
• second slider members moving the remaining transfer rollers between the respective transfer positions and the respective ready positions;
• and
• a driving unit moving the first slider members and the second slider members,
• wherein:
• the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members;
• and
• when the plurality of transfer rollers move from the respective transfer positions to the respective ready positions, the first slider members and the second slider members move simultaneously during a first time and only one of either the first slider members and the second slider members move during a second time after the first time in accordance with the first cam members and the second cam members.

A transfer device comprising:

• a transfer belt to which images formed on a plurality of photoconductors are transferred;
• a plurality of transfer rollers corresponding to the plurality of photoconductors, and being movable between transfer positions where the images are transferred to the transfer belt and ready positions separated from the transfer positions;
• first slider members moving one of the plurality of transfer rollers between the transfer position and the ready position;
• second slider members moving the remaining transfer rollers between the transfer positions and the ready positions;
• and
• a driving unit moving the first slider members and the second slider members,
• wherein:
• the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members;
• and
• when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different in accordance with the first cam members and the second cam members,
• wherein the time when movement of the first slider members is completed is earlier than the time when movement of the second slider members is completed.

A method of transfer in an image forming apparatus comprising:

• moving one of a plurality of transfer rollers between a transfer position and a ready position;
• moving other of the plurality of transfer rollers between respective transfer positions and respective ready positions;
• and
• moving first slider members and second slider members, wherein when the plurality of transfer rollers moves from the respective transfer positions to the respective ready positions, the first slider members and the second slider members move simultaneously during a first time and only one of either the first slider members and the second slider members move during a second time after the first time.