Image forming apparatus and image forming method

Abstract

An image forming apparatus forms an image on a recording medium by transferring an image formed on an intermediate transfer body to the recording medium. The image forming apparatus includes: a first liquid deposition device which performs deposition of a first liquid onto the intermediate transfer body, the first liquid containing solvent-insoluble material; a second liquid deposition device which performs deposition of a second liquid onto the intermediate transfer body before the deposition of the first liquid, the second liquid having a function of causing the solvent-insoluble material to aggregate; and a deposition control device which controls the deposition in such a manner that a minimum thickness of a layer of the second liquid formed on the intermediate transfer body at the deposition of the first liquid is not smaller than 1 μm, and a volume of the deposition of the second liquid per unit surface area is not smaller than a volume of the deposition of the first liquid per unit surface area.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The nature of this invention, as well as other objects and advantages thereof, will be explained in the following with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures and wherein:

FIG. 1 is a general schematic drawing showing a general view of an inkjet recording apparatus according to an embodiment of the present invention;

FIG. 2 is a plan diagram showing an ejection surface of a recording head in the inkjet recording apparatus;

FIG. 3 is a partial cross-sectional diagram along line 3-3 in FIG. 2;

FIG. 4 is a principal block diagram showing the system composition of the inkjet recording apparatus;

FIGS. 5A and 5B are diagrams for explaining the conditions required in order to achieve good transfer;

FIGS. 6A and 6B are diagrams showing the relationship between the deposition volumes of treatment liquid and ink, and the transfer rate;

FIG. 7 is a graph showing the relationship between the spreading rate of the ink droplets and the height of the ink droplets;

FIGS. 8A to 8C are diagrams showing examples of deposition of the treatment liquid according to a second ejection control condition;

FIGS. 9A and 9B are diagrams for explaining aspects of wetting and spreading of the treatment liquid on the surface of an ink droplet; and

FIG. 10 is a graph showing the relationship between the maximum thickness of the treatment liquid layer and the spread rate of the ink droplet.

Claims

1. An image forming apparatus which forms an image on a recording medium by transferring an image formed on an intermediate transfer body to the recording medium, the apparatus comprising: a first liquid deposition device which performs deposition of a first liquid onto the intermediate transfer body, the first liquid containing solvent-insoluble material;a second liquid deposition device which performs deposition of a second liquid onto the intermediate transfer body before the deposition of the first liquid, the second liquid having a function of causing the solvent-insoluble material to aggregate; anda deposition control device which controls the deposition in such a manner that a minimum thickness of a layer of the second liquid formed on the intermediate transfer body at the deposition of the first liquid is not smaller than 1 μm, and a volume of the deposition of the second liquid per unit surface area is not smaller than a volume of the deposition of the first liquid per unit surface area.

2. An image forming apparatus which forms an image on a recording medium by transferring an image formed on an intermediate transfer body to the recording medium, the apparatus comprising: a first liquid deposition device which performs deposition of a first liquid onto the intermediate transfer body, the first liquid containing solvent-insoluble material;a second liquid deposition device which performs deposition of a second liquid onto the intermediate transfer body before the deposition of the first liquid, the second liquid having a function of causing the solvent-insoluble material to aggregate; anda deposition control device which controls the deposition in such a manner that a minimum thickness of a layer of the second liquid formed on the intermediate transfer body at the deposition of the first liquid is not smaller than 1 μm, and the second liquid is deposited not only onto a first liquid deposition region onto which the first liquid is to be deposited, but also onto a peripheral region surrounding the first liquid deposition region.

3. The image forming apparatus as defined in claim 2, wherein the peripheral region extends from every side of the first liquid deposition region by at least a length corresponding to a diameter of a dot formed by the first liquid.

4. The image forming apparatus as defined in claim 1, wherein the maximum thickness of the layer of the second liquid is not greater than 9 μm.

5. The image forming apparatus as defined in claim 2, wherein the maximum thickness of the layer of the second liquid is not greater than 9 μm.

6. The image forming apparatus as defined in claim 1, wherein a surface tension of the second liquid is not higher than a surface tension of the first liquid.

7. The image forming apparatus as defined in claim 2, wherein a surface tension of the second liquid is not higher than a surface tension of the first liquid.

8. The image forming apparatus as defined in claim 1, wherein the solvent-insoluble material includes a coloring material.

9. The image forming apparatus as defined in claim 2, wherein the solvent-insoluble material includes a coloring material.

10. The image forming apparatus as defined in claim 1, wherein the solvent-insoluble material includes at least one of a material which enhances fixing characteristics on the recording medium, a material which enhances wear resistance properties, and a material which enhances a transfer rate.

11. The image forming apparatus as defined in claim 2, wherein the solvent-insoluble material includes at least one of a material which enhances fixing characteristics on the recording medium, a material which enhances wear resistance properties, and a material which enhances a transfer rate.

12. An image forming method for forming an image on a recording medium by transferring an image formed on an intermediate transfer body to the recording medium, the method comprising the steps of: depositing a first liquid onto the intermediate transfer body, the first liquid containing solvent-insoluble material; anddepositing a second liquid onto the intermediate transfer body before the deposing step of the first liquid, the second liquid having a function of causing the solvent-insoluble material to aggregate,wherein a minimum thickness of a layer of the second liquid formed on the intermediate transfer body at the deposing step of the first liquid is not smaller than 1 μm, and a volume of the deposited second liquid per unit surface area is not smaller than a volume of the deposited first liquid per unit surface area.

13. An image forming method for forming an image on a recording medium by transferring an image formed on an intermediate transfer body to the recording medium, the method comprising the steps of: depositing a first liquid onto the intermediate transfer body, the first liquid containing solvent-insoluble material; andbefore the deposing step of the first liquid, depositing a second liquid not only onto a first liquid deposition region onto which the first liquid is to be deposited on the intermediate transfer body, but also onto a peripheral region surrounding the first liquid deposition region, the second liquid having a function of causing the solvent-insoluble material to aggregate,wherein a minimum thickness of a layer of the second liquid formed on the intermediate transfer body at the deposing step of the first liquid is not smaller than 1 μm.