Image forming apparatus and printing control method therefor

In an image forming apparatus connected to a personal computer and having no two-sided printing mechanism for reversing a paper sheet and automatically printing on two sides of the paper sheet, a printing control method comprising the steps of:

• setting in response to that a two-sided printing instruction to print on both of the front and back sides of the paper sheet and printing data are given from the personal computer to the image forming apparatus, the image forming apparatus to a two-sided printing mode not accepting any other printing data than a given data,
• executing the front side printing by printing front side printing data among the given printing data on the paper sheet and discharging the printed paper sheet to the outside of the apparatus;
• detecting that a predetermined OK signal is given from the personal computer after setting the two-sided printing mode, and starting time measurement at the end of the front side printing;
• executing the back side printing, when the paper sheet is set in a predetermined paper feed section before the measuring time is over a predetermined time, by printing back side printing data among the given printing data on the set paper sheet and discharging the printed paper sheet to the outside of the apparatus;
• and
• releasing the set two-sided printing mode when the paper sheet is not set in the predetermined paper feed section before the measuring time is over the predetermined time.

In an image forming apparatus having no two-sided printing mechanism for reversing a paper sheet and automatically printing on two sides of the paper sheet, an image forming apparatus comprising:

• a means for setting a two-sided printing instruction to print on both of the front and back sides of the paper sheet and a two-sided printing mode not accepting any other data than given data, in response to printing data being given;
• a front side printing executing means for printing front side printing data among the given printing data on the paper sheet and discharging the printed paper sheet to the outside of the apparatus in the two-sided printing mode;
• an OK signal detecting means for detecting a signal indicating a user's approval of executing predetermined assisting actions after the two-sided printing mode is set;
• a time measuring means for starting time measurement at the end of printing executed by the front side printing means, in response to the OK signal detecting means detecting the signal;
• a means for detecting whether a paper sheet has been set in a predetermines paper feed section or not by the time the measuring means measures a predetermined first time;
• a back side printing executing means for taking a paper sheet in response to the paper detecting means detecting that the paper sheet is set, printing back side printing data among the given printing data on the paper sheet and discharges the printed paper sheet to the outside of the apparatus;
• a two-sided printing mode interrupting means for interrupting the two-sided printing mode, enabling to print other data than the given printing data and waiting restoration of the two-sided printing mode, when the paper sheet has not been set in the predetermined paper feed section by the time the measuring means completes measuring the predetermined first time;
• and
• a restoring means for restoring the two-sided printing mode, when a signal to print back side printing data among the given printing data is given by the time the measuring means completes measuring a predetermined second time longer than the first time.

In an image forming apparatus connected to a personal computer and having no two-sided printing mechanism for reversing a paper sheet and automatically printing on two sides of the paper sheet, a printing control method comprising the steps of:

• setting in response to that a two-sided printing instruction to print on both of the front and back sides of the paper sheet and printing data are given from the personal computer to the image forming apparatus, the image forming apparatus to a two-sided printing mode not accepting any other printing data than a given data;
• executing the front side printing by printing front side printing data among the given printing data on the paper sheet and discharging the printed paper sheet to the outside of the apparatus;
• detecting that a predetermined OK signal is given from the personal computer after setting the two-sided printing mode, and starting time measurement at the end of the front side printing;
• executing the back side printing, when the paper sheet is set in a predetermined paper feed section before the measuring time is over a predetermined time, by printing back side printing data among the given printing data on the set paper sheet and discharging the printed paper sheet to the outside of the apparatus;
• interrupting the set two-sided printing mode, when the paper sheet is not set in the predetermined paper feed section before the measuring time is over the predetermined first time;
• and
• waiting in a state where the interrupted two-sided printing mode is restorable and at the same time printing other data than the given printing data is possible during the time after the measuring time is over the predetermined first time and before it is over a predetermined second time which is longer than the first time.