Image forming apparatus

An image forming apparatus comprising:

• an image bearing member;
• a charging member for uniformly charging a surface of said image bearing member while contacting thereto with a predetermined voltage;
• developing means for visualizing the electrostatic latent image into a toner image with toner;
• an image transfer means for transferring the toner image onto a transfer material;
• voltage applying means for applying the predetermined voltages to said charging member, said developing means and said image transfer means;
• control means for controlling said voltage applying means;
• and
• fixing means for heat-fixing the toner image onto the transfer material;
• wherein said control means is operable with an operational sequence which is selected from a plurality of operational sequences on the basis of an output of detecting means for detecting a state of image forming process, and
• wherein said detecting means detects a temperature of said fixing means.

An image forming apparatus comprising:

• an image bearing member;
• developing means for forming a toner image by developing an electrostatic image formed on said image bearing member with toner at a developing position, said developing means being capable of collecting residual toner from said image bearing member;
• a transfer member, contacted to said image bearing member, for transferring the toner image onto the transfer material passing between said image bearing member and said transfer member;
• and
• control means for effecting a jam recovery sequence after a jammed transfer material is removed and before start of image forming operation, wherein in a jam recovery sequence operation effected by said control means, toner passing through a contact portion between said transfer member and said image bearing member is charged to a regular charging polarity, and an electric field is formed at the contact portion in a direction of moving the regular-charge toner charged to the regular charging polarity from the transfer member toward said image bearing member, and wherein in said jam recovery sequence, an electric field is formed at said developing position in a direction of moving the regular-charge toner from said image bearing member to said developing means.

An image forming apparatus comprising:

• an image bearing member;
• developing means for forming a toner image by developing an electrostatic image formed on said image bearing member with toner at a developing position;
• transferring means for effecting an image transfer operation for transferring the toner image from said image bearing member onto a transfer material at an image transfer position;
• fixing means for heat fixing the toner image on the transfer material;
• temperature detecting means for detecting a temperature of said fixing means;
• transfer material detecting means for detecting a jam of the transfer material in a transfer material feeding path;
• and
• control means for effecting, in the case that an electric power supply is shut off without said transfer material detecting means detecting the jam during an image forming operation of said apparatus and then the electric power is resumed, the image transfer operation onto a transfer material which stays in the transfer material feeding path upstream of the image transfer position with respect to a feeding direction of the transfer material when the temperature detected by said temperature detecting means is higher than a predetermined temperature.