JPH06293140A - Ink transfer printer and method - Google Patents

Abstract

PURPOSE: To obtain an inexpensive ink transfer printing apparatus enabling high speed image printing of high resolution by changing the viscosity of ink in the vicinity of an orifice to allow the ink to flow out to a perforated surface through orifices to enable the transfer of the ink. CONSTITUTION: In an ink transfer printing apparatus wherein ink is transferred to a printing medium from an ink reservoir 2 through a perforated surface equipped with a large number of orifices 6, the viscosity of ink present in the vicinity of the orifices is changed by a viscosity control device containing a thermal, magnetic and electrical technique. By this constitution, the ink is allowed to flow out to the perforated surface through the orifices 6 to enable the transfer of the ink. As a result, an expensive ink transfer printing apparatus enabling high speed image printing of high resolution can be obtained.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to the field of ink transfer printing, and more particularly to ink transfer printing driven by changes in ink viscosity.

[0002]

BACKGROUND OF THE INVENTION Over the years, many attempts have been made to develop printing techniques with simple mechanical structures. It was hoped that such printing techniques would result in reliable, low cost products. For some reason, printing techniques have not adequately met these objectives. Known thermal printing techniques have several drawbacks. In the case of direct thermal printing, for example, special thermal paper is required. Thermal transfer printing is less efficient at utilizing the ink ribbon and, especially for color printing, the cost of using the ribbon is high. Another drawback of thermal printers is that their printing speed is too slow for high volume printing.

Although ink-jet printing has many advantages, it still suffers from some reliability problems. The main problem with ink jets, or bubble type ink jet devices, is that organic compounds in the ink decompose at high temperatures (eg, 350 ° C.) to form deposits in the nozzles. is there. This high temperature is necessary to generate the bubbles that eject the ink droplets. As a result, bubble-type ink jets are prone to nozzle clogging and cling formation problems. Another problem with ink jets is that the inks used must have low viscosities (eg, generally <10 centipoise), which severely limits the types and types of inks available. The ink jet print speed is again too slow for high volume printing.

For additional background information on known printing techniques, see San Die, published in 1988.
Robert Robert C. of Go. Durbeck and Sol
"Computer Graphic" by Sherr
s-Technology and Applicati
ons ", Vol. II- "Output Hardc
can be found at "opy Devices".
US Pat. No. 4,608,577 to Hori describes an ink jet type thermal printer.
The printer includes a film or belt with a plurality of holes corresponding to conventional ink jet nozzles. The holes in the film or belt are filled with ink. The bubble pressure then heats (evaporates) the ink in the holes until the ink is sprayed against the paper.

Bupara US Pat. No. 4,675,6
No. 94 has a description of printers. The printer includes a perforated printing plate, an independent heater, and an ink container. The inks utilized are phase change or hot melt inks that are solid at room temperature. When a part of the solid ink contained in the holes of the printing plate is heated, the printer causes volume expansion (because of the change from the solid state to the liquid state), and the ink is ejected from the heated holes. It operates on the principle of sending out. As the ink expands in the predetermined holes, the print medium is brought into contact with the liquefied ink and the transfer takes place. The print medium must be contacted with the liquefied ink before the ink has cooled. Alternatively, the print medium can be contacted with the printing plate prior to volume expansion.

US Pat. No. 4,275,2 to Cielo et al.
No. 90 describes a thermally actuated liquid ink printer. The printer includes an ink reservoir with multiple orifices. The driving force of the printer is the localized heating of the ink in the orifice, which will cause at least partial evaporation of the ink and / or reduced surface tension. .
As a result, ink flows out of the heated orifice. Desirably, the heating produces bubbles that eject ink droplets. In the alternative, the effect of heating only lowers the surface tension and causes the ink to flow out through the heated orifice. This alternative operation utilizes a static pressure that is lower than the surface tension of the unheated ink on the ink surface.

US Pat. No. 4,164,7 to Cielo et al.
No. 45 describes a method for varying the amount of ink adhering to a sheet passing through an orifice based on the viscosity of the ink. For example, the printed line width is
It is controllable. The described method cannot completely control the ink flow. That is, the ink flow is continuous. The only variable is the amount of ink flow. In this regard, in the case of Cielo et al. ('745), the continuous flow of ink out of the orifice is
A bypass is provided to prevent crossing the gap and reaching the paper, but only while the viscosity is above a predetermined value. The ink flowing out of the orifice must cross the gap before it reaches the paper.

Furthermore, the known prior art erroneously evaluates the advantages and benefits of viscosity driven printing. In the case of the present invention, printing can be controlled easily and accurately by changing the viscosity of the ink. Such control is superior to that obtained by bubble, phase transition, or surface tension driven printing. Cielo and others ('
In the case of (745), it is assumed that the ink always flows through the orifice, and the ink viscosity is used to try to control the amount of the ink adhering to the paper. In the case of Bupara,
It operates by the volume expansion of solid ink as its phase changes from solid to liquid. The Bupara technique is very cumbersome and time consuming because it requires multiple steps to transfer the ink to the paper. In the case of Cielo et al. ('290), the ink is ejected from the orifice to cross the gap and reaches the paper, or the ink under pressure flows out from the orifice when heated to the surface tension and pressure mode. Works with. The evaporation mode of Cielo et al. Is a bubble type ink jet and is therefore quite different from the present invention. The surface tension and pressure modes of Cielo et al.
There is a problem in feasibility. That is, since the paper does not contact the orifice plate, the method of transferring the ink is unclear. Furthermore, it is extremely difficult, if not impossible, to construct a practical printer that relies on surface tension to control the printing process.

It has been found that surface tension and viscosity vary with temperature, but the magnitude of changes in surface tension and viscosity are quite different. In Table 1 (shown below), the change in viscosity of an ink-like fluid is more dramatic for a temperature change of 80 ° C compared to the slight difference in surface tension.
In the present invention, the well-known fluids of glycerol and ethylene glycol are used to model useful ink properties.

[0010]

[Table 1]

As shown in Table 1, the magnitude of the change in viscosity far exceeds the change in surface tension. The large change in viscosity allows for the high level of control needed to produce reliable, low cost products. On the other hand, in the case of a device that relies on surface tension, the magnitude of the change in surface tension with respect to an appropriate temperature change is not significant from the viewpoint of design or engineering, and is therefore difficult to control. In short, the known prior art erroneously evaluates the advantages and advantages of printers driven by ink viscosity changes.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a novel, non-obvious printing technique that has potentially widespread applicability. Another object of the invention is to overcome many of the drawbacks of known printing techniques,
It is to provide a printing technique that is not only simple in design and reliable, but also capable of high resolution printing using a wide variety of inks. Yet another object of the present invention is to provide related technologies applicable to printers, digital copiers, video printers, facsimile machines, etc., and useful for color and gray scale printing or copying. .

