JPH02171251A - Image forming device - Google Patents

Abstract

PURPOSE:To form a satisfactory image even on plane paper with a coarse surface by previously fusing and transferring a base agent whose surface is smoothed by a base forming means in the recorded area of a recorded material on which a coloring material is fused and transferred. CONSTITUTION:As a base forming medium, a coating ribbon 30 forms a coating ink 53 as a base agent on a film main body 52. A paper P is wound around a platen drum 20, and after its leading edge passes through the printing area of the base forming means 25, a thermal head 21 is pressed against the platen drum 20. At this time, the coating ink 53 of the coating ribbon 30 is fused and transferred in the recorded area of the paper P, and its surface is smoothed.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention relates to a thermal printer that forms an image by melting and transferring a colorant on an image forming medium to a recording medium via a thermal recording head. , relates to a thermal transfer type image forming apparatus such as a thermal copying machine.

(Prior Art) In recent years, a color tU photocopier has been developed and put into practical use as a thermal transfer type image forming apparatus.

In the case of full-color copying, such an apparatus uses four colorants (inks) of the image forming medium (ink ribbon) on the recording medium (paper): yellow, magenta, cyan, and black.
or three colors of yellow, magenta, and cyan are transferred in layers. Furthermore, in the case of a single color such as black, transfer is performed in one transfer operation, but conventional devices were not equipped with any means to smooth the surface of the recording area of the recording medium in advance. .

For this reason, when plain paper with a rough surface is used as a recording medium, good image formation cannot be achieved. For this reason, expensive high-quality paper with a smooth surface is used.

(Problems to be Solved by the Invention) As described above, in the past, there was a problem in that expensive high-quality paper was designated and used as the recording medium, which was extremely uneconomical.

The present invention has been made based on the above-mentioned circumstances, and its object is to provide an extremely economical thermal transfer type image forming apparatus that can use inexpensive plain paper.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides an image forming means for forming an image by melting and transferring a colorant on an image forming medium to a recording medium via a thermal recording head, and A structure comprising a base forming means for previously melting and transferring a base agent for smoothing the surface using a base forming medium to the recording area of the recording medium to which the colorant is melt-transferred by the forming means. This is what I did.

(Function) In this invention, since a base agent is melt-transferred in advance to the recording area of the recording medium to which the colorant is melt-transferred to make the surface smooth by the base-forming means, it is possible to use plain paper with a rough surface. Good image formation is possible even if there is such a difference.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows, as an example of the image forming apparatus of the present invention, a thermal transfer type color copying machine capable of making multicolor copies. That is, 1 is a main body of a copying machine, and an operation panel (not shown) is provided at the front of the upper surface of the main body 1. A document scanning section 3 for scanning and reading a document set on a document table (transparent glass) 2 is provided at the top of the main body 1, and an image forming section 4 is provided at the top. In addition,
Reference numeral 5 denotes a document cover provided on the document table 2 so as to be openable and closable.

The document scanning unit 3 includes an exposure lamp 7 whose back is surrounded by a reflector 6, a first mirror 8, a second mirror 9, a third mirror 10, a lens 11, a fourth mirror 12, and a fifth mirror 13. , and a photoelectric converter 14.

Further, the exposure lamp 7 and the first mirror 8 are mounted on a first carriage 15 that is movable along the lower surface of the document table 2, and the second mirror 9 and the third mirror 1
0 is mounted on the second carriage 16. The first carriage 15 and the second carriage 16 are configured to move in conjunction with each other by a drive mechanism (not shown), and move in the same direction at 1/2 the speed of the first carriage 15. , the optical path length to the lens 11 is kept constant.

When scanning a document, the first carriage 15 moves from left to right with the exposure lamp 7 turned on, and the second carriage 16 also moves in the same direction at 1/2 the speed. Then, the reflected light from the original is guided to the lens 11 via the first mirror 8, the second mirror 9, and the third mirror 10 in order. and a fifth mirror 13 in order to be guided to a photoelectric converter 14.

