# US 5,353,104 A · Defining member for defining thickness of one-component developer and developing device equipped with it > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,353,104 A - Document ID: US5353104A - Status: Granted - Kind: A - Application number: 08/018,715 - Filed: 1993-02-17 - Granted: 1994-10-04 - Earliest claimed: 1992-02-20 - Assignees: Canon Kabushiki Kaisha - Inventors: Junichi Kato; Masaharu Ohkubo; Masahiro Watabe; Noriyuki Yanai; Masaki Ojima; Hiroshi Sato - Web page: https://patentgrep.com/patent/US5353104A ## CPC - G03G 15/0812: {characterised by the developer regulating means, e.g. structure of doctor blade} - G03G 15/09: using magnetic brush - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract An elastic blade which is maintained in contact with the developing sleeve for defining the thickness of one-component developer to be transported by the developing sleeve to a developing area, is composed of an elastic base member, and a surface layer coated thereon and giving friction on the one-component developer, and the surface layer contains a substance chargeable frictionally to a polarity opposite to the triboelectric polarity of the one-component developer and another substance chargeable frictionally to a polarity the same as the triboelectric polarity of the one-component developer, and is charged frictionally, in total, to a polarity opposite to the polarity of the one-component developer. ## Claims ### Claim 1 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 charged 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 said one-component developer. ### Claim 2 (depends on 1) A developing device according to claim 1, wherein said elastic base member is composed of rubber, and said first and second substances are composed of substances other than rubber. ### Claim 3 (depends on 2) A developing device according to claim 2, wherein a thickness of said surface layer is smaller than that of the elastic base member. ### Claim 4 (depends on 3) A developing device according to claim 3, wherein the first substance of the surface layer is a binder, in which the second substance is dispersed as particles. ### Claim 5 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. ### Claim 6 (depends on 5) A developing device according to claim 5, wherein the first substance of the surface layer is a binder, in which the second substance is dispersed as particles. ### Claim 7 (depends on 6) A developing device according to claim 6, wherein the particles of the second substance are substantially spherical. ### Claim 8 (depends on 6, 7) A developing device according to claim 6 or 7, wherein said elastic base member is composed of rubber, and said first and second substances are composed of substances other than rubber. ### Claim 9 (depends on 8) A developing device according to claim 8, wherein a thickness of said surface layer is smaller than that of the elastic base member. ### Claim 10 (depends on 9) A developing device according to claim 9, wherein a sliding friction coefficient of said surface layer with respect to the developer bearing member is 3 or less. ### Claim 11 (depends on 10) A developing device according to claim 10, wherein said sliding friction coefficient is 1 or less. ### Claim 12 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. ### Claim 13 (depends on 12) A developing device according to claim 12, wherein said elastic base member is composed of rubber, and said binder substance and particles are composed of synthetic resins other than rubber. ### Claim 14 (depends on 12) A developing device according to claim 12, wherein a thickness of said surface layer is smaller than that of the elastic base member. ### Claim 15 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. ### Claim 16 (depends on 15) A defining member according to claim 15, wherein said elastic base member is composed of rubber, and said first and second substances are composed of materials other than rubber. ### Claim 17 (depends on 16) A defining member according to claim 16, wherein a thickness of the surface layer is smaller than that of the elastic base member. ### Claim 18 (depends on 17) A defining member according to claim 17, wherein the first substance of the surface layer is a binder, in which the second substance is dispersed as particles. ### Claim 19 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. ### Claim 20 (depends on 19) A defining member according to claim 19, wherein said first substance in the surface layer is a binder, in which said second substance is dispersed as particles. ### Claim 21 (depends on 20) A defining member according to claim 20, wherein the particles of said second substance are substantially spherical. ### Claim 22 (depends on 20, 21) A defining member according to claim 20 or 21, wherein said elastic base member is composed of rubber, and said first and second substances are composed of materials other than rubber. ### Claim 23 (depends on 22) A defining member according to claim 22, wherein a sliding friction coefficient of said surface layer to the developer bearing member is 3 or less. ### Claim 24 (depends on 23) A defining member according to claim 23, wherein said sliding friction coefficient is 1 or less. ### Claim 25 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. ### Claim 26 (depends on 25) A defining member according to claim 25, wherein said elastic base member is composed of rubber, and said binder substance and said particles are composed of materials other than rubber. ### Claim 27 (depends on 26) A defining member according to claim 26, wherein a thickness of said surface layer is smaller than that of the elastic base member.