Image forming apparatus

An image forming apparatus comprising:

• a toner image forming unit that forms a toner image on a sheet recording member;
• an area calculating unit that calculates an image area of the toner image;
• a pair of conveying members that form a conveying nip by contacting an endlessly-moving surface of one of the conveying members to that of the other of the conveying members and conveys the sheet recording member with sandwiching the sheet recording member by the conveying nip while the toner image is being formed or after the toner image is formed;
• a behavior detecting unit that detects behavior of the sheet recording member fed out of the conveying nip;
• an index calculating unit that calculates an index value indicating windability of the sheet recording member with respect to the conveying members based on at least the image area and the behavior;
• and
• a wearing determining unit that determines wearing of the pair of conveying members based on the index value;
• wherein
• the image forming apparatus further comprises a stiffness obtaining unit that obtains a bending stiffness of the sheet recording member, and the index calculating unit is configured to calculate the index value further based on the bending stiffness as well as the image area and the behavior, and
• the stiffness detecting unit includes a deflection-receiving unit that receives a deflection-repelling force of the sheet recording member being conveyed while undergoing a deflection and a plurality of pressure detecting units that are located so as to respectively be in contact with an opposite surface to a deflection-receiving surface of the deflection-receiving unit, and the plurality of pressure detecting units detect pressures added to the deflection-receiving unit by the sheet recording member undergoing a deflection, and the stiffness detecting unit detects, as the bending stiffness, the detecting result obtained by the plurality of pressure detecting units.

An image forming apparatus comprising:

• a toner image forming unit that forms a toner image on a sheet recording member;
• an area calculating unit that calculates an image area of the toner image;
• a pair of conveying members that form a conveying nip by contacting an endlessly-moving surface of one of the conveying members to that of the other of the conveying members and conveys the sheet recording member with sandwiching the sheet recording member by the conveying nip while the toner image is being formed or after the toner image is formed;
• a behavior detecting unit that detects behavior of the sheet recording member fed out of the conveying nip;
• an index calculating unit that calculates an index value indicating windability of the sheet recording member with respect to the conveying members based on at least the image area and the behavior;
• and
• a wearing determining unit that determines wearing of the pair of conveying members based on the index value;
• wherein
• the image forming apparatus further comprises a stiffness obtaining unit that includes a curvature guiding unit that guides the sheet recording member in a direction of feeding the sheet recording member while inflecting the sheet recording member at upper-stream from the conveying nip in conveying direction of the sheet recording member, and
• a feeding-time measuring unit that measures a time for feeding the sheet recording member at a guide position by the curvature guiding unit, and the index calculating unit is configured to calculate the index value further based on the time for feeding the sheet recording member as well as the image area and the behavior.

An image forming apparatus comprising:

• a toner image forming unit having a photoconductor and that forms a toner image on a sheet recording member;
• a processor having circuitry that calculates an image area of the toner image;
• a pair of conveying members that form a conveying nip by contacting an endlessly-moving surface of one of the conveying members to that of the other of the conveying members and conveys the sheet recording member with sandwiching the sheet recording member by the conveying nip while the toner image is being formed or after the toner image is formed;
• a behavior detector having a sensor and that detects behavior of the sheet recording member fed out of the conveying nip;
• the processor further having circuitry that calculates an index value indicating windability of the sheet recording member with respect to the conveying members based on at least the image area and the behavior;
• and
• the processor further having circuitry that determines wearing of the pair of conveying members based on the index value;
• wherein
• the processor further having circuitry that obtains a bending stiffness of the sheet recording member, and the index value is further based on the bending stiffness as well as the image area and the behavior, and
• a plurality of pressure detectors that are respectively located so as to be in contact with an opposite surface to a deflection-receiving surface that receives a deflection-repelling force of the sheet recording member being conveyed while undergoing a deflection, wherein the plurality of pressure detectors detect pressures applied by the sheet recording member undergoing a deflection, and the bending stiffness is obtained from the plurality of pressure detecting units.

An image forming apparatus comprising:

• a toner image forming unit having a photoconductor and that forms a toner image on a sheet recording member;
• a processor having circuitry that calculates an image area of the toner image;
• a pair of conveying members that form a conveying nip by contacting an endlessly-moving surface of one of the conveying members to that of the other of the conveying members and conveys the sheet recording member with sandwiching the sheet recording member by the conveying nip while the toner image is being formed or after the toner image is formed;
• a behavior detecting unit having a sensor and that detects behavior of the sheet recording member fed out of the conveying nip;
• the processor further having circuitry that calculates an index value indicating windability of the sheet recording member with respect to the conveying members based on at least the image area and the behavior;
• and
• the processor further having circuitry that determines wearing of the pair of conveying members based on the index value;
• wherein
• a curvature guide member that guides the sheet recording member in a direction of feeding the sheet recording member while inflecting the sheet recording member at upper-stream from the conveying nip in conveying direction of the sheet recording member, and
• the processor further having circuitry that measures a time for feeding the sheet recording member at a guide position by the curvature guide member, and the index value is calculated based on the time for feeding the sheet recording member as well as the image area and the behavior.