JPH079641Y2 - Image printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an image printing apparatus that expresses the gradation of a pixel, which is the smallest unit of an image, by a change in the recording area in the pixel or a change in the print density. Of these, the present invention relates to a blade-type image printing apparatus that uses a blade as a head for changing a printing area.

[Conventional technology]

The image for printing is composed of a set of pixels which is the minimum unit. Therefore, an image printing apparatus has been developed which records and transfers each of these pixels on the basis of image information based on image information. In this type of image printing apparatus, the printing area in the pixels is changed or the printing density of the pixels is changed. By doing so, gradation expression in each pixel is performed.

Among such image printing apparatuses, a blade-type image printing apparatus using a blade as a head for changing the print area of a pixel is conventionally configured, for example, as follows. That is, a band-shaped convex surface formed to have the same width as one pixel on the outer circumference of the transfer roller is in contact with the surface of the paper mounted on the peripheral surface of the rotary cylinder, and the convex surface of the ink fountain Ink is supplied through the deposition roller. Also, on this convex surface,
The tips of the blades are in contact with each other, and when the transfer roller rotates, the ink on the convex surface is scraped off by the blades, flows down on the blade surface, and collects in the drain receiver of the blade base. The blade is provided with a driving device for advancing and retracting the blade in the perspective direction with respect to the convex surface, and the amount of ink scraped is changed by the advancing and retracting.

With this configuration, when the drive attachment advances or retracts the blade based on the image information for each pixel, the amount of ink scraped by the blade changes, and the amount of ink transferred from the convex surface to the paper changes. The printing area of the pixels printed on the paper changes, and the gradation expression for each pixel becomes possible. In this way, one line is printed by moving the paper by rotating the cylinder while rotating the transfer roller, and an image is formed by scanning the entire mounting in the width direction of the paper for each one line printing.

[Problems to be solved by the device]

However, in such a conventional image printing apparatus, the ink that should have been scraped off by the blade may be scratched and may remain thin on the scraped portion of the convex surface of the transfer roller, and in this state, the image is transferred. When printing is performed, there is a problem that pixels that should be white on the paper surface are stained and the image quality is degraded. And the cause of failure to scrape, such as the surface state of the transfer roller such as roughness and scratches, or the wear of the blade is considered, the surface of the transfer roller is a mirror surface state without scratches, the blade It has been a very difficult problem to prevent abrasion.

[Means for Solving the Problems]

In order to solve such a problem, in the present invention, a frame body that axially supports a transfer roller is movably supported in a direction in which the peripheral surface of the transfer roller comes in contact with and separates from the surface of the paper.
A guide roller, which has an axial direction parallel to the transfer roller and is in contact with the paper surface, is rotatably supported by the frame body with a phase difference with respect to the transfer roller in the axial direction, and the support shaft serves as a roller fitting portion. An eccentric shaft whose eccentricity with the shaft hole fitting portion is rotatable and adjustable.

[Action]

When the eccentric shaft is rotated and adjusted while the guide roller is in contact with the paper surface, the eccentric action causes the frame body to swing and the peripheral surface of the transfer roller to be slightly separated from the paper surface by a desired amount. Even if a small amount of the ink that could not be scraped off remains, it is not transferred to the paper surface.

〔Example〕

1 to 5 show an embodiment of an image printing apparatus according to the present invention. FIG. 1 is a schematic side view thereof, FIG. 2 is an enlarged side view of the vicinity of a transfer roller, and FIG. 3 is a guide roller supporting portion. FIG. 4 is a perspective view of the vicinity of the transfer roller, and FIG. 5 is a plan view and a side view of a printed line of pixels. In the figure, paper 2 is mounted on the peripheral surface of a rotary drum 1 that rotates in a direction indicated by an arrow A, and an image printing apparatus indicated by reference numeral 3 is provided on the outside of the rotary drum 1 as a machine base. The support shaft 4 on the frame side is arranged so as to be swingable and movable back and forth between the front side and the paper back side in FIG. The image printing device 3 includes a carriage 5 and a frame 6 supported by a support shaft 4, an ink fountain 8 which is supported by the frame 6 and stores ink 7, an original roller 9 which rotates in the ink 7, and A transfer roller 11 having an outer peripheral belt-shaped convex surface 11a with which the contact roller 10 rotates in contact with the original roller 9 and the contact roller 10 contacts.
And each roller 9,10,11 pivotally supported by the frame body 6.
Is rotated in the direction shown by the arrow in the figure, the ink 7 in the ink fountain 8 is attached to the peripheral surface of the convex surface 11a by the attachment roller 10 via the original roller 9.

