Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
  • G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
  • G01F23/26—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/17—Ink jet characterised by ink handling
  • B41J2/175—Ink supply systems ; Circuit parts therefor
  • B41J2/17503—Ink cartridges
  • B41J2/17506—Refilling of the cartridge
  • B41J2/17509—Whilst mounted in the printer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/17—Ink jet characterised by ink handling
  • B41J2/175—Ink supply systems ; Circuit parts therefor
  • B41J2/17503—Ink cartridges
  • B41J2/17513—Inner structure
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
  • B41J—TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
  • B41J2/00—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed
  • B41J2/005—Typewriters or selective printing mechanisms characterised by the printing or marking process for which they are designed characterised by bringing liquid or particles selectively into contact with a printing material
  • B41J2/01—Ink jet
  • B41J2/17—Ink jet characterised by ink handling
  • B41J2/175—Ink supply systems ; Circuit parts therefor
  • B41J2/17566—Ink level or ink residue control

Definitions

• the present invention relates generally to the field of printing presses, and more particularly to the features of the preamble of claims 1, 8 and 22, and relates to a method, a liquid supply unit and a measuring device for an ink printer for indicating a filling level.
• Ink printers are characterized by the selective application of liquid, in particular an ink jet, to a recording material, wherein the ink printer is a matrix printer in which the formation of an image on a surface of ink droplets is produced by a targeted launching or deflecting of small ink droplets.
• a liquid supply unit is necessary.
• the liquid supply unit consists in principle of a fluid pressure system, which supplies by means of a fluid device, a liquid from a reservoir of a printing device, wherein the printing device may be additionally equipped with a reservoir for the liquid.
• the printing device of a liquid supply unit requires a sufficient filling of the reservoir with liquid for proper function.
• the amount of liquid in the liquid supply unit is monitored by measuring a liquid level with sequence control.
• a liquid level As a follow-up device, all devices are understood with which measured values or measurement signals are processed directly or indirectly. This can be, for example, a microprocessor.
• the measuring method for determining the ink supply or the ink supply in the ink reservoir is based on an optical detector, which monitors an actuator, which is connected to a complex mechanism.
• a disadvantage is that not directly the level is measured, but an ink blank signal. which is determined by a predetermined time while the chamber of a pump has not expanded.
• Ink jet printer which consists of a plurality of electrically conductive rods of different lengths, which measure the liquid level in a separate chamber of a container to contact the liquid ink contained therein.
• the rods are connected to an impedance network which provides a series of output signals representing the level of ink within the shielded chamber.
• Measuring method consists in the size of the sensor and no contactless measurement between the sensor and the medium takes place and a continuous level can not be determined.
• a contactless level detector which is located in a recovery storage tank.
• This level detector operates as a level indicator and is of the capacitive or Hall effect type, wherein the non-contact measurement is made through the wall of the recovery reservoir. The measurement is made to avoid overflow of the reservoir and consequently to detect the volume of ink contained in the reservoir. Disadvantage of this ink circuit is the voluminous size of the double-sided support block, whereby use in the question in question printing machines, especially the commercial ink printers, is not possible.
• the level detector is used only to avoid the malfunction of the overflow of the reservoir, for control.
• the invention is therefore based on the object to provide a method, a liquid supply unit and a measuring device of the type mentioned above, which avoids the aforementioned disadvantages of the known arrangements and makes it possible for the mass-produced particularly cost-effective, with simple functional geometry and small size measuring device manufacture.
• the invention proposes that the measuring device advantageously consists of a sensor with integrated evaluation, wherein the measurement of the liquid state in the supply unit is performed by a measuring device, the Presence of a liquid already detected at the output of the printing device. Due to the immediate proximity of the measuring device to the printing device, the size of the liquid supply unit can be reduced.