[0013]

SUMMARY OF THE INVENTION In accordance with the present invention, an ink transfer printing apparatus is provided with an ink reservoir for storing ink held under pressure. The ink reservoir is associated with an ink transfer surface having a plurality of holes. The operating principle of the present invention is to drive the ink transfer process by changing the ink viscosity near a given hole. The ink viscosity near each hole can be varied using a number of techniques including thermal, magnetic, and electrical techniques. Under ambient conditions, the viscosity of the ink prevents the flow of ink through the pores of the ink transfer surface. Varying the ink viscosity near the given holes causes a controlled amount of ink near each of the given holes to flow through the given holes to the ink transfer surface. That is, the ink flows only after the viscosity of the ink is changed.

The ink flowing to the ink transfer surface forms ink dots on the ink transfer surface above these predetermined holes. The image can then be printed by transferring the ink dots to the print medium. Ink dots can be transferred by contacting the print media with an ink transfer surface. Alternatively, it may be desirable to first transfer the ink dots to the intermediate surface and then transfer the ink dots from the intermediate surface to the print medium. In addition, print results are improved if the spread of ink dots on the ink transfer surface is controlled. By providing at least one concentric region on the ink transfer surface around each hole for an ink transfer printing device, ink spreading can be accurately controlled. The concentric regions form an ink flow barrier that prevents ink spreading at each orifice.
The improved dot size control afforded by the present invention allows printing devices to improve print quality.

The present invention offers several advantages, including: The printing technique of the present invention is capable of high speed, high resolution printing. In addition, this printing technique is capable of performing gray scale toning, continuous toning, and full color printing when printing images. The printing technique of the present invention is also capable of utilizing a wide range of inks for excellent print quality on a variety of print media. Further, the printing technique can be designed to print characters, lines, or pages at once.

[0016]

1 shows a perforated ink transfer device 1 including an ink reservoir 2 and an ink transfer surface 4 (contact surface). The ink used for printing is stored in the ink reservoir 2. Ink transfer surface 4
Has a plurality of orifices 6. Each orifice 6 in the ink transfer surface 4 corresponds to an ink dot that can be printed on the print medium.

Before describing the detailed operation of the ink transfer device 1, the ink reservoir 2 and the ink transfer surface 4 are described.
It is helpful to discuss the physical characteristics of. Generally speaking, the size, shape and structure of both the ink reservoir 2 and the ink transfer surface 4 are very versatile. In particular, referring to FIG. 1, the ink transfer surface 4 is a flat, perforated sheet. However, a variety of other perforated surfaces can be utilized (see, eg, FIGS. 11, 13A-13E). Therefore, the size and shape of the ink transfer surface 4 is not critical.
For example, the ink transfer surface 4 can have a cylindrical shape with a circumference that is less than, equal to, or longer than the length of the page.

It may be desirable to have the size of the ink transfer surface 4 slightly exceed the page size of the paper (ie, the page size ink transfer surface). Page size ink transfer surface 4 1 at a time
Printing speed is increased by transferring ink page by page. Compared to printing one character or one line at a time, when printing one page at a time, the print medium only needs to contact the ink transfer surface 4 once for each page. , It is usually faster. On the other hand, as shown in FIG. 2, the ink transfer device 1 can also form a print head 8 in which the length and width of the ink transfer surface 4 is relatively small compared to the size of the page. In these cases, the print head 8
The print medium 10 must be contacted several times for each page to be printed (see the dashed line in FIG. 2).
The print head 8 can have various sizes and shapes. For example, as shown in FIG. 3, the print head may be a line head that prints one line at a time.
It can also be the print head 12.

Therefore, the physical characteristics of the ink transfer device 1 are not critical. Therefore, the ink transfer device 1
The size, shape, and configuration of (ink reservoir 2 and ink transfer surface 4) can be designed for a particular application. The present invention is applicable to a wide range of resolutions, that is, from a low resolution of 10 dpi (dots / inch) to 1
It is possible to achieve extremely high resolutions in excess of 000 dpi. Each dot corresponds to an orifice 6 in the ink transfer surface 4. Thus, a 600 dpi ink transfer device would have an orifice of 36,000 / square inch.

The shape of the orifice 6 shown in FIG. 1 is circular, but the shape of the orifice is not critical.
For example, the orifice 6 can be elliptical or square. The size of the orifice 6 on the ink transfer surface 4 is from 10 μm depending on the desired printing resolution.
It varies in the range of 200 μm. The thickness of the orifice 6 is
It varies in the range of 10 μm to 500 μm depending on the desired printing resolution. The orifice 6 is commonly known in the semiconductor processing arts as laser ablation, wet etching,
Alternatively, it is formed by micromachining such as plasma etching. The ink transfer surface 4 (eg, perforated sheet) can be made from a wide variety of materials. That is, the perforated sheet is formed by a stainless steel mesh screen, electroformed with nickel, or treated polyimide (eg, E.
I. DuPont Company and Ube Com
KAPTON or UP made by panyof Japan
ILEX).

The operation of the ink transfer device 1 will be described in detail below. FIG. 4 shows a cross-sectional view of the ink transfer device 1 in the non-printing state. The ink reservoir 2 contains ink 14. Ink at room temperature 1
Desirably, the viscosity of 4 is greater than 20 centipoise (cps). A wide variety of inks, including inexpensive commercial products, meet (or can simply be made to meet) the viscosity requirements of the present invention. A positive pressure is applied to the ink 14 by the pressure inlet 16 to the ink reservoir 2. The amount of pressure exerted on the ink 14 depends on the viscosity of the ink 14 and the geometry of the orifice 6. For example, a diameter of 50 μm and a thickness of 125
In the experiment using glycerol for the orifice of μm,
The inventor utilized a pressure of about 8-20 Torr. It is desirable that the pressurization be constant so that the amount of ink in each ink droplet is constant.

