JPH05338128A - Ink jet printer and ink jet head - Google Patents

Abstract

PURPOSE:To improve the printing quality on uniformly even surface by using an ink jet head with a nozzle which prints data using a line image, in a thermal page-type ink jet printer. CONSTITUTION:A printer head is composed of a head 2 for printing a dot image and a head 1 for printing a line image. The head 2 is of a conventional ink jet type with a nozzle plate 21 consisting of dot-type nozzles for ink ejection. The head 1 is of an ink jet type capable of outputting a line with a nozzle plate 11 consisting of narrow channel-type nozzles for ink ejection. Next, the two heads are installed on a guide shaft 4 and allow an image to be output in units of page with a concurrent scan action over a printing sheet surface. The line head moves over a fixed width through a guide shaft 4, with a head rotating mechanism 3. It is possible to print data on a uniformly even surface of any given width by tilting the head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ink jet printer.

[0002]

2. Description of the Related Art Conventionally, the nozzle portion of an ink jet head has a dot shape, and by forming a dot, characters,
I was printing a figure.

[0003]

However, the quality of the prints printed by such a conventional printer head is because the ink bleeds considerably on the paper surface in order to cause the ink to fly, especially in the case of the ink jet system. The unevenness of the paint was emphasized during the solid paint.
Further, there is a problem that when the inter-dot distance or the bleeding method varies, a streak pattern is formed in the scanning direction of the head.

Further, since the printing is developed by the dot image, there is a problem that it takes a long printing time when the printing area is large.

Therefore, an ink jet printer and an ink jet head according to the present invention are intended to solve such a problem, and an object thereof is to provide a printer and an ink jet head having improved printing quality on a uniform and uniform surface. To provide.

[0006]

The ink jet printer and the ink jet head of the present invention include two ink jet heads, a conventional dot output dot image head and a line image head capable of uniform and uniform surface printing. It is characterized in that it is mounted and the line image head prints a uniform and uniform surface in a page print image.

[0007]

That is, by using the line image head, it is possible to reduce the color unevenness on the uniformly and uniformly printed surface, and it is possible to shorten the printing time per page.

[0008]

EXAMPLES The present invention will be described in detail below based on examples.

First, the structure of the print head of the present invention will be described. FIG. 1 shows an explanatory view of a printer head equipped with two dot image printing heads 2 and line image printing heads 1. The dot image head 2 is
A conventional inkjet head (hereinafter referred to as a dot head) uses a nozzle plate 21 having a plurality of dot-shaped nozzles to eject ink. The line image head 1 is an inkjet head capable of line output (hereinafter referred to as a line head), and uses a nozzle plate 11 having nozzles in the shape of narrow grooves to eject ink. The above two heads are attached to the guide shaft 4, and the image is output page by page while scanning the printing paper surface.
The line head moves through the guide shaft 4 within a certain width, but has a head rotating mechanism 3. Thus, by tilting the head as shown in FIG. 2, it is possible to print on a uniform and uniform surface of an arbitrary width. As shown in FIG. 3, it is possible to drive by using different guide shafts 4 without mounting the heads on the same axis, so that the printing time can be shortened.

The structure of the line head is shown in FIGS.
The head includes a nozzle plate 11 that ejects ink, a cavity 12 that forms a flow path 14, a heating element 13, and an ink supply source 15. The nozzle plate was a 10-micron-thick SUS substrate, the cavity was an injection-molded product of polycarbonate, and the flow path shape was a triangular prism. At the time of ink ejection, by heating the heating element, bubbles are generated in the flow channel, and the ink in the flow channel is ejected through the nozzle. The nozzle holes were shaped to have 30 x 20,000 micron grooves with 50 micron diameter cylindrical grooves at both ends. In order to output a line image, it is necessary to take a large amount of discharge, and heating elements are attached to both sides of the flow path wall surface as a discharge energy source. By forming the flow path into the shape of a triangular prism, the bubbles generated around each heating element can generate a considerable pressure symmetrically at the nozzle portion, and the ink ejection can be made to go straight. In order to output a line image, a large amount of ink ejection energy is required, and several ejection energy sources are conceivable. However, the thermal inkjet system that can obtain a large volume change is most suitable.

