Back to results
US 2026/0177946 A1Published application
Developing apparatus
AssigneeCanon Kabushiki Kaisha
InventorTomonori Yuyama
Life of this patent
Estimating the term…
Abstract
In a state where an edge of a second duct wall on the suction port side is referred to as a point P, a point on an outer peripheral surface of a first rotatable member closest to the second duct wall is referred to as a point U, a point where a straight line passing the point P and a rotation center O of the first rotatable member intersects the outer peripheral surface of the first rotatable member is referred to as a point Q, and a sign of the Fθ is positive in a state where a direction of the Fθ is a same direction as the rotational direction of the first rotatable member, Fθ<0 is satisfied across a range from the point Q to the point U with respect to the rotational direction of the first rotatable member.
Claims20
A developing apparatus comprising:
- a developing container including a first chamber configured to contain a developer including a toner and a carrier, and a second chamber partitioned from the first chamber by a partition wall;
- a first rotatable member to which the developer is supplied, the first rotatable member being configured to carry and feed the developer to a developing position where an electrostatic latent image formed on an image bearing member is developed;
- a first magnet provided non-rotatably and stationarily inside the first rotatable member, the first magnet having a first magnetic pole provided to face the image bearing member at the developing position, a second magnetic pole provided downstream of the first magnetic pole and adjacent to the first magnetic pole, with respect to a rotational direction of the first rotatable member and having a different magnetic polarity as that of the first magnetic pole, a third magnetic pole provided downstream of the second magnetic pole and adjacent to the second magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the second magnetic pole, a fourth magnetic pole provided downstream of the third magnetic pole and adjacent to the third magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the third magnetic pole, and a fifth magnetic pole provided downstream of the fourth magnetic pole and adjacent to the fourth magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the fourth magnetic pole;
- a second rotatable member disposed to face the first rotatable member and configured to receive the developer delivered from the first rotatable member by a magnetic field generated by the first magnet, the second rotatable member being configured to carry and feed the developer after developing the electrostatic latent image to collect the developer in the second chamber;
- a second magnet provided non-rotatably and stationarily inside the second rotatable member, the second magnet having a sixth magnetic pole having a different magnetic polarity as that of the fifth magnetic pole, wherein the developer after developing the electrostatic latent image is delivered from the first rotatable member to the second rotatable member by a magnetic field generated between the fifth magnetic pole and the sixth magnetic pole;
- and
- a duct portion including a suction port and configured to extend downstream in the rotational direction of the first rotatable member from the suction port, the duct portion including a first duct wall disposed to face the second rotatable member, and a second duct wall disposed to face the first rotatable member, and also disposed to face the first duct wall and configured to form a space between the first duct wall through which air sucked in through the suction port flows, the second duct wall being positioned on an outer side than the first duct wall with respect to a rotation center of the second rotatable member in a radial direction of the second rotatable member,
- wherein,
- in a state where an edge of the second duct wall on the suction port side, which is an end point on the first rotatable member side, is referred to as a point P,
- a point on an outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is a maximum value is referred to as a point T,
- a point on an outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is a maximum value is referred to as a point R,
- a point on an outer peripheral surface of the first rotatable member closest to the second duct wall is referred to as a point U, and
- a point where a straight line passing the point P and a rotation center O of the first rotatable member intersects the outer peripheral surface of the first rotatable member is referred to as a point Q,
- the point Q is positioned downstream of the point T and upstream of the point R with respect to the rotational direction of the first rotatable member,
- the point U is positioned downstream of the point Q and upstream of the point R with respect to the rotational direction of the first rotatable member, and
- wherein,
- in a state where a magnetic force in a tangential direction with respect to the outer peripheral surface of the first rotatable member among the magnetic force acting on a carrier on the outer peripheral surface of the first rotatable member is referred to as Fθ,
- a sign of the Fθ is positive in a state where a direction of the Fθ is a same direction as the rotational direction of the first rotatable member, and
- a sign of the Fθ is negative in a state where a direction of the Fθ is an opposite direction as the rotational direction of the first rotatable member,
- Fθ<0 is satisfied across a range from the point Q to the point U with respect to the rotational direction of the first rotatable member.
