Image forming apparatus

• US 20050058475A1
• Filed: 07/28/2004
• Published: 03/17/2005
• Est. Priority Date: 07/30/2003
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Tsurusaki, Teruaki
• Granted Patent: US 7,127,207 B2
• Time in Patent Office: Days
• US Class Current: 399/358
• CPC Class Codes: G03G 21/105 Arrangements for conveying toner waste

Abstract

The invention provides an image forming apparatus, in which carrying tubes for carrying the toner discharged from image forming portion are mutually connected, capable of stable operation with satisfactory toner carrying at the connecting portion and not causing toner clogging. There is preferably provided an image forming apparatus of a low cost, capable of smooth toner carrying even in case one of toner carrying directions is an upward carrying. There is provided an image forming apparatus in which toner is carried by plural carrying tubes incorporating toner carrying screws, in which an aperture is formed on a lateral face of the carrying tube, and, an aperture of an upstream carrying tube and an aperture of a downstream carrying tube are mutually opposed to connect plural carrying tubes, wherein, in case an angle formed by a toner carrying direction of the downstream carrying tube and a gravitationally downward direction is larger than that in the upstream carrying tube, a carrying amount per unit time of the carrying screw of the downstream carrying tube is made larger than that in the upstream carrying tube.

Claims

1. An image forming apparatus comprising:

image forming means;

a first carrying tube for carrying toner discharged from said image forming means toward a recovery portion;

first carrying means contained in said first carrying tube and for carrying the toner toward said recovery portion;

a second carrying tube connected to an aperture of said first carrying tube and for carrying the toner carried from said first carrying tube; and

second carrying means contained in said second carrying tube and for carrying the toner toward said recovery portion,

wherein, in case an angle formed by a toner carrying direction of said second carrying tube and a gravitationally downward direction is larger than an angle formed by a toner carrying direction of said first carrying tube and a gravitationally downward direction, a carrying ability of said second carrying means is made larger than a carrying ability of said first carrying means.

2. An image forming apparatus according to claim 1, wherein said second carrying tube has an introducing aperture for introduction from said first carrying tube and a discharging aperture for toner discharge toward said recovery portion, and executes an upward carrying in which said discharging aperture is positioned higher than said introducing aperture.

3. An image forming apparatus according to claim 1, wherein the carrying ability of said carrying means is changed by a change in a rotation speed of said carrying means.

4. An image forming apparatus according to claim 1, wherein said aperture is provided on a wall of said first carrying tube parallel to the carrying direction thereof, and is connected so as to be opposed to a second aperture provided on a wall of said second carrying tube parallel to the carrying direction thereof, said first carrying tube and said second carrying tube are mutually connected so as to transfer the toner in a substantially horizontal direction, and a carrying power of said first carrying means in the vicinity of said aperture is smaller than at an upstream side of said aperture.

5. An image forming apparatus according to claim 4, wherein said carrying means is a carrying member having a spiral portion, and a change in the carrying power includes a change in a pitch or a carrying direction of said spiral portion.

6. An image forming apparatus according to claim 1, wherein said aperture is provided in an end portion of said first carrying tube, and said first carrying means loses a carrying power within a range opposed to said aperture.

7. An image forming apparatus according to claim 1, wherein said first carrying means is a carrying member having a spiral portion, said first and second carrying tubes have carrying directions which substantially perpendicularly intersect with each other at said aperture, and said spiral portion rotates, at the side of said aperture, in a forward direction to the carrying direction of said second carrying tube.

8. An image forming apparatus comprising:

image forming means;

a first carrying tube for carrying toner discharged from said image forming means toward a recovery portion;

first carrying means contained in said first carrying tube and for carrying the toner toward said recovery portion;

a second carrying tube for carrying the toner carried from said first carrying tube; and

second carrying means contained in said second carrying tube and for carrying the toner toward said recovery portion,

wherein said first and second carrying tubes respectively have apertures on walls parallel to carrying directions, are connected with each other in such a manner that the apertures are mutually opposed, and are mutually connected so as to transfer the toner from said first carrying tube to said second carrying tube in a substantially horizontal direction, and

said first carrying means has a carrying power smaller in the vicinity of said aperture than in an upstream side of said aperture.

9. An image forming apparatus comprising:

image forming means;

a first carrying tube for carrying toner discharged from said image forming means toward a recovery portion;

first carrying means contained in said first carrying tube and for carrying the toner toward said recovery portion, said first carrying means including a rotary member having a spiral portion;

a second carrying tube for carrying the toner carried from said first carrying tube; and

second carrying means contained in said second carrying tube and for carrying the toner toward said recovery portion,

wherein said first and second carrying tubes respectively have apertures on walls parallel to carrying directions, are connected with each other in such a manner that the apertures are mutually opposed, are mutually connected so as to transfer the toner from said first carrying tube to said second carrying tube in a substantially horizontal direction, and have carrying directions substantially perpendicularly intersecting with each other at said aperture, and wherein said spiral portion rotates, at the side of said aperture, in a forward direction to the carrying direction of said second carrying tube.