IMAGE FORMING APPARATUS AND SEPARATING DEVICE

• US 20180059582A1
• Filed: 05/27/2016
• Published: 03/01/2018
• Est. Priority Date: 05/27/2015
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Nagata, Teppei, Tanaka, Akinori
• Granted Patent: US 10,310,419 B2
• Time in Patent Office: Days
• CPC Class Codes: G03G 15/0815 characterised by the developer handling means after the developing zone and before the supply, e.g. developer recovering roller
• CPC Class Codes: G03G 15/0844 Arrangements for purging used developer from the developing unit
• CPC Class Codes: G03G 15/0879 for dispensing developer from a developer cartridge not directly attached to the development unit
• CPC Class Codes: G03G 15/0887 Arrangements for conveying and conditioning developer in the developing unit, e.g. agitating, removing impurities or humidity
• CPC Class Codes: G03G 15/0896 Arrangements or disposition of the complete developer unit or parts thereof not provided for by groups G03G15/08 - G03G15/0894
• CPC Class Codes: G03G 15/10 using a liquid developer
• CPC Class Codes: G03G 15/104 Preparing, mixing, transporting or dispensing developer
• CPC Class Codes: G03G 15/105 Detection or control means for the toner concentration
• CPC Class Codes: G03G 15/11 Removing excess liquid developer, e.g. by heat
• CPC Class Codes: G03G 21/0005 for removing solid developer or debris from the electrographic recording medium
• CPC Class Codes: G03G 21/0023 with electric bias
• CPC Class Codes: G03G 21/0076 Plural or sequential cleaning devices
• CPC Class Codes: G03G 21/0082 Separate cleaning member for toner and debris
• CPC Class Codes: G03G 21/0088 removing liquid developer
• CPC Class Codes: G03G 21/10 Collecting or recycling waste developer
• CPC Class Codes: G03G 21/105 Arrangements for conveying toner waste
• CPC Class Codes: G03G 21/12 Toner waste containers
• CPC Class Codes: G03G 21/1676 for the developer unit
• CPC Class Codes: G03G 21/169 for the cleaning unit

Abstract

An image forming apparatus includes an image forming portion configured to form a toner image on a recording material with a liquid developer containing a toner and a carrier liquid, wherein the carrier liquid contains a first substance for imparting an electrical polarity to the toner and a second substance, higher in volume resistivity than the first substance, as a dispersion medium for dispersing the toner; and a carrier separating device configured to separate the carrier liquid into the first substance charged to an opposite polarity to a charge polarity of the toner and the second substance by applying an electric field to the liquid developer collected from the image forming portion so as to collect each of the first substance and the second substance.

Claims

1. An image forming apparatus comprising:

an image forming portion configured to form a toner image on a recording material with a liquid developer containing a toner and a carrier liquid,

wherein the carrier liquid contains a first substance for imparting an electrical polarity to the toner and a second substance, higher in volume resistivity than the first substance, as a dispersion medium for dispersing the toner; and

a carrier separating device configured to separate the carrier liquid into the first substance charged to an opposite polarity to a charge polarity of the toner and the second substance by applying an electric field to the liquid developer collected from said image forming portion so as to collect each of the first substance and the second substance.

2. An image forming apparatus according to claim 1, further comprising a toner separating device configured to separate the liquid developer into the toner and the collect containing at least the second substance by applying an electric field to the liquid developer collected from said image forming portion.

3. An image forming apparatus according to claim 2, wherein said carrier separating device is capable of supplying the collect from which the toner is separated by said toner separating device, and separates the collect, supplied from said toner separating device, into the first substance charged to the opposite polarity to the charge polarity of the toner and the second substance.

4. An image forming apparatus according to claim 1, wherein said carrier separating device comprises:

a rotatable electroconductive electrode roller;

an external electrode member, provided with a gap with part of said electrode roller, configured to form an electric field between itself and said electrode roller, wherein said external electrode member is capable of applying the electric field such that the first substance moves toward said electrode roller when the liquid developer passes through between said electrode roller and said external electrode member;

a supplying portion configured to supply the liquid developer, collected from said image forming portion, into the gap between said electrode roller and said external electrode member;

a collecting roller configured to collect the first substance from said electrode roller using an electric field, wherein said collecting roller is provided rotatably in contact with said electrode roller at a position downstream of said external electrode member and upstream of said supplying portion with respect to a rotational direction of said electrode roller; and

a collecting portion configured to collect the second substance from said electrode roller, wherein said collecting portion is provided at a position downstream of said external electrode member and upstream and said collecting roller with respect to the rotational direction of said electrode roller.

5. An image forming apparatus according to claim 4, wherein when a line passing through a center of said electrode roller and a top of said electrode roller with respect to a direction of gravitation is 0°

, an upstream end portion of external electrode member with respect to the rotational direction of said electrode roller is positioned in a range of 0°

or more and less than 180°

with respect to the rotational direction of said electrode roller, and

wherein a downstream end portion of said external electrode member with respect to the rotational direction of said electrode roller is positioned below the upstream end portion with respect to the direction of gravitation.

6. An image forming apparatus according to claim 1, further comprising a supplying device configured to supply the second substance, separated by said carrier separating device, to said image forming portion.

7. A separating device comprising:

a supplying portion configured to supply a liquid developer carrier tanking a toner, a first substance for imparting an electrical polarity to the toner and a second substance, higher in volume resistivity than the first substance, as a dispersion medium for dispersing the toner;

a separating portion configured to separate the liquid developer into the first substance charged to an opposite polarity to a charge polarity of the toner and the second substance by applying an electric field to the liquid developer supplied to said supplying portion; and

a collecting portion configured to collect each of the first substance and the second substance which are separated by said separating portion.

8. An image forming apparatus comprising:

a photosensitive member configured to form a latent image thereto;

a developing device configured to develop the latent image, formed on said photosensitive member, into a toner image using a liquid developer containing a toner and a collect;

a transfer device configured to transfer the toner image from said photosensitive member onto a recording material;

a collecting device configured to collect the liquid developer remaining on said photosensitive member,

wherein the carrier liquid contains a first substance for imparting an electrical polarity to the toner and a second substance, higher in volume resistivity than the first substance, as a dispersion medium for dispersing the toner; and

a separating device configured to separate the carrier liquid into the first substance charged to an opposite polarity to a charge polarity of the toner and the second substance by applying an electric field to the liquid developer collected from said collecting device so as to collect each of the first substance and the second substance,

wherein the second substance collected from said separating device is supplyable to said developing device.