JP2000510780A - Ink jet printhead module with common ink supply - Google Patents

Abstract

A system for supplying ink to a composite printing head (12) has a first compartment (20A) in fluid flow communication with a first set of orifices (14, 12A), and a second compartment (20B) in fluid flow communication with a second set of orifices (14, 12B). The first and second compartments (20A, 20B) are configured to allow the egress of ink to maintain the level of ink therein at a desired fill height. A reservoir (24) is also provided for supplying ink to the first and second compartments (20A, 20B).

Description

DETAILED DESCRIPTION OF THE INVENTION     Ink jet printhead module with common ink supply   The present invention generally relates to inkjet printers. In particular, the invention relates to liquid A series of drop-on-demand ink-jet printing A device for feeding to a orifice.   As is well known, ink jet printing devices apply one or more ink droplets. Utilizes a printhead that discharges from the orifice to the target surface. Impulse With this type of drop-on-demand printing, the ejection of ink from the orifice is It is controlled by creating a pressure pulse in the ink chamber in the lint head. Is controlled. Referring to FIG. 1 of the prior art, a typical printhead 2 has a row of The orifice has a target surface moving relative to the printhead. Control to eject ink droplets 4 that form the desired image on the target surface Is done. The orifices have individual channels in each printhead that communicate with the inlet 6. Ink is supplied from the chamber 5. Ink is supplied from reservoir 7 to ink supply line It is supplied by capillary action to each inlet 6 via 9.   An appropriate static pressure, typically a small negative static pressure, is used to avoid ink dripping It is important that the ink jet orifice is achieved. Static in printhead The pressure is such that the capillary force in a given printhead is To a large extent, the flow of the printhead will cancel any changes in the pressure head. It is a function of the hydrostatic pressure at the inlet. Thus, the static pressure at the inlet is immediately Affects pressure at nearby inkjet orifices. Optimal static pressure is viscous And physical properties of the ink, such as surface tension and wetting and orifice Is determined by the substrate material used.   Secondary, the optimal static pressure of the ink is a negative pressure of one to three inches of water. In FIG. As can be seen, and as known from hydraulic theory, the static pressure at the inlet is It is a function of the difference in height (H) between the mouth and the ink level of the reservoir. In particular, each The static pressure at the orifices is the difference in height between each orifice and the reservoir ink level. Function.   In commercial inkjet printing applications, the target surface is Large enough to create a large image on the target surface without passing through many times It would be advantageous to provide a printing device having a print area. This is By vertically stacking or "sewing" the printheads. However, the configuration of vertically stacked printheads is associated with static pressure control It raises special challenges and their commercial advantage is that ink storage and supply With increased cost or complexity. Stacked configuration It is not possible to supply all printheads from a common reservoir. This is because a uniform static pressure cannot be achieved. As can be seen in FIG. 1, the reservoir Printheads located above the fluid level experience a negative static pressure, but Printheads located below are subjected to sexual static pressure. Besides, as shown in Figure 2 As such, it is possible to provide a separate saber-controlled reservoir for each printhead. However, the cost of such an arrangement is prohibitive. In addition, the space between printheads Restrictions and close spacing require that reservoirs and level controls be installed in this form Makes it physically impossible.   Prior art dispensing devices have been identified because of the complexity and cost associated with manufacturing and maintenance. Not easily applicable to stacked printhead configurations. Thus easy and cheap The print heads in a stacked configuration are suitable for the static pressure of the ink supplied. An ink jet fluid dispensing device that provides off-line and reliable control is desired.   According to the invention, the first set of orifices is located higher than the second set of orifices. An apparatus for supplying a liquid to a composite printhead having   Fluid flow communication with the first set of orifices so that liquid outflow fills the liquid level as desired. A first compartment configured to be maintained at a height;   Fluid flow communication with the second set of orifices so that liquid outflow fills the liquid level as desired. A second compartment configured to be maintained at a height;   A reservoir for supplying liquid to the first and second compartments; There is provided the device having:   In a preferred embodiment of the present invention, several print heads are each printed on a substrate. It has a set of orifices for marking or marking. Each printhead has It is supplied from one of the compartments of the multi-compartment reservoir via separate supply lines. Parcel Ink reservoir uses a weir device to maintain a predetermined optimal static pressure in each compartment I do. The supply pressure to each printhead is high at the inlet close to one set of orifices. It is controlled by the relative height of the fluid column in each compartment. Fluid height Is controlled by the height of the weir associated with the compartment or the level of fluid by such weir May be done.   The present invention provides significant advantages over other inkjet fluid dispensing devices. Weir Since the system automatically maintains the desired level of ink in each compartment, Eliminates the need for individual level detectors, thereby reducing parts and cost .   The present invention will now be described by way of example with reference to the accompanying drawings.   FIG. 1 is a diagram of a prior art printhead and ink distribution device as described above. .   FIG. 2 relates to an independent level control for a stacked printhead structure This is an example of the problem.   FIG. 3 shows a preferred embodiment of the present invention.   