Charging device and image forming apparatus

A charging device comprising:

• a charged body;
• a charging member that is disposed at a predetermined distance from a surface of the charged body, and that extends parallel to the surface of the charged body, a charging voltage being applied between the charging member and the charged body;
• a cleaning member that is in contact with the charging member, and that moves in an extending direction of the charging member to remove matter adhering to the charging member;
• an air introduction path that introduces airflow at a position along the charging member flowing in an airflow direction along the extending direction of the charging member;
• and
• a cover member that is supported to cover the charging member along the extending direction of the charging member,
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in the airflow direction,
• wherein the cleaning member is separated from the charging member when the cleaning member moves in a direction opposite to the airflow direction in a state in which the airflow is generated,
• wherein the cover member and the charged body surround a region having a cross-section area in a plane perpendicular to the direction of the axis line of the charging member, and
• wherein the cross-section area of the region is reduced in the airflow direction.

A charging device comprising:

• a charged body;
• a charging member that is disposed at a predetermined distance from a surface of the charged body, and that extends parallel to the surface of the charged body, a charging voltage being applied between the charging member and the charged body;
• a cleaning member that is in contact with the charging member, and that moves in an extending direction of the charging member to remove matter adhering to the charging member;
• and
• an air introduction path that introduces airflow at a position along the charging member flowing in an airflow direction along the extending direction of the charging member,
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in the airflow direction,
• wherein the cleaning member is separated from the charging member when the cleaning member moves in a direction opposite to the airflow direction in a state in which the airflow is generated, and
• wherein the cleaning member stands ready at a downstream side in the airflow direction in a time period from termination of an operation of cleaning of the charging member to start of a next operation of cleaning of the charging member.

A charging device comprising:

• a charging member that is disposed at a predetermined distance from a surface of a charged body, a charging voltage being applied between the charging member and the charged body;
• a cleaning member that is in contact with the charging member, and that moves in a extending direction of the charging member to remove matter adhering to the charging member;
• and
• an air introduction path that introduces airflow at a position along the charging member flowing in an airflow direction along the extending direction of the charging member,
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in the airflow direction such that a contact pressure of the cleaning member on the charging member increases as the cleaning member moves along the charging member,
• wherein a contact pressure between the cleaning member and the charging member when the cleaning member moves in a direction opposite to the airflow direction is set to be less than a contact pressure therebetween when the cleaning member moves in the airflow direction in a state in which the airflow is generated.

A charging device comprising:

• a charging member that is disposed at a predetermined distance from a surface of a charged body, a charging voltage being applied between the charging member and the charged body;
• a cleaning member that is in contact with the charging member, and that moves in a extending direction of the charging member to remove matter adhering to the charging member;
• an air introduction path that introduces airflow at a position along the charging member flowing in an airflow direction along the extending direction of the charging member;
• and
• a cover member that is supported to cover the charging member along the extending direction of the charging member,
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in the airflow direction,
• wherein a contact pressure between the cleaning member and the charging member when the cleaning member moves in a direction opposite to the airflow direction is set to be less than a contact pressure therebetween when the cleaning member moves in the airflow direction in a state in which the airflow is generated,
• wherein the cover member and the charged body surround a region having a cross-section area in a plane perpendicular to the direction of the axis line of the charging member, and
• wherein the cross-section area of the region is in the airflow direction.

A charging device comprising:

• a charging member that is disposed at a predetermined distance from a surface of a charged body, a charging voltage being applied between the charging member and the charged body;
• a cleaning member that is in contact with the charging member, and that moves in a extending direction of the charging member to remove matter adhering to the charging member;
• and
• an air introduction path that introduces airflow at a position along the charging member flowing in an airflow direction along the extending direction of the charging member,
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in the airflow direction,
• wherein a contact pressure between the cleaning member and the charging member when the cleaning member moves in a direction opposite to the airflow direction is set to be less than a contact pressure therebetween when the cleaning member moves in the airflow direction in a state in which the airflow is generated, and
• wherein the cleaning member stands ready at a downstream side in the airflow direction in a time period from termination of an operation of cleaning of the charging member to start of a next operation of cleaning of the charging member.

An image holder unit comprising:

• an image holder that has a photoreceptor layer provided around an endless circumferential surface, and that has a surface adapted to move;
• a charging member that is disposed at a predetermined distance from a surface of the image holder, and that extends in a direction perpendicular to a direction of movement of the image holder, a charging voltage being applied between the charging member and the charged body;
• a cleaning member that is in contact with the charging member, and that moves in an extending direction of the charging member to remove matter adhering to the charging member;
• and
• an air introduction path that introduces airflow at a position along the charging member flowing in an airflow direction along the extending direction of the charging member,
• the image holder, the charging member, the cleaning member, and the air introduction path being formed substantially integrally with an image forming apparatus body,
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in the airflow direction such that the contact pressure of the cleaning member on the charging member increases as the cleaning member moves along the charging member, and
• wherein the cleaning member is separated from the charging member when the cleaning member moves in a direction opposite to the airflow direction in a state in which the airflow is generated.

An image forming apparatus comprising:

• an image holder that has a photoreceptor layer provided around an endless circumferential surface;
• a charging device that charges the circumferential surface of the image holder to a predetermined potential level;
• an image exposure device that forms a latent image by irradiating image light onto the circumferential surface of the image holder;
• a developing device that forms a toner image by transferring toner to the latent image formed on the image holder;
• a transfer device that transfers the toner image formed on image holder to a transferred material;
• and
• an air supply and exhaust device that at least supplies air to the charging device and exhausts air from the charging device such that an airflow flows from a front side to a rear side along the charging member,
• the charging device comprising:
• a charging member that extends in a direction of width of an endless circumference, and that is disposed at a predetermined distance from the endless circumferential surface to extend from a front side to a rear side, a charging voltage being applied between the charging member and the charged body;
• and
• a cleaning member that is in contact with the charging member, and that moves in an extending direction of the charging member to remove matter adhering to the charging member;
• wherein the cleaning member is in contact with the charging member when the cleaning member moves in a direction of airflow such that a contact pressure of the cleaning member on the charging member increases as the cleaning member moves along the charging member, and
• wherein, when the cleaning member moves in a direction opposite to the airflow in a state in which the airflow is generated, the cleaning member is separated from the charging member, or a contact pressure between the cleaning member and the charging member is set to be less than a contact pressure therebetween when the cleaning member moves in the direction of airflow.