12 is formed in a rectangular plate shape, and a frame body 6 is provided via a bracket 13.
It is a blade pivotally supported by the blade, its tip edge is in contact with the convex surface 11a, and is configured to scrape off the ink 7 adhering to the convex surface 11a. This blade 12
Is fixed to the working end of a piezoelectric element 14 as a drive attachment, and its operation causes the blade 12 to swing so as to move the cutting edge in the perspective direction with respect to the convex surface 11a. Then, the piezoelectric element 14 is electrically connected to the control device in which the print image is stored, and the piezoelectric element 14 is actuated by the command according to the position of the pixel in the print image and the blade 12 swings,
The blade 12 is configured to intermittently scrape the ink 7. Below the blade 12, the blade 12
An unillustrated drain receiver is provided to collect and collect the ink 7 flowing down on the upper surface of the. Then, after being scraped off by the blade 12, the ink 7 remaining on the convex surface 11a is transferred to the paper 2 by the movement of the paper while rotating the transfer roller 11, and printing is performed. Although not shown, the convex surface after transfer
A blade for scraping off the ink 7 remaining on 11a and a drain receiver for collecting and collecting the scraped ink 4 are provided.

An eccentric shaft 15 is fixed to the frame body 6 by a bolt 16 so as to be rotatable and adjustable above the transfer roller 11.
A guide roller 17 having an axial direction parallel to the transfer roller 11 is rotatably fitted in the shaft 15. The guide roller 17 and the transfer roller 11 are out of phase with each other in the circumferential direction of the rotary cylinder 1 and also in the axial direction so as not to interfere with the printing line. The eccentric shaft 15 is eccentric by the center of the fitting portion with the bolt 16 and the center of the fitting portion with the guide roller 17 by the symbol t in FIG. 3, and the eccentric shaft 15 is rotated by loosening the bolt 16. By adjusting, the counter contact of the guide roller 17 to the paper 2 moves in the radial direction. That is, if this adjustment is performed with the guide roller 17 in contact with the paper 2,
The frame 6 swings to adjust the clearance between the transfer roller 11 and the paper 2.

The operation of the image printing apparatus 3 configured as above will be described. The paper 2 is attached to the peripheral surface of the rotary cylinder 1, the rotary cylinder 1 is rotated, and the convex surface 11a of the transfer roller 11 is brought into contact with the surface of the paper 2 while rotating the rollers 9, 10, 11 and the piezoelectric element 1
When 4 is driven by the controller, the ink 7 in the ink fountain 8
Is adhered to the convex surface 11a of the transfer roller 11 by the attachment roller 10 via the original roller 9, and the ink 7 is scraped off by the blade 12. The ink 7 in the non-scraping portion remaining on the convex surface as a result of the scraping is transferred to the paper 2 and printed. In this case, since the width of the convex surface 11a is formed to have the same size as the width of the pixel, the paper 2 is printed with the same width as the pixel as indicated by the symbol W in FIG. Further, since the piezoelectric element 14 is actuated by the signal from the control device based on the image information to swing the blade 12, the scraped portion and the non-scraped portion within the length of each pixel indicated by the symbol L in FIG. The area ratio with the part changes,
As shown in FIG. 5, the paper 2 is subjected to one-line printing 18 in which the area ratio between the printed portion 18a and the non-printed portion 18b within each pixel length L is changed in the same manner as the image information. After the transfer onto the paper 2, the ink 7 remaining on the convex surface 11a is scraped off by another blade and collected in the drain receiver. In this way, every time one line is printed, the entire image printing apparatus 3 becomes the first
The image is printed by repeating the printing by scanning in the paper spine direction in the figure.

In such a printing operation, as described above, the convex surface 11
Convex surface 11a due to finish roughness of a and wear of blade 12
In some cases, the ink 7 may not be completely scraped off and remains, and this may be transferred to the paper 2 and the non-printed portion of FIG.
18b may get dirty. However, in the present device, the provision of the guide roller 17 can prevent this. That is, when the bolt 16 is loosened in a state where the peripheral surface of the guide roller 17 is in contact with the surface of the paper 2, and the eccentric shaft 15 is rotated by the wrench provided in the wrench hole 15a,
Due to the eccentric action, the counter contact point of the guide roller 17 changes in the radial direction and the frame body 6 swings around the support shaft 4, so that a desired gap is formed between the convex surface 11a and the surface of the paper 2. You can FIG. 2 shows a state in which the guide roller 17 is pressed against the paper 2 after this adjustment and a gap t ₂ is formed between the convex surface 11 a and the paper 2. By doing this, the convex surface 11
If the size of the gap between a and the paper 2 is set to be larger than the ink thickness of the unscraped portion and smaller than the ink thickness of the non-scraped portion, even if the ink 7 is transferred in this state, The remaining ink is not transferred to the paper, and the non-scraped ink is correctly transferred to the paper 2.

