Source: https://patents.google.com/patent/EP1016533B3/en
Timestamp: 2018-05-27 16:08:38
Document Index: 476586409

Matched Legal Cases: ['art 30', 'art 54', 'art 55', 'art 54', 'art 54', 'art 54', 'art 64', 'art 64', 'art 64', 'art 64', 'art 64', 'art 64', 'art 64', 'art 64', 'art 91', 'art 121', 'art 121']

EP1016533B3 - Ink supply unit - Google Patents
EP1016533B3
EP1016533B3 EP19990929867 EP99929867A EP1016533B3 EP 1016533 B3 EP1016533 B3 EP 1016533B3 EP 19990929867 EP19990929867 EP 19990929867 EP 99929867 A EP99929867 A EP 99929867A EP 1016533 B3 EP1016533 B3 EP 1016533B3
EP1016533A1 (en )
In order to enhance color print quality, recording device is available, which uses plural kinds of ink, i. e. ink of different optical densities, for the same type color. In such recording device, the number of ink tubes is increased as the kinds of ink are increased. Since each ink tube must be guided to follow the movement of the carriage, a structure for wiri ng each tube becom es complicated or restricted. Further, the elasticity and rigidity of the tube influences the movement of the carriage, hindering high-speed printing.
To solve such a problem, as disclosed in Japanese published unexamined patent application No. Hei10-244685 , a recording device has been proposed, which includes an ink supply unit, mounted on a carriage, for supplying ink to an ink-jet recording head, an ink cartridge installed on the body side, and an Ink supplementing unit which is connected by a conduit and detachably engaged with the ink supply unit.
However, as the supply of inkfrom the ink cartridge installed on the body side to the ink supply unit depends upon slight negative pressure caused by expansion force of an elastic member preliminarily installed in the ink supply unit, the recording device suffers from a problem that the negative pressure decreases to reduce the filled quantity of ink and to consume increased time period for ink filling as air is accumulated in the ink supply unit in association with a large number of times the ink filling is repeated.
To solve this problem, as disclosed in Japanese published unexamined patent application Hei8-174860 , a recording device has been proposed, in which a differential pressure valve mechanism is disposed between the ink storage chamber side of the ink supply unit and the recording head, the mechanism having a membrane opened or closed depending upon the differential pressure of ink.
EP-A-0 794 059 discloses an ink supply unit in the form of a regulator module including two separate ink accumulator chambers. A diaphragm based, backpressure regulator mechanism is mounted in the regulator side ink accumulator chamber. A torsion spring is provided as a biasing mechanism.
EP-A-0 760 288 also discloses a torsion spring. Forces are balanced in this spring-loaded regulator embodiment using a diaphragm and said torsion spring. The torsional spring is designed to counteract the diaphragm force to achieve an equilibrium balance providing an appropriate predetermined backpressure.
Therefore, an object of the present invention is to provide an ink supply unit suitable therefor, which can finely maintain negative pressure with high precision, and supply ink stably to a recording head.
Fig. 1 shows an embodiment of an ink-jet recording device with the outline of its ink supply mechanism.
Fig. 2 is a perspective view showing an embodiment of an ink supply unit according to the present invention which is used for the device.
Figs. 3 (a) and 3 (b) respectively show a state in which films for sealing the surface and the backface are detached and a state in which the films for sealing are omitted of the one embodiment of the ink-supply unit.
Fig. 10 shows relationship between a filter and a passage in case in which the filter attaching position is changed from the embodiment shown in Fig. 8 in a state in which the valve is open and Figs. 11 (a) and 11 (b) respectively showrespective sides of the ink supply unit to show a groove and a through hole forming the passage.
Fig. 1 shows an ink-fet recording device. A carriage 1 is guided by a guide member 2, and can be reciprocated by driving means not shown. A plurality of ink supply units 3 (four ink supply units in this embodiment), each constructed according to the presentinvention, are mounted on the upper part of the carriage 1, and a recording head 4 is provided on the lower surface of the carriage 1. A cartridge holder 6 for accommodating an ink cartridge 5 therein is disposed on each of the sides of an area where the carriage 1 is moved (only one side is shown in Fig. 1). An ink supplementing unit 7 is disposed above an non-printing area in the area where the carriage 1 is moved.
The casing 30 is divided vertically by a wall 33, and laterally by a wall 34 as shown in Fig. 4, so that thin grooves 35 and 35' for communicating with the air are provided in the upper wall 33, and the lower part is divided into the ink storage chamber36 and a valve chamber 37. A thick part 30b extended from the side to the bottom is formed on one side 30a of the valve chamber 37 of the casing 30 to define an ink supply passage 38 in the form of a groove having an upper end 38a communicated with the ink inlet 9, and a lower end 38b apart from an ink inflow port 39 of the wall 34 by a gap G. The groove is offset in the direction of the thickness of the casing 30.
By locating the lower end of the ink supply passage_38 in the vicinity of the ink inflow port 39 in this manner, highly degassed ink injected from the ink cartridge 5 can flow to the recording head 4 via the ink supply passage 38 located in the lower part while avoiding contact with the air.