Since the viscosity of the ink 14 at room temperature is usually extremely high, the ink transfer device 1 is usually in a non-printing state. That is, due to the high viscosity of the ink 14 within the ink reservoir, the pressurized ink 14 does not flow through the orifice 6 of the ink transfer surface 4. In a technical sense, ink flow could be observed in the orifice 6 for several years, but this flow would not be noticeable to the naked eye. Therefore, in the non-printing state, the positive pressure is the pressure inlet 16
The ink does not flow out of the orifice 6 of the ink transfer surface 4, i.e., is extruded, even if applied via That is, when a particular ink 14 is utilized, the pressure applied is not great enough to cause the ink to flow through the orifice 6 at room temperature. Therefore, regardless of whether the print medium 10 contacts the ink transfer surface 4, the ink cannot be transferred to the print medium 10 when the ink transfer device 1 is in the non-printing state.

On the other hand, the ink transfer device 1 includes the print medium 10
It is possible to switch to a printing state in which the ink can be selectively transferred to. Ink transfer device 1
Locally switches the ink viscosity associated with each orifice 6 to switch from a non-printing state to a printing state for each orifice. When the viscosity of the normally high ink 14 decreases, the reduced viscosity ink 14 flows through the orifice 6 to the ink transfer surface 4 to form ink dots. The ink 14 of which the viscosity has decreased can flow to the ink transfer surface 4 by a capillary action,
The ink 14 in the ink reservoir 2 has a pressure inlet 16
It is desirable to apply a slight positive pressure through. The pressure applied to the ink reservoir 2 should be sufficient to force the reduced viscosity ink through the orifice 6 but not high enough to cause the non-viscosity ink to flow out of the orifice 6. Is set. The ink transfer process is described in further detail in connection with Figure 5A.

FIG. 5A is a sectional view of the ink transfer device 1 in a printing state. 4 and 5A show the device of FIG.
It is basically the same structure except that it includes a divergent orifice wall and a thermal barrier 17, which will be described in more detail. The orifice wall shown in FIG. 5A is divergent, but can also be converged as shown in FIG. 4, or
It is also possible to make it straight. It is also possible to diverge the orifice 6. In FIG. 5A, three orifices 6 of the ink transfer surface 4 are shown. However, FIG.
As shown in A, the ink flowed through the intermediate orifice 6 only and onto the ink transfer surface 4. The ink flowing to the ink transfer surface 4 via the intermediate orifice 6 is transferred to the print medium 1
Transferring 0 to the print medium by contacting the ink transfer surface 4 of the ink transfer device 1. The ink transfer surface 4 can then be reused as soon as the ink is depleted (although microscopic residues are present).

In the case of FIG. 5A, only the viscosity of the ink 14 near the intermediate orifice 6 has dropped. As a result, the ink 14 close to the intermediate orifice 6 will mainly be absorbed by the pressure inlet 1.
Due to the pressure applied through 6, the intermediate orifice 6
Through to the ink transfer surface 4. On the other hand, the viscosity of the ink near the left and right orifices 6 does not drop and thus remains high enough to prevent the pressure applied from pushing the ink out of the left and right orifices 6. It was Therefore, as shown in FIG. 5A, the ink 14 near the left and right orifices 6 did not flow to the ink transfer surface 4.

FIG. 5B shows the ink transfer device 1 shown in FIG. 5A.
3 is a detailed view of the orifice 6 of FIG. FIG. 5B is shown to clarify what it means to reduce the viscosity of the ink near (or in close proximity to) a particular orifice. In the case of FIG. 5B, the orifice 6 is partially filled with ink as shown and is directly coupled to the ink reservoir 2 below the orifice 6. The dot dash line (a) shown in FIG. 5B shows a portion of the reduced viscosity ink 14, that is, ink that can be considered to be near the orifice 6. However, in reality, the orifice 6
Other parts of the ink further away from will also change in viscosity, but to a lesser extent. Nevertheless, this concept starts with the ink closest to the orifice 6 and reduces the viscosity of the ink so that a given amount of ink
It flows through the orifice 6 to the outer surface of the ink reservoir 2, forming ink dots of a particular size. The actual operating parameters can easily be determined experimentally according to the technique used, the size of the orifice, the viscosity of the ink at ambient conditions, the pressure, the desired size of the ink dot, etc.

It is important that the viscosity of the ink 14 drops only near the orifice 6 through which the ink 14 will flow. An image can be printed by selectively reducing the viscosity of the ink 14 near the orifice 6 where the ink dot or pixel is desired. That is, each orifice 6 represents an ink dot on the image to be printed. As the viscosity of the ink 14 near the particular orifice decreases, the ink dots form a printed image at the location corresponding to the particular orifice. On the other hand, ink 1 near a specific orifice
If the viscosity of 4 is not reduced, no ink dot will be formed on the printed image at the position corresponding to the specific orifice.

The ink flowing on the ink transfer surface 4 will remain on the ink transfer surface 4 until transferred to the print medium 10. That is, regardless of whether the ink viscosity returns to its normal viscosity level, the reduced viscosity ink that has flowed to the ink transfer surface does not recede back to the orifice from which the ink came out. Thus, the ink transfer process implemented by the present invention is viscosity driven. That is, the viscosity of the ink is used as a switch. Normally, at ambient conditions, the viscosity of the ink is high enough for the applied pressure to prevent (or turn off) ink flow. On the other hand, under operating conditions, when the viscosity of the ink near the orifices corresponding to the ink dots decreases, ink dots are formed (ie, turned on) on the printed image.

The ink viscosity relationship is as follows: Viscosity = f [T, E, H, pH, hv] where T is temperature, E is electric field and H is magnetic field. Therefore, the viscosity of the ink near the predetermined orifice 6 raises the temperature, applies an electric field or magnetic field, and lowers the pH,
It can be lowered in several different ways, such as increasing hv. Temperature and hv are closely related because increasing light intensity is one way to increase temperature. Although reducing the viscosity of the ink is critical, the method or technique utilized to reduce the viscosity is not critical.

Regardless of the technique utilized, localized viscosity reduction is at least 50 for reliable viscosity control.
% Is desirable. Ink is at room temperature (ambient conditions)
It can be a solid ink or an ink of any viscosity whose viscosity exceeds 10 cps. The viscosity of the ink is preferably more than 100 cps. However, under operating conditions, the ink becomes a low viscosity liquid. Generally, the viscosity of ink under operating conditions is 1 to 100 cp.
fluctuates in the range of s. However, it is also possible to utilize higher viscosities at correspondingly higher pressures.

Ambient conditions are defined as the conditions under which the ink transfer device 1 is in a non-printing state. For example, in ambient conditions,
No external excitation energy (heat, electricity or magnetism) is applied to the device 1. As a result, all the ink in the ink transfer device 1 is at room temperature or actively controlled temperature. On the other hand, the operating condition is defined as a condition under which the ink transfer device 1 is in a printing state. For example, for operating conditions, external excitation energy (heat, electricity, or magnetism) is applied to the device 1. The ink may or may not be room temperature, depending on the type of energy applied.