FIG. 4 is a diagram showing the features of the vacuum chamber of the present invention.   Referring to FIG. 3, a fluid device embodying the present invention includes a plurality of inkjet printers. And a composite printhead 12 including printheads 12A-12D. Composite pudding The printhead 12 is stationary and moves relative to the composite printhead. (Not shown) arranged to print the image. As a modification, the composite print The head 12 may be movable with respect to the target surface, or may be a composite printhead. Both the target 12 and the target surface may be movable relative to each other.   Only schematically shown as four spaced printheads 12A-12D. However, the composite printhead 12 preferably has ink ejected from the printhead. Three or four attached together to distribute the ink evenly when It has a separate internal printhead or manifold. The desired width of the area to be printed It will be appreciated that any number of printheads may be used to make.   Preferably, each printhead 12A-12D is a set of injection nozzles or orifices. Nozzles or orifices with respective printheads 12A-12D. The fluid is supplied by a common chamber or manifold 16 therein. A set of There are 12 orifices as shown, but more or less Selecting the number of orifices and the pattern of these orifices is Within the scope of the trader. The manifold 16 has an associated inlet 18 and printhead. Fluid is supplied via a supply line 19 attached to the nodes 12A-12D. Although it is desirable to have a separate printhead for each set of orifices, Two or more sets of orifices with a single printhead having an associated inlet May be provided. Also, several sets of orifices are shown as forming a single row. However, even if there are multiple rows of orifices in a set or other forms Often, these are well understood by those skilled in the art.   To supply ink from the supply line 19 to the print heads 12A to 12D Each of the print heads 12A-12D uses a weir 22A-22D to maintain a constant ink. An associated compartment 20A-20D is provided for maintaining fluid levels. Each weir 22 To allow ink flow from one compartment to the next lower compartment, or In the case of the lower compartment 20D, an opening for returning to the reservoir 24, a drain or Has other outlets. Pump 26 is at the top from reservoir 24 via return line 27 Provides a low volume flow of ink to the reservoir 20A. Appropriate ink holdings are the main savings A detector 28 is also provided to ensure supply from the storage container to the reservoir 24. ing. Return line 27 to ensure that the proper amount of ink is supplied to the compartment. An apparatus is provided for controlling the flow rate of the fluid therein. For example, a valve or other control device May be used, or the ink may be pumped from the supply line at a desired constant flow rate. The pump may be configured as follows.   As will be appreciated, the ink level in each compartment 20 is kept constant, thus , Determined by the supply line height H above the ink level in the associated compartment The static pressure at the inlet of each printhead is the same for each printhead. You. Print heads 12, preferably the entire set of orifices per print head 12 In the associated compartment 20, a negative pressure is created in the supply line 19. Located above the ink level, this negative pressure is combined with the feed line capillary force , An appropriate pressure is created at the inlet 18 immediately adjacent to the orifice 14.   Above the reservoir to reduce the vapor pressure of the gas and reduce dissolved air in the ink A degassing device such as a partial vacuum over the membrane or ink in each container is provided. Strange As an example, a single vacuum chamber, as shown in nest 4, with all of containers 20A-20D It may be inside the member 30. As shown, the container 20 is placed inside the chamber 30. To create a low negative pressure that is stacked and reduces dissolved air in the ink And has a single port 32. As shown, the container 20 may also be Outflow in the opposite direction, thereby keeping the space close to the vertical alignment of the container. Are stacked to exist. An appropriate amount of fluid is dispensed from reservoir 24 to containers 20A-20 A control device 34 is provided to be supplied to D.   In addition, the print head 12A for the ink level in the compartments 20A-20D. -12D, and thus an adjustment mechanism for adjusting the height of the set of orifices 14 may be provided. . This type of adjustment mechanism is known in the art and allows the composite printhead 12 to be It may be configured to adjust as a unit. The adjustment mechanism is also the print head Or printheads 12A-12D, provided that they are not joined together. May be independently adjusted.   Similarly, printheads 12A-12D and their associated sets of orifices 14, the height of the compartments 20A-20D with respect to the height of the A moving mechanism for adjusting the height of the hook may be provided. The compartment 20 is a staggered unit The moving mechanism adjusts the height of the entire assembly if It may be configured. As a variant, the moving mechanism adjusts the height of the compartment independently. It may be configured as follows. This individual adjustment is a US patent application filed October 10, 1996. Performed by a moving mechanism such as the device disclosed in co-pending application Ser. No. 08 / 728,866. May be.   Instead of using one or more return lines to feed the top container 20A, It will be appreciated that the vessels may be supplied individually. Also valve, siphon or similar To control the discharge of ink from each container using various other devices such as Is also good.   Although the invention has been shown in schematic form, weirs may be surrounded by individual cartridges or Surrounding it as part of an elongated container, thereby Obtaining a compact ink device is not within the skill of the art. Each weir is completely Pump to ensure proper static pressure for multiple printheads. Monitoring the flow of supplied ink and the flow to each printhead is an aspect of the present invention. Is within the range.   Thus, each printhead in a stacked arrangement can be easily and inexpensively constructed. Ink jet fluid providing proper and reliable control of the static pressure of ink supplied to the ink A dispensing device is provided.

