Developing device

Patent metadata

Field	Value
Publication number	US-11815828-B2
Application number	US-202117551403-A
Country	US
Kind code	B2
Filing date	Dec 15, 2021
Priority date	Jan 25, 2021
Publication date	Nov 14, 2023
Grant date	Nov 14, 2023

Abstract

A developing device includes a developer carrying member configured to carry a developer, containing toner and a carrier, for developing an electrostatic latent image formed on an image bearing member, a developer container configured to accommodate the developer, and an oscillation circuit including a resonance circuit including a coil and a circuit portion containing a capacitor and configured to oscillate a signal for detecting a toner concentration of the developer accommodated in the developer container. The coil is formed integrally with the developer container by a metal film, and the coil is disposed on an inner wall surface of the developer container.

First claim

What is claimed is:

1. A developing device comprising:
a developer carrying member configured to carry a developer, containing toner and a carrier, for developing an electrostatic latent image formed on an image bearing member;
a developer container configured to accommodate the developer; and
an oscillation circuit including a resonance circuit including a coil and a circuit portion containing a capacitor and configured to oscillate a signal for detecting a toner concentration of the developer accommodated in said developer container,
wherein said developer container includes an inner wall surface which is a wall surface on a side where the developer is accommodated and an outer wall surface which is a wall surface on a side where the developer is not accommodated, and
wherein said coil is formed integrally with said developer container by a metal film, and said coil is disposed on said inner wall surface of said developer container.

2. A developing device according to claim 1 , wherein said circuit portion is disposed on said outer wall surface of said developer container.

3. A developing device according to claim 2 , wherein said coil and said circuit portion are connected to each other via a through hole penetrating said inner wall surface of said developer container and said outer wall surface of said developer container.

4. A developing device according to claim 3 , wherein the through hole is closed with a sealing member.

5. A developing device according to claim 2 , wherein said circuit portion is formed integrally with said developer container by a metal film.

6. A developing device according to claim 1 , wherein said circuit portion is disposed on said inner wall surface of said developer container.

7. A developing device according to claim 6 , wherein said circuit portion is disposed on a side wall portion of said inner wall surface of said developer container.

8. A developing device according to claim 6 , further comprising a feeding member configured to feed the developer accommodated in said developer container,
wherein said circuit portion is provided downstream of said coil with respect to a developer feeding direction of said feeding member.

9. A developing device according to claim 8 , wherein said circuit portion is disposed on a side wall portion of said inner wall surface of said developer container.

10. A developing device according to claim 6 , wherein said circuit portion is formed integrally with said developer container by a metal film.

11. A developing device according to claim 1 , further comprising an insulating member configured to insulate said coil and the developer accommodated in said developer container,
wherein a surface of said coil is coated with said insulating member.

12. A developing device according to claim 11 , wherein a surface resistance value of said insulating member is 500Ω or more.

13. A developing device according to claim 1 , wherein said circuit portion is formed integrally with said developer container by a metal film.

Assignees

• Canon Kk

Inventors

• Sobue Fumitaka
• Ino Koichiro
• Hata Yosuke
• Moriya Masaaki
• Negishi Norio

Classifications

• G03G15/0853 Primary

  the concentration being measured by magnetic means · CPC title

• G03G15/0889

  for agitation or stirring · CPC title

• G03G15/086

  the level being measured by electro-magnetic means · CPC title

• G03G15/0851 Primary

  the concentration being measured by electrical means · CPC title