Transferring device and image forming apparatus equipped with mult-mode cleaning arrangement

• US 6,311,031 B1
• Filed: 02/22/2000
• Issued: 10/30/2001
• Est. Priority Date: 03/24/1999
• Status: Expired due to Fees

• Current Assignee: Toshiba Tec Corporation (Toshiba Corporation)
• Original Assignee: Toshiba Tec Corporation (Toshiba Corporation)
• Inventors: Hirano, Kouji
• Primary Examiner(s): BRASE, SANDRA L
• Application Number:
  US09/507,901
• Time in Patent Office: 616 Days
• Field of Search: 399/98, 399/99, 399/101, 399/55, 399/66, 399/297, 399/310, 399/312, 399/314, 399/316, 399/345, 399/349
• US Class Current: 399/101
• CPC Class Codes: G03G 15/168 with means for conditioning the transfer element, e.g. cleaning
• CPC Class Codes: G03G 2215/1661 of transfer belt

Abstract

A transferring device of the present invention includes a transferring belt configured to electrostatically adsorb an image receiving medium and convey the image receiving medium in one direction, a transferring device for transferring a toner image on a photosensitive body onto the image receiving medium adsorbed electrostatically to the transferring belt, a cleaning blade arranged so as to be able to contact/separate with/from the transferring belt and clean toner on the transferring belt when brought in contact with the transferring belt, and a cleaning brush arranged so as ato be able to contact/separate with/from the transferring belt at the downstream side in the conveying direction lower than the cleaning blade and clean the toner on the transferring belt when brought in contact with the transferring belt. The transferring device further includes a control unit to control a switching between a first mode to bring the cleaning blade contact with the transferring belt at the time of starting to use and a second mode to separate the cleaning blade from the transferring belt and bring a cleaning brush in contact with the transferring belt when the running distance of the transferring belt reaches a prescribed value.

Claims

1. A transferring device comprising:

transferring means for transferring a toner image on a photosensitive body onto an image receiving medium adsorbed electrostatically to a transferring belt and conveyed by the transferring belt;

a first cleaning means which is selectively contactable with the transferring belt for cleaning toner from the transferring belt when brought in contact with the transferring belt;

a second cleaning means which is selectively contactable with the transferring belt for cleaning toner from the transferring belt when brought in contact with the transferring belt, said second cleaning means being selectively contactable with the transferring belt at a position which is downstream, with respect to the direction of movement of the transferring belt, of a position at which the first cleaning means is brought in contact with the transferring belt;

first control means for controlling a switching of the first and second cleaning means between;

a first mode wherein the first cleaning means is brought into contact with the transferring belt at an initial stage of use wherein the running distance of the transferring belt is less than a prescribed value, and

a second mode wherein, when the running distance of the transferring belt reaches the prescribed value, the first cleaning means is separated from the transferring belt and the second cleaning means is brought into contact with the transferring belt; and

second control means for temporarily inducing both the first and second modes and temporarily causing the first and second cleaning means to both contact the transferring belt when a humidity of a transferring device operating environment exceeds a prescribed humidity or when the conveyance of image receiving medium becomes defective.

2. A transferring device as claimed in claim 1, wherein the first cleaning means includes a blade and the second cleaning means includes a brush.

3. A transferring device as claimed in claim 1, further comprising:

transferring bias applying means for always applying a prescribed transferring bias to the transferring belt in the first mode when the toner image is continuously transferred onto a plurality of image receiving media and applying the prescribed transferring bias to the transferring belt at a timing when the image receiving media pass through the transferring position in the second mode.

4. An image forming apparatus comprising:

developing means for supplying toner and developing an electrostatic latent image formed on a photosensitive body;

a transferring belt configured to electrostatically adsorb an image receiving medium and convey the image receiving medium in one direction;

transferring means for transferring a toner image on the photosensitive body developed by the developing means, onto the image receiving medium electrostatically adsorbed to the transferring belt;

a cleaning blade arranged to clean toner from the transferring belt when selectively brought in contact with the transferring belt;

a cleaning brush selectively contactable with the transferring belt at a position downstream, with respect to the direction of movement of the transferring belt, of the position at which the cleaning blade is contactable with the transferring belt;

first control means for controlling a switching between;

a first mode wherein the cleaning blade is brought into contact with the transferring belt at an initial stage wherein the running distance of the transferring belt is below a prescribed value, and

a second mode wherein the cleaning blade is separated from the transferring belt and the cleaning brush is brought into contact with the transferring belt when the running distance of the transferring belt reaches the prescribed value; and

second control means for temporarily inducing the cleaning blade and the cleaning brush to both contact the transferring belt when a humidity of an operating environment about the image forming apparatus exceeds a prescribed humidity or the conveyance of image receiving medium becomes defective.

