JPS63309446A - Head of image printer - Google Patents

Abstract

PURPOSE:To form a grave image of high quality, by a method wherein a transfer roller which is equipped with a solved beltlike protruding surface on its outer peripheral surface and a blade which scratches off ink supplied to the protruding surface is provided, and the ink is scratched off according to gradation by a pixel unit with this blade. CONSTITUTION:The top surface of a blade 8 is brought into contact with all the width directional surface of a protruding surface 3a of a transfer roller 3 by turning on and driving an actuator 9 based on image information of each pixel. Ink 7a which is supplied and sticked to the protruding surface 3a is scratched off, and variation is given an printing area in pixels which are printed on a paper surface 4 by scratching off ink 7a which has been supplied and sticked to the protruding surface 3a. Thereby, expression by gradation of a pixel, a minimum unit is performed by variation of a recording area in the pixels, and an image is formed. Further, when transferred to the paper, a film thickness of the ink supplied onto an image forming transfer roller can be made thick to an extent not to be crushed. Therefore, profoundness as actual feeling of the image can be satisfactorily realized.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a head for an image printing device that expresses the gradation of a pixel, which is the smallest unit constituting an image, by changing the recording area in the pixel. It is something.

[Conventional technology]

In an image printing device where an image is composed of a set of pixels, which are the smallest unit, and each pixel is recorded and transferred based on image information for each pixel, it is necessary to express gradation at each pixel.
Methods of changing the print area in a pixel or changing the print density of a pixel are employed.

A dot matrix method is known as an example of a method for changing the printing area in a pixel, and this method is used in wire tod printers, inkjet printers, and the like. This method assumes that the number of dots in one pixel is nXm (n and m are positive integers), and by changing the number of dots formed on the matrix in one pixel, the area ratio is manipulated to express light and shade. be.

[Problem that the invention seeks to solve]

However, in such conventional methods, it is necessary to have many wires and ink jet outlets according to the matrix, and the size of the dot itself must also be changed in order to fill 100% of one pixel. such as not becoming
This required an extremely complex mechanical configuration and control. Furthermore, in the wire tod method, since the pins are pressed against the paper via the ink ribbon, the outline of the dots may be blurred or blurred, and the thickness of the ink adhesion film is thin, resulting in a less solid image. was there. Similarly, the inkjet method has the problem that the ink deposition film thickness is thin and it is difficult to control the dot shape.

[Means for solving problems]

The present invention has been made in view of these problems, and includes a belt-shaped convex portion that protrudes from the outer peripheral surface of the head of an image printing device that realizes gradation expression of an image by changing the printing area in a pixel. A head roller comprising a surface, a means for supplying ink to the convex surface of the head roller, and a means for contacting the entire width direction of the convex surface of the head roller to scrape off ink that is supplied and adhered to the convex surface of the head roller. The blade is made up of a blade.

[Effect]

The ink supplied onto the convex portion of the head roller is scraped off by the blade in an amount corresponding to the image information.

[Real example]

The present invention will be explained in detail below. FIG. 1 is a diagram showing an example of an image printing apparatus equipped with a print head using the present invention. In the figure, reference numeral 1 denotes a carriage mounted so as to be able to reciprocate along a guide rod 2, and a print head as shown in FIG. 2 is constructed on this carriage 1.

In Fig. 2, 3 is a transfer roller (head roller);
1 is an auxiliary roller that rotates in contact with this transfer roller 23;
0 is an ink supply roller rotating in contact with this auxiliary roller 11, and 7 is an ink supply to this ink supply roller 10. As shown in FIG. 3(,), the transfer roller 3 has a band-shaped convex surface 3a protruding from its outer peripheral surface, and the width W of this convex surface 3a corresponds to the size of one pixel. is set. The outer circumferential surface of the auxiliary roller 11 comes into contact with this convex surface 3a and rotates, and the tip surface of the blade 8, which is formed wider than the width W of this convex surface 3a, When an actuator 9 attached to the blade 8 is turned on, the blade 8 comes into contact with the entire widthwise surface of the convex surface 3a of the transfer roller 3.

That is, by turning on the actuator 9 based on image information for each pixel, the tip end surface of the blade 8 is brought into contact with the entire widthwise surface of the convex surface 3a of the transfer roller 3, and the blade is supplied to the convex surface 3a. The attached ink 7a is scraped off to change the print area of each pixel printed on the paper surface 4. 3(a) shows a state in which the supplied ink 7a has been scraped off by the tip end surface of the blade 8 on the convex surface 3a of the transfer roller 3. FIG. Furthermore, FIG. 3(b) shows how ink is scraped off as shown in the lower part according to the actuator drive signal of upper ψ11. In the figure, in each pixel divided by length,
The white portion is the ink scraping portion (ink scraping area) produced by the blade 8 scraping off the adhered ink. That is, depending on the area ratio of the ink-applied portion and the scraped-off portion on the convex surface 3a of the transfer roller 3, it is possible to express the gradation of each pixel printed on the paper surface 4. In FIG. 2, reference numeral 13 denotes a drain receiver for the ink scraped off by the blade 8.

With this configuration, an image is formed using a completely new method as an image printing device that expresses the gradation of a pixel, which is the smallest unit, by changing the recording area in that pixel, and it is also possible to form a pixel with a 100% area ratio. This is easy to perform, and the thickness of the ink film supplied onto the image forming transfer roller can be increased to such an extent that it will not be crushed when transferred to paper, so that a sufficiently thick image can be realized.

FIG. 4 shows an example of its application, in which an image reading device 12 such as a television camera or an image sensor reads a subject image 13 such as a photograph, and a converter 14 converts it into a digital signal depending on the density of the image. This signal is stored in the image memory 16 via the image processing device 15, and printing is started by the printing device 17 based on the stored image information. In the printing device 17, a paper feed driver and a carrier movement driver are driven in accordance with a signal supplied from the image processing device 15, and a print actuator is driven via a head movement driver.

In the one in Figure 2, the image forming transfer roller moves back and forth, so
Although two blades 8 are provided, only one blade is required for forward rotation only. Furthermore, if the image forming sections are arranged in parallel on the image forming transfer roller and a plurality of transfer sections are provided, the printing speed can be improved.

Furthermore, four print heads are arranged in parallel or in series, and black,
Color images can be produced by using indigo, red, and yellow inks.

〔Effect of the invention〕

As explained above, the present invention includes a transfer roller having a band-shaped convex surface projected on its outer peripheral surface, and a blade for scraping off ink supplied to the convex surface of the transfer roller. Since the ink is scraped off according to the gradation on a pixel-by-pixel basis, it is possible to set the area ratio within one pixel to any desired area ratio, and the ink film thickness can also be made thicker than with conventional methods. , it is now possible to form deep, high-quality images.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing a practical example of this invention, Fig. 2 is a block diagram showing a print head, Fig. 3 (, ) is a left side view of the print head shown in Fig. 2, and Fig. 3 ) is a diagram showing the actuator drive signal and the ink scraping state, and FIG. 4 is a block diagram showing an example of application. 1... Carriage, 2... Guide rod, 3...
Image forming transfer roller, 4... Paper, 7... Ink, 8... Blade, 9... Actuator.

Claims (1)

[Claims] A head of an image printing device that forms an image includes: a head roller having a band-shaped convex surface protruding from its outer peripheral surface; an ink supply means for supplying and adhering ink to the convex surface of the head roller; and the head. 1. A head for an image printing apparatus, comprising an ink scraping means that contacts the entire widthwise surface of a convex surface of a roller and scrapes off ink that is supplied and deposited on the convex surface.