1. Field of the Invention
The present invention relates to an image forming apparatus which executes printing processing based on a printing job received from an information processing apparatus.
2. Description of the Related Art
A photocopier and printer, having a tab facing mode which can output printed material with tabbed sheets (also called tab sheets) inserted in predetermined positions of printed material output from an image forming apparatus, for example, have been proposed. Tabbed sheets of a predetermined number are combined to be one set, and for example, for five-tab sheets, five sheets make up one set.
In the case that tab facing positions are only set in three locations, if tabbed sheets where five sheets make up one set are used, after the first through third sheets are used, the fourth and fifth tabbed sheets remain within the image forming apparatus. In this case, the page first using a tab sheet in the next set will be printed using the fourth tab sheet, whereby the user may not obtain desired printed material.
Thus, a method has been proposed in Japanese Patent Laid-Open No. 2002-003063 wherein a user sets the photocopier by removing the extra tabbed sheet before printing or automatically outputting the extra tabbed sheets for each set.
In a printing environment such as a POD market, the quality of printed material as product is highly valued. Accordingly, a function has been proposed to execute printing for confirmation (also may be called “confirmation printing”) according to user instructions, even during printing. For example, in the case that executing confirmation printing is instructed during printing of the 51st of 100 pages, the printing apparatus outputs the results of the 51st page confirmation printing to an output unit different from that of the first through 50th pages. In this case, the printing apparatus outputs the 51st page for confirmation printing, while outputting printed material for and after the 51st page again as to the output unit of the first through 50th pages. That is to say, the printing apparatus prints the confirmation printing 51st page and the main printing 51st page.
As a result, the user can confirm color changes, print position changes, and so forth without stopping the printing even during printing of a large number of copies.
However, in the case of executing such printing, the following problems may occur. For example, in a situation wherein, as a result of instructions for confirmation printing while the printing apparatus is continuously executing printing, the pages subjected to confirmation printing use a set sheet such as tabbed sheets. In this case, since the set sheets to be used for the main printing are used for the confirmation printing, desired printing results cannot be obtained.
This problem will be described in detail with reference to FIGS. 23A and 23B. Tab sheets 2403 of which five sheets make up one set are set in a cassette 2402 of the printing apparatus as shown in FIG. 23A. The printing apparatus 2401 prints printing data 2404, and as a result of confirmation printing being instructed at a timing to printing page 2405, the tab sheet to be printed for page 2405 is used for the confirmation printing.
That is to say, the cassette 2407 after confirmation printing does not have the tab sheet on which page 2405 is to be printed. In this state, if the printing apparatus 2401 prints page 2405 again for the main printing, since the page 2405 is printed using the tab sheet 2406, the numeral “5” which is to be printed on the tab sheet is not printed, and the user may not be able to obtain the desired printed material.
Automatically outputting the tab sheets remaining in the cassette 2407 may be considered using the arrangement described in Japanese Patent Laid-Open No. 2002-003063, but after automatic outputting, the state returns to that of cassette 2402. Therefore, in the case of using the leading tab sheet for confirmation printing and for main printing there is no problem, but for example confirmation printing is executed as to pages to be printed using the third sheet out of five tab sheets, and thereafter upon automatically outputting, the tab sheet to be used for the next main printing becomes the first tab sheet. Accordingly, the problems addressed by the present invention cannot be solved even by using the technique in Japanese Patent Laid-Open No. 2002-003063.