[Procedure of Amendment] Article 184-8, Paragraph 1 of the Patent Act [Submission date] April 24, 1998 (1998.24.24) [Correction contents] Function.   In commercial inkjet printing applications, the target surface is Large enough to create a large image on the target surface without passing through many times It would be advantageous to provide a printing device having a print area. This is By vertically stacking or "sewing" the printheads. However, the configuration of vertically stacked printheads is associated with static pressure control It raises special challenges and their commercial advantage is that ink storage and supply With increased cost or complexity. Stacked configuration It is not possible to supply all printheads from a common reservoir. This is because a uniform static pressure cannot be achieved. As can be seen in FIG. 1, the reservoir Printheads located above the fluid level experience a negative static pressure, but Printheads located below are subjected to sexual static pressure. Besides, as shown in Figure 2 As such, it is possible to provide a separate saber-controlled reservoir for each printhead. However, the cost of such an arrangement is prohibitive. In addition, the space between printheads Restrictions and close spacing require that reservoirs and level controls be installed in this form Makes it physically impossible.   Prior art dispensing devices have been identified because of the complexity and cost associated with manufacturing and maintenance. Not easily applicable to stacked printhead configurations. Thus easy and cheap The print heads in a stacked configuration are suitable for the static pressure of the ink supplied. An ink jet fluid dispensing device that provides off-line and reliable control is desired.   According to the invention, a composite having at least two sets of vertically arranged orifices Apparatus for supplying ink to a printhead, wherein said set of orifices is provided. For each, having a liquid compartment for flowing liquid through the orifice, Each of the compartments maintains the level of liquid in the compartment at the desired fill height and provides extra Wherein said squeezer is adapted to flow out of said compartment over its edge, Chambers are positioned relative to each other to allow liquid to flow from the compartment to the next lower compartment The ink compartment from the lowermost compartment of the ink compartment, Further comprising a reservoir (24) for supplying to the uppermost compartment of the compartment. An apparatus is provided. In a preferred embodiment of the present invention, several print heads are each printed on a substrate. The scope of the claims 1. a composite pudding having at least two sets of vertically arranged orifices (14) A device for supplying ink to the printhead (12),   For each of said sets of orifices (14), wherein the orifice is liquid And a liquid compartment (20A-20D) through which the liquid flows. Maintain the level of liquid in the compartment at the desired fill height and remove excess liquid from the compartment. The compartments (20A-D) are configured to allow the liquid to flow over the rim. Positioned relative to each other to drain from the chamber to the next lower compartment, Receiving ink from the lowermost compartment in the ink compartment, The above device, further comprising a reservoir (24) for feeding an upper compartment. 2. The desired filling height of each compartment (20A-D) is to determine the difference in upper static height At a lower height than the inlet (18) to its respective orifice (14). Claim 1 which creates a negative pressure acting on the liquid in the Tayu Utanokuchi (18). An apparatus according to claim 1. 3. The desired filling height of the compartments (20A-D) is determined for each set of Lower than the lowest orifice, thereby each orifice in the set of orifices The apparatus according to claim 1 or 2, wherein a desired negative pressure is maintained. 4. The difference in static height defined for each compartment (20A-D) is substantially the same. And therefore acts on the liquid in the inlet (18) to each set of orifices (14). 4. The apparatus according to claim 2, wherein the negative pressure is substantially the same. 5. A single supply for supplying liquid from the reservoir (24) to the uppermost compartment (20A). 5. The device according to claim 1, further comprising a supply line (27). On-board equipment. 6. In each compartment (20A-D), maintain the desired fill height and allow To the compartment (or, in the case of the lowest compartment, to the reservoir (24)) The outlet openings (22A-D) adapted to drain the liquid from the compartments Apparatus according to any one of claims 1 to 5, wherein the apparatus is configured. 