WO2007110042A2 - Ink writing device and method for controlling the ink flow at the tip of the pen nib - Google Patents

Abstract

The invention relates to an ink writing device comprising a tubular shaft, a storage reservoir for admitting the ink and which is provided with an aeration opening, a writing insert with a pen nib, an ink guiding system with a temporary storage reservoir for guiding the ink to the tip of the pen nib, a micro pump, a valve and a battery or accumulator as well as an electronic control of the ink flow. The ink writing device is characterized by at least two effective control circuits for regulating the ink flow from the storage reservoir (1) and the temporary storage reservoir (6) to the tip of the pen nib (10). A first control circuit is provided for refilling the temporary storage reservoir (6) by means of an electronically controllable micro valve (32) disposed between the storage reservoir (1) and the temporary storage reservoir (6) while the second control circuit is provided for adjusting the operational pressure at the writing insert (60) by means of a pressure sensor (31) and at least one micro pump (34) disposed in the main channel. Furthermore, the temporary storage reservoir (6) is embodied as a control capillary for the second control circuit and capillary traps (16) are arranged between each control capillary (17) and the main channel. The invention also relates to a method for controlling the ink flow at the tip of the pen nib.

Description

Ink pen and method for controlling ink flow at the nib tip

The invention relates to an ink pen, in particular a fountain pen and a method for controlling the flow of ink at the nib tip.

Various types of fountain pens, Tuscheschreibgeräten, fiber pens for demand-dependent dispensing of writing fluids are known. A common feature of these designs is that the writing fluid is taken during the actual writing process from a capillary secondary fluid container whose capillarity generates a defined negative pressure, which compensates for the suction behavior of the paper, temperature and air pressure fluctuations and the hydrostatic pressure. This secondary fluid reservoir must be refilled from time to time by opening a vent valve on the reservoir. Writing tip and reservoir are connected by a main passage, the main passage having a branch connected to the secondary fluid reservoir.

This type of compensation of the hydrostatic pressure and the temperature and air pressure fluctuations has its limits. In particular, in case of sudden reduction of the air pressure or sudden increase in temperature, there is a need to prevent expulsion of the writing fluid from the reservoir due to the expansion of the trapped air. But even the vent valve, which opens at conventional writing instruments at a certain negative pressure or opens or closes depending on the level in the secondary fluid container, works by the dependence on different difficult-to-control parameters is not precise. The effect of various constructive compensation measures can only partially account for the different levels of liquid containers. Also the actual delivery of the writing fluid to the Paper depends on parameters that can not be influenced, such as the absorbency of different types of paper.

Therefore, many attempts are known to improve the operation of the compensation by the use of electronically controlled functional elements.

In DE 32 20 750 an arrangement is described in which between the reservoir and the capillary secondary fluid container, an electronically controllable valve is arranged, which is opened or closed depending on the level in the secondary container.

In a fountain pen according to DE 44 19 735 A1, the exiting writing fluid is metered by a pumping element which presses the writing fluid to the nozzle of the writing tip. The pumping element is activated via a pressure transducer and a microcircuit, in that when the writing tip is placed on the paper, a piezo quartz tube gives the start and stop signal for the microcircuit, and the ascertained contact force determines the pumping frequency of the pumping element. As a liquid reservoir is a removable cartridge which is pierced when inserted on both sides with cannulas, wherein in the bottom of the cartridge, a partition made of semipermeable material is embedded, which is permeable to air and impermeable to the ink. Due to the direct ventilation of the cartridge, the entire system is in a constant pressure equalization with the outside air, so that separate compensation measures for temperature and air pressure changes can be omitted. The pumping element and the microcircuit are powered by a battery. On the division of the reservoir into a primary and secondary reservoir was omitted because the micropump determines the flow rate. However, this device has the disadvantage that the micropump pump constantly and thus would need to consume energy. Further, the current level of the cartridge and the compensation of the hydrostatic pressure are not detected by the control. A compensation of the different suction behavior of the paper is not possible. In DE 43 28 312 an arrangement is described, are used in the variable volume liquid reservoir both as a primary reservoir and secondary fluid container. In one embodiment, it is proposed to use an electronically controlled valve between the two liquid containers, is opened and closed depending on the pressure conditions in the secondary liquid container. The primary reservoir is under an overpressure, so that upon opening of the valve writing fluid flows into the secondary fluid reservoir and fills this container again. Assuming that the secondary fluid reservoir must be under negative pressure, so that the writing fluid does not leak through the pen tip, the necessary forces in turn by the negative pressure of the chamber in which the secondary fluid reservoir is located or difficult to control forces of elasticity of the variable volume Liquid reservoir applied. Thus, the pressure conditions are again subject to the conditions of the environment such as temperature and atmospheric pressure, which you just wanted to avoid. In another embodiment in DE 43 28 312 is dispensed with a secondary fluid container and directly regulated the pressure in the reservoir. Thus, the control must remain active during the entire writing operation to compensate for the pressure change during ink extraction. In addition, no standard commercial cartridges can be used.

