TR201907687U4 - Inkjet printer with printhead cleaning tool. - Google Patents

Abstract

For printing with ink on a substrate, the inkjet printer includes at least one inkjet printhead to eject ink onto the substrate while the relative movable substrate is passed, and the printhead cleaning means for cleaning the at least one printhead. The print head has a lower nozzle plate containing inkjet nozzles. The printhead cleaner includes cleaning surface provided with at least one cleaning fluid opening to direct the cleaning liquid to the lower nozzle plate of the print head. The printer is equipped with the controller configured to apply negative printing pressure, positive cleaning pressure and rinsing pressure according to the ambient atmosphere, to adjust the ink reverse pressure in the inkjet nozzles.

Description

DESCRIPTION INK WITH PRINTHEAD CLEANING TOOL JET PRINTER The present invention is an inkjet having a printhead cleaning device. relates to the printer.

Controlled use of inkjet inks suitable for inkjet printing well known for recording an image on a substrate by spraying is a technique. Typically, the inkjet printer tool is used with a variety of printers. head, eg at least one for each color, eg each of blue, red, yellow and black white and/or transparent inks as a supplement and optionally for or additional printheads for any supporting color ink. Each The printhead includes a nozzle plate, where multiple nozzles are provided. More than one ink is fed to the nozzle from an ink cabinet. The printheads to be printed It can be configured to scan the width of the substrate back and forth. Alternative As a result, printheads cover at least the width of the substrate to be printed. arranged in a fixed manner in rows. Substrate paper or paper-based materials, It can be plastic or textile product. Typically the substrate comes from one feed end of the printer. throughout the writing section where the substrate is printed and curing if present or through a conveyor to an outlet end during additional processes such as drying.

The substrate can be fed as individual layers or as a mesh. feeding section and The carrier as well as the discharge section is generally adapted to the configuration of the substrate. For example, if the substrate to be written is a net wound on a reel, the feed section may contain an opening station, the print section temporarily support rollers and/or a drum to which it is fixed, or in the case of textiles An endless conveyor equipped with an adhesive coating to which the substrate temporarily adheres. a take-up reel on which the printed substrate is wound may contain. Sheet feeders are applied in the case of a sheet-like substrate.

During printing, the printhead nozzles are filled with (semi-)hardened/dried ink and may be partially clogged with particles/dust from the environment and/or substrate. Powder also nozzle It can also stick to the plate. This inevitable contamination of printheads is low. may affect the printing process, resulting in image quality. Therefore, Maintenance is required for the printhead during operation. Part of the maintenance procedure In addition, printheads often restore print performance and image quality. cleaned, wiped and/or rinsed to bring Cleaning the printheads a flow of ink by printing through the nozzles (but at a much slower speed than the includes removing ink. A special cleaning of the rinse nozzle plate includes contact with the liquid. Printhead after cleaning and rinsing usually the nozzle plate is cleaned with, for example, a rubber squeegee or an ink-absorbing fabric. During printing, a back pressure (negative relative to ambient pressure) is applied to the ink in the nozzle. pressure) creates an ink meniscus in the nozzle itself, so that the ink meniscus is retracted into the nozzle and does not protrude from there.

If print back pressure is maintained during maintenance, residue, cleaning fluid and/or excess ink is drawn into the nozzles and the ink contained in the nozzles mix. This causes discoloration in the relevant ink, affecting the color strength and physical properties, such as surface tension and viscosity, which in turn affect image quality. causes deterioration. Also, especially if you already have nozzles on the same nozzle plate. When different colored inks used are fed, the ink from different nozzles mingling with each other. These printheads are for two or more different inks. It has an independent ink path.

