Patent ID: 8073354

Claim:
An image forming apparatus for printing sheets on the basis of a print instruction input therein, comprising: a limit quantity storage unit storing a predetermined limit quantity; an accounting storage unit storing a first unit price for printing one sheet to be used until the predetermined limit quantity is reached, and a second unit price for printing one sheet after the predetermined limit quantity is reached, the first unit price being greater than zero and the second unit price being greater than the first unit price; and a printing authorization unit calculating a number of sheets to be printed and an amount of toner to be used to complete the print instruction, determining whether or not a quantity of a consumer product consumed by printing reached the limit quantity stored in the limit quantity storage unit based on the calculated number of sheets to be printed and the amount of toner to be used, and authorizing execution of printing, when the print instruction is input, on condition that a user pays a price for printing sheets beyond the predetermined limit quantity obtained by multiplying the number of sheets to be printed beyond the predetermined limit quantity by the second unit price when it is determined by the printing authorization unit that the quantity of the consumer product consumed by printing reached the limit quantity, and presenting a user with an option of printing either on both sides of a sheet or printing image data for multiple sheets on a single sheet when the limit quantity is reached; wherein, when the print instruction is entered into the image forming apparatus, the printing authorization unit determines whether or not the number of sheets scheduled for printing is graspable, and then if the printing authorization unit determines that the number of sheets scheduled for printing is graspable, the printing authorization unit notifies the user of a total price to be paid for printing the number of sheets to be printed before any printing occurs; and if the printing authorization unit determines that the number of sheets scheduled for printing is not graspable, sheets are printed until the limit quantity is reached, at which point the user is then notified that all subsequent printing will be performed at the second unit price.