6 and 7 show another embodiment of the present invention.
The figure shows a schematic side view of the image printing apparatus shown in correspondence with FIG.
FIG. 7 is an enlarged side view of the vicinity of the transfer roller shown in correspondence with FIG. In this embodiment, the guide roller 17A is arranged diagonally below the transfer roller 11. The other structure is the same as that of the above-mentioned embodiment, and the same reference numerals are given and the description thereof is omitted. With this structure, the transfer of the unscraped ink to the paper is prevented, as in the above-described embodiment.

Further, FIG. 8 is a partially cutaway front view of a guide roller and an eccentric shaft according to another embodiment of the present invention. In the figure, an eccentric shaft 21 is rotatably supported by a pair of bearings 20 provided on the frame body 6 side, and a nut 22 for rotating the eccentric shaft 21 is screwed into a protruding end thread portion thereof. Has been done. A guide roller 17 is rotatably fitted to the eccentric shaft 21.
Has a center of a fitting portion of the guide roller 17 and a center of a fitting portion of the bearing 20 which are eccentric by a symbol t in the drawing. A lock nut 23 fixes the eccentric shaft 21. With this configuration, the lock nut 23 is loosened and the nut 22
The guide roller 17 is eccentrically rotated by rotating the eccentric shaft 21 with a spanner. The action of the guide roller 17 is the same as in the above embodiment.

The arrangement of the ink fountain 8 and the rollers 9 and 10 and the number of rollers are not limited to those in the above embodiments, and the blade
The twelve drivers need not be piezoelectric elements. Furthermore, paper 2
May be fixed on the table and the image printing device 3 may be moved to perform printing.

[Effect of device]

As will be apparent from the above description, according to the present invention, in the image printing apparatus provided with the transfer roller which is in contact with the paper surface, and the blade for scraping ink which is moved forward and backward by the drive device with the tip of the transfer roller being in contact with each other, A frame that supports the transfer roller is movably supported in a direction in which the peripheral surface of the transfer roller comes into contact with and separates from the surface of the paper, and a guide roller that is in axial contact with the transfer roller and faces the paper surface. The transfer roller is rotatably supported on the frame by shifting the phase in the axial direction, and the supporting shaft is a rotation-adjustable eccentric shaft in which the roller fitting portion and the shaft hole fitting portion are eccentric. When the eccentric shaft is rotated, the frame swings and the gap between the peripheral surface of the transfer roller and the paper surface can be set arbitrarily, so that the ink is not scratched on the scraping part without being scratched by the blade. Even if it remains, this inn There without being transferred to the paper,
Only the ink film having a desired film thickness or more can be transferred onto the paper surface, and the image quality is significantly improved.

[Brief description of drawings]

1 to 8 show an embodiment of an image printing apparatus according to the present invention, FIG. 1 is a schematic side view thereof, FIG. 2 is an enlarged side view of the vicinity of a transfer roller, and FIG. 3 is a guide roller supporting portion. FIG. 4 is a perspective view of the vicinity of a transfer roller, FIG. 5 is a plan view and a side view of a printed line of pixels, and FIGS. 6 and 7 are other embodiments of the present invention. , FIG. 6 is a schematic side view of the image printing apparatus shown in correspondence with FIG. 1, and FIG.
FIG. 8 is a perspective view of the vicinity of the transfer roller shown in correspondence with the figure, and FIG. 1 ... Rotating cylinder, 2 ... Paper, 3 ... Image printing device, 4 ...
Support shaft, 6 ... Frame, 7 ... Ink, 11 ... Transfer roller, 11a ... Convex surface, 12 ... Blade, 14 ... Piezoelectric element, 1
5,21 …… Eccentric shaft, 17 …… Guide roller.

Claims (1)

[Scope of utility model registration request] 1. A peripheral surface of a transfer roller that rotates in contact with a printing paper surface is brought into contact with a tip of a blade that advances and retreats by a driving device, and ink supplied to the peripheral surface of the transfer roller by an inking device is intermittently applied by the blade. In an image printing apparatus that performs printing by moving the ink in the scraped portion and the non-scraped portion onto the paper surface, a frame supporting the transfer roller is attached to the peripheral surface of the transfer roller against the surface of the paper. A guide roller, which is movably supported in the direction of separation, is axially parallel to the transfer roller and is in contact with the paper surface. The image printing apparatus is characterized in that the supporting shaft is an eccentric shaft whose rotation can be adjusted such that the roller fitting portion and the shaft hole fitting portion are eccentric.