The composition of the ink is selected based on the method used to change the viscosity of the ink. For example, in embodiments where a magnetic field is utilized to induce a change in viscosity, the ink includes a material such as magnetic toner.
Similarly, in an embodiment in which an electric field is used to induce a change in viscosity, the ink may have a shape of Lord Corporation.
T. SAE Technical by Ducios
"Design of Devices Using" in Paper Series, # 881134.
Electrological Fluid
s ”(1988), an electrorheological fluid.

In the case of the thermally induced viscosity reduction embodiment, the ink may comprise 2-10% by weight of colorant, 93-60% by weight of carrier, 5-30% by weight of additives. it can. The carrier or intermediary material can be a wax, a monomer, an oligomer, or a polymer. For example, waxy materials include carnauba
Natural waxes such as waxes and synthetic waxes such as stearic acid derivatives are included. Monomeric, oligomeric and polymeric carrier materials include acrylics, vinyl derivatives, ester type monomers and copolymers. The carrier material also includes glucose and rosin derivatives. The mediator or carrier is also a solvent such as water and a glycol chain (ethylene.
Glycols, diethylene glycols, propylene glycols, butanediols, glycerols, etc.) and polyethylene glycol trains.
The ink vehicle or carrier can also include commercially available lithographic, screen printing, gravure inks. Additives include, for example, various surfactants and viscosity reducers, hardening and strengthening agents, dye optical properties (transparency) and solubility improvers. Additives are not a critical requirement. Nevertheless, the purpose of the additive is to modify the viscosity and surface tension of the ink to improve print quality and system reliability.

One way to control the viscosity of the ink 14 is with temperature. Ink 1 at room temperature
4 preferably has a viscosity of at least 20 cps. However, as the temperature of the ink 14 increases, the viscosity of the ink 14 decreases. Table 1 shows the magnitude of the viscosity change for some fluids representing inks with respect to a temperature change of 80 ° C. That is, the viscosity of glycerol was reduced by about 95% and the viscosity of ethylene glycol was reduced by about 70%. Local heating thus acts to induce a flow of ink 14 from the ink reservoir 2 to the ink transfer surface 4 via the orifice 6. That is, by applying heat to a given orifice,
The ink near these orifices is heated. Heating the ink reduces the viscosity of the ink. When the viscosity of the ink falls below a critical level, the pressure applied causes the heated ink to flow through the corresponding orifice to the ink transfer surface 4.

6A-6D show various structures that can be used to locally heat the ink 14 close to some of the orifices 6 to reduce its viscosity. In the case of FIG. 6A, a thermal print head 8 with a heating element 18 is shown. The heating elements 18 are preferably located near (and preferably above) each orifice 6 where ink dots are desired. Once so arranged, the heating element 18 serves to heat the ink contained in the orifice 6 by applying a heat flux to the ink near the orifice 6 above which the print head 8 is arranged. To do. Next, the heated ink
It flows to the surface of the ink transfer surface 4 (perforated sheet) and stays there until transferred to the print medium 10. Thus, a printed image can be formed by moving the thermal print head 8 over each orifice 6 where ink dots are desired.

One of the important advantages of the present invention is that after heating each orifice 6 over the entire page, it is possible to transfer the resulting ink to the print medium 10. This is ink
This is because once the ink has flown to the ink transfer surface 4 through the specific orifice 6, the ink thus flowing does not need to be kept heated. That is, since the ink is not drawn back to the orifice 6 from which it came out, once it reaches the ink transfer surface 4, cooling is possible. Therefore, the ink will remain on the ink transfer surface 4 until transferred to the print medium 10. This advantage is obtained regardless of the method used to induce the reduction in viscosity (eg T, E, H, pH, hv). As a result, the size of the print head 8 is very small, such that only ink near a single orifice is heated at a time (see FIG. 6A).
At the same time, it is possible to vary to very large sizes so that all orifices can be heated. A reasonable compromise of speed and cost will lead to a print head 8 occupying a position between the poles, for example a line print head as shown in FIG.

In FIG. 6B, a heater 20 (resistor) and a heat conductor 22 are used to generate the thermal energy necessary to selectively reduce the viscosity of the ink 14 near a given orifice 6. The heaters 20 are mounted underneath the ink transfer surface 4 for each orifice 6 as shown, but the heaters 20 may be arranged in any manner when closely associated with the orifices 6. It is possible. For example, the heater 20 can be arranged in a recessed part inside the perforated sheet 4 itself. Each heater 20 includes a heat conductor 22 to facilitate heat transfer from the heater 20 to the ink 14 in the corresponding orifice.
Are combined. It is desirable to heat the ink close to the orifice 6 in a harmonious manner so that uniform heating can be performed. For example, the heater 20 can have a ring shape, or four small heaters can be evenly spaced around each orifice.

In FIG. 7, a wire 24 is provided for each orifice.
Shows a layer of ink transfer surface 4 with coaxial resistors 20 'connected in a matrix to each other. Also shown in FIG. 7 is a controller / energy source 25 for controlling the supply of electrical energy to the resistor 20 '. The ink transfer surface 4 can be made from a wide variety of materials such as ceramics, glass, plastics and the like. Each coaxial resistor 20 is connected by a wire 24.
It is possible to supply electrical energy to the coaxial resistor 20 'which is individually addressed to the'and the ink dots correspond to the desired orifice. Heaters 20 and 2
The 0'and the wire 24 can be formed by a thick film or thin film process which is a well-known technique.

On the back surface of the ink transfer surface 4 (perforated sheet), for example, a glass substrate, a resistance layer, a metal conductor, and
It is possible to provide a passivation layer. Thin film structures are well known in the art and can be found in Hewl
ett-Packard Journal, Vol. 36, No. 5, and above all, at the beginning of page 27 of the journal, "De
velocity of the Thin-Fil
m Structure for the Think
Similar to the ThinkJet print head, which is detailed in the article entitled "Jet Print". However, since the generation of ink bubbles is not necessary, the thin film structure of the present invention is further simplified. Ink that places a resistive layer on the substrate and below the orifice
Unlike the jet device, the present invention positions the resistive layer so that the heat generated by the resistive layer is in close proximity to the orifice 6. For example, in the case of FIG. 6B, the heater 20
Is coaxial with the orifice and is fixed to the inner surface of the ink transfer surface 4. Alternatively, the heater 20 could be located on the orifice itself or on the outer surface of the ink transfer surface 4. In the case of this embodiment, it is possible to sufficiently reduce the viscosity of the ink in the orifice within about 100 microseconds. In addition, the heat conductor 22 can be utilized to help heat the ink in the orifice.

