Developing roller for electrophotography, developing apparatus, apparatus unit and image forming apparatus

A developing apparatus comprising:

• a toner hopper for containing therein a non-magnetic, one-component toner for developing an electrostatic latent image formed on a surface of an image bearing member;
• and
• a developing roller for transporting the non-magnetic, one-component toner from said toner hopper, while causing the toner to adhere to a surface of said developing roller,
• wherein said developing roller includes:
• a conductive mandrel;
• a charge-providing layer having a charge-providing performance to the toner, formed at said surface of said developing roller;
• a base layer having an elasticity, formed at a position nearer to a position of said mandrel than a position of said charge-providing layer;
• and
• an elastic intermediate layer formed at a position between positions of said base layer and said charge-providing layer,
• wherein a contact angle to water of said intermediate layer is smaller than a contact angle to water of said base layer.

An apparatus unit detachably mountable to the main body of an image-forming apparatus, comprising:

• a toner hopper for containing therein a non-magnetic, one-component toner for developing an electrostatic latent image formed on a surface of an image bearing member;
• and
• a developing roller for transporting the non-magnetic, one-component toner contained in said toner hopper, while causing the toner to adhere to a surface of said developing roller,
• wherein said developing roller includes:
• a conductive mandrel;
• a charge-providing layer having a charge-providing performance to the toner, formed at said surface of said developing roller;
• a base layer having an elasticity, formed at a position nearer to a position of said mandrel than a position of said charge-providing layer;
• and
• an elastic intermediate layer formed at a position between positions of said base layer and said charge-providing layer,
• wherein a contact angle to water of said intermediate layer is smaller than a contact angle to water of said base layer.

An image-forming apparatus comprising:

• an image bearing member for bearing thereon an electrostatic latent image;
• a charging assembly for primarily charging said image bearing member;
• an exposure assembly for forming the electrostatic latent image on a surface of said image bearing member having been primarily charged;
• a plurality of developing apparatuses, each for developing the electrostatic latent image by the use of a non-magnetic toner to form a toner image;
• an intermediate transfer member for sequentially transferring thereto the toner image formed by each of said plurality of developing apparatuses to form a multiple toner image;
• and
• a transfer assembly for transferring to a transfer medium at one time the multiple toner image transferred to said intermediate transfer member,
• wherein each of said plurality of developing apparatuses includes:
• a toner hopper for containing therein a non-magnetic, one-component toner for developing the electrostatic latent image formed on said surface of said image bearing member;
• and
• a developing roller for transporting the non-magnetic, one-component toner contained in said toner hopper, while causing the toner to adhere to a surface of said developing roller,
• wherein said developing roller includes:
• a conductive mandrel;
• a charge-providing layer having a charge-providing performance to the toner, formed on said surface of said developing roller;
• a base layer having an elasticity, formed at a position nearer to a position of said mandrel than a position of said charge-providing layer;
• and
• an elastic intermediate layer formed at a position between the positions of said base layer and said charge-providing layer,
• wherein a contact angle to water of said intermediate layer is smaller than a contact angle to water of said base layer.

An image-forming apparatus comprising:

• an image bearing member for bearing thereon an electrostatic latent image;
• a charging assembly for primarily charging said image bearing member;
• an exposure assembly for forming the electrostatic latent image on a surface of said image bearing member having been primarily charged;
• a plurality of developing apparatuses, each for developing the electrostatic latent image by the use of a non-magnetic toner to form a toner image;
• and
• a transfer assembly for sequentially transferring to a transfer medium the toner image formed by each of said plurality of developing apparatuses,
• wherein each of said plurality of developing apparatuses includes:
• a toner hopper for containing therein a non-magnetic, one-component toner for developing the electrostatic latent image formed on said surface of said image bearing member;
• and
• a developing roller for transporting the non-magnetic, one-component toner contained in said toner hopper, while causing the toner to adhere to a surface of said developing roller,
• wherein said developing roller includes:
• a conductive mandrel;
• a charge-providing layer having a charge-providing performance to the toner, formed on said surface of said developing roller;
• a base layer having an elasticity, formed at a position nearer to a position of said mandrel than a position of said charge-providing layer;
• and
• an elastic intermediate layer formed at a position between the positions of said base layer and said charge-providing layer,
• wherein a contact angle to water of said intermediate layer is smaller than a contact angle to water of said base layer.

The image-forming apparatus comprising

• a plurality of image-forming units each including;
• an image bearing member for bearing thereon an electrostatic latent image;
• a charging assembly for primarily charging the image bearing member;
• an exposure assembly for forming the electrostatic latent image on a surface of said image bearing member having been primarily charged;
• and
• a plurality of developing apparatuses, each for developing the electrostatic latent image by the use of a non-magnetic toner to form a toner image,
• wherein each of said plurality of developing apparatuses includes:
• a toner hopper for containing therein a non-magnetic, one-component toner for developing an electrostatic latent image formed on said surface of said image bearing member;
• and
• a developing roller for transporting the non-magnetic, one-component toner contained in said toner hopper, while causing the toner to adhere to a surface of said developing roller,
• wherein said developing roller includes:
• a conductive mandrel;
• a charge-providing layer having a charge-providing performance to the toner, formed on said surface of said developing roller;
• a base layer having an elasticity, formed at a position nearer to a position of said mandrel than a position of said charge-providing layer;
• and
• an elastic intermediate layer formed at a position between the positions of said base layer and said charge-providing layer,
• wherein a contact angle to water of said intermediate layer is smaller than a contact angle to water of said base layer;
• and
• a transfer assembly for sequentially transferring to a transfer medium the toner images formed by the plurality of the image-forming units.