Image forming apparatus adapted for reversal developing process which is diminished in ozone and nitrogen oxide emissions

In an image forming apparatus including a drivingly rotatable image bearing member, first charging means for charging the image bearing member to a first polarity, means for forming an electrostatic latent image on the charged image bearing member, means for developing the electrostatic latent image with toner by reversal development, and second charging means for imparting to the image bearing member a charge having a second polarity opposite to the first polarity to transfer the toner image from the image bearing member onto a sheet, a method of controlling the apparatus comprising the steps of:

• turning off the second charging means after the rear end of the image area of said image bearing member where the latent image is formed has moved past the second charging means,
• subsequently turning off the first charging means after the rear end of the image area has moved past the first charging means;
• and
• stopping the rotation of the image bearing member a predetermined period of time after the first charging means is turned off.

In an image forming apparatus including a drivingly rotatable image bearing member, first charging means for charging the image bearing member to a first polarity, means for forming an electrostatic latent image on the charged image bearing member, means for developing the electrostatic latent image with toner by reversal development, second charging means for imparting to the image bearing member a charge having a second polarity opposite to the first polarity to transfer the toner image from the image bearing member onto a sheet, and erasing means for irradiating with light the image bearing member to erase charges thereon, a method of controlling the apparatus comprising the steps of:

• turning off the second charging means after the rear end of the image area of said image bearing member where the latent image is formed has moved past the second charging means,
• turning off the erasing means after the rear end of the image area has moved past the erasing means;
• subsequently turning off the first charging means after the rear end of the image area has moved past the first charging means;
• and
• stopping the rotation of the image bearing member a predetermined period of time after the first charging means is turned off.

An image forming apparatus comprising:

• a drivingly rotatable image bearing member;
• means for charging the image bearing member to a first polarity;
• means for forming an electrostatic latent image on the charged image bearing member;
• means for developing the electrostatic latent image with toner by reversal development;
• transfer means for imparting to the image bearing member a charge having a second polarity opposite to the first polarity to transfer the toner image from the image bearing member onto a sheet;
• and
• control means for controlling the charging means and the transfer means so as to turn off the transfer means after the rear end of the image area of the image bearing member where the latent image is formed has moved past the transfer means, and subsequently to turn off the charging means when a predetermined time period has elapsed from a time when the transfer means has been turned off, the predetermined time period being a time required for a portion of the image bearing member to move from a position opposed to the transfer means to a position opposed to the charging means.