In the technique, during maintenance, the ink pressure from the normal printing back pressure It is known to temporarily increase the pressure to a pressure above eg, a liquid drain device, such as an inkjet printer with a printhead is explained. This known tool makes contact with the nozzle-forming surface of a printhead. nozzle-forming surface by performing a relative movement with respect to the nozzle-forming surface while a wiping element wiping the surface; at least one of a printhead and wiper element a cleaning liquid supply section that supplies the cleaning liquid; and an ink circulation of ink circulated between the storage compartment and the printhead. A device that can set a second alignment speed faster than the first speed during erasing. Includes circulation rate adjustment section. Thanks to the circulation at a higher speed, The reverse pressure in the nozzles becomes a positive pressure during the head cleaning process. so that the foreign materials remaining on the nozzle forming surface are transferred to the nozzles. It is stated that it prevents entry. Gaps in the printhead to the ink nozzles It is fed from a reservoir throughout. The reservoir, on the other hand, is a conduit to create a recirculation flow. through a collection channel equipped with a circulation pump and a supply channel attached to a tank. The velocity of the ink circulated between the tar and the reservoir, and pressure, in addition to the circulation pump, there is also another pump connected to the tank. by an ink circulation mechanism that includes a pressure adjustment mechanism. is set. In the illustrated embodiments, the cleaning fluid is applied to an ink-fed surface. is fed, the corner between the ink-fed surface and the nozzle-forming surface flows down to the section. The squeegee then moved in a first direction on the ink-fed surface it contacts this corner section, bends and forms a nozzle. It is moved a little more in contact with the surface. In this way, the cleaning liquid will be wiped by pushing the corner from the corner along the surface forming the nozzle, dust and are believed to have been removed. Additional cleaning in the reverse direction The wiper operation is performed by feeding or not feeding the liquid. This cleaning process can be repeated depending on the write load. Optionally forward or backward During movement, the nozzles allow the speed of the circulating ink to be faster than the second speed. It can be cleared by a third higher alignment lift.

A disadvantage of this known tool is the complexity of its operation. Also, cleaning drifting during application of liquid and wiping ink remnants Due to the ink being ejected during printing, dust and other particles may not enter the nozzle. from the forming surface to the ink nozzles and also the ink containing the reservoir It is still possible to reach the circulation mechanism and the tank. So still ink contamination may occur. To nozzles on one and the same printhead If dyes of different colors are fed, there is still a risk of mixing with each other. Particularly used inks contain paint particles dispersed in a solvent. In the case of disperse inks, the pressure of the squeegee will come into contact with the nozzle forming surface. Doing so will easily damage the nozzles. These particles are the squeegee and nozzle forming surface. can get stuck in between and abrade the nozzle plate, thereby improving the printing process and image quality may affect. Also, wiper wear due to particles affects the cleaning process.

Therefore, an advanced printer with a reduced risk of contamination (mixing) head cleaning tool and process are needed.

In light of this information, the present invention is suitable for ink printing on a substrate. It provides an inkjet printer that includes: at least one inkjet printer for spraying ink onto the substrate at least one inkjet printhead, multiple inkjet printheads has a lower nozzle plate containing the nozzle, a conveyor to pass the substrate across the printer and under at least one printhead. a printer for cleaning at least one printhead of the inkjet printer. head cleaning tool and where the printhead and the printhead cleaning tool are interlocked in a maintenance position. configured to perform a relative movement relative to where the printhead cleaning tool pours the cleaning fluid into the bottom nozzle of the printhead. supply at least one cleaning fluid to direct upwards in the direction of the platen an upward-facing cleaning surface provided with the element; here to adjust the back pressure of the ink in the printer inkjet nozzles It is equipped with a controller configured to: during the printing process, the inkjet nozzles application of negative printing pressure, where ink jet onto the substrate an image is recorded on the substrate by ejecting ink from its nozzles; and part of the cleaning process in which the ink jet nozzles are cleaned with ink During the cleaning phase, the inkjet nozzles are subjected to a certain temperature relative to the ambient atmosphere. application of positive cleaning pressure; and the nozzle plate's cleaning fluid supply A part of the cleaning process in which it is rinsed with cleaning liquid supplied by the a rinse pressure to the inkjet nozzles during the rinse phase. application, where the cleaning pressure is higher than the rinse pressure, the rinse pressure is higher than printing pressure.

Inkjet printer for printing with ink on a substrate Contains at least one printhead for applying the ink onto a substrate.

