Image forming apparatus with improved cleaning operation

An image forming apparatus comprising:

• a photoreceptor,
• image forming means for forming a toner image on said photoreceptor,
• an intermediate transfer medium for receiving the toner image formed on said photoreceptor,
• transferring means for transferring the toner image on said intermediate transfer medium to a sheet,
• cleaning means for removing toner from said intermediate transfer medium,
• signal output means for providing an image formation start signal for starting the image formation operation of said image forming means,
• first control means responsive to said provided image formation start signal for carrying out a preliminary cleaning of a predetermined time period and for starting image formation by said image forming means when said preliminary cleaning is terminated,
• second control means for carrying out a subsequent cleaning of a predetermined time period after the termination of said transfer process by said transferring means, and
• third control means for canceling cleaning of said second control means and for reducing the time period of the preliminary cleaning by said first control means, when an image formation start signal is provided by said signal output means during said subsequent cleaning,.

An image forming apparatus comprising:

• a photoreceptor
• image forming means for forming a toner image on said photoreceptor,
• an intermediate transfer medium for receiving the toner image formed on said photoreceptor,
• transferring means for transferring the toner image on said intermediate transfer medium to a sheet,
• cleaning means for removing toner from said intermediate transfer medium,
• signal output means for providing an image formation start signal for starting the image formation operation of said image forming means,
• first control means for cleaning the entire area of said intermediate transfer medium when the transfer process by said transferring means is terminated, and
• second control means for starting image formation by said image forming means after continuing the cleaning of a not-yet cleaned area of said intermediate transfer medium, when an image formation start signal is provided by said signal output means during the cleaning by said first control means.

An image forming apparatus comprising:

• a photoreceptor,
• image forming means for forming a toner image on said photoreceptor,
• an intermediate transfer medium for receiving the toner image formed on said photoreceptor,
• transferring means for transferring the toner image on said intermediate transfer medium to a sheet,
• cleaning means for removing toner from said intermediate transfer medium,
• means for providing an image formation start signal for starting the image formation operation of said image forming means,
• first control means responsive to said provided image formation start signal for cleaning the entire area of said intermediate transfer medium by said cleaning means and for starting image formation by said image forming means after the cleaning is terminated,
• second control means for cleaning the entire area of said intermediate transfer medium, after the termination of said transfer process by said transferring means, and
• third control means for starting image formation by said image forming means after continuing the cleaning of the not-yet cleaned area of said intermediate transfer medium, when an image formation start signal is provided by said signal output means during cleaning by said second control means.