Developing apparatus having stop period during which no AC electric field is exerted between developer carrying member and image carrying member

A developing apparatus for developing an electrostatic latent image formed on an image carrying member under application of a developing bias, comprising:

• a developer carrying member for conveying a developer to a developing area opposite to the image carrying member with the developer held on its surface;
• and
• a developing bias in which an exertion period during which an AC electric field is exerted and a stop period during which no AC electric field is exerted are alternately repeated,
• a direction of a first and a last electric field portion of the AC electric field in one exertion period being the same,
• the direction of the last electric field portion of the AC electric field in the exertion period and the direction of the first electric field portion of the AC electric field in a subsequent exertion period after an elapse of the stop period being the same.

A developing apparatus for developing an electrostatic latent image formed on an image carrying member under application of a developing bias, comprising:

• a developer carrying member for conveying a developer to a developing area opposite to the image carrying member with the developer held on its surface;
• and
• a developing bias in which an exertion period during which an AC electric field is exerted and a stop period during which no AC electric field is exerted are alternately repeated,
• a direction of a first and a last electric field portion of the AC electric field in one exertion period being the same,
• the direction of the last electric field portion of the AC electric field in the exertion period and the direction of the first electric field portion of the AC electric field in a subsequent exertion period after an elapse of the stop period being opposite to each other.

A developing apparatus for developing an electrostatic latent image formed on an image carrying member under application of a developing bias, comprising:

• a developer carrying member for conveying a developer to a developing area opposite to the image carrying member with the developer held on its surface;
• and
• a developing bias in which an exertion period during which an AC electric field is exerted and a stop period during which no AC electric field is exerted are alternately repeated,
• a direction of a first and a last electric field portion of the AC electric field in one exertion period being opposite to each other,
• the direction of the last electric field portion of the AC electric field in the exertion period and the direction of the first electric field portion of the AC electric field in a subsequent exertion period after an elapse of the stop period being the same.

A developing apparatus for developing an electrostatic latent image formed on an image carrying member under application of a developing bias, comprising:

• a developer carrying member for conveying a developer to a developing area opposite to the image carrying member with the developer held on its surface;
• developing bias applying means for applying a developing bias between the developer carrying member and the image carrying member;
• and
• developing bias control means for so controlling the developing bias that an exertion period during which an AC electric field is exerted and a stop period during which no AC electric field is exerted are alternately repeated, a direction of a first and a last electric in field portion of the AC electric field in one exertion period are the same, and the direction of the last electric field portion of the AC electric field in the exertion period and the direction of the first electric field portion of the AC electric field in a subsequent exertion period after an elapse of the stop period are the same.