Charging device and image forming apparatus containing the charging device

An image forming apparatus comprising:

• an object to be charged and moving a predetermined moving direction;
• a charging member which contacts said object in a contacting region and charges the object in a separating region disposed in a downstream part from said contacting region in the moving direction of said object where surfaces of said charging member and said object move away from each other;
• an electric power supply for applying a voltage to the charging member;
• and
• a discharging restriction means for restricting the discharging between said charging member and said object in a closing region disposed in an upstream part from said contacting region where surfaces of said charging member and said object move closer to each other;
• wherein
• said discharging restriction means is an insulation layer formed on a part of surface of said charging member facing said object in said closing region.

A charging device for charging a moving object comprising:

• a charging member which contacts said object in a contacting region and charges the object in a separating region disposed in a downstream part from said contacting region in the moving direction of said object where surfaces of said charging member and said object move away from each other;
• an electric power supply for applying a voltage to the charging member;
• and
• a discharging restriction means for restricting the discharging between said charging member and said object in a closing region disposed in an upstream part from said contacting region where surfaces of said charging member and said object move closer to each other;
• wherein
• said discharging restriction means comprises an insulation layer formed on a part of surface of said charging member facing said object in said closing region.

A charging device for charging a moving object comprising:

• a charging member which contacts said object in a contacting region and charges said object in a separating region disposed in a downstream part from said contacting region in the moving direction of said object where surfaces of said charging member and said object move away from each other;
• an electric power supply for applying a voltage to said charging member;
• and
• a charging restriction means for restricting the charging of said object in a closing region disposed in an upstream part from said contacting region where surfaces of said charging member and said object move closer to each other;
• wherein
• said charging restriction means is a light exposing device for exposing at least said surfaces of said charging member and said object in said closing region,
• said charging member is a blade comprising a transparent layer for guiding light beam from said light exposing device to said closing region and a shading layer for shading said light beam to said contacting region and said separating region;
• and
• said light exposing device is disposed in the vicinity of an end of said transparent layer opposite to the other end in said closing region in a section parallel to said moving direction of said object.

An image forming apparatus comprising:

• an object to be charged and moving a predetermined moving direction;
• a charging member which contacts said object in a contacting region and charges the object in a separating region disposed in a downstream part from said contacting region in the moving direction of said object where surfaces of said charging member and said object move away from each other;
• an electric power supply for applying a voltage to the charging member;
• and
• a charging restriction means for restricting the charging of said object in a closing region disposed in an upstream part from said contacting region where surfaces of said charging member and said object move closer to each other;
• wherein
• said charging restriction means is a light exposing device for exposing at least said surfaces of said charging member and said object in said closing region,
• said charging member is a blade comprising a transparent layer for guiding light beam from said light exposing device to said closing region and a shading layer for shading said light beam to said contacting region and said separating region, and
• said light exposing device is disposed in the vicinity of an end of said transparent layer opposite to the other end in said closing region in a section parallel to said moving direction of said object.