The charging converter 14 converts the image on the original into cyan by photoelectrically replacing the light reflected from the original.

Green, yellow (or red, green.

It separates and outputs a color signal of (blue) light, and is mainly composed of, for example, a CCD type line image sensor. In this case, one pixel of the original corresponds to three consecutive elements (C, GSY) of the CCD sensor. The output of the optical @converter 14 is output to an A/D converter (not shown).

Further, the image forming section 4 has a configuration as shown in FIG. That is, the platen drum 20 is disposed approximately at the center of the image forming section 4 .

The platen drum 20 has a periphery made of an elastic material such as rubber, and functions as a platen roller for a thermal recording head (hereinafter referred to as a thermal head) 21 and 22. The platen drum 20 has a gripper 23 that holds the leading edge of a sheet of paper P as a recording medium, and rotates clockwise to wrap the sheet of paper P around itself, so that the sheet of paper P is secured during overlay printing. I try not to shift.

Also, pressure rollers 24 are provided around the platen drum 2o at predetermined intervals to prevent the paper P from floating up from the platen drum 20. The circumference of the platen drum 20 is slightly longer than the length of the maximum paper size in the longitudinal direction.

A base forming means 25 equipped with the thermal head 21 is provided diagonally below the left side of the platen drum 20, and an image forming means 26 equipped with the thermal head 22 is provided further above. The thermal head 21.
22 is attached to a heat radiator integrally formed on the rear end surface of the holder. A coating ribbon 30 serving as a base forming medium is interposed between the platen drum 20 and the thermal head 21.

Further, an ink ribbon 31 as an image forming medium is interposed between the platen drum 20 and the thermal head 22.

Pre-coating ribbon 30 and ink ribbon 24
The winding cores 32, 33, 34, and 35 are connected to a drive shaft of a motor (not shown) via a drive force transmission mechanism (not shown),
It is designed to be rotated as needed.

Further, a paper feed roller 40 is provided at the lower part of the main body 1, and a paper feed roller 40 is provided in a lower portion of the main body 1.
are taken out one by one. The paper P taken out by the paper feed roller 40 is sent to a pair of registration rollers 43 disposed diagonally above and to the left by a single sheet conveyance means 42 consisting of a feed roller and a separation roller, and its leading edge is aligned. .

Then, as the pair of registration rollers 43 rotate, the sheet is further fed and transferred toward the platen drum 20 via the pair of guide plates 44, and its tip is held by the gripper 23. Next, as the platen drum 20 rotates clockwise, the platen drum 20 is wound around the platen drum 20, and the press is held in a state without lifting by the rollers 24, and is accurately fed.

Further, the ink film 31 as an image forming medium has a structure having a plurality of colorant regions. That is, as shown in FIG. 2, yellow, magenta, cyan, and black inks 5 as colorants are applied on the film body 50.
1a, 51b.

The regions 51c and 51d are formed sequentially in the length direction. In addition, ink 51a as a colorant
~51d consists of a mixture of waxes, resins, pigments and additives. Further, the coating ribbon 30 as a base forming medium is attached to a film body 52 as shown in FIG.
A coating ink 53 is formed thereon as a base material, and this coating ink 53 is made of a mixture of wax, resin, and additives.

After the paper P is wound around the platen drum 20 as described above and the leading edge passes through the printing area of the base forming means 25, the thermal head 21 is moved around the platen drum 20.
is pressurized. At this time, the coating ink 53 of the coating ribbon 30 is melted and transferred to the recording area of the paper P, making the surface smooth.

In this way, after the base printing is completed in advance, the platen drum 20 is in a state of having rotated approximately one revolution.

Here, the pressurizing operation of the thermal head 21 is once released. Next, the leading edge of the paper P is fed until it passes the printing area of the image forming means 26, the thermal head 22 is pressed against the platen drum 20, and the ink ribbon 31 is pressed against the platen drum 20.
The cue for the first color is performed. Then, the platen drum 20 starts rotating clockwise again, and printing by the thermal head 22 is performed.