The electrical energy supplied to the heater depends on several parameters such as, for example, ink composition, resistance, voltage, pulse width, and period. These parameters can be easily determined for a particular design. Even so, the thermal embodiment (FIG. 6B) utilizing a glycerol-based ink is 5
A heater having a resistance of ~ 200 ohms, a voltage of 0.5 to 50 volts, and a pulse width of 5 μsec to 4 msec applied to the heater can be used to function well.

As shown in FIGS. 6C and 6D, light (hv)
Can be used to supply thermal energy to the ink near the orifice 6. The light can be generated by, for example, a laser beam, an infrared bulb, a flash bulb, an ultraviolet bulb, or an incandescent bulb. In the case of FIG. 6C, laser 26 causes a laser beam to be generated, reflected at mirror 30 and directed to a predetermined orifice 6 in ink transfer surface 4. In this type of set up, the ink transfer surface 4 can be easily and quickly addressed to each orifice 6 so that the laser beam can locally heat the ink. Figure 6D
In case of infrared light (IR) source 32 and reflective housing 3
4 is used to focus the infrared light on the orifice 6 of the ink transfer surface 4. It is also possible to use other types of light sources to heat the ink at the orifice.
Alternative methods for controlling the viscosity of the ink 14 include applying an electric field (E), a magnetic field (M), or lowering the pH. The pH reduction is closely related to the application of the electric field (ie the application of the electric field serves to lower the pH), so this method will not be discussed separately.

FIGS. 8A and 8B show an embodiment of the present invention in which an electric field is generated to induce a decrease in viscosity.
In the case of FIG. 8A, the electrode 38 is provided below the ink transfer surface 4.
-1, 38-2 are provided. Electrodes 38-1, 38
-2 is connected to an alternator 42 by a conductor 40. The AC generator 42 induces an electric field E in the orifice 6 of the ink transfer surface 4 under the control of a control device (not shown), and as a result, the viscosity of the ink 14 near the orifice 6 decreases. In the case of FIG. 8B, the electrodes 38-1 and 38-2 have different orientations. That is, the electrode 38-1
Is an upper electrode, and the electrode 38-2 is a lower electrode. Further, in the case of this embodiment, a thermal barrier 17 (described later)
Is provided. Many other electrode configurations can be utilized to generate the required electric field. For example, as the upper electrode, a roller or a platen that supplies the print medium 10 to the ink transfer device 1 can be used.

FIG. 9 shows an embodiment of the present invention in which a magnetic field (H) is selectively generated at the orifice to induce a decrease in viscosity. In this embodiment, the electrodes 38-1, 3 are
8A is structurally similar to FIG. 8A except that coils 46-1 and 46-2 are used instead of 8-2.
The coils 46-1 and 46-2 can be manufactured by using the technique used for manufacturing a thin film head for magnetic recording. By the AC generator 42, the coil 46-1,
When 46-2 is excited, a magnetic field H is generated in the orifice 6. The magnetic field H reduces the viscosity of the ink near the orifice 6. Many other configurations are possible as long as the magnetic field is generated near the orifice. An optional feature of the present invention is to thermally separate the ink 14 in each hole. Thermal isolation improves the performance of the ink transfer device by reducing heat loss to the surrounding ink and by protecting it from cross talk between the orifices 6.

In the ink transfer device 1 shown in FIG. 5A,
A thermal barrier 17 is included which serves to provide thermal isolation between adjacent orifices. That is, the barrier 17 serves to reduce heat loss to the surrounding ink in the ink reservoir and to protect against cross talk between adjacent orifices. Barrier 17 shown in FIG. 5A
Is coaxial with the intermediate orifice 6 to thermally separate the ink 14 near the intermediate orifice 6 from the ink near other orifices. The barrier 17
It extends approximately 50 μm downward from the inner surface of the ink transfer surface 4 into the ink reservoir 2. Barrier 17
Is a dry film resist (eg, Wilmington) that can be etched, deposited, or photographically imaged.
on, Del. E. I. DuPont Compan
It may be formed using a number of conventional techniques, such as a polymer material under the trade name RISTON or VACREL by y). The depth and configuration of barrier 17 described above is not critical.

The structural design of the ink channels within the ink reservoir can also provide thermal isolation between the orifices. That is, thermal separation of the ink occurs by separating a portion of the ink within the ink channel that supplies the ink to a given orifice. Orifices 6 are shown in FIGS. 10A, 10B and 11.
Can be used to perform thermal separation between
An example of the ink channel 48 is shown. In such a case, ink reservoir 2 is the primary ink source and ink channel 48 receives ink from the primary source.

In FIG. 10A, the ink channel 48
Supplies the ink 14 to the orifice 6. As a result, the ink associated with a particular orifice is thermally separated from other orifices 6. In FIG. 10B, FIG.
A side view of the ink channel 48 shown in FIG. Ink 14 in the ink reservoir 2 is channel 4
It is supplied to the orifice 6 via 8. In the ink channel 48, the ink initially flows up from the reservoir 2 and further reaches the orifice 6. Therefore, the ink 14 is supplied to the orifice 6 in the direction perpendicular to the direction in which the ink 14 flows out from the orifice 6 in the printing state.

FIG. 11 is a plan view of circular print heads 4, 8 with orifices 6 arranged in a circular pattern. Ink channels 48, shown in FIG. 11, supply ink to all of the orifices 6 of the print heads 4, 8. Again, similar to FIGS. 10A and 10B, the ink 14 is in a direction perpendicular to the direction in which the ink 14 flows out of the orifice 6 during printing.
It is supplied to the orifice 6. Ink chamber 48 shown in FIG.
The configuration of is more advantageous because the pressure of the ink 14 at each orifice 6 is the same. On the other hand, FIG.
Using the configuration of the ink chamber 48 shown in A and 10B,
Since multiple channels 48 are utilized and the ink path for each orifice 6 is not always the same length, the pressure of the ink 14 at the orifice 6 is not evenly distributed. In addition, the channels 48 reduce cross talk but also require higher pressure than the embodiments shown in FIGS. 4 and 5 without such channels.

