Image forming apparatus using trapezoidal shaped electric field and method for forming image

An image forming apparatus, comprising:

• an image carrying member which is adapted to carry an electrostatic latent image;
• a developer container which is adapted to contain a developer including a toner, a carrier for charging the toner, and opposite polarity particles to be charged opposite to a charge polarity of the toner;
• a developer carrying member which is adapted to convey the developer supplied from the developer container;
• a toner carrying member which is adapted to receive the toner from the developer on the developer carrying member and to convey the toner to a development position facing the image carrying member to develop the electrostatic latent image on the image carrying member;
• and
• an electric field forming section which is adapted to form an electric field between the image carrying member and the toner carrying member, the electric field including a DC component overlapped with an AC component,
• wherein the AC component of the electric field formed by the electric field forming section includes a developing component which moves the toner to the image carrying member and a reverse-developing component which moves the toner to the toner carrying member, and a blank is formed within the reverse-developing component.

A method for forming an image, the method comprising the steps of:

• forming an electrostatic latent image on an image carrying member;
• supplying a developer carrying member with a developer including a toner, a carrier for charging the toner, and opposite polarity particles to be charged opposite to a charge polarity of the toner;
• transferring the toner from the developer carrying member onto the toner carrying member;
• conveying the toner to a position facing the image carrying member by a movement of a surface of the toner carrying member, the opposite polarity particles being attached to the toner;
• and
• forming an electric field including a DC component overlapped with an AC component between the image carrying member and the toner carrying member to develop the electrostatic latent image on the image carrying member with the toner on the toner carrying member, the AC component including a trapezoidal wave.

A method for forming an image, the method comprising the steps of:

• forming an electrostatic latent image on an image carrying member;
• supplying a developer carrying member with a developer including a toner, a carrier for charging the toner, and opposite polarity particles to be charged opposite to a charge polarity of the toner;
• transferring the toner from the developer carrying member onto the toner carrying member;
• conveying the toner to a position facing the image carrying member by a movement of a surface of the toner carrying member, the opposite polarity particles being attached to the toner;
• and
• forming an electric field including a DC component overlapped with an AC component between the image carrying member and the toner carrying member to develop the electrostatic latent image on the image carrying member with the toner on the toner carrying member, the AC component including a developing component which moves the toner to the image carrying member and a reverse-developing component which moves the toner to the toner carrying member, and a blank being formed within the reverse-developing component.