Image forming apparatus having air duct facing fixing member

An image forming apparatus, comprising:

• a fixing member having a cylindrical or annular shape for fixing an image onto a sheet which is in pressure contact with an outer surface thereof;
• a heating source for heating the fixing member to a fixing temperature;
• a duct which is provided in a position facing the fixing member and which has an inlet for taking in fine particles generated from the fixing member;
• an exhaust fan provided inside the duct or in an outlet of the duct for generating an air flow going from the inlet to the outlet of the duct;
• a first filter member which is provided upstream or downstream from the exhaust fan inside the duct and which can trap the fine particles which flow through the duct in the air flow;
• and
• a control section for controlling an amount of the air flow passing through the first filter member according to initial burst conditions under which the fine particles are emitted from the fixing member;
• wherein the control section controls the air flow according to the initial burst conditions, depending on whether or not a preset standby time has elapsed after start of heating of the fixing member upon turning on a main body of the image forming apparatus or upon returning from standby state of the main body of the image forming apparatus.

An image forming apparatus, comprising:

• a fixing member having a cylindrical or annular shape for fixing an image onto a sheet which is in pressure contact with an outer surface thereof;
• a heating source for heating the fixing member to a fixing temperature;
• a duct which is provided in a position facing the fixing member and which has an inlet for taking in fine particles generated from the fixing member;
• an exhaust fan provided inside the duct or in an outlet of the duct for generating an air flow going from the inlet to the outlet of the duct;
• a first filter member which is provided upstream or downstream from the exhaust fan inside the duct and which can trap the fine particles which flow through the duct in the air flow;
• a control section for controlling an amount of the air flow passing through the first filter member according to initial burst conditions under which the fine particles are emitted from the fixing member;
• a temperature sensor for measuring temperature of the fixing member, wherein the control section controls the air flow according to the initial burst conditions, depending on whether or not the temperature of the fixing member measured with the temperature sensor has reached a preset threshold temperature;
• a switching mechanism capable of switching between a first state in which the air flow passes through the first filter member and a second state in which the air flow avoids the first filter member;
• and
• wherein the control section controls the switching mechanism so as to switch from the second state to the first state only for a preset operating time after the temperature of the fixing member measured with the temperature sensor has reached the preset first threshold temperature.

An image forming apparatus, comprising:

• a fixing member having a cylindrical or annular shape for fixing an image onto a sheet which is in pressure contact with an outer surface thereof;
• a heating source for heating the fixing member to a fixing temperature;
• a duct which is provided in a position facing the fixing member and which has an inlet for taking in fine particles generated from the fixing member;
• an exhaust fan provided inside the duct or in an outlet of the duct for generating an air flow going from the inlet to the outlet of the duct;
• a first filter member which is provided upstream or downstream from the exhaust fan inside the duct and which can trap the fine particles which flow through the duct in the air flow;
• a control section for controlling an amount of the air flow passing through the first filter member according to initial burst conditions under which the fine particles are emitted from the fixing member;
• an outside air introduction port provided upstream from the first filter member with respect to the air flow in the duct;
• and
• an opening and closing mechanism capable of switching between an opened state in which air from outside a casing of the image forming apparatus or from a part distant from the fixing member inside the casing is introduced into the duct through the outside air introduction port and a closed state in which the outside air introduction port is blocked, wherein
• the control section controls the opening and closing mechanism so as to switch between the opened state and the closed state according to the initial burst conditions;
• wherein the control section controls the air flow according to the initial burst conditions, depending on whether or not a preset standby time has elapsed after start of heating of the fixing member upon turning on a main body of the image forming apparatus or upon returning from standby state of the main body of the image forming apparatus.

An image forming apparatus, comprising:

• a fixing member having a cylindrical or annular shape for fixing an image onto a sheet which is in pressure contact with an outer surface thereof;
• a heating source for heating the fixing member to a fixing temperature;
• a duct which is provided in a position facing the fixing member and which has an inlet for taking in fine particles generated from the fixing member;
• an exhaust fan provided inside the duct or in an outlet of the duct for generating an air flow going from the inlet to the outlet of the duct;
• a first filter member which is provided upstream or downstream from the exhaust fan inside the duct and which can trap the fine particles which flow through the duct in the air flow;
• a control section for controlling an amount of the air flow passing through the first filter member according to initial burst conditions under which the fine particles are emitted from the fixing member;
• an outside air introduction port provided upstream from the first filter member with respect to the air flow in the duct;
• and
• an opening and closing mechanism capable of switching between an opened state in which air from outside a casing of the image forming apparatus or from a part distant from the fixing member inside the casing is introduced into the duct through the outside air introduction port and a closed state in which the outside air introduction port is blocked, wherein
• the control section controls the opening and closing mechanism so as to switch between the opened state and the closed state according to the initial burst conditions;
• a temperature sensor for measuring temperature of the fixing member, wherein
• the control section controls the air flow according to the initial burst conditions, depending on whether or not the temperature of the fixing member measured with the temperature sensor has reached a preset threshold temperature;
• wherein the control section controls the opening and closing mechanism so as to switch from the opened state to the closed state only for a preset operating time after the temperature of the fixing member measured with the temperature sensor has reached the preset threshold temperature.

An image forming apparatus, comprising:

• a fixing member having a cylindrical or annular shape for fixing an image onto a sheet which is in pressure contact with an outer surface thereof;
• a heating source for heating the fixing member to a fixing temperature;
• a duct which is provided in a position facing the fixing member and which has an inlet for taking in fine particles generated from the fixing member;
• an exhaust fan provided inside the duct or in an outlet of the duct for generating an air flow going from the inlet to the outlet of the duct;
• a first filter member which is provided upstream or downstream from the exhaust fan inside the duct and which can trap the fine particles which flow through the duct in the air flow;
• a control section for controlling an amount of the air flow passing through the first filter member according to initial burst conditions under which the fine particles are emitted from the fixing member;
• an outside air introduction port provided upstream from the first filter member with respect to the air flow in the duct;
• and
• an opening and closing mechanism capable of switching between an opened state in which air from outside a casing of the image forming apparatus or from a part distant from the fixing member inside the casing is introduced into the duct through the outside air introduction port and a closed state in which the outside air introduction port is blocked, wherein
• the control section controls the opening and closing mechanism so as to switch between the opened state and the closed state according to the initial burst conditions;
• an auxiliary duct communicating with the outside air introduction port;
• and
• an outside air introduction fan provided inside the auxiliary duct or in an inlet thereof for introducing air from outside of the casing of the image forming apparatus or from a part inside the casing distant from the fixing member into the duct, wherein
• the control section controls rotation frequency of the outside air introduction fan according to the initial burst conditions.