Method and apparatus for image forming apparatus capable of accurately detecting toner image patterns

An image forming apparatus, comprising:

• means for conveying a sheet-formed medium;
• a plurality of means for forming a latent image, developing said latent image into a toner image with toner, and transferring said toner image onto said sheet-formed medium carried on the means for conveying, said plurality of image forming means being arranged in a conveying direction of said sheet-formed medium;
• detection means for detecting arbitrary toner images formed at said plurality of image forming means and then directly transferred onto said means for conveying;
• and
• contact and separation enabling means for enabling said means for conveying to contact and separate from each of said plurality of image forming means;
• wherein said contact and separation enabling means is configured to be driven so as to separate said means for conveying from each of said plurality of image forming means before said each toner image contacts respective following of said plurality of image forming means.

An image forming apparatus, comprising:

• a belt configured to convey a sheet-formed medium;
• a plurality of recording units arranged in a conveying direction of said sheet-formed medium and respectively including rotating image bearing members configured to perform a process of forming a latent image on each surface of said image bearing members, developing said latent image into a toner image with toner, and transferring said toner image onto said sheet-formed medium carried on the belt;
• a detection device configured to detect arbitrary toner images formed at said plurality of recording units and then directly transferred onto said belt;
• and
• a contact and separation device configured to enable said belt to contact and separate from said image bearing members;
• wherein said contact and separation device is configured to be driven so as to separate said belt from said image bearing members before said arbitrary toner images transferred onto said belt contact respective following recording units, and
• wherein said detection device is configured to move based on whether said belt is in contact with or separated from said image bearing members.

An image forming apparatus, comprising:

• means for conveying a sheet-formed medium;
• a plurality of means for forming a latent image, developing said latent image into a toner image with toner, and transferring said toner image onto said sheet-formed medium carried on the means for conveying, said plurality of image forming means being arranged in a conveying direction of said sheet-formed medium;
• detection means for detecting arbitrary toner images formed at said plurality of image forming means and then directly transferred onto said means for conveying;
• and
• contact and separation enabling means for enabling said means for conveying to contact and separate from said plurality of image forming means;
• wherein said contact and separation enabling means is configured to be driven so as to separate said means for conveying from said plurality of image forming means before said each toner image contacts respective following of said plurality of image forming means, and
• wherein said detection means moves based on whether said means for conveying is in contact with or separated from said plurality of image forming means.