Image forming apparatus and image forming method

Abstract

According to one embodiment, an image forming apparatus includes an image forming portion, a fixer, a control operation selection portion which selects any one of a monochrome control operation of keeping the fixing temperature at a first temperature at which a monochrome image can be fixed, and a color control operation of keeping the fixing temperature at a second temperature higher than the first temperature, and a controller. In the state in which the monochrome control operation is selected, when the fixing temperature reaches the first temperature during rise, the controller executes a monochrome ready display and the monochrome control operation, the controller raises the fixing temperature up to the second temperature to print the color image when printing of a color image is instructed while the monochrome control operation is executed, and the controller executes the monochrome control operation after printing the color image.

1 . (canceled) 
     
     
         2 . An image forming apparatus, comprising:
 an image forming portion that forms a toner image on a recording medium;   a fixer that heats the recording medium on which the toner image is formed;   a display which displays a state of the image forming apparatus;   a setting portion that sets as an operation mode one of a monochrome mode for keeping a temperature of the fixer at a first temperature at which a monochrome image can be fixed and a color mode for keeping the temperature of the fixer at a second temperature higher than the first temperature, at which a color image can be fixed; and   a controller,   wherein,   when the temperature of the fixer reaches the first temperature during rise, the controller causes the display to display a ready display,   when the color mode is set by the setting portion, the controller performs control to keep the temperature of the fixer at the second temperature regardless of absence of a color image forming request after displaying the ready display.   
     
     
         3 . The apparatus according to  claim 2 ,
 wherein, in the monochrome mode, when printing of a color image is instructed before displaying the ready display, the controller consecutively raises the temperature of the fixer to the second temperature to print the color image, and executes the monochrome mode after completion of the printing of the color image.   
     
     
         4 . The apparatus according to  claim 2 ,
 wherein the first temperature is a temperature at which a fixing offset is generated in printing of the color image, and   the second temperature is a temperature at which the fixing offset is not generated in printing of both of the monochrome image and the color image.   
     
     
         5 . The apparatus according to  claim 2 ,
 wherein mode and the color mode can be selected for each state during warm-up operation when the power supply is ON and during return operation from a sleep mode.   
     
     
         6 . The apparatus according to  claim 2 ,
 wherein the fixer includes   a heating portion that heats the recording medium; and   a pressing portion that comes into press-contact with the heating portion via the recording medium to press the recording medium.   
     
     
         7 . The apparatus according to  claim 6 , further comprising:
 a heater portion that raises the temperature of the heating portion by heating itself.   
     
     
         8 . An image forming method, comprising:
 forming a toner image on a recording medium of an image forming apparatus;   heating the recording medium on which the toner image is formed;   displaying a state of the image forming apparatus;   setting as an operation mode one of a monochrome mode for keeping a temperature of a fixer at a first temperature at which a monochrome image can be fixed and a color mode for keeping the temperature of the fixer at a second temperature higher than the first temperature, at which a color image can be fixed;   displaying a ready display when the temperature of the fixer reaches the first temperature during rise; and   when the color mode is set, keeping the temperature of the fixer at the second temperature regardless of absence of a color image forming request after displaying the ready display.   
     
     
         9 . The method according to  claim 8 ,
 when printing of a color image is instructed before displaying the ready display, consecutively raising the temperature of the fixer to the second temperature to print the color image, and executing the monochrome mode after completion of the printing of the color image.   
     
     
         10 . The method according to  claim 8 ,
 wherein the first temperature is a temperature for generating a fixing offset in printing of the color image, and   the second temperature is a temperature for not generating the fixing offset in printing of both of the monochrome image and the color image.   
     
     
         11 . The method according to  claim 8 , further comprising
 selecting mode and the color mode for each state during warm-up operation when the power supply is ON and during return operation from a sleep mode.   
     
     
         12 . The method according to  claim 8 ,
 wherein heating includes   heating the recording medium; and   pressing the recording medium.   
     
     
         13 . The method according to  claim 12 , further comprising:
 raising the temperature of the heating portion by heating itself.