Inkjet printhead with multiple inkjet nozzles It has a lower nozzle plate fitted. In one embodiment, blue, red, yellow and black and optionally each different color such as white, transparent and/or additional backing colors. At least one inkjet printhead is provided for ink. In one embodiment, The inkjet printer is of the scanner type, where at least one printhead moves in the width direction, e.g., forward and backward along a support rail It is mounted on carriers that can handle it. Another single pass type printer arrangement, the printheads are fixed in the width direction of the printer. arranged, the various printheads for one type of ink occupies the full width of the print. In this arrangement, the printheads fixed layout prevents them from moving in the width direction, but cleaning height to allow tool(s) to pass under the printheads movement is possible. In yet another embodiment, the inkjet printheads are placed in two or more different ink containers for different inks. Includes nozzle plates with independent ink path. inkjet The printer is also used to pass the substrate along the printer from a feed end to an output end. includes a transport tool, where the substrate is located under the printheads in the printing section. is passed. Depending on the type of ink hardening means, the ink may be (partially) downstream of each printhead station to harden, for example thermal downstream of the final print head, as well as dryers and/or UV emitters. final hardening agent can be provided. The substrate is commonly used as described above. any of the substrates used.

The inkjet printer also has at least one printer of the inkjet printer. includes a printhead cleaning tool for cleaning the head. printheads and The associated cleaning tools can move relative to each other. Cleaning process, printer head and printhead cleaning tool in a maintenance location, eg, a scanner type In the case of an inkjet printer, a little bit of the longitudinal edge of the carriage performed while being brought beyond. Printheads for single pass type printer If it is permanently installed as described, the cleaning tool printer passed over their heads. with the cleaning tool passing under the printhead. is configured.

The cleaning tool, at a small interval during cleaning, the above cleaned printer It includes an upward-facing cleaning surface that faces the nozzle plate of the head.

Cleaning surface for spraying, spraying or flowing cleaning fluid one or more of the nozzles used, such as Sprayers or just holes Equipped with cleaning fluid supply element. Cleaning surface with cleaning process A drop of cleaning fluid is provided on it, which contacts the nozzle plate. Cleaning The liquid penetrates the cleaning plate and removes any dirt, particles and sticky ink. loosens residue. Liquid waste is discharged.

To adjust the ink back pressure in the printer inkjet nozzles, use a to apply a negative printing pressure during the printing process. Equipped with a configured controller. The controller also ensures that the nozzles are filled with ink. media during an optional cleaning phase of the cleaning process a positive atmosphere in the range of 80-500 mbar, such as 100 mbar, advantageously compared to the atmosphere. configured to apply purging pressure. The controller also during a rinse phase of the cleaning process where it is rinsed with cleaning liquid, advantageously in the range of -10mbar to +10mbar, preferably -5mbar to +5mbar a rinse pressure in the range, more preferably in the range of -3 mbar to +3 mbar configured to implement. The cleaning pressure is higher than the rinse pressure. high, the rinse pressure is higher than the print pressure.

During the cleaning phase, the back pressure of the ink in the nozzles is determined by the controller. adjusted to the pressure required for cleaning or rinsing. Advantageously, rinsing The flow of ink through the printhead is stopped during

In this way, the nozzle plate is thoroughly cleaned with or without the use of a wiper mechanism. While cleaning by wetting, the ink in the nozzles may contain dirt, cleaning liquid and/or other Contamination with ink is effectively prevented.

In one embodiment, when the controller is run by a processor and processor computer-readable commands that perform operations including: moving the printhead and printhead cleaner into a maintenance position; Required cleaning pressure of backpressure in printhead nozzles or rinsing pressure adjustment; optionally interrupting the flow of ink through the printhead; cleaning the printhead nozzles with ink; or cleaning fluid into the printhead cleaner's cleaning fluid supplies nutrition.

During cleaning, ink flows into a drain tray. The cleaning liquid used for removal, preferably the printhead cleaning tool, as well as liquid waste. by applying a low pressure to at least one suction opening to remove includes at least one suction opening connected to the configured suction means. nozzle plate After exposure to cleaning fluid, for example using a vacuum pump A low pressure is created through the einine, which means whatever sticks to the nozzle plate removes liquid waste. In this case, the commands are executed at at least one suction opening of the suction vehicle. where a low pressure will be created and the liquid waste will be removed from the nozzle plate It includes operating in the form. The cleaning tool and printhead are typically Since the head performs a relative movement relative to each other in the longitudinal direction, the suction a slit, preferably across the width of the printhead, is advantageously relative It is located downstream of the cleaning fluid openings when viewed in the direction of movement. This In this case, the cleaning cycle is advantageously only during relative movement in one direction. is performed and is not performed during movement back to the starting position, but suction can continue during the return movement.