Another optional feature of the present invention is that
It is a post-processing area where the ink transferred to the print medium 10 is rapidly fixed. FIG. 12 shows an ink transfer system including an ink transfer area and a post-treatment area. The ink transfer area includes the ink transfer device 1 described in detail above. The print medium 10 is fed to an ink transfer area where the ink transfer device 1 serves to transfer ink to the print medium 10. At this point, the print medium 10 contains the print image, but the ink is moist or sticky. In addition, the image is often not durable and is often raised. Therefore, the print medium 1
The image should be fixed or cured at zero. Next, the print medium 10 with ink is sent to the post-processing area where the thermal ink fixing device 50 is provided. The thermal ink fixing device 50 uses heat to fix and / or fuse the ink to the print medium 10. A wide variety of thermal ink fixing devices 50 can be used. For example, the heat of the thermal ink fixing device 50 may be generated by a laser beam, a light source, a heating roller or platen, or
It can be produced by an oven. Another advantage of using a heated roller or platen is that it allows the image to be flattened by slightly applying pressure to the roller.

Another optional feature of the present invention is that
The use of colored ink. That is, the present invention can be easily applied to color printing. Since the present invention is able to utilize such a wide variety of inks, all that is really needed is to change the color of the ink in the ink reservoir. For example, at the basic level,
The ink transfer device 1 is capable of printing with the color ink contained in the ink reservoir 2. But,
For full-color printing, inks corresponding to the three primary colors of cyan, magenta, and yellow, and black must be supplied at the same time. Therefore, full color printing is possible by pre-aligning four ink transfer devices 1 with respect to each other, each device comprising a different color ink. The construction of such a device is relatively simple compared to existing color printers. Moreover, many of the advantages of the present invention remain.
That is, it has a high resolution, is inexpensive to produce, and has a simple structure.

13A-13E, some structural embodiments of the color ink transfer device 52 are shown. However, it is important to note that color ink transfer device 52 may exist in a wide variety of sizes and shapes. FIG. 13A shows a pagewidth linear array embodiment in which the ink transfer device 52 is capable of printing the width of the print medium 10 with each of the four colors. For pagewidth linear arrays,
A cyan chamber 1a, a magenta chamber 1b, a yellow chamber 1c, and a black chamber 1d are included. Each chamber 1a-1d has a collar
Supply ink. That is, the cyan chamber 1a supplies cyan color ink to the orifice 6a, and the magenta chamber 1b supplies magenta color ink to the orifice 6b.
The yellow chamber 1c supplies yellow color ink to the orifice 6c, and the black chamber 1d supplies black ink to the orifice 6c.
supply to d. Thus, by combining ink from different chambers, full color printing is possible.

An example of a full page array is shown in FIG. 13B. The ink chambers 1e-1h allow the color / ink transfer device 52 to print one page at a time for each of the three primary colors and black. In this example, the ink chambers 1e-1h are slightly larger than the page to be printed. FIG. 13C shows a cubic array in which each side is an ink transfer device 1 with ink chambers 1i-1l containing different color inks. FIG.
Shown at D is a curved cubic array with color ink chambers 1m-1p. FIG. 13E shows a cylindrical array with color ink chambers 1g-1t. The size and shape of the ink chambers 1a-1t are flexible but are determined by the desired configuration of the color ink transfer device 52.

Another optional feature of the present invention is that
The use of the intermediate transition surface. FIG. 14 shows an ink transfer device 1 that utilizes an intermediate transfer surface 54 to assist in transferring ink from the surface of the ink reservoir 2 to the print medium 10. As mentioned above, an advantage of the present invention is that a wide variety of print media 10, including plain and transparencies, can be utilized. However, since the present invention can work with a wide variety of print media, paper quality and absorbency can vary widely. as a result,
First, it is desirable to transfer the ink on the outer surface of the ink reservoir 2 to the intermediate transfer surface 54.

For example, FIG. 14 shows a cylindrical ink reservoir 2 in contact with a cylindrical intermediate transfer surface 54. The intermediate transfer surface 54 has a known quality and absorbency so that the ink transfers cleanly to the intermediate transfer surface 54. That is, almost no ink remains on the outer surface of the ink reservoir 2. For example, the outer surface of the intermediate transition surface 54 can be made of a polymeric material such as mylar or rubber. further,
The size of the intermediate transfer surface 54 need not be similar to the size of the ink reservoir 2.

Once the ink is transferred onto the intermediate transfer surface 54, the ink is transferred to the print medium 10 by contacting the print medium 10 with the intermediate transfer surface 54 using any of several techniques. You can FIG. 14 shows the ink that is transferred to the print medium 10 using the rollers 56 that press the print medium 10 against the intermediate transfer surface 54. Once the ink has transferred to the print medium 10, the intermediate transfer surface 54 is cleaned to remove residual ink that has not transferred. A rubber doctor blade (not shown) can be used to perform the cleaning process.

Yet another optional feature of the present invention is probably the preferred method for pressurizing the ink reservoir 2. According to this feature, the ink reservoir 2 is pressurized without the need for the pressure inlet 16 itself (see Figure 4). 15, 16A, and
16B shows an embodiment of this feature. The ink reservoir 2 further includes a piston 58, an internal pressure chamber 60, and an ink chamber 61, but no longer includes the pressure inlet 16. An O-ring 62 is attached to the piston 58 so that the ink chamber 61 is separated from the internal pressurizing chamber 60. During printing, as ink flows out of the orifice 6, the pressure exerted by the internal pressure chamber 60 causes the piston 58 to move towards the ink transfer surface 4.

FIG. 15 illustrates this feature with a rectangular ink reservoir and FIGS. 16A and 16B illustrate this feature with respect to a cylindrical ink reservoir. An internal cylinder is also required in connection with the cylindrical ink reservoir. In this case, the piston 58 and the O-ring 62 contact the inner cylinder 64, as shown in FIG. In addition, the inner cylinder 64 is a cylindrical ink
Shorter than reservoir 2. At the time of printing, when the ink flows out from the orifice 6, the piston 58 moves to move the pressure chamber 60.
Is expanded to reduce the volume of the ink chamber 61. By the movement of the piston, the ink is pushed out of the ink chamber 61 and is pushed to the orifice 6 through the channel 66 (see FIG. 16B). Therefore, the ink is pressurized using the pressure chamber 60. The pressure applied to the ink decreases as the amount of ink in the ink chamber 61 decreases, but the device can be configured so that the pressure fluctuations are within an acceptable operating range.

