Defining member for defining thickness of one-component developer and developing device equipped with it

A developing device for developing an electrostatic latent image, comprising:

• a developer bearing member for bearing and transporting a one-component developer to a developing area, said developer bearing member being adapted to frictionally charge the one-component developer to a predetermined polarity for developing an electrostatic latent image;
• and
• a defining member for limiting a thickness of the one-component developer transported by said developer bearing member to the developing area, said defining member being in contact with the developer bearing member to form a nip therebetween, through which the one-component developer passes;
• wherein said defining member includes an elastic base member and a surface layer formed on said elastic base member and serving to form said nip, and said surface layer includes a first substance charged to a polarity opposite to said predetermined polarity by friction with the one-component developer, and a second substance serving as a solid lubricant, and is charged, in total, to a polarity opposite to said predetermined polarity, by friction with said one-component developer.

A developing device for developing an electrostatic latent image, comprising:

• a developer bearing member for bearing and transporting a one-component developer to a developing area, said developer bearing member being adapted to frictionally charge the one-component developer to a predetermined polarity for developing an electrostatic latent image;
• and
• a defining member for limiting a thickness of the one-component developer transported by said developer bearing member to the developing area, said defining member being in contact with the developer bearing member to form a nip therebetween, through which the one-component developer passes;
• wherein said defining member includes an elastic base member and a surface layer formed on said elastic base member and serving to form said nip, and said surface layer includes a binder substance charged to a polarity opposite to said predetermined polarity by friction with the one-component developer, and substantially spherical particles dispersed in said binder substance, and is charged, in total, to a polarity opposite to said predetermined polarity by friction with the one-component developer.

A defining member for limiting a thickness of a one-component developer borne and transported by a developer bearing men, her to a developing area, comprising:

• an elastic base member;
• and
• a surface layer provided on said elastic base member and adapted to contact the developer bearing member for forming a nip therebetween, through which the one-component developer passes, said surface layer being adapted to frictionally charge the one-component developer to a predetermined polarity for developing an electrostatic latent image;
• wherein said surface layer contains a first substance chargeable to a polarity opposite to said predetermined polarity by friction with the one-component developer, and a second substance chargeable to a polarity the same as said predetermined polarity by friction with the one-component developer, and is charged, in total, to a polarity opposite to said predetermined polarity by friction with the one-component developer.

A defining member for limiting a thickness of a one-component developer borne and transported by a developer bearing member to a developing area, comprising:

• an elastic base member;
• and
• a surface layer provided on said elastic base member and adapted to contact the developer bearing member for forming a nip therebetween, through which the one-component developer passes, said surface layer being adapted to frictionally charge the one-component developer to a predetermined polarity for developing an electrostatic latent image;
• wherein said surface layer contains a first substance chargeable to a polarity opposite to said predetermined polarity by friction with the one-component developer, and a second substance serving as a solid lubricant, and is charged, in total, to a polarity opposite to said predetermined polarity by friction with the one-component developer.

A defining member for limiting a thickness of a one-component developer borne and transported by a developer bearing member to a developing area, comprising:

• an elastic base member;
• and
• a surface layer provided on said elastic base member and adapted to contact the developer bearing member for forming a nip therebetween, through which the one-component developer passes, said surface layer being adapted to frictionally charge the one-component developer to a predetermined polarity for developing an electrostatic latent image;
• wherein said surface layer contains a binder substance chargeable to a polarity opposite to said predetermined polarity by friction with the one-component developer, and substantially spherical particles dispersed in said binder substance, and is charged, in total, to a polarity opposite to said predetermined polarity by friction with the one-component developer.