The printhead cleaning tool is preferably downstream of the cleaning fluid supply element(s). direction and, if present, upstream of the suction opening. may contain a deletion element.

The invention is further described by means of the accompanying figures, which are explained below.

Figure 1 is an ink cartridge having a printhead cleaning means according to the invention. illustrates an embodiment of the ink printer; Figure 2 shows a printhead cleaning tool relative to the printhead during cleaning. shows a schematic view of its arrangement; and Figure 3 is a diagram that describes computer-readable commands for the controller. shows an example of sema; and Figure 4 is a diagram of a back pressure in nozzles during printing and maintenance. shows the example.

In Figure 1, an inkjet printer as a whole, with the reference number (10) is shown. The inkjet printer (10), in the embodiment shown a feeder comprising an opening roller for feeding the printable substrate (14). section (12). The printer also includes several print stations (18). unit (16), where each print station (18) is the width of the printer. It includes at least one inkjet printhead 20 movable in its direction.

Between neighboring print stations, curing tools (not shown) and there is also a final curing agent arranged downstream of the printing unit (16). (22) eg a UV emitter or thermal dryer may be present. In the output section (24) the imprinted substrate (14) is collected and put into a denial as shown, for example. (26) is wrapped. Passing the substrate (14) through the printer, some of which a controller (30) cylinder connected to suitable (electric) drives (not shown) under the control It is carried out by means of transport in the form of (28). Maintenance of the printheads their positions are located adjacent to one of the longitudinal sides of the carrier.

Figure 2 shows a printhead (20) array (schematic with dashed lines) during cleaning. one embodiment of the printhead cleaning means 50 according to shows the seinatic appearance. Each printhead (20) has a lower nozzle plate (32) wherein multiple nozzles 34 are provided. Nozzles of each printhead (20) (34) has an internal ink flow channel (38) and feed chute (40) and return chute It has fluid communication with a common ink container 36 through 42.

Pump (44) and flow and pressure controller (46) in ink flow supply chute (40) provided by. Flow and pressure comprising a reverse pressure processor (48) and memory (49) controlled by the controller (46).

The cleaning means 50 is a cleaning body having an upper cleaning surface 54 (52) includes. At the cleaning surface 54, a pump via an internal manifold 58 A miscellaneous cleaning fluid supply is connected to the cleaning fluid reservoir (59) and the cleaning fluid reservoir (60). The element 56 provides clarity in this embodiment. Cleaning tool (50) with arrow A it can move relative to the printhead (20) in line with the width of the printer shown.

Evacuation of liquid waste from the cleaning surface into a waste cabinet (not shown) one or more drains along the edges of the cleaning surface (54) to channel (62) is provided. As seen in the width shown, the cleaning The rear end (downstream end) (64) of body 52 It is equipped with a suction opening 66 connected to the suction means 68. Cleaning process During cleaning, the cleaning fluid fed through the cleaning elements (56) form a drop (70) at the top of the surface of the printhead (20), where the drop (70) it contacts the nozzle plate (32) and drains to the side edges, from where the discharge channels (62) evacuated throughout. Droplets adhering to lower nozzle plate (32) wiper (72) It is removed by the einine device (68) and through the suction opening (66) is taken.

Figure 3 is about performing a cleaning operation after the printer has stopped. the step S1 to S9 illustrates an instruction scheme 80.

In SL, the printhead and the cleaning tool are brought into a cleaning position relative to each other.

Optionally, back pressure at S2 can be changed from a negative (printing) pressure to a positive adjusted to the cleaning pressure. Then in S3, cleaning the nozzles with ink is performed. After optional cleaning, back pressure cleaning rinse with a lower pressure than the printing pressure, but higher than the printing pressure. pressure and optionally the ink flow is cut off at S4. next step In SS, vacuum is applied to the crotch opening. Next, cleaning on the nozzle plate Sö rinsed with liquid. Suction is stopped at S7 after rinsing. In SS, reverse nozzles the pressure is set to negative printing pressure and, if appropriate, the ink flow is restarted. On the S9, the printhead is in the print position and the cleaning tool is an active returns to the non-standby mode. At this point, the printer does a subsequent print is ready for the job.