Further, by mounting the heating elements on both sides, the timing of the voltage applied to the heating elements is shifted, whereby the ink flight deflection can be managed and a line curve can be output as a print output.

Further, as shown in FIG. 6 as the nozzle shape of the nozzle plate, when a nozzle having a mesh shape is included, not only the line output but also the printing of a uniform pattern such as a broken line and shading moves the ink jet head This is possible by adjusting the speed variably. That is, it is possible to print a sparse image by scanning the head quickly and a dense image by scanning the head slowly.

FIG. 7 shows a flowchart for outputting a page. First, (1) the printer receives a page print image from a personal computer or the like. Therefore, (2) the controller extracts a uniform uniform image portion of the output image. Among them, (4) the line head is decomposed into a printable line output portion and a portion where a dot image is required. At this time, the (5) line output impossibility image and the (2) dot image described above are separated into (6) dot patterns for printing as dot images. The dot image is printed by the control method similar to the conventional one. In order to obtain an arbitrary line width, the pattern decomposed into the line output portion (7) controls the rotation of the head and the scanning speed of the head, and ejects ink to obtain a line output. From now on, by performing (8) line output and (9) dot output, printing can be performed in units of (10) pages.

FIG. 8 shows the printed image. In this embodiment, since the print width of the line head is about 3 lines,
A solid uniform surface 61 is formed by line scanning of an ordinary head. In this way, the uniform surface of a plurality of lines is printed at once, so that the printing time can be shortened. The print image 62 is a character formed by dots as in the conventional case. Further, by tilting the line head, it is possible to print the line 63 having an arbitrary width. At this time, as can be seen in FIG. 2, there is a portion that cannot be printed, but this portion is supplemented by printing with a dot head.

Further, by using the above-mentioned nozzle plate with mesh and controlling the moving speed of the head,
In addition to solid painting, uniform pattern (hatching printing image) 6
4 can be printed.

Further, as described above, by controlling the heat generation timing of the pair of heat generating elements in the line head, it is possible to print the line 65 having a curve (line curve print image).

In this embodiment, an ink jet printer equipped with two heads that can be used for printing characters and pictures has been described, but when printing only a line (bar) of an arbitrary width such as a bar code, the line is printed. By using the head alone, it is possible to provide a high-speed printer with good print quality as compared with a conventional printer.

[0018]

As described above, the ink jet printer according to the present invention can obtain a print image with less color unevenness in printing on a uniform surface. Moreover, since a line head can be used to print a uniform image of several lines, the printing speed is increased.

[Brief description of drawings]

FIG. 1 is a diagram illustrating an inkjet head according to an exemplary embodiment of the present invention.

FIG. 2 is a diagram showing that the print line width of the line head in one embodiment of the present invention can be varied.

FIG. 3 is a perspective view of an inkjet head according to an embodiment of the present invention.

FIG. 4 is an explanatory diagram of a structure of a line head in one embodiment of the present invention.

FIG. 5 is a perspective view of a line head according to an embodiment of the present invention.

FIG. 6 is an explanatory diagram of a nozzle portion of the line head according to the embodiment of the present invention.

FIG. 7 is a diagram showing a printing flowchart in one embodiment of the present invention.

FIG. 8 is a diagram illustrating a print image according to an embodiment of the present invention.

[Explanation of symbols]

 1 Line image head (line head) 2 Dot image head (dot head) 3 Line head rotating part 4 Head moving guide 5 Drum 6 Printing paper 11 Nozzle plate 111 Nozzle hole 12 Cavity 13 Heat generating element 14 Ink flow path 15 Ink Supply unit 16 Flying ink 60 Printing pattern 61 Uniform and uniform printing image 62 Dot printing image 63 Line printing image 64 Hatching printing image 65 Line curve printing image

Claims (3)

[Claims] 1. A thermal type page type ink jet printer in which ink is ejected from a nozzle using a heating element as an ejection energy source, wherein an ink jet head having a nozzle capable of printing a line image is used. 2. The inkjet printer according to claim 1, wherein a nozzle plate having a narrow groove nozzle having a groove width of 50 μm or less is used for printing a line image. 3. The ink jet head according to claim 2, wherein the inside of the nozzle portion has a mesh shape.