• the liquid is detected by a capacitive measuring method, wherein the fill level is detected by the capacitive method and converted into a further processable condition or information.
• the condition or information is based on the change of the electric field in the vicinity of the active measuring zone of the sensor. According to this change, the sensor generates a signal, which is fed to the transmitter.
• the sensor essentially consists of an RC oscillator as transducer, a demodulator and an output stage.
• the level change of the liquid in the chamber of the measuring device ie in the active measuring zone of the capacitive sensor, causes a capacitance change of the capacitor, whereby the RC oscillator changes its oscillation frequency.
• This causes the oscillator downstream trigger stage tilts and the switching amplifier changes its output state. Due to the immediate vicinity of the transmitter on the sensor stray capacitances and disturbances of the connecting lines between the sensor element and the transmitter locked out.
• the signal generated by the transmitter or the signal jump is supplied to a device control, which makes the switching on or off of a fluid device which is arranged between the reservoir and the printing device.
• the fluid device provides for the liquid level in the liquid supply unit and thus for the level of the liquid in the pressure and measuring device.
• the liquid from the reservoir is conveyed by means of the fluid device through a feed line into the printing device, while the liquid flows into the integrated reservoir of the printing device and fills it out slowly.
• the level of liquid in the upward-pointing spout rises into the spouted chamber of the measuring device mounted on the printing device.
• the sensor of the measuring device detects the presence of liquid in the outlet and ensures that the printing device is completely filled with liquid.
• the measuring device according to the invention is thus suitable as a level sensor for determining a liquid level in a liquid supply unit, wherein the liquid from a water- or solvent-based fluid with or without color particles, which in turn may be present as solutions or pigments.
• the measuring device for continuous level measurement for aggressive media can also be used in other areas of technology.
• FIG. 1 shows a sectional view of a liquid supply unit in principle
• FIG. 2 shows a measuring device according to the invention in a perspective view
• FIG. 3 is a perspective view of the central surface element of the sensor with chamber for the liquid
• Figure 4 is a perspective view of the inside of the outer surface element, which is not carrier of the evaluation and
• FIG. 5in perspective view of the inside of the outer surface element, which is the carrier of the evaluation. 1 shows in section a liquid supply unit 1 of an ink printer, not shown, for applying liquid 22 to a recording material.
• the liquid supply unit 1 comprises a storage container 2, which is connected via a fluid device 3 and optionally via a fluid line 4 to a pressure device 5.
• the pressure device 5 has a housing 6 with an inlet opening 7 and an outlet opening 10 and comprises a reservoir 8 with a print head 9 arranged underneath.
• a measuring device 11 with a feed flange 13 is connected to the outlet opening 10, which is connected to an inlet opening 14 via an inlet opening 14 the measuring device 1 arranged chamber 15 leads.
• the chamber 15 has on its housing on the opposite side to the inlet flange 13 arranged on an overflow flange 16 with an overflow opening 17. This is a valve 18 connected. In particular, it serves to protect against contamination for a liquid or ink present in the chamber 15.
• the measuring device 1 is designed by a preferably multi-part sensor 12, which is designed according to the present embodiment as a capacitive sensor 12 and at least partially consists of printed circuit board material. But it is also the use of all other known electrical sensors 12, for example. Inductive or optoelectric sensors, possible.
• the measuring device 1 is used to determine the liquid level in the reservoir 8 and for its targeted control.
• the measuring device 1 is connected in terms of control with the preferably designed as a pump fluid device 3.
• an outer side of the sensor 12 is a
• Evaluation electronics 19 mounted. It is connected to the power supply via printed conductors 27 with a connector plug 28 and for signal processing via printed conductors 24 with contact elements 21. To the contact elements 21, a device control (not shown) of the ink printer (not shown) can be connected via a signal line, not shown.