5. An image forming apparatus comprising:

developing means for supplying toner and developing an electrostatic latent image formed on a photosensitive body;

a transferring belt configured to electrostatically adsorb an image receiving medium and convey the image receiving medium in one direction;

transferring means for transferring a toner image on the photosensitive body developed by the developing means onto the image receiving medium electrostatically adsorbed to the transferring belt;

a cleaning blade arranged to selectively contact the transferring belt and clean toner therefrom;

a cleaning brush arranged so selectively contact the transferring belt at a location downstream with respect to the conveying direction of the transferring belt of the position at which the cleaning blade contacts the transferring belt;

first control means for controlling a switching of the first and second cleaning means between;

a first mode wherein the first cleaning means is brought into contact with the transferring belt at an initial stage of use wherein the running distance of the transferring belt is less than a prescribed value, and

a second mode wherein, when the running distance of the transferring belt reaches the prescribed value, the first cleaning means is separated from the transferring belt and the second cleaning means is brought into contact with the transferring belt; and

developing bias applying means for applying a prescribed developing bias;

corresponding to the running distance of the transferring belt to the developing means at a timing not to form the toner image and supplying a prescribed amount of the toner onto the transferring belt in the first mode and for suspending the supply of the toner onto the transferring belt without applying the prescribed developing bias to the developing means at a timing not to form the toner image in the second mode.

6. A transferring device comprising:

a transferring belt configured to electrostatically adsorb an image receiving medium and convey the mage receiving medium in one direction;

transferring means for transferring a toner image on a photosensitive body onto the image receiver medium adsorbed electrostatically to the transferring belt at a transferring position;

a cleaning blade arranged so as to be able to contact/separate with/from the transferring belt and clean toner on the transferring belt when brought in contact with the transferring belt;

a cleaning brush arranged so as to be able to contact/separate with/from the transferring belt at the downstream side in the conveying direction and clean the toner on the transferring belt when brought in contact with the transferring belt lower than the cleaning blade;

first control means for controlling a switching the first and second cleaning means between;

a first mode wherein the first cleaning means is brought into contact with the transferring belt at an initial stage of use wherein the running distance of the transferring belt is less than a prescribed value, and

a second mode wherein, when the running distance of the transferring belt reaches the prescribed value, the first cleaning means is separated from the transferring belt and the second cleaning means is brought into contact with the transferring belt; and

second control means for temporarily inducing both the first and second modes and causing the first and second cleaning means to both contact the transferring belt when a humidity of an operating environment exceeds a prescribed humidity or when the conveyance of image receiving medium becomes defective.

7. A transferring device as claimed in claim 6, further comprising:

transferring bias applying means for always applying a prescribed transferring bias to the transferring belt in the first mode when the toner image is continuously transferring onto a plurality of image receiving media and applying the prescribed transferring bias to the transferring belt at a timing when the image receiving media pass through the transferring position in the second mode.

8. A transferring device comprising:

a transferring belt configured to electrostatically adsorb an image receiving medium and convey the image receiving medium in one direction;

transferring means for transferring a toner image on a photosensitive body onto the image receiving medium adsorbed electrostatically to the transferring belt at a transferring position;

a cleaning blade arranged so as to be able to contact/separate with/from the transferring belt and clean toner on the transferring belt when brought in contact with the transferring belt at an upstream position with regard to the moving of the transferring belt;

a cleaning brush arranged so as to be able to contact/separate with/from the transferring belt at a downstream position lower than the cleaning blade to clean the toner on the transferring belt when brought in contact with the transferring belt;

cleaning bias applying means for applying a prescribed cleaning bias to the cleaning brush; and

control means for controlling a switching between a first mode to bring the cleaning blade in contact with the transferring belt at an initial stage of belt use wherein the running distance of the transferring belt is less than a prescribed value, and a second mode to separate the cleaning blade from the transferring belt and bring the cleaning brush in contact with the transferring belt when the running distance of the transferring belt reaches the prescribed value.

9. A transferring device as claimed in claim 8, further comprising:

second control means for controlling in the second mode so as to use the first mode jointly temporarily with the second mode when a using environment exceed a prescribed humidity or the conveyance of image receiving medium becomes defective.