In DE 33 21 301 an energetically improved ink supply system is described in which a peristaltic pump pushes the writing fluid from the reservoir into a secondary fluid container, which also acts as a valve.

Energetically much cheaper is an arrangement according to DE 100 54 599. As described in DE 44 19 735, the ink discharge from the primary liquid container is influenced to the secondary liquid container via an electronically controllable valve. The secondary liquid container is, as is conventional in conventional, ie not electronically controlled writing instruments, at a branch between the reservoir and the discharge of the Writing fluid, for example, arranged on a nib. The electronically controlled valve control signal provides a sensor that measures the level of the capillary secondary fluid reservoir. It is expected that this electronically controlled valve will operate much more precisely than the capillary closure of the primary fluid tank vent used in conventional writing instruments.

A disadvantage of this type of valve control for the discharge of writing fluid from the reservoir is that the pressure conditions in the writing system are different, depending on whether the valve is open or closed or the secondary fluid container is filled or emptied. Also can not be compensated by this arrangement, the different absorption behavior of the paper and a desired line intensity can be adjusted.

In DE 102 12 278.4, therefore, a flow meter is proposed, which measures the actual flow of writing fluid to the writing tip and compares with a target value, which results from the placement force of the writing tip. The difference between the two values provides a control signal for a micropump. The valve between the storage tank and the secondary liquid tank is only opened when the capacity of the micropump exceeds a specified maximum value. Between the ink reservoir and the micropump a small secondary liquid container for writing fluid is arranged for dynamic decoupling. This arrangement ensures both the independence of the ink flow from the opening state of the valve between the reservoir and the secondary liquid container and the adjustability of the line width depending on the paper quality. The individual typeface of a fountain pen, which results inter alia because of the individually varying pressure force, is retained. Energetically, this design is not optimal, since the micropump in the write mode constantly and partially must work at full capacity. Regardless, little attention is paid in all solutions shown so far, especially in fountain pens the use value in the formation of an individual typeface represents a very significant factor. But this individuality is next to the Aufsetzkraft also influenced by the type of spring guidance, ie by direction, speed acceleration and inclination angle. Thus, a direct proportionality between Aufsetzkraft and pumping power as in DE 44 19 735 or, although better, between placement force and ink flow as in DE 102 12 278.4 does not lead to an optimal result. In addition, the precise determination of the placement force and the measurement of the actual flow under the dynamic conditions of writing at frequencies up to IkHz is very complex.

The invention has for its object to provide a metering device for a liquid, in particular writing fluids, with compensation of air pressure and temperature changes by electronic control circuits whose individual writing behavior in terms of placement force and writing direction corresponds to a conventional, not electronically controlled fountain pen, beyond has the ability to adjust the line intensity and adjust the ink flow to the paper quality and is very energy efficient.

The object is achieved in that a first control circuit using different capillary forces of at least two control capillaries and a micropump optimal conditions for

Supplying a conventional writing insert in all

Ensures operating conditions and that a second control circuit consisting of a valve with electronic control worried the refilling of the control capillaries. Optionally, a third control loop with a second micropump, a flow meter, and a tandem capillary of stepped cross section becomes effective.

The invention represents a further improvement of the writing instrument, as already described in DE 102 12 278.