• the task of the measuring device 11 arranged in the liquid supply unit 1 is to detect the presence of liquid or to ensure that a reservoir 8 formed in the pressure device 5 is always filled with liquid 22.
• the sensor 12 is arranged at the outlet opening 10 of the printing device 5 and detects different liquid levels 23 in the chamber 15 formed outside the printing device 5 in the sensor 12 as a measured variable.
• the sensor 12 first generates measuring signals which correspond to the Evaluation electronics 19 are transmitted. It processes the measurement signals and compares their values with at least two threshold values stored in it. They correspond to a minimum and a maximum level in the chamber 15th
• the transmitter 19 If, for example, the liquid level 23 in the chamber 15, which results in a change in capacity, below the minimum level, the transmitter 19 generates a switch-on signal for switching on the fluid device 3.
• the switching can on the one hand via a direct connection between the fluid device. 3 and the transmitter 19 can be realized.
• the switch-on signal can be sent to a device controller (not shown) connected to the evaluation unit 19, which then switches on the fluid device 3.
• control lines between the device control and the fluid device or between the transmitter 19 and the fluid device are provided. On and off signals could also be sent via radio.
• the fluid device 3 promotes receipt of the turn-on signal from the reservoir 2 liquid 22 via the liquid line 4 and the pressure device 5 into the chamber 15 until the maximum level is exceeded.
• the evaluation electronics 19 detects the exceeding of the maximum fill level by comparing the electrical measurement signals supplied to it with the threshold value for the maximum fill level, wherein the electrical measurement signals in the present case correspond to sensed capacitance changes.
• the transmitter 19 If the excess of the maximum level detected by the transmitter 19, it sends itself a turn-off signal to the fluid device 3 and turns them off. Alternatively, this can be done analogously to the case described above via a connected to the transmitter 19 device control.
• the fluid level 23 drops until the minimum fluid level has been reached and the fluid device 3 is switched on by a device control or the evaluation electronics according to the method described above.
• FIG. 2 shows a perspective view of an advantageous embodiment of the measuring device 11 according to the invention with the sensor 12 in a miniaturized version of a multi-part housing 6 with connection or positioning elements 20.
• the sensor 12 can be connected via an inlet flange 13 with inlet opening 14 to an outlet opening 10 of the pressure device 5. Opposite the narrow housing edge of the inlet flange 13, on located on the narrow housing edge, an overflow flange 16 with an overflow opening 17. Thereafter, a valve 18 is mounted. Furthermore, it can be seen from FIG. 2 that the sensor 12 has at least one conductor track 24 and at least one contact element 21 connected thereto, which has the electrical connection to surface electrodes 30, 33 arranged in the chamber 15, as well as via electrical conductor tracks 27 associated connector 28 produces.
• the power supply of the transmitter 19 can also be provided, for example, in the immediate vicinity of the evaluation 19 batteries provided.
• the transmitter 19 is advantageously arranged as a printed circuit on the outer surface 37 of the housing 6 of the sensor 12.
• the housing 6 is therefore at least partially formed by a conductor material. It is also conceivable, however, to use a microprocessor soldered onto the conductor material, for example, as evaluation electronics 19.
• the housing 6 of the sensor 12 is designed in several parts and in a broad sense rectangular, wherein the sensor 12 is preferably formed of three flat elements 29, 31, 32. Two of the elements 29,32 thereby form the two outer large-area housing halves, while the element 31 is arranged as a middle layer between the two elements 29,32 and forms with the two elements 29,32 the circumferential narrow housing edge 35.
• the two outer planar elements 29, 32 are designed as carriers for the electrodes 30, 33.
• the electrodes 30, 33 are of planar design and are arranged in a recess on the inner surface 36 of the elements 29, 32 (see FIGS. 4 and 5). Conceivable for fixing the electrodes 30,33 but also all other known connection options for metal surfaces. For example.
• the electrodes 30, 33 can be vapor-deposited onto the conductor material. Furthermore, as in the present embodiment of the invention, it is not mandatory that two electrodes 31, 32 be necessary for their function of sensing level change. An electrode 30, 33 is in principle sufficient for this purpose.
