Image forming system, image forming apparatus, finisher and method of controlling image forming system

An image forming apparatus comprising:

• an image forming unit configured to form an image on a sheet;
• a finisher unit provided with a slit unit for trimming edges of sheets which are successively supplied from the image forming unit, and configured to assemble an output product by joining the trimmed sheets;
• and
• a control unit configured to control each of the image forming unit and the finisher unit, wherein the finisher unit can assemble the output product with sheets of a plurality of paper types including a standard paper type and a non-standard paper type which is different from the standard paper type,
• the control unit comprising:
• a paper type notification unit configured to notify which of the standard paper type and non-standard paper type is supplied to the finisher unit from the image forming unit;
• a finisher control unit configured to control an operation of the slit unit in accordance with the paper type of sheets supplied to the finisher unit;
• and
• an offset amount designation unit configured to designate an offset amount corresponding to a displacement of a sheet width of the non-standard paper type in relation to a sheet width of the standard paper type, wherein
• when the paper type notification unit notifies that the non-standard paper type is supplied, the finisher control unit trims the edge of a sheet on the basis of the offset amount designated by the offset amount designation unit.

An finisher provided with a slit unit for trimming edges of sheets which are successively supplied from the sheet, source, and configured to assemble an output product by joining sheets of a plurality of paper types including a standard paper type and a non-standard paper type which is different from the standard paper type, said finisher comprising:

• a paper type notification unit configured to notify which of the standard paper type and non-standard paper type is supplied from the sheet source?
• a finisher control unit configured to control an operation of the slit unit in accordance with the paper type of sheets supplied from the sheet source;
• and
• an offset amount designation unit configured to designate an offset amount corresponding to a displacement of a sheet width of the non-standard paper type in relation to a sheet width of the standard paper type, wherein
• when the paper type notification unit notifies that the non-standard paper type is supplied, the finisher control unit trims the edge of a sheet on the basis of the offset amount designated by the offset amount designation unit.

A method of controlling an image forming system which comprises:

• an image forming apparatus configured to form an image on a sheet;
• and
• a finisher provided with a slit unit for trimming edges of sheets which are successively supplied from the image forming apparatus, and configured to assemble an output product by joining sheets of a plurality of paper types including a standard paper type and a non-standard paper type which is different from the standard paper type, said method comprising:
• a first step of notifying which of the standard paper type and non-standard paper type is supplied to the finisher from the image forming apparatus;
• a second step of designating an offset amount corresponding to a displacement of a sheet width of the non-standard paper type in relation to a sheet width of the standard paper type;
• and
• a third step of, when the paper type notification unit notifies that the non-standard paper type is supplied, trimming the edge of a sheet on the basis of the designated offset amount.