The idea underlying the invention will be explained in more detail in the following description with reference to an embodiment which is illustrated in the drawings. Show it:

1 is a schematic of the channel structure of a conventional fountain pen,

2 shows the pressure curve in an ink cartridge,

3 is an illustration of the control system of a conventional fountain pen,

Fig. 4 is a diagram of the channel structure of the invention

Writing system with micropump in the main channel,

5 is a flowchart of the control process,

Fig. 6 is a schematic of the channel structure of the invention

Writing system with micropump in the control capillary,

Fig. 7 is a diagram of the channel structure of the invention

Writing system with two micropumps and a tandem capillary,

Fig. 8 is an illustration of the control system of the invention

fountain pen,

9 shows a cross section through the writing module,

10 is a layout of the channel structure of the writing module from the front side,

11 shows a cross section for the arrangement of the hydrophobic membrane,

12 is an overall view of the ink writing device in longitudinal section, Fig. 13 is a coupling between the main channel and the ink conductor.

For a better understanding of the invention will be discussed first again on the operation of a conventional writing system. Fig. 1 shows first the scheme of a conventional fountain pen, as it has been known for at least 100 years. When placing the writing spring 62 on the surface of the paper 12, the writing liquid from the capillary system of the secondary liquid container 6 is pulled against the capillary force acting in this container by the suction force of the paper, which is formed by the paper capillarity 11. The process is initiated by overcoming a capillary interruption on the writing spring 62 when placed on the paper surface 12 and supported by the hydrostatic pressure in the main channel 8. The nib 62 is known to be split and has a bevel for scratch-free writing individually for right or left handed. Acts a placement force, the writing spring 62 is divided, the ink flow is spread and distributed to several paper capillaries 11. As a result, the line width increases and there is the characteristic of a fountain pen individual typeface. The process of removing writing fluid 2 from the secondary ink container 6 continues until this container is largely emptied. Further writing creates a negative pressure in the main channel 8, since due to the surface tension of the writing fluid 2 and the menisci forming at channel constrictions 13 no air can be drawn through the secondary fluid container 6 into the main channel 8. The resulting negative pressure continues through the main channel 8 in the reservoir 1 and causes an increase in the negative pressure of the air volume. 3

The vent valve 4, which is often designed as a short channel is closed by a liquid meniscus. If the negative pressure in the air volume 3 exceeds a certain level, the meniscus ruptures and an air bubble penetrates into the reservoir 1, which leads to a reduction of the negative pressure in the air volume 3. Thus, supported by the capillary forces, writing fluid 2 flows through the main channel 8 in the chambers of the secondary fluid container 6 until this process passes through the capillary restriction 7 is interrupted. The negative pressure in the entire system, in particular in the reservoir 1, is reduced until a liquid meniscus again forms on the venting valve 4 and prevents further air entry. Fig. 2 illustrates the pressure profile of the air volume 3 in the reservoir 1. After a continuous construction of the negative pressure occurs a sudden reduction in the negative pressure upon entry of an air bubble through the vent valve 4 a. With increasing emptying of the reservoir 1, the time intervals from jump to jump are longer. This writing system, which is built entirely from mechanical and fluidic functional elements without electronic aids, works millions of times in practice, with certain exceptions. Reductions in the air pressure or temperature increases thus lead to a reduction of the negative pressure in the air volume 3, which leads to expulsion of writing fluid 2 from the reservoir 1, without actually requiring a writing system. Excess writing fluid 2 can indeed be absorbed by the capillary system in the secondary fluid container 6 and in the writing insert 60 (see FIG. 12) with a nib 9 to an extent, an undesirable release of writing fluid 2, in particular after placing the nib 9 on the paper surface 12th but can not be completely avoided. Furthermore, the course of the negative pressure in the reservoir 1 with increasing emptying, as shown in Fig. 2, acts as a disturbance function with pressure fluctuations of the order of 500 Pascal within an otherwise carefully tuned capillary. Accordingly, the discharge of writing liquid 2 to the nib tip 61 varies, and the writing intensity changes as the ratio of the discharged amount of the writing liquid 2 in relation to the nip force F _{s of} the nib tip 61.