7. The outflow of liquid from the compartment is opposite to the flow of liquid from the next lower compartment. To the compartment (20A-D), and the reservoir (24). 7. A device according to claim 1, wherein the device allows a substantially vertical stacking arrangement. Equipment. 8. An appropriate amount of liquid is supplied from the reservoir (24) to the compartment (20A-20D). The control device according to any one of claims 1 to 7, further comprising a control unit configured as described above. On-board equipment. 9. Pump for supplying liquid from reservoir (24) to first compartment (20A) The device according to any one of claims 1 to 8, further comprising (26). 10. The compartments (20A-D) are configured to contain substantially the same volume of liquid. An apparatus according to any one of claims 1 to 9, wherein 11. Partially above the liquid in each compartment to reduce the vapor pressure of the gas in the compartment. 11. The device according to claim 1, further comprising a device for creating a sky. An apparatus according to claim 1. 12. The height of the compartments (20A-D) to further control the height of the liquid in the compartment. Any one of claims 1 to 11, further comprising an adjusting mechanism for adjusting the height. The device according to item. 13. Each set of orifices (14) is a respective component of the composite printhead. The print head according to any one of claims 1 to 12, which is formed on a lint head. apparatus. 14. Each of the compartments (20A-D is used to determine the level of liquid in the     And drain excess liquid from the compartment over its edge     14. The device according to any one of claims 1 to 13, comprising a weir (22A-D).     Equipment.

────────────────────────────────────────────────── ─── Continuation of front page    (81) Designated countries EP (AT, BE, CH, DE, DK, ES, FI, FR, GB, GR, IE, IT, L U, MC, NL, PT, SE), OA (BF, BJ, CF) , CG, CI, CM, GA, GN, ML, MR, NE, SN, TD, TG), AP (GH, KE, LS, MW, S D, SZ, UG), EA (AM, AZ, BY, KG, KZ , MD, RU, TJ, TM), AL, AM, AT, AU , AZ, BA, BB, BG, BR, BY, CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, G B, GE, GH, HU, IL, IS, JP, KE, KG , KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, N O, NZ, PL, PT, RO, RU, SD, SE, SG , SI, SK, TJ, TM, TR, TT, UA, UG, UZ, VN, YU

Claims (1)

[Claims] 1. Position the first set of orifices (14) higher than the second set of orifices (14) An apparatus for supplying a liquid to the composite print head having a,   The first set of orifices (14) is in fluid flow communication with the first set of orifices (14) so that liquid outflow is at a liquid level. A first compartment (20A) configured to maintain a desired filling height;   The second set of orifices (14) is in fluid flow communication with the orifice (14) so that the outflow of liquid is at a liquid level. A second compartment (20B) configured to maintain a desired filling height;   A reservoir (2) for supplying a liquid to the first and second compartments (20A, 20B). 4) and The device comprising: 2. The desired filling height of the first compartment (20A) is determined to determine the difference between the upper static heights. At a height lower than the inlet (18) to the first set of orifices (14), The desired filling height of the compartment (20B) is determined by the second set of At a height lower than the inlet (18) to the orifice (14), said upper and lower The difference in static height creates a negative pressure acting on the liquid in the inlet (18). The device of range 1. 3. The desired filling height of the first compartment (20A) is the highest of the first set of orifices (14). Lower than the lower orifice, the desired filling height of the second compartment (20B) is the second set of The orifice (14) is lower than the lowest orifice so that each set of 3. The method according to claim 1, wherein a desired negative pressure is maintained at each orifice in the orifice. On-board equipment. 4. The difference in the upper static height is substantially the same as the difference in the lower static height, and therefore the first set And the negative pressure acting on the liquid in the inlet (18) to the second set of orifices (14) is 3. The device according to claim 2, which is substantially the same. 5. A single unit for supplying liquid from the reservoir (24) to the first compartment (20A). Further comprising a supply line (27), wherein the liquid from the first compartment (20A) is supplied to the second compartment; (20B), and liquid from the second compartment is directed to the reservoir ( Device according to any one of claims 1 to 4, which is directed to 24). 