JPH0520277B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field The present invention relates to a paper holding mechanism for an inkjet printer.

(2) Prior Art The ink used in inkjet printers requires contradictory properties: it is difficult to dry to avoid clogging in the ejection nozzle, and it dries quickly after adhering to the paper surface. It is difficult to obtain ink that satisfies this requirement. Therefore, in conventional inkjet printers, a method has been adopted in which the paper to be used is specified and the ink is quickly absorbed into the paper using water-absorbent paper with a high internal porosity.

According to this method, it is not possible to use paper other than specified specially processed paper, such as plain paper, and expensive paper must be used.

(3) Purpose The purpose of the present invention is to provide an inkjet printer that solves the above-mentioned problems and can also use plain paper.

(4) Configuration Embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic perspective view showing the paper pressing mechanism of the present invention, FIG. 2 is a diagram showing the operation of the paper pressing mechanism of the present invention, and FIG. 3 is a diagram showing the roller having serrated projections used in the present invention. It is a detailed view.

Reference numeral 1 denotes a platen, which is disposed opposite to an inkjet type printing head 7. 2 is a paper guide.
The recording paper 3 is wrapped around the platen 1, is sandwiched between the paper feed roller 8 arranged below the platen 1, and the platen 1, and is sent out in the direction of the arrow B as the platen 1 rotates in the direction of the arrow A. It will be done. The paper holding mechanism of the present invention is provided above the platen 1, and the shaft 6
A pair of paper press rollers 4 that press both ends of the paper 3 on top
and a roller 5 disposed between the pair of paper pressing rollers and having a large number of serrated protrusions on the outer periphery having a slightly smaller outer diameter than the paper pressing rollers. Reference numeral 51 denotes a cover for the roller 5. In FIG. 1, only one roller 5 is covered with the cover 51, and the other rollers 5 are shown with the cover 51 removed so that the shape can be easily understood.

Figures 3a and 3b show the details of the roller having the serrated projections described above, and a disk 5 having the serrated projections is made by punching out a metal plate with a thickness of about 0.2 mm using a press or the like.
2 and a plastic cover 5 from both sides.
3 to form a roller 5.

The operation of the present invention will be explained based on FIG.

When plain paper was used as the recording paper 3 and printing was performed with the inkjet printing head 7, the paper surface became wet depending on the amount of ink jetted, the paper stretched and wrinkled, and the paper 3 that was in close contact with the platen 1 floated. However, since a plurality of rollers 5 are arranged between a pair of paper pressing rollers 4, the lifting amount can be dispersed and the recording paper 3 is prevented from coming into contact with the nozzle surface of the print head 7.

(5) Effects As explained above, the paper holding mechanism of the present invention includes a roller with extremely thin serrated protrusions formed on the circumference, so even if the paper floats and touches the tips of these protrusions, the ink will not be absorbed. Does not dry and does not stain the printed surface.

Furthermore, since the roller on which the serrated protrusions are formed has a smaller outer diameter than the paper pressing roller, it does not touch the paper when the amount of paper elongation is minute, so it does not stain the paper surface as described above.

Further, since the roller having serrated projections simply presses down the thin metal plate from both sides with press plates made of plastic or the like, it is simple and inexpensive.

According to the paper holding structure of the present invention, plain paper can be used without specifying the recording paper, and can be used without any restrictions on ink or heads, so the range of use of inkjet printers can be expanded.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a paper pressing mechanism of the present invention. FIG. 2 is a diagram for explaining the operation of the present invention. FIG. 3 is a detailed view of the roller 5 shown in FIG. 1.

Claims (1)

[Scope of Claims] 1. In an inkjet printer that performs recording by ejecting ink droplets from a print head, two paper press rollers that rotate in contact with a platen and coaxially arranged between the paper press rollers are provided. A paper holding mechanism for an inkjet printer, comprising a plurality of rollers having a diameter smaller than the paper holding roller and having thin serrated projections on the outer periphery that do not contact the platen. 2. The paper holding mechanism for an inkjet printer according to claim 1, characterized in that it comprises at least five rollers having serrated projections.