Yet another optional feature of the present invention is to control the size of the generated ink dots. Image quality can be improved not only by increasing the resolution, but also by utilizing halftone techniques. Half tone
The information content of the image exceeds the resolution and the
It includes size and may even have different shapes of ink dots. For example, with a dot size of 16 1
A 50 dot / inch (dpi) image has a quality comparable to a 600 dpi image with a single dot size. Therefore, in order to form a high quality print image using the ink transfer printing apparatus 1, not only the amount of ink flowing from the orifice 6 to the ink transfer surface 4 but also the spread of the ink flowing to the ink transfer surface 4 is determined. Also, it is desirable to add consistent control. ink·
By controlling the spread of the dots, images formed utilizing continuous toning and multicolor printing will have excellent print quality.

The amount of ink flowing through the orifice 6 is
It can be adjusted by controlling the quality and duration of the viscosity reducing energy applied. Basically, as the applied energy increases, so does the amount of flowing ink.
Viscosity-reducing energy is typically provided by heat, electricity, or magnetic means. For example, in a thermally actuated system, the light source or resistive heating element heats the ink near a particular orifice 6. It is also possible to increase the pulse width, the voltage, and / or the period in order to increase the amount of ink flowing through the specific orifice 6 to the ink transfer device 1. The result is ink dots with an increased amount of ink.

As the amount of ink dots increases, the spread of ink on the ink transfer surface 4 must be taken into account even more. If the amount of ink in the ink dot is small, the spread of the ink dot is not a big problem. However, as the amount of ink dots increases, ink spread becomes more important. The spread of ink dots is continuous toning, so when printing dots of various sizes, or because of multicolor printing, different color
This is especially important when mixing inks.

Furthermore, when performing multicolor printing, it is advantageous to control both the spread and the amount of ink for each orifice. When controlling both quantity and spread, it is possible to mix color inks in a variety of ways. For example, if you have a color ink transfer printing device and want to print magenta pixels centered around red, you can do the following steps: First, a large amount of magenta
Send out ink. Control is added to the magenta ink spread to ensure that the magenta ink spreads outwardly from the orifice by a predetermined, relatively long radius. The magenta ink dots are transferred to the intermediate surface or print medium. Next, a small amount of yellow ink is delivered to the ink transfer surface. Control is added to the spread of the yellow ink on the ink transfer surface to ensure that the yellow ink only spreads out of the orifice by a relatively short, predetermined radius. Then a small amount of yellow dots are transferred to the center of the larger magenta dot on the intermediate surface or print medium. Next, the yellow ink
Mixing the dots with the magenta ink will result in a red center in the magenta dots. After this, the ink is fixed to the print medium.

Therefore, by controlling the ink spread (so-called "ink dot spread") for each orifice 6, a better and visually attractive print quality can be obtained. That is, continuous gray scale toning is possible by controlling the spread of the ink dots. Further, in the case of color ink transfer printing devices, controlling both the amount and the spread of the ink dots for each color of ink allows a unique mix of various color inks. Two examples for controlling the spread of ink dots are described below. In the case of the first embodiment, a ring of alternating wet and non-wet surfaces on the ink transfer surface 4 is formed. In the case of the second embodiment, an etching groove is formed on the ink transfer surface 4.

According to the first embodiment, a ring of alternating wet and non-wet surfaces is formed around each orifice 6 of the ink transfer surface 4. FIG. 17 shows a plan view of the ink transfer surface 4 according to the first embodiment. The ink transfer surface 4 shown in FIG. 17 contains nine orifices 6. The orifice 6 has a diameter of 50
μm, and the centers are spaced from each other by 100 μm. Surrounding each orifice 6 are three wet rings 72 and two non-wet rings 74. The width of each ring is 5 μm. The number, size, and shape of the rings shown in FIG. 17 are for illustration only and are not limiting of the invention. For example, ring 7
The 2,74 shapes can also be oval or square.

Wet ring 72 and non-wet ring 74
Form a flow barrier that prevents the spread of the ink dots. That is, at each transition from the wet ring 72 to the non-wet ring 74, the ink dots attempting to spread out of the orifice encounter the flow barrier. The barrier results from the transition from the low surface tension region to the high surface tension region. The flow barrier impedes the spread of ink dots until the ink volume increases and overcomes this barrier.

One method of forming the wet ring 72 and the non-wet ring 74 is to coat the portion of the ink transfer surface 4 corresponding to a given ring with a wet or non-wet material. Is. For example, a wet ring and a non-wet ring can be produced by applying a chemical coating to selected portions of the ink transfer surface 4. For aqueous inks, examples of wet chemicals are silicon dioxide and aluminum oxide. Examples of non-wetting chemicals are fluorocarbon compounds such as fluorescent aliphatic polymeric esters (eg FC-430 from 3M Company).

The upper surface of the external ink transfer surface 4 is a water-based ink or polyimide (eg, EI DuPont).
For non-wettable surfaces such as fluorocarbon compounds (eg TEFLON) for Company KAPTON), plasma enhanced chemical vapor deposition processes are utilized to coat wet chemicals such as silicon dioxide. By applying, it is possible to form a wet ring 72. That is, the wetting agent is applied to the coaxial region of the upper surface around each orifice 6. The coaxial region of the wetting agent thus applied forms the wetting ring 72. The coaxial regions have a common center, but the coaxial regions of the applied wetting agent do not touch each other. That is, the coaxial wetting regions formed by the wetting agent are separated by the coaxial non-wetting regions. Since the top surface is non-wetting, no surface treatment is required to form the non-wetting ring 74. Thus, when the wet ring 72 is formed, the non-wet ring 74 is identified.

Another way to form the wet ring 72 is to modify the coaxial region of the ink transfer surface 4. These surface modifications can be performed utilizing conventional methods. One conventional method is to expose the coaxial region of the ink transfer surface 4 to a gas plasma.
For example, the ink transfer surface 4, except for its coaxial region,
Assuming a non-wettable surface such as KAPTON, the entire surface of the ink transfer surface 4 is shielded by the mask. The ink transfer surface 4 is then exposed to a gas plasma that transforms the unmasked portion of the surface into a wet ring 74. Examples of usable gases are oxygen plasma, CH4 /
There is O2 plasma or ion implantation.

