Image forming apparatus having a humidification section

An image forming apparatus comprising:

• an image holding section that holds an image;
• a transfer section that includes a transfer member disposed in contact with an image holding surface of the image holding section and an opposite member disposed at a position facing the transfer member across the image holding section, connects a transfer power supply to the opposite member to apply a transfer electric-field to a transfer region between the image holding section and the transfer member, and electrostatically transfers the image held by the image holding section onto a recording medium transported to the transfer region;
• contact sections that are provided upstream and downstream of the recording medium a direction of transport of the recording medium across the transfer region and act as electrodes to ground while being in contact with the recording medium when the recording medium passes through the transfer region;
• a humidification section that is provided upstream of the transfer region in the direction of transport of the recording medium and humidifies the recording medium;
• a first control section that performs control to transfer the image on the image holding section to the recording medium without humidification by the humidification section;
• a second control section that performs control to cause the humidification section to humidify the recording medium, to transport the humidified recording medium to the transfer region, and to transfer the image on the image holding section to the recording medium through a transfer current path from the opposite member to the contact section via the recording medium;
• and
• a selection section that selects the first control section or the second control section depending on a type of the recording medium,
• wherein the selection section selects the second control section when the recording medium has a high resistance equal to or more than a predetermined resistance value and;
• the recording medium includes a medium base containing a conductive agent, a medium that is black, a medium base containing carbon black, or the image held by the image holding section includes a planar background image formed with an opaque background image-forming agent.

An image forming apparatus comprising:

• an image holding section that holds an image;
• a transfer section that includes a transfer member disposed in contact with an image holding surface of the image holding section and an opposite member disposed at a position facing the transfer member across the image holding section, connects a transfer power supply to the opposite member to apply a transfer electric-field to a transfer region between the image holding section and the transfer member, and electrostatically transfers the image held by the image holding section onto a recording medium transported to the transfer region;
• contact sections that are provided upstream and downstream of the recording medium a direction of transport of the recording medium across the transfer region and act as electrodes to ground while being in contact with the recording medium when the recording medium passes through the transfer region;
• a humidification section that is provided upstream of the transfer region in the direction of transport of the recording medium and humidifies the recording medium;
• a first control section that performs control to transfer the image on the image holding section to the recording medium without humidification by the humidification section;
• a second control section that performs control to cause the humidification section to humidify the recording medium, to transport the humidified recording medium to the transfer region, and to transfer the image on the image holding section to the recording medium through a transfer current path from the opposite member to the contact section via the recording medium;
• and
• a selection section that selects the first control section or the second control section depending on a type of the recording medium,
• wherein when the first control section is selected, the transfer member is grounded directly or with a low resistance equal to or less than a predetermined resistance value, and when the second control section is selected, the transfer member is grounded with a high resistance equal to or higher than the predetermined resistance value.