The membrane valve 53, designed as a movable valve, includes a membrane part 54 formed of flexible material to be elastically deformed by receiving differential pressure, and athickfixed part 55 that supports the periphery of the membrane part 54, that is formed of hard material and that is held between the casing 30 and the fixing member57. It is preferable to manufacture the membrane valve 53 integrally through two-color molding of high polymer materials. At the central part of the membrane part 54, a thick sealing part 54b is provided, which has an ink flow port 54a opposite to the ink flow port 52c of the spring holder 52.
When printing is started in this state and ink is consumed by the recording head 9, pressure in the groove 44 forming the ink passage is decreased to gap g is formed between the membrane part 64 and the valve seat 57c' as shown in Fig. 8 (b). This permits ink in the ink storage chamber 52 to flow into the ink supply port 23 as shown by F such the ink, from which air bubbles and dusts are removed by the filter 56, passes through the ink flow port 64c of the membrane part 64 and an outflow port 67. In this manner, when differential pressure is decreased to some extent, the membrane part 64 is pushed back to the valve seat 57c' by the spring 61 and the ink flow port 64c is closed as shown in Fig. 8 (a). As the pressure of the spring 61 is received by the valve seat 57c' in this state, the thin part 64a is not deformed excessively and fluid-tight property can be kept for a long term.
Soft high polymer material is likely to cause contraction, etc. subsequently to injection molding, and the thin part 64a may faces a difficulty to keep a planar surface. To cope with this difficulty, an annular bent part 64d' having a approximately S-shape in section is formed in the support area side of the thin part 64a as shown in Fig. 8 (c) to keep the thin part 64a planar.
In the above embodiments, the filter is disposed to face the differential pressure valve mechanism, however, as shown in Fig. 10, the similar effect is obtained even if the filter is disposed at a position not facing the differential pressure valve mechanism, for example, at a position below the differential pressure valve mechanism 50. That is, it suffices that the ink storage chamber 36 is communicated with one surface of a filter 70, and theothersurface of the filter 70 is communicated with the ink inflow port of the differential pressure valve mechanism 50 via a through-hole 71 formed in a thick portion of the casing 30.
A main tank 80 is formed at the bottom of one side thereof with a connection port 81 to which an ink supply unit 90 is connected. The inside of the main tank 80 is divided into plural chambers, e.g. three firstto third ink chambers 84, 85 and 86 by two partitions 82 and 83 in this embodiment. The lower parts of the partition 82 and 83 are respectively formed with communicating ports 82a and 83a, where the upper surfaces 82b and 83b are set to be lower than the upper end of the connection port 81 and to be gradually lowered as they are apart from the connection port 81 for the ink supply unit.
The membrane valve 104 and the spring 103 are fixed by a valve fixing frame 109 provided with a recess for defining a second ink chamber 108. A passage connecting the second ink chamber 108 to the ink guidepath 4a of the recording head 4 is constructed by a through-hole formed through the valve fixing frame 109; or constructed such that grooves 109c and 109d are provided on the surface and the grooves 109c and 109d are sealed by a film (in this embodiment, a film 98b on the wall 95 forming the ink storage chamber 92 is used). The valve fixing frame 109 can be securely fixed by sharing the film 98b on the wall 95 of the ink storage chamber 92 in this manner. A reference number 110 denotes a filter provided to the ink inflow port 102, and 111 denotes packing for sealing.
The further depression inthis state causes the protruded portion 87a to move the valve 94 backwardly to a limit point in a direction shown by an arrow A against the spring 93 of the connection part 91, thereby opening a passage as shown in Fig. 14 (b).
Further, when the main tank 80 is depressed further, the valve 94 supported at the limit point, in turn, depresses the protruded portion 87a backwardly in a direction shown by an arrow B against the spring 88 to separate the sealing valve 87 from the connection port 81, thereby releasing the passage as shown in Fig. 14(c). This permits ink in the main tank 80 to flow into the ink storage chamber 92 of the ink supply unit 90 as shown in Fig. 15 (a).
Figs. 16 show other embodiments of the main tank. In the above embodiment, the main tank is divided into three ink chambers, however, as shown in Figs. 16(a) and 16 (b), the main tank may be divided by three partitions or seven partitions, where the upper ends of communicating windows in the lower parts are positioned upper as the communicating windows are located closer to the connection port 81. As the volume of each ink chamber is set smaller in this manner, dynamic pressure by ink flow of ink associated with the change from one chamber to another chamber can be reduced.
Figs. 18 show another embodiment of the present invention. In this embodiment, acommunicating passage 120 is formed, which is connected to an ink storage chamber 92 and extended to a position opposite to an ink chamber of an ink cartridge 80. At least one hollow needle, hollow needles 121 corresponding in number to chambers in the ink cartridge 80 in this embodiment, is implanted to the upper surface of the communicating passage 120 to communicate with the communicating passage 120.
