Image forming apparatus having charging member

An image forming apparatus comprising:

• a movable image bearing member having a photosensitive layer;
• image forming means for forming an image on said image bearing member, said image forming means including a contact charging member, contactable to said image bearing member, for charging said image bearing member for image formation, and light radiating means for radiating light on said image bearing member;
• detecting means for detecting a current flowing through said charging member while said charging member is constant-voltage controlled using a predetermined voltage value;
• controlling means for controlling, in response to a detection result of said detecting means, an amount of light radiated from said light radiating means to be increased with increase in the detected current increasing beyond a predetermined value;
• wherein a voltage applied to said charging member during image formation is reduced with increase in the detected current increasing beyond a predetermined value.

An image forming apparatus comprising:

• a movable image bearing member having a photosensitive layer;
• image forming means for forming an image on said image bearing member, said image forming means including a contact charging member, contactable to said image bearing member, for charging said image bearing member for image formation, and light radiating means for radiating light on said image bearing member;
• detecting means for detecting a current flowing through said charging member while said charging member is constant-voltage controlled using a predetermined voltage value;
• controlling means for controlling, in response to a detection result of said detecting means, an amount of light radiated from said light radiating means to be increased with increase in the detected current increasing beyond a predetermined value;
• wherein the current applied to said charging member during the image formation is increased with increase in the detected current increasing beyond a predetermined value.

An image forming apparatus comprising:

• a movable image bearing member having a photosensitive layer;
• image forming means for forming an image on said image bearing member, said image forming means including a contact charging member, contactable to said image bearing member, for charging said image bearing member for image formation, and light radiating means for radiating light on said image bearing member;
• detecting means for detecting a voltage applied to said charging member while said charging member is constant-current controlled using a predetermined current value;
• controlling means for controlling, in response to a detection result of said detecting means, an amount of light radiated from said light radiating means to be increased with decrease in the detected voltage decreasing beyond a predetermined value;
• wherein a current applied to said charging member during the image formation is reduced with decrease in the detected voltage decreasing beyond a predetermined value.

An image forming apparatus comprising:

• a movable image bearing member having a photosensitive layer;
• image forming means for forming an image on said image bearing member, said image forming means including a contact charging member, contactable to said image bearing member, for charging said image bearing member for image formation, and light radiating means for radiating light on said image bearing member;
• detecting means for detecting a voltage applied to said charging member while said charging member is constant-current controlled using a predetermined current value;
• controlling means for controlling, in response to a detecting result of said detecting means, an amount of light radiated from said light radiating means to be increased with decrease in the detected voltage decreasing beyond a predetermined value;
• wherein a current applied to said charging member during the image formation is increased with decrease in the detected voltage decreasing beyond a predetermined value.

An image forming apparatus comprising:

• a movable image bearing member having a photosensitive layer;
• image forming means for forming an image on said image bearing member, said image forming means including a contact charging member contactable to said image bearing member for charging said image bearing member, and light radiating means for radiating light on said image bearing member;
• detecting means for detecting a current flowing through said charging member during a constant-voltage control period n which a predetermined voltage is applied to said charging member;
• and
• controlling means for controlling an amount of light radiated from said light radiating means to said image bearing member, such that in accordance with a result of the detection, the amount of the light increases with increase of the detected current beyond a predetermined level, and the amount of the light is constant below the predetermined level of the detected current.

An image forming apparatus comprising:

• a movable image bearing member, having a photosensitive layer;
• image forming means for forming an image on said image bearing member, said image forming means including a charging member for charging said image bearing member;
• detecting means for detecting voltage-current characteristic between said charging member and said image bearing member;
• and
• controlling means for controlling variably the surface potential of said image bearing member, in response to said detecting means.

An image forming apparatus comprises:

• a movable image bearing member;
• image forming means for forming an image on said image bearing member, said image forming means including a charging member for charging said image bearing member;
• detecting means for detecting current flowing through said charging member while said charging member is constant-voltage controlled using a predetermined voltage value;
• and
• controlling means for controlling the surface potential of said image bearing member charged by said charging member, to decrease with increase of the current beyond a predetermined value, in response to said detecting means.