6. In the first compartment (20A), the desired filling height is maintained and the liquid is supplied to the second compartment. Liquid is now drained from the first compartment to direct to (20B) An outflow opening (22A) is formed, and the desired filling height is provided in the second compartment (20B). From the second compartment to maintain the pressure and to direct the liquid to the reservoir (24). An outflow opening (22B) for discharging is formed in claim 5, The described device. 7. Outflow of liquid from the first compartment (20A) is due to liquid from the second compartment (20B). Of the first compartment (20A), the second compartment An arrangement that allows a substantially vertical stacking of the compartments (20B) and reservoirs (24); The device of claim 6. 8. An appropriate amount of liquid is supplied from the reservoir (24) to the compartment (20A-20D). The control device according to any one of claims 1 to 7, further comprising a control unit configured as described above. On-board equipment. 9. Pump for supplying liquid from reservoir (24) to first compartment (20A) The device according to any one of claims 1 to 8, further comprising (26). 10. The first and second compartments (20A, 20B) contain substantially the same volume of liquid. Apparatus according to any one of claims 1 to 9, wherein the apparatus is configured to: 11. In order to reduce the vapor pressure of the gas in the first and second compartments, Further comprising a device for creating a partial vacuum on the surface. An apparatus according to any one of the preceding claims. 12. To further control the height of the liquid in the first and second compartments, Claims further comprising an adjusting mechanism for adjusting the height of the compartments (20A, 20B). 12. The apparatus according to any one of claims 1 to 11. 13. Upper printhead (12A) higher than lower printhead (12B) And the upper and lower print heads (12A, 12B) are A composite pre-pump having an inlet (18) in fluid flow communication with the orifice (14). A device for supplying ink to a print head (12),   An upper print head (12A) for supplying ink to the upper print head. )) In fluid flow communication with the upper compartment (20A);   An upper print head (12B) for supplying ink to the lower print head. ) A lower compartment (20B) in fluid flow communication with   A reservoir (24) for supplying ink to the upper compartment;   A supply line (27) for supplying ink from the reservoir to the upper compartment;   A pump (26) for delivering ink from the reservoir to the upper compartment. ,   The upper compartment (20A) drains to a desired height lower than the height of the upper set of orifices An opening (22A), whereby the inlet of the upper printhead and the upper compartment Defining a difference in upper static height between the level of ink maintained in (20A) and Creating a back pressure acting on the ink in the inlet,   The lower compartment (20B) is opened from the outflow opening (22A) of the upper compartment (20A). The ink to be discharged is overflowed, and the lower compartment ( 20B) is to lower the lower static height to determine the same lower static height difference as the upper static height difference. Outlet opening (22B) at a height lower than the head inlet (18). Back pressure acting on the ink in the orifice of the printhead Such an apparatus, wherein the back pressure acting on the ink in the orifice is substantially the same. 14. Replace the upper set of orifices (12A, 14) with the lower set of orifices (12B, 1B). 4) To supply liquid to a composite printhead (12) having a higher position than The upper set of orifices has an associated upper inlet (18, 12). A) and the lower set of orifices has an associated lower set of inlets (18, 12). B)   Maintaining the liquid in the compartment at a desired level relative to the height of the upper and lower inlets. The compartments here, so as to force the inlet back to the desired back pressure. Means (22A-22D) for discharging the chamber (20A-20D) empty liquid;   Means (24, 26) for supplying liquid to said compartments (20A-20D); The device, further comprising: 15. With at least two vertically arranged printheads (12A-12B) An apparatus for supplying ink to the formed composite printhead (12), ,   For each of the print heads (12A-12D), In order to maintain the pressure, an eye located at a predetermined height with respect to the corresponding printhead Has a compartment (20A-20D),   Each of the ink compartments (20A-20D) contains a desired amount of ink in the compartment. (22A-22D) for maintaining the pressure and discharging excess ink from the compartment Has,   The compartments (20A-20D) allow ink to flow out of one compartment to the next compartment. Positioned relative to each other to receive in the lower compartment lower,   A reservoir for receiving ink escaping from the lowermost compartment of the ink compartment Ba (24),   The uppermost compartment (20A) of the ink compartments from the reservoir (24). )), Further comprising a pump (26) for pumping ink to the device.