According to the second embodiment, the coaxial region is etched into the ink transfer surface 4. FIG. 18 shows a detailed sectional view of the ink transfer surface 4 according to the second embodiment. In the case of FIG. 18, the coaxial region is the etching region 7
6, 78. The etching regions 76 and 78 have a width of 1
μm and the depth is 0.2 μm. The numbers, depths, and widths of the etched regions 76, 78 shown in FIG. 18 are for illustration only and are not limiting of the present invention. The etching rings 76, 78 control the spread of the ink dots. The ink transfer surface 4 is preferably non-wetting, but the etching rings 76, 78 can be wet or non-wet. Etching ring 76,
78 is reactive ion etching, ion beam
It can be formed on the ink transfer surface 4 using conventional methods such as milling or excimer laser ablation.

This example utilizes the non-wetting surface of the ink transfer surface to limit the spread of ink dots. Once the etching rings 76, 78 are formed, the non-wetting rings 80, 82 are identified. Non-wetting ring 80, 82
The ink flowing from the orifice 6 due to the surface tension of
It does not try to flow over the non-wetting rings 80, 82.
However, as additional ink flows through orifice 6,
The amount of ink dots will exceed the surface tension of the non-wetting ring 80. When the surface tension is exceeded, the ink spreads just before the next non-wetting ring 82.

By the etching rings 76, 78,
The flow barrier for ink dot spread is enhanced. That is, in order for the ink dots to spread and cross the non-wetting ring 82, the increase in ink volume must exceed the surface tension of the non-wetting ring 82. In this non-wetting ring 82, the surface tension encountered by the ink dots is greater than the surface tension encountered when the ink dots try to spread beyond the non-wetting ring 80.
That is, by providing the etching ring 76 immediately in front of the non-wetting ring 82, the barrier that the ink dot must overcome in order to spread to the next ring will be enlarged. Therefore, in order to overcome this barrier, it is necessary to further increase the ink amount.

The etching rings 76, 78 can be etched using conventional methods. For example, the ink transfer surface 4 can be a non-wetting polyimide (eg, KAPTON) for aqueous inks. A mask pattern corresponding to the areas that should not be etched is placed on the ink transfer surface 4. Next, the etching rings 76, 78 are etched on the ink transfer surface 4 by excimer laser ablation.

It is advantageous to clean the ink transfer surface 4 after each use. That is, transferring ink dots on the ink transfer surface 4 to an intermediate surface or print medium may leave some residual ink. This residual ink can be removed using a rubber or cloth doctor blade. For embodiments utilizing an etching ring, a doctor blade made of felt material or other cloth-like material is preferred. First
In some cases it may be advantageous to combine the features of the second embodiment with. For example, the ink transfer surface can utilize a wet ring, a non-wet ring, and an etch ring.

[0072]

As described above, by using the present invention, it is possible to provide a device such as a printer or a copying machine that is inexpensive and can perform high-speed, high-resolution image printing.

[Brief description of drawings]

FIG. 1 is a three-dimensional view of a perforated ink transfer device including an ink reservoir and a perforated sheet according to the present invention.

FIG. 2 is a three-dimensional view showing a print head that is smaller than the page to be printed.

FIG. 3 is a three-dimensional view of a line print head as compared to the page to be printed.

FIG. 4 is a cross-sectional view of the perforated ink transfer device in a non-printing state.

FIG. 5A is a cross-sectional view of the perforated ink transfer device in a printed state.

5B is a detailed cross-sectional view of the orifice of the ink transfer device shown in FIG. 5A.

FIG. 6A is a schematic diagram illustrating various techniques for selectively providing thermal energy to an orifice.

FIG. 6B is a schematic diagram illustrating various techniques for selectively providing thermal energy to an orifice.

FIG. 6C is a schematic diagram illustrating various techniques for selectively providing thermal energy to an orifice.

6A-6D are schematic diagrams illustrating various techniques for selectively providing thermal energy to an orifice.

FIG. 7 is a plan view showing a wire matrix connected to a resistor coupled to each orifice.

FIG. 8A is a sectional view showing an example for selectively applying an electric field to an orifice.

FIG. 8B is a sectional view showing an example for selectively applying an electric field to the orifice.

FIG. 9 is a cross-sectional view showing an embodiment for selectively applying a magnetic field to the orifice.

FIG. 10A is a plan view showing ink channels formed under a perforated sheet.

FIG. 10B is a side view of the ink channel shown in FIG. 10A.

FIG. 11 is a plan view showing ink channels formed under a circular print head.

FIG. 12 is a three-dimensional view showing an ink transfer system including an ink transfer area and a post-processing area.

FIG. 13A is a three-dimensional view depicting a structural embodiment of a color ink transfer device.

FIG. 13B is a three-dimensional view depicting a structural implementation of a color ink transfer device.

FIG. 13C is a three-dimensional view depicting a structural implementation of a color ink transfer device.

FIG. 13D is a three-dimensional view depicting a structural implementation of a color ink transfer device.

FIG. 13E is a three-dimensional view depicting a structural embodiment of a color ink transfer device.

FIG. 14 is a three-dimensional diagram illustrating an ink transfer system that utilizes an intermediate transfer surface.

FIG. 15 is a cross-sectional view of a rectangular ink reservoir that includes a pressure chamber and a piston that pressurizes the ink.

FIG. 16A is a three-dimensional view of a cylindrical ink reservoir that includes an internal cylinder, a pressure chamber, and a piston that pressurizes the ink.

16B is a cross-sectional view of the cylindrical ink reservoir shown in FIG. 16A.

FIG. 17 is a detailed plan view of the ink transfer device shown in FIG. 1, showing the coaxial rings disposed around each orifice.

FIG. 18 is a detailed cross-sectional view of the orifice of an ink transfer device with an etching ring.

[Explanation of symbols]

 1, 52: Ink transfer device 2: Ink reservoir 4: Ink transfer surface 6: Orifice 8: Print head 10: Print medium 12: Line print head 14: Ink 16: Pressure inlet 17: Thermal barrier 18: Heating Element 20: Heater 22: Heat conductor 24: Wire 32: Infrared light source 34: Reflective housing 38: Electrode 42: Alternator 46: Coil 48: Ink channel 50: Thermal ink fixing device 54: Intermediate transfer surface 56: roller 58: piston 60: internal pressure chamber 61: ink chamber 62: O ring 64: internal cylinder 66: channel 72: wet ring 76, 78: etching region 74, 80, 82: non-wet ring

Claims (1)

[Claims] 1. An ink transfer printing apparatus in which ink is transferred from an ink reservoir to a print medium via a perforated surface having a plurality of orifices, wherein the viscosity of the ink near the orifices is changed, thereby changing the viscosity of the ink. An ink transfer printing apparatus, wherein ink is made to flow out to the perforated surface via the orifice to enable transfer of the ink.