The operation of the conventional writing system can be represented by an electrical analogy corresponding to FIG. 3. The hydrostatic pressure P _p in the reservoir 1 represents in the electrical analogy an electro-motive force (EMF), which is completely compensated when the vent valve 4 is closed by the negative pressure PL of the air volume. These two voltages change depending on the degree of filling of the reservoir 1 and position of use of the writing instrument. Breaks the Meniscus in the vent valve 4 through, the hydrostatic pressure P _p acts and flows a current IL in the capacitor C γ. The switch S _v stands for the vent valve 4. The capillary secondary liquid container 6 is shown as a capacitor CT, which receives charge and due to its charging voltage again charge can deliver as current flow over time. In series there is an EMF E _z , which symbolizes the capillary force of the secondary liquid container 6.

Another EMF with the voltage E _p represents the suction behavior of the paper. This voltage is variable and of the respective

Paper properties dependent. The switch Su symbolizes the placement of the

Quill 62 on the paper 12 and thus entering the flow Is the

Writing fluid 2. In the flow Is, various resistances Rs, RT and Rv are arranged, which stand for the flow resistance of the individual functional elements and connecting channels. The resistor R _s represents a variable

Resistance whose size depends on the acting contact force P _s .

The writing behavior of a writing instrument as an interaction between individually different placement force and writing direction is now decisively influenced by the design of the writing tip. Wing feathers are known, for example, which are characterized by a special oscillatory behavior of the side wings, a special inner grinding which makes it easy to skip the ink when the paper surface is touched, and certain material properties. Assuming that the design of the writing tip and its writing behavior are desired characteristics that have developed to develop a personal character of the typeface in the course of development, an electronically controlled writing implement should respect and support this personal character ,

The basic idea of the invention assumes that the writing tip is characterized under all operating conditions caused by different environmental conditions, opening and closing of valves are, optimal operating conditions are secured by electronic means. For this purpose different operating conditions are considered:

A) Writing with the vent valve closed B) Writing with the vent valve open

C) idle state

In operating state A, optimal ratios relative to the writing insert 60, consisting of writing spring 62 with writing tip tip 61, ink guide 9 and holder 69, are achieved when a constant counterforce E _z acts, _for example, through a capillary having a constant cross section on the writing fluid, which in the secondary Liquid container is stored. Incidentally, this condition is already largely met in a conventional fountain pen. This counterforce, represented by the emf E _z in FIG. 3, can be measured at point N by a voltage or pressure gauge as the value P _N. The optimal operating pressure for the writing insert at point N should be designated PN _SO II. It can be seen from the scheme that the individual modulation of the ink flow l _{s can be influenced} inter alia by the ratio of the resistances R _s , RT and Rv. This results in two possibilities of the practical setting of a typeface. Once, by choosing the diameter of the capillaries in the secondary liquid container, the average value of the flow l _s can be influenced. On the other hand, by dimensioning the resistance RT in relation to the mean value of the resistance Rs, the dynamics of the individual modulation of the ink flow Is can be changed.

In Fig. 4, a way is shown, as with the aid of a control capillary 14 and a compensation capillary 17 in combination with a micropump 30 of the pressure at point N during the operating conditions A and B oiι to the optimum value optimal writing P _Ns can be regulated.

Such a control capillary 14 or compensation capillary 17 consists of a capillary, which at one end with a Kapillarfalle 16 or 19, at the other end with an air-permeable membrane 15 or 18 or with another Capillary trap is completed. The air-permeable membrane 15 or 18 is impermeable to liquids and can be made, for example, from hydrophobic coated fabric.

In the operating state A, the meniscus 21 is located in the control capillary 14 between the two possible end positions. The capillary 14 has a capillary force Ez which, in interaction with the suction force of the paper Ep and the fixed resistors R _F and Rj and the variable resistor Rs, produces an optimum typeface of a fountain pen. By choosing the cross section of the control capillary 14, the intensity of the typeface can be determined to a certain extent by changing the mean flow Is. With increasing duration of the writing process, the capillary section 22 is emptied and the meniscus 21 moves in the direction of the capillary trap 16. The control process which now starts should be explained with reference to FIGS. 4 and 5.

