JPS6058698B2 - Non-impact dot printing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a so-called dot printing method, in which specific points are selected from a number of points (dots) arranged in a grid pattern vertically and horizontally within a certain section, and these points are printed to print a specific character or The dots are made to represent a figure, and the dots selected in this way are printed or printed on paper.In the present invention, as a means of printing these dots, small dots generated on the surface of the ink are used. It utilizes small droplets of ink that fly off when bubbles burst.

Conventional non-impact dot printers have already been proposed, such as those that use a combination of thermal paper and a heating point with an array of minute heating elements, printing machines that use discharge breakdown like facsimile machines, and inkjet printing devices. However, these methods have drawbacks such as requiring special thermal copying paper, using high voltage, or having a very complicated structure.

As a dot printing method that does not exhibit such drawbacks, the present inventor focused on the phenomenon in which droplets are ejected from the liquid surface when a bubble bursts, and generated small bubbles at a specific position on the liquid surface in a certain section. We investigated the possibility of using the minute ink droplets released when small bubbles burst for printing or printing. The droplet release phenomenon that occurs when bubbles burst is, for example, when small carbon dioxide gas bubbles rise to the surface of a carbonated drink and burst, or when water is heated to a temperature of 40 to 60 degrees Celsius, and bubbles float up and burst. Under appropriate conditions, when a single bubble bursts, a single droplet is ejected vertically upward onto the liquid surface.

The present inventor has long discovered that when small bubbles rise from the liquid and burst on the liquid surface, for example, as seen in carbonated drinks poured into a glass, only one relatively coarse droplet appears on the liquid surface. He was conducting research on the phenomenon of being lifted vertically,
As a result, when the surface tension of the liquid and the bubble diameter meet certain conditions, 1 J of relatively small bubbles (for example, 0.3 wrm
~2TwLφ) When a bubble rises from the liquid and bursts on the liquid surface, only one droplet of a size corresponding to the bubble diameter (approximately 1/10 of the bubble diameter) splashes vertically to the liquid surface. I learned that it exhibits a special phenomenon called being able to rise.

To explain this phenomenon more easily than in 7 using diagrams, attached Figure 1 shows the state of droplet ejection using an enlarged sectional view as a series of diagrams illustrating changes over time in Figures a to f. When a bubble bursts, a shock wave caused by the instantaneous rupture of the surface tension caused by the bubble bursting propagates along the inner surface of the bubble and concentrates in the center, causing droplets to protrude from this area.
If the conditions are met, only one droplet will be thrown up perpendicular to the liquid surface. The inventor of the present invention predicted that applying this phenomenon to a dot printing method would bring about various advantages without the drawbacks mentioned above, and investigated the possibility.

As a result, the present inventor arranged a large number of minute electric heating elements directly below the ink liquid surface, and selectively heated the electric heating elements at specific positions to correspond to specific characters or figures. A non-impact dot printing method in which a row of small bubbles is formed, which are burst, and the ejected ink droplets are received by paper or other printing surface placed directly above the liquid surface to print or print. I devised it. According to the present invention, there is no noise, water-based ink can be used, so there is no danger of odor or ignition, and high voltage is not required, making the device safe and simple, and there is no need for special printing paper. Inventive step can be achieved.

Hereinafter, the present invention will be explained in more detail with reference to the accompanying drawings.

FIG. 2 is a partially divided perspective view for explaining the outline of an apparatus for carrying out the non-impact dot printing method according to the present invention, and FIG. 3 shows a large number of micro heating elements arranged in the printing section. FIG. 3 is a perspective view illustrating a specific example of a means for selecting a specific position from among the images.

In Fig. 2, 2 has a small section next to it in which a large number of micro heating elements 1 are regularly arranged in a lattice shape as shown in the figure. A large number of printing units are arranged side by side, and the ink liquid 3 is always kept at a constant level and filled to the extent that the heating element is slightly submerged.