Figure 4 is a list of sequential operations performed on the printer according to the diagram in Figure 3. It shows the back pressure with respect to the ambient pressure as a function. clearly seen such as when the cleaning pressure is positive, the rinse pressure is PDRIN, and P is RINSE,, It is in a working area limited to ± 3 mbar, approximately ambient is under pressure.

Claims (6)

REQUESTS 1. At least one inkjet printhead (20) with a lower nozzle plate (32) containing multiple inkjet nozzles (34) to eject ink onto the substrate (14) onto a substrate (14), comprising a transport means (28) for passing under at least one printhead (20), and a printhead cleaning means (50) for cleaning at least one printhead (20) of the inkjet printer (10). an inkjet printer (10) for printing with ink, characterized in that the printhead (20) and the printhead cleaning means (50) are configured to perform a relative movement relative to each other in a maintenance position; the printhead cleaning means (50) includes an upward facing cleaning surface (54) equipped with at least one cleaning fluid supply element (56) for directing the cleaning fluid upwardly in the direction of the bottom nozzle plate (32) of the printhead (20); Media is supplied to the inkjet nozzles (34) during a printing process in which an image is recorded onto the substrate (14) by ejecting ink from the inkjet nozzles (34) onto the substrate (14) to adjust the backpressure of the ink in the inkjet nozzles (34) of the inkjet printer (10). applying a negative printing pressure with respect to the atmosphere; applying a positive cleaning pressure relative to the ambient atmosphere to the inkjet nozzles (34) during a cleaning phase of the cleaning process wherein the inkjet nozzles (34) are cleaned with ink; and a rinse to the inkjet nozzles (34) during a rinse phase of the cleaning process in which the lower nozzle plate (32) is rinsed with cleaning liquid supplied by the cleaning liquid supply (56) with the cleaning pressure higher than the rinse pressure and the rinse pressure higher than the print pressure. Equipped with a controller configured to apply pressure. 2. An inkjet printer (10) according to claim 1, characterized in that the cleaning pressure is within the range of 80-500 mbar according to the ambient pressure. Inkjet printer (10) according to claim 1 or claim 2, characterized in that the rinsing pressure is within the range of -10 mbar to +10 mbar, preferably -5 mbar to +5 mbar, more preferably -3 mbar to +3 mbar, depending on the ambient pressure. is that. An inkjet printer (10) according to any one of the preceding claims, characterized in that the controller is configured to cut off the flow of ink through the inkjet printhead (20) during a cleaning operation. An inkjet printer (10) according to any one of the preceding claims, characterized in that the controller includes a processor (48) and a memory (49) in which computer readable commands (S 1 -89) are stored, which, when operated by the processor, performs operations including: moving the printhead (20) and the printhead cleaning means (50) into a maintenance position; adjusting the back pressure in the ink jet nozzles (34) to the required cleaning pressure or rinse pressure; optionally interrupting the flow of ink through the printhead (20); cleaning the printhead nozzles (34) with ink; or supplying cleaning fluid to the cleaning fluid elements (56) of the printhead cleaner (50). An inkjet printer (10) according to any one of the preceding claims, characterized in that the printhead cleaning means (50) is also connected to at least one suction means (68) configured to apply a low pressure to at least one suction opening (66) to remove liquid waste. contains a suction opening. An inkjet printer (10) according to claim 5, characterized in that the commands further include operating the suction means (68) in such a way that a low pressure is created in at least one suction opening (66) and the liquid waste is removed from the lower nozzle plate (32). It is an inkjet printer (10) according to any one of the preceding claims, characterized in that the print head (20) is fixed in a fixed way10 in the width of the printer (10) and the cleaning tool (50) is configured to move in the width of the printer (10) during the cleaning process. An inkjet printer (10) according to any one of the preceding claims 1-7, characterized in that the print head (20) is configured to move in the width of the printer (10) and the maintenance position is located along one longitudinal edge of the printer (10), the cleaning tool being (50) is configured to perform a relative movement with respect to the printhead (20) during the cleaning process. An ink jet printer (10) according to any of the preceding claims, characterized in that the cleaning means (50) is configured to perform a cleaning operation during movement in one direction. An inkjet printer (10) according to any one of the preceding claims, characterized in that the inkjet print head (20) includes a lower nozzle plate (32) having inkjet nozzles (34) different from different ink containers (36) in the print head (20). The nozzles (34) are provided with two or more independent ink paths for different inks.