If the meniscus touches the capillary trap 16, further writing fluid 2 is removed from the thinner compensation capillary 17. The negative pressure measured by the pressure gauge 31 increases in accordance with the larger capillary force of the compensation control capillary 17 briefly, the micropump 30 starts in the pump _control loop to regulate the negative pressure to the setpoint P _Nso iι. As a result, in the operating state B, the micro-valve 32 is opened and writing fluid 2 flows after. Thus, the negative pressure P _N measured by the pressure gauge 31 briefly decreases below the setpoint value PN _SO II. The micropump 30 switches over the pumping direction and generates a pressure PD counter to the flow direction of the writing fluid 2, so that the actual value PN again corresponds to the desired value PN _S OII , The ink flow IL, which flows from the storage container 1 through the microvalve 32 through the main channel 8, is divided into a flow into the compensation capillary 17 and into the control capillary 15 and into a flow Is in the direction of the nib 9. The self-adjusting back pressure P _{0 of} the micropump reaches a maximum when both the control capillary 14 and the compensation capillary 17 are filled and the suction effect of both capillaries is eliminated. At this time, the full hydrostatic pressure P _{P of} the writing fluid 2 in the reservoir 1 acts Stabilization of the back pressure PD to a stationary value causes the closing of the microvalve 32. The writing system in turn returns to the operating state A, in which a pumping action of the micropump 30 is not required. The corresponding equivalent circuit diagram is shown in FIG. 8.

An alternative structure in which the micropump 30 and the control capillary 14 and the compensation capillary 17 are arranged sequentially in a tandem capillary 20, Fig. 6. The meniscus 21 is located in the operating state A in the capillary 25 of the tandem capillary 20. If the Meniscus 21 pulled into the channel portion 24, the micro-valve 32 opens and writing fluid 2 flows after. The micropump 30 in turn assumes the stabilization of the pressure PN, which is measured with the pressure gauge 31, to a desired value PN _SO II. The arrangement of the micropump 30 supports the filling of the tandem capillary 20. The changing pressure conditions, when the meniscus 21 reaches the channel section 27 of the tandem capillary 20, lead to the closing of the microvalve 32 and deactivation of the micropump 30.

Another arrangement of the invention is shown in Fig. 7. Again, in a tandem capillary 20, the individual control capillaries in the form of various capillary sections 24 to 27 arranged sequentially one behind the other. The special feature is that in the operating state A two capillary sections 25 and 26 are available, which have a different cross section and thus a different capillary force. Thus, without the aid of a micropump, different intensities of the flow Is of the writing fluid can be set, depending on in which channel section 25 or 26 the meniscus is located. The opening of the microvalve 32 and the activation of the micropump 33 are triggered when the meniscus 21 leaves a channel section and is drawn into the next channel section. Another micropump 34 may be used to achieve rapid switching of the intensity of the writing line from high intensity to low intensity. Both micropumps 30 and 34 are activated in order to quickly pump out the channel section 26 and excess writing fluid 2 is returned to the storage container 1 pump back. With the aid of a flow meter 33, it is possible to measure the mean flow Is and to respond to the measured value by switching to another channel section 25 or 26. The representation of two channel sections 25 and 26 is to be regarded only as an example. In principle, more than two channel sections are conceivable in which the meniscus 21 is in the operating state. In general, an arrangement with two micropumps 30 and 34 is useful if, in addition, the leakage flow of the microvalve 32 should be compensated.

The overall structure of the writing module is shown in Fig. 9 to 11. Fig. 9 shows a section. The needle 49 contacts the reservoir 1, which is designed in the form of a cartridge. The writing fluid 2 passes into the valve chamber 45 and from there into the nozzle channel 54. The inlet opening 47 can be closed by a valve tappet 53. The valve stem 53 itself is moved by a valve driver 42, e.g. designed as a magnetic or piezo drive. After the nozzle channel 54, the pumping chamber 59 connects, which in turn communicates with the pressure measuring chamber 56 via the connecting channel 38. To the pressure measuring chamber 56, the pressure sensor 44 is fluidically coupled via the pressure equalization channel 55. The writing fluid 2 then flows via the fluidic adapter 48 into the cannula 50, which is fluidically coupled to the writing insert 60. The entire main channel 8 described in FIGS. 4, 6 and 7 consists in the described exemplary construction of the needle 49, the inlet opening 47, the valve chamber 45, the nozzle channel 54, the pumping chamber 59, the connecting channel 38, the pressure measuring chamber 56, the fluidic adapter 48 and the cannula 50.