When printing of this negative color is completed, the platen drum 20 has also rotated about one revolution. here,
Once the thermal head 22 is released, the ink ribbon 31
is wound up by a predetermined amount and the next color is cued up. Then, the platen drum 20 starts rotating clockwise again, printing is performed by the thermal head 22, and the next color is overprinted (printed).

In this way, when full-color copying is performed on paper P with a rough surface such as plain paper, the coating ink 53 as a base material is transferred, and yellow, magenta, cyan, etc.
Total number of transfers of each black ink 51a to 51d = 15 times, or transfer of coating ink 53 as a base material,
and yellow, magenta, and cyan inks 51a to 5.
Image formation is performed by a total of four transfer operations including transfer 1c.

In the case of a single color such as black, a total of two transfer operations including the transfer of coating ink 53 as a base material are performed.

Further, the paper P on which image formation has been completed in this way is peeled off from the platen drum 20 and is formed by a pair of paper ejection guide plates 55, a pair of transport rollers 56, a pair of paper ejection guide plates 57, a pair of transport rollers 58, etc. The paper is discharged onto the paper discharge tray 60 via five paper discharge paths.

That is, at the time of paper ejection, the trailing edge of the paper P is in the paper ejection path 5.
Rotate the platen drum 20 clockwise until it faces the starting end of the platen drum 9.
counterclockwise, and use the separation claw (not shown) to separate the paper P.
The rear end is separated from the platen drum 20 and guided to a pair of paper discharge guide plates 55.

Finally, the leading edge of the paper P is released from the gripper 23, is transported through the paper transport path 59, and is ejected onto the paper ejection tray 60.

FIGS. 4(a) to 4(c) show the image forming process on paper P, and FIG. 4(a) shows the state without surface treatment. (b) shows a state in which the surface has been smoothed by melting and transferring the iron ink 53, which is a base material. In addition, in (C), the surface has been treated to be smooth with coating ink 53, and ink 51a to 5 as coloring agent
1d shows the image formed.

In this way, in this invention, ink 5, which is a colorant,
1a to 51d, the coating ink 53 as a base material can be melted and transferred to the recording area of the paper P in advance, making it possible to form a good image even on plain paper with a rough surface.

Note that if the paper P is high-quality paper with no surface roughness, the base forming means 25
The coating ribbon 30 is switched to a mode in which it is inactive, thereby avoiding wasteful use of the coating ribbon 30 as a base material.

In the above embodiment, the ink ribbon 31 is configured to include the black ink 51d, but the present invention is not limited to this, and color image formation is possible as long as the ink ribbon 31 includes at least the inks 51a to 51c as yellow, magenta, and cyan colorants. Of course.

2. It goes without saying that this invention can be modified in various ways without departing from the gist thereof.

[Effects of the Invention] As detailed above, according to the present invention, it is possible to provide an extremely economical thermal transfer type image forming apparatus that can use inexpensive plain paper.

[Brief explanation of the drawing]

The drawings are for explaining one embodiment of the present invention, and FIG. 1 is a schematic longitudinal sectional front view showing the overall configuration of an image forming apparatus, FIG. 2 is an explanatory diagram of the configuration of an image forming medium, and FIG. The figure is an explanatory diagram of the structure of the base forming medium, and FIG. 4 is an explanatory diagram showing the image forming process. P...paper (recorded object), 21.22...thermal head (thermal recording head), 25...base forming means,
26... Image forming means, 30... Coating ribbon (base forming medium) 31... Ink ribbon (image forming medium), 51a to 51d... Ink (coloring agent), 53
...Coating ink (base agent). Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] An image forming means for forming an image by melting and transferring the colorant on the image forming medium to the recording medium via a thermal recording head, and a recording area of the recording body to which the colorant is melted and transferred by the image forming means. 1. An image forming apparatus comprising: a base forming means that uses a base forming medium to melt and transfer a base agent to smooth the surface of the medium in advance.