• the planar element 29 is additionally carrier of the evaluation electronics 19, the evaluation electronics 19 being fastened to the outer surface 37 of the element 29 facing away from the surface electrode 30.
• the housing 6 of the measuring device 11 is provided with an opening 34, preferably with a slot.
• the elongated hole 34 serves to receive a fastener (not shown), whereby the liquid supply unit 1 can be mounted in a printing device or an ink printer.
• the element 31, which is the center position of the sensor occupies.
• the middle surface element 31 is shown in a perspective view in FIG.
• the surface element 31 is made in one piece and made of plastic by injection molding.
• the surface element 31 is provided with a chamber 15 forming the opening. It serves to receive liquid in the sensor 12, wherein the side walls of the chamber 15 are formed on the one hand by the inner contour 38 and on the other hand by the elements 29,32.
• the chamber 15 is a measuring space formed within the sensor 12, in which side walls are formed by the two planar electrodes 30, 33. Due to the size of the chamber 15 in the element 31 results in a frame-shaped contour 39, on the outer contour 40, the opposite flanges 13,16 are arranged with the openings 14,17 for access to the chamber 15, wherein the flange 13 for connection to the Printing device 5 and the
• pins 41 are arranged on the surface element 31 as connection or positioning elements, and other connecting elements 20 are also conceivable.
• the pins 41 are located on both sides of the frame 39 and serve to fasten the surface elements 29,31,32.
• the pins 41 ensure the firm connection of the elements 29,31,32 with each other, wherein the assembly is carried out by joining the elements 29,31,32.
• the joining of the elements 29,31,32 can also be done by the bonding technique of bonding, whereby the combination of the assembly of the elements 29,31,32 by gluing and pressing is possible.
• the elements 29,31,32 possibly also be welded without mechanical fasteners. However, at least one positioning aid should be provided.
• the surface element 32 which forms an outer element of the housing 6 of the sensor 12.
• the surface element 32 comprises an inner surface 36, on which the electrode 33 is arranged with the conductor track 24 and a bore 42, which serves to receive the contact element 21.
• the bore 42 can optionally with or without
• the contact element 21 establishes the electrical connection with the evaluation electronics 19 arranged on the outer surface 37 of the surface element 29.
• the surface element 32 consists according to the invention
• the surface element 32 preferably consists of printed circuit board material with one-sided lamination for the surface electrode 33 lying on the inner surface 36 with associated conductor track 24.
• the surface element 32 includes, as the element 31 of the intermediate layer, an opening which is formed as a slot 34. Furthermore, relatively small openings, preferably bores 43, are provided for receiving the connecting or positioning elements 20 of the surface element 31.
• the surface element 29 also essentially consists of printed circuit board material and is laminated on two sides. The surface element 29 is thus a carrier of the electrode 30 located on the inner surface 36 and carrier of the evaluation electronics 19 located on the outer surface 37.
• the surface element 29 contains, as the element 31 of the intermediate layer, an opening which is formed as a slot 34. Furthermore, relatively small openings, preferably bores 43, which serve to receive the connection or positioning elements 20 of the surface element 31 for joining the housing parts, are present.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Electromagnetism (AREA)
• Power Engineering (AREA)
• Thermal Sciences (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Ink Jet (AREA)
• Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
• Measuring Fluid Pressure (AREA)

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Applications Claiming Priority (2)

Publications (2)

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Citations (3)

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• 2006
  • 2006-01-20 DE DE200610003054 patent/DE102006003054B4/de active Active
• 2007
  • 2007-01-11 US US12/161,500 patent/US8841926B2/en active Active
  • 2007-01-11 CN CN200780007561.2A patent/CN101395005B/zh active Active
  • 2007-01-11 JP JP2008550667A patent/JP4827930B2/ja not_active Expired - Fee Related
  • 2007-01-11 WO PCT/EP2007/000205 patent/WO2007087971A2/de not_active Ceased
  • 2007-01-11 EP EP07711332A patent/EP1973743B1/de active Active
  • 2007-01-11 ES ES07711332T patent/ES2343760T3/es active Active

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