17 more elements
A developing apparatus comprising:
- a developing container including a first chamber configured to contain a developer including a toner and a carrier, and a second chamber partitioned from the first chamber by a partition wall;
- a first rotatable member to which the developer is supplied, the first rotatable member being configured to carry and feed the developer to a developing position where an electrostatic latent image formed on an image bearing member is developed;
- a first magnet provided non-rotatably and stationarily inside the first rotatable member, the first magnet having a first magnetic pole provided to face the image bearing member at the developing position, a second magnetic pole provided downstream of the first magnetic pole and adjacent to the first magnetic pole with respect to a rotational direction of the first rotatable member and having a different magnetic polarity as that of the first magnetic pole, a third magnetic pole provided downstream of the second magnetic pole and adjacent to the second magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the second magnetic pole, a fourth magnetic pole provided downstream of the third magnetic pole and adjacent to the third magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the third magnetic pole, and a fifth magnetic pole provided downstream of the fourth magnetic pole and adjacent to the fourth magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the fourth magnetic pole;
- a second rotatable member disposed to face the first rotatable member and configured to receive the developer delivered from the first rotatable member by a magnetic field generated by the first magnet, the second rotatable member being configured to carry and feed the developer after developing the electrostatic latent image to collect the developer in the second chamber;
- a second magnet provided non-rotatably and stationarily inside the second rotatable member, the second magnet having a sixth magnetic pole having a different magnetic polarity as that of the fifth magnetic pole, wherein the developer after developing the electrostatic latent image is delivered from the first rotatable member to the second rotatable member by a magnetic field generated between the fifth magnetic pole and the sixth magnetic pole;
- and
- a duct portion including a suction port and configured to extend downstream in the rotational direction of the first rotatable member from the suction port, the duct portion including a first duct wall disposed to face the second rotatable member, and a second duct wall disposed to face the first rotatable member, and also disposed to face the first duct wall and configured to form a space between the first duct wall through which air sucked in through the suction port flows, the second duct wall being positioned on an outer side than the first duct wall with respect to a rotation center of the second rotatable member in a radial direction of the second rotatable member,
- wherein,
- in a state where an edge of the second duct wall on the suction port side, which is an end point on the first rotatable member side, is referred to as a point P,
- a point on an outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is a maximum value is referred to as a point T,
- a point on an outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is a maximum value is referred to as a point R, and
- a point where a straight line passing the point P and a rotation center O of the first rotatable member intersects the outer peripheral surface of the first rotatable member is referred to as a point Q,
- the point Q is positioned downstream of the point T and upstream of the point R with respect to the rotational direction of the first rotatable member, and
- wherein
- an absolute value of maximum value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is 1.2 times or more than an absolute value of maximum value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member.
12 more elements
A developing apparatus comprising:
- a developing container including a first chamber configured to contain a developer including a toner and a carrier, and a second chamber partitioned from the first chamber by a partition wall;
- a first rotatable member to which the developer is supplied, the first rotatable member being configured to carry and feed the developer to a developing position where an electrostatic latent image formed on an image bearing member is developed;
- a first magnet provided non-rotatably and stationarily inside the first rotatable member, the first magnet having a first magnetic pole provided to face the image bearing member at the developing position, a second magnetic pole provided downstream of the first magnetic pole and adjacent to the first magnetic pole, with respect to a rotational direction of the first rotatable member and having a different magnetic polarity as that of the first magnetic pole, a third magnetic pole provided downstream of the second magnetic pole and adjacent to the second magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the second magnetic pole, a fourth magnetic pole provided downstream of the third magnetic pole and adjacent to the third magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the third magnetic pole, and a fifth magnetic pole provided downstream of the fourth magnetic pole and adjacent to the fourth magnetic pole, with respect to the rotational direction of the first rotatable member, and having a different magnetic polarity as that of the fourth magnetic pole;
- a second rotatable member disposed to face the first rotatable member and configured to receive the developer delivered from the first rotatable member by a magnetic field generated by the first magnet, the second rotatable member being configured to carry and feed the developer after developing the electrostatic latent image to collect the developer in the second chamber;
- a second magnet provided non-rotatably and stationarily inside the second rotatable member, the second magnet having a sixth magnetic pole having a different magnetic polarity as that of the fifth magnetic pole, wherein the developer after developing the electrostatic latent image is delivered from the first rotatable member to the second rotatable member by a magnetic field generated between the fifth magnetic pole and the sixth magnetic pole;
- and
- a duct portion including a suction port and configured to extend downstream in the rotational direction of the first rotatable member from the suction port, the duct portion including a first duct wall disposed to face the second rotatable member, and a second duct wall disposed to face the first rotatable member, and also disposed to face the first duct wall and configured to form a space between the first duct wall through which air sucked in through the suction port flows, the second duct wall being positioned on an outer side than the first duct wall with respect to a rotation center of the second rotatable member in a radial direction of the second rotatable member,
- wherein,
- in a state where an edge of the second duct wall on the suction port side, which is an end point on the first rotatable member side, is referred to as a point P,
- a point on an outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is a maximum value is referred to as a point T,
- a point on an outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is a maximum value is referred to as a point R, and
- a point where a straight line passing the point P and a rotation center O of the first rotatable member intersects the outer peripheral surface of the first rotatable member is referred to as a point Q,
- the point Q is positioned downstream of the point T and upstream of the point R with respect to the rotational direction of the first rotatable member, and
- wherein
- in a state where a half-value width of a magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is half the value of an absolute value of maximum value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is referred to as BH1, and
- in a state where a half-value width of a magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member where an absolute value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is half the value of an absolute value of maximum value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is referred to as BH2,
- a difference between BH1 and BH2 is within a range of ±1°, and
- an absolute value of maximum value of magnetic flux density of the third magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member is equal to or greater than an absolute value of maximum value of magnetic flux density of the fourth magnetic pole in a normal direction with respect to the outer peripheral surface of the first rotatable member.
15 more elements
Dependencies are inferred from the claim text.