The distance between this heating element and the surface of the ink liquid is preferably a depth approximately equal to the diameter of the generated bubbles. Maintaining this constant liquid level is public! Achieved by the liquid level controller 4 of
This also serves to replenish ink liquid from the ink liquid tank 5. When the amount of ink remaining in the ink liquid tank 5 becomes less than a certain amount, the remaining amount detection device 6 issues an alarm. A large number of printing papers 14 are stored in the paper bag 12,
At the start of printing, one sheet is automatically taken out and transferred to the printing unit 2 by the feed roller 13 and suction conveyor belt 16.
is sent to the location. At this time, when the leading edge of the paper passes the point of the paper feed monitoring means 10 (for example, a known photoelectric relay switch), a relay in the control box is activated and the rotation of the paper feed roller 13 is stopped. At this time, the paper is attracted to the lower surface of the belt 16 of the conveyance means by an air suction suction conveyance means arranged above the printing section, and is maintained at a constant distance above the ink liquid surface, and at the printing section shown in the figure. It is sent out to position 2. This suction conveyance means consists of an air box 15 with a large number of suction ports arranged, a conveyance belt 16 that moves around this box fu, and a pulse motor 11 for driving this belt.The pulse motor is driven by a control box. Controlled by control means. When one horizontal line of dot printing on the printing paper is completed, the pulse motor 11 is actuated by one line of characters by the relay means housed in the control box 9 to move the belts 16 and 16a. is advanced to the position of the next line, and then printing of the next line based on input signal No. 3 1 is started again in response to a command signal from the control box.

The case shown is a specific example suitable as a dot printing device for typesetting printing, but of course it can also be used for copying printed matter or figures, and in that case, the printing section should be divided into subdivisions. It is convenient to arrange the foam dots (print dots) over the entire surface, and to selectively activate the print dots by signals based on light from points corresponding to these dots on the original drawing. In this case, it is also preferable to arrange the print dots in one row horizontally so that the feeding speed of the original image and the feeding speed of the printing paper are synchronized. As shown in the figure, the delivery belt 16a is disposed surrounding the heating box 17, and is designed to dry the printed paper by heating it with a heater 18 and send it out.

The paper printed in this manner is discharged onto the receiving plate 19. For dot printing based on the input signal 1, this signal is passed through the converter 8 in the scanning switch control section 7 to electrically heat the corresponding heating element as a current in a circuit corresponding to a certain combination of columns and rows of dots. This is done by FIG. 3 shows a specific example of the structure of the printing section according to the present invention, which is convenient for selectively energizing heating elements at specific positions. The micro heating element array 23 is connected to each of the parallel conducting wires pulled out from equally spaced positions on the conducting wire 20 and arranged in a regular arrangement, while the other connecting wire from each heating element is connected as shown in the figure. The heating elements arranged in each horizontal row are connected in parallel to one conductor, and the terminals of the connection wires in each column and row are connected to the corresponding terminals of the switch control unit 7 by independent connection wires. . In response to the input signal 1 to the controller 9, a circuit connecting a specific set of columns and rows is closed, and a heating element at a specific position is heated by electricity, thereby creating small bubbles in the ink liquid, which burst and break up the ink liquid. Dot printing is performed by splashing the drops. It is convenient for the scan switch control section to be a known switching means using, for example, a microscopic switching element configured to be turned on and off by a stepwise gate bias voltage, and used in combination with a converter.

[Brief explanation of the drawing]

Fig. 1 is an explanatory view of changes over time to explain the droplet release situation accompanying bubble breakage, and Fig. 2 is a partial perspective view illustrating a specific example of an apparatus for carrying out the non-impact dot printing method according to the present invention. FIG. 3 is an explanatory diagram showing an example of the arrangement and wiring structure of the micro heating elements arranged in the printing section. 1...Minute heating element, 2...Printing section, 3
... Ink liquid, 4 ... Liquid supply and liquid level controller, 5 ... Ink liquid tank, 6 ...
...Residual liquid amount detection means, 7...Scanning switch control unit, 8...Converter, 9...Controller, 10...Paper feeding monitoring Means, 11...
...Pulse motor, 12...Print paper back, 1
3...Paper feed roller, 14...Print paper,
15... Suction air box, 16, 16a...
...Transport belt, 17...Heating box,
18... Heater, 19... Receiving plate, 20...
...Column terminal, 21...Horizontal terminal, 22...
...Insulating material, 23...Minute heating element.

Claims (1)

[Claims] 1. Non-impact printing that selects points corresponding to specific characters or figures from a large number of dots arranged in a certain area and prints these points on the printing surface of paper, etc. In the dot printing method, a large number of micro heating elements are arranged as dots under the ink liquid surface, electricity is selectively applied to these micro heating elements to form bubbles, and as these bubbles burst, micro droplets of ink are formed. A non-impact dot printing method characterized by emitting ink droplets and using the ejected minute ink droplets for printing or printing.