Image forming apparatus

Abstract

Provided is an image forming apparatus jointly using both a heat fixing method and a wet fixing method wherein bleeding and aggregation of a toner, curl and creases of a recording medium, and the like do not occur when a fixing fluid is applied to a toner image. Power consumption is significantly lower than that of a past heat fixing method. A high-quality image is stably formed. The image forming apparatus includes a toner image forming section, an intermediate transfer section, a secondary transfer section, a fixing fluid applying section, a fixing section having a driving roller in which a heating section is built, and a conveying section. There is provided a fixing fluid amount controlling section which controls a fixing fluid amount applied to a toner image on a recording medium by the fixing fluid applying section so as to increase as the recording medium approaches the fixing section.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Other and further objects, features, and advantages of the invention will be more explicit from the following detailed description taken with reference to the drawings wherein:

FIG. 1 is a sectional view schematically illustrating an image forming apparatus according to a first embodiment of the invention;

FIG. 2 is an enlarged sectional view illustrating a essential portion of the image forming apparatus shown in FIG. 1;

FIG. 3 is an enlarged sectional view illustrating essential portions of the image forming apparatus showing in FIG. 1;

FIG. 4 is a schematic block diagram schematically illustrating a configuration of the fixing fluid amount controlling section in the embodiment of the invention;

FIG. 5 is a block diagram schematically illustrating a configuration of a droplet ejection control of the fixing fluid by the fixing fluid amount controlling section shown in FIG. 4;

FIG. 6 is a circuit diagram schematically illustrating a configuration of a droplet ejection system for an ink jet head;

FIG. 7 is a flowchart illustrating control operation by the fixing fluid amount controlling section;

FIG. 8 is a plan view illustrating an ejection state of the fixing fluid to the recording medium;

FIG. 9 is a sectional view schematically illustrating a configuration of essential portions of an image forming apparatus according to a second embodiment of the invention; and

FIG. 10 is a sectional view schematically illustrating a configuration of essential portions of an image forming apparatus according to a third embodiment of the invention.

Claims

1. An image forming apparatus comprising: a toner image forming section which forms a toner image according to image information;a transfer section which transfers the toner image on a recording medium formed by the toner image forming section;a fixing section which fixes the toner image transferred on the recording medium by the transfer section;a conveying section which conveys the recording medium on which the toner image is transferred from the transfer section to the fixing section;a fixing fluid applying section which is placed between the transfer section and the fixing section and applies to the toner image on the recording medium a fixing fluid which softens and/or swells a toner, after the toner image is transferred on the recording medium by the transfer section, which recording medium is conveyed to the fixing section by the conveying section; anda fixing fluid amount controlling section which controls an amount of the fixing fluid applied to the toner image on the recording medium by the fixing fluid applying section so as to increase as the recording medium approaches the fixing section.

2. The image forming apparatus of claim 1, wherein the fixing fluid applying section includes: a fixing fluid reservoir which stores the fixing fluid therein;a droplet supplying section having fixing fluid spray nozzles from which the fixing fluid is supplied to the toner image on the recording medium; anda supply tube through which the fixing fluid in the fixing fluid reservoir is supplied to the droplet supplying section.

3. The image forming apparatus of claim 2, wherein a spray nozzle pitch is lower than an image resolution of the toner image forming section.

4. The image forming apparatus of claim 3, wherein the spray nozzle pitch is 150 dpi or less.

5. The image forming apparatus of claim 1, wherein the fixing fluid amount controlling section controls the amount of the fixing fluid applied from the fixing fluid applying section to the toner image on the recording medium according to the image information.

6. The image forming apparatus of claim 1, further comprising: a heating section for heating the recording medium on which the toner image is transferred, the heating section being provided upstream of a position of applying the fixing fluid to the toner image on the recording medium by the fixing fluid applying section in a direction of conveying the recording medium on which the toner image is transferred by the conveying section.

7. The image forming apparatus of claim 1, wherein the fixing section includes: a driving roller;a pressing roller;a conveyer belt tightly suspended by the driving roller and the pressing roller and which is formed in a loop shape, for conveying the recording medium on which the toner image is transferred; anda heating section provided inside the driving roller and/or the pressing roller.