The complete fluidic structure on the channel body 40 is covered by a cover membrane 39 made of LTCC (Low-Temperature Ceramics) ceramic, which is connected to the electronics carrier 41, which is also made of LTCC ceramic, by means of a sintering process. The cover membrane 39 also serves as a carrier of the piezo plate 43. Cover membrane 39 and piezo plate 43 together form a bimorph, that is, when the piezo plate is subjected to a voltage, the bimorph deforms and causes a pressure on the pumping chamber 59. The volume displacement depends on the to the poles of Piezo plate 43 applied pulse shape and size. The channel body 40 itself is made of glass, for example, which has been etched.

In the plan view of the channel body according to the section line A-A of Fig. 9, the position of the compensation capillary 17 and the control capillary 14 can be seen in Fig. 10. Both capillaries begin in the valve chamber 45, are protected with the Kapillarfallen 16 and 19 against air entering the valve chamber 45 and terminate in end chambers 35 and 36, which are covered with a hydrophobic membrane 57.

In Fig. 11 is shown by a section of the writing module 70, as the hydrophobic membrane 57 between the circuit board 52, electronics carrier 41 and the channel body 40 is fixed.

Fig. 12 shows a cross section through the writing instrument with writing insert 60 in the front part of the housing base 73. The writing insert 60 is modeled on a conventional fountain pen in its design and consists of the nib 62 with the nib 61, a pen nib 69 with integrated ink guide. 9 as an extension of the main channel 8 and is connected via the coupling 63 with the cannula 50 of the writing module 70. In the upper housing part 72 are located as a reservoir 1, an ink cartridge and a battery compartment for receiving the battery 71. The battery compartment is closed by a cover 74. The storage container 1 designed as an ink cartridge is closed with a sealing plug 75 which is pierced with a needle 49 when it is inserted into the writing instrument. The needle 49 is mounted in the writing module 70 as shown in Fig. 9, and includes all fluidic functional elements such as micropumps, reservoirs and valves. From the writing module 70, the writing fluid 2 passes via a cannula 50 and an elastic coupling 63 to the writing insert 60 of conventional design. One or more LEDs 65 indicate the operating state of the device. Laterally attached to the housing base 73 is a touch contact 66, which signals the controller that a writing process is imminent. This control element 66 can be combined with the opening of the cap 76, so that after prolonged leaving the writing instrument with remotely Cap 76 is first promoted by the micropump 30, a small amount of writing fluid 2 to the writing insert 60 to bridge any capillary breaks in the ink channel 62 and to allow an immediate cover letter.

The method for controlling the flow of ink at a nib 61 of an ink writing device is characterized by setting a constant operating pressure PN at the input of the writing insert 60 by a control loop with comparison of the actual pressure with a nominal operating pressure PNS _O II, wherein the pressure difference means a bidirectional operating micropump 30 is regulated. The setpoint of the operating pressure PN _SO II for the writing insert 60 is dimensioned so that in a conventional writing insert 60 with conventional writing spring 62 results in a characteristic of a fountain pen line as a function of placement force and writing direction. The capillary force in the control capillary 14, 17 for compensating the suction force of the paper and the hydrostatic pressure is dimensioned such that when the microvalve 32 is closed, the setpoint operating pressure for the writing insert 60 is established without a pumping action of the micropump 30 being required. The micropump 30 is advantageous only when 32 pressure fluctuations in deviation from the setpoint of the operating pressure PN _SO II occur when opening the microvalve or correct other deviations from the default settings of the ink writing device, such as leakage flow of the microvalve 32 or deviating from the norm of the absorbency paper. A further embodiment of the method consists in that different capillary sections 24, 25, 26 of the control capillary 28 can be selected and thus different nominal operating pressures PN _SO II can be set for the writing tip tip 61 for different writing intensities. In a further embodiment feature is exploited that the flow resistance in the coupling 63 between the main channel 8 and the ink guide 9, as shown in Fig. 13, for example, by means of a hose clamp 67 is adjustable and thus due to the placement force modulation of the writing line is affected ,

Claims

claims: 1. ink pen with a sleeve-shaped pen shank, a serving for receiving the ink reservoir with vent, a writing insert with nib, the ink for Nib head leading ink delivery system with a buffer, a micropump, a valve and a battery or battery and an electronic control of ink flow, characterized by - at least two effective control circuits for regulating the Ink flow from the reservoir (1) and from the buffer (6) to the nib (10), wherein a first control circuit for refilling the buffer (6) with an electronically controllable micro-valve (32) between the reservoir (1) and the buffer (6) and a second control circuit for adjusting the operating pressure at the writing insert (60) by means of pressure sensor (31) and with at least one micropump (34) in the main channel (8) is effective and that the latch (6) designed as a control capillary for the second control loop is and in each case between the control capillary (17) and main channel (8) Kapillarfallen (16) are arranged. 2. An ink writing device according to claim 1, characterized in that at least two parallel arranged control capillaries (14, 17) are arranged, which open into the main channel (8), have different cross-section and each have a Kapillarfalle (16, 19). 3. An ink writing implement according to claim 1, characterized in that the control capillaries (14, 17) as a tandem capillary (20) one behind the other in series and in several longitudinal sections (24, 25, 26) stepped stepped cross sections. 4. An ink writing device according to claim 3, characterized in that a second micropump (34) in the tandem capillary (20) is arranged. 5. ink writing device according to claim 4, characterized in that the micropump (30, 34) is a bidirectionally effective micropump. 6. ink writing implement according to claim 1 - 4, characterized in that the fluidic structure on the channel body (40) with main channel (8), valve (32), control capillaries (14, 17) Kapillarfallen (16, 19), bidirectional micropump (30, 34) is arranged on one side on a common carrier, which is covered with a printed circuit board (52) made of LTCC ceramic, wherein the circuit board (52) at the same time carrier of the piezo plate (43) for the bidirectional micropump (30). 7. ink pen according to claim 6, characterized in that the fluidic component is designed in a sandwich construction and the channel body (40) by a composite of at least two ceramic layers consisting of a cover membrane (39) and a circuit board (41) is covered. 8. An ink writing device according to claim 6, characterized in that the pressure sensor (31) on the ceramic layer of the cover (41) is arranged. 9. ink writing device according to claim 6, characterized in that the control capillaries (14, 17) are designed meandering. 10. The ink writing device according to claim 6, characterized in that the control capillaries (14, 17) in end chambers (35, 36) lead, which is covered by a common hydrophobic membrane (57). 11. ink pen with a sleeve-shaped pen shank, a serving for receiving the ink reservoir with vent, a writing insert with nib, the ink for Pen tip leading ink delivery system with a buffer, a micropump, a valve and a battery or battery and electronic control of ink flow, characterized by - three effective control circuits for regulating the flow of ink from the reservoir and from the buffer to the nib tip, wherein a first control loop for refilling the buffer (6) with an electronically controllable microvalve (32) between the reservoir (1) and the buffer (6) and a second control circuit for adjusting the operating pressure at the writing insert (60) by means of a pressure sensor (44) and at least one micropump (30 ) in the main channel (8) is effective that the buffer (6) is designed as a control capillary (17) for the second control loop and a third control loop with a second micropump (34) a flow meter (33) and a tandem capillary (20) with graduated Cross section is arranged and each between the St capillary (17, 14) and main channel (8) Kapillarfallen (16, 19) are arranged. 12. A method for controlling the flow of ink on a nib of a writing ink pen as described in claim 1, characterized in that measured at the input of the writing insert (60) of the actual pressure and compared with a nominal operating pressure and the resulting difference is the control a bidirectional micropump (30) causes. 13. The method according to claim 12, characterized in that the capillary force in the control capillary (14, 17) is dimensioned such that when the microvalve (32) of the set operating pressure for the writing insert (60) adjusts without a pumping effect of Micropump (30) is required. 14. The method according to claim 12, characterized in that different Kapillarabschnitte (24, 25, 26) of the control capillary (28) are selectable, so that different target operating pressures for the Schreibfederspitze (61) are adjustable for different writing intensities. 15. The method according to claim 12, characterized in that is influenced by an adjustable and variable flow resistance of the main channel (8) between the pressure measuring chamber (56) and the nib (62) caused by the placement force modulation of the writing line.