The inkcartridge 80 is divided into plural chambers 84', 85' and 86' by partitions 82' and 83', and formed with ink supply ports 125. Each ink supply port 125 has a valve 124 constantly biased downwardly by a spring 123, which is located opposite to the hollow needle 121 in the case where the ink cartridge 80 is mounted to a holder 122. The ink supply ports 125 are sealed by a film 126.
That is, when the ink cartridge 80 is aligned with the holder 122 and pushed into the holder, the hollow needle 121 pierces the film 126 and then pushes into and widens the through-hole 127a of the elastic plate 127 to establish the communicate. In this state, as the periphery of the hollow needle 121 is sealed by the elastic plate 127, the leakage of ink, the evaporation of ink solvent, and further, the inflow of air are securely prevented. In this embodiment, it is preferable that the hollow needle 121 has a small-diameter part 121 a on the leading end side, and a large-diameter part 121 b with a tapered leading end on the area contacting the elastic plate 127.
After the ink storage chamber 36 is supplemented with ink of predetermined quantity, the ink inlet 9 is sealed, and further the pump unit 10 of the ink refilling unit 7 is operated to reduce the pressure of ink in the ink storage chamber 36, so that ink in the ink storage chamber can be fully degassed. Needless_to say, since pressure in the ink storage chamber 36 is decreased, and the differential pressure valve mechanism 50 connected between the ink storage chamber 36 and the recording head 4 acts as a check valve, no air flows in via the recording head 4 and unnecessary high suction force does not act on the recording head.
When negative pressure is applied by the capping means 132, the negative pressure acts on the differential pressure valve mechanism 50 from the groove 44 forming an ink passage via the ink guidepath 4a. Since the differential pressure valve mechanism 50 is opened when pressure on the side of the recording head 4 is decreased as described above, ink in the valve chamber37 is filtered by the filter 56 (see Fig. 5), passes through the differential pressure regulating mechanism 50 and flows into the recording head 4.
The ink supply unit according to the present invention comprises a differential pressure valve including a coil spring and a movable membrane adapted to elastically contact a valve seat by means of the coil spring. Since pressure of ink supplied to an ink-jet recording head is kept negative by the coil spring, the fluctuation of the movable membrane associated with movement of a carriage can be suppressed by the coil spring. Therefore, ink can be stably supplied to the recording head while maintaining suitable negative pressure.
An ink supply unit (3, 90), wherein:
a differential pressure valve including a coil spring (51, 103) and a movable membrane (53) adapted to elastically contact a valve seat (57c) by means of said coil spring (51, 103) is accommodated in a container having an ink storage chamber (36, 92) communicating with an ink supply port (23) adapted to be connected to an ink-jet recording head (4), wherein said movable membrane (53) is located between said valve seat (57c) and said coil spring (51, 103),
said movable membrane (53) is arranged vertically when said ink supply unit (3, 90) is mounted to a carriage (1), and
said movable membrane (53) is arranged in parallel to a plane perpendicular to a direction in which said carriage (1) is moved.
An ink supply unit (3, 90) according to Claim 1, wherein:
said differential pressure valve includes a disc-like elastic membrane member (54) formed at its center with an ink flow port (54a), a valve seat (57c) located in an upstream side of ink flow and facing said ink flow port (54a), and a coil spring (51) located in a downstream side and pressing said ink flow port (54a) of said elastic membrane member (54) onto said valve seat (57c).
said movable membrane (53) receives pressure of said coil spring (51, 103) via a holder (52).
An ink supply unit (3, 90) according to any one of claims 1 to 3, wherein:
said casing (30) includes a frame-like casing provided at its side surface with a window, and an air intercepting film (31) sealing said window.
said ink storage chamber (36) communicates with an ambient air via a capillary formed in said container.
An ink supply unit (3, 90) according to Claim 5, wherein:
said capillary includes a groove (97) formed on an upper wall of said ink storage chamber (36, 92), and an air intercepting film (98) sealing said groove (97).
said capillary includes a groove (97) formed on an side wall of said ink storage chamber (36, 92), and an air intercepting film (98) sealing said groove (97).
said movable membrane (53) includes a movable part (54, 105) made of soft material, and a fixing part (55, 106) made of hard material and fixed to a periphery of said movable part (54, 105).
An ink supply unit (3, 90) according to Claim 8, wherein:
a supporting part is formed in an outer periphery of said movable part (54); and
said movable part (54, 105) is connected to said fixing part (55, 106) via said supporting part.
a movable part (54) is provided to said movable membrane (53); and
a supporting part is formed in an outer periphery of said movable part (54, 105).
An ink supply unit (3, 90) according to Claim 1, 8 or 10, wherein:
said movable membrane (53) is provided with a movable part (54, 105); and
an annular bent part is formed in the vicinity of an outer periphery of said movable part (54, 105).
An ink supply unit (3, 90) according to Claim 10, wherein:
said movable part (54, 105) is located approximately at a center in a thickness direction of said supporting part.
An ink supply unit (3, 90) according to Claim 8 or 10, wherein:
a central area of said movable part (54, 105) is offset from a peripheral area thereof.
said fixing part (55, 106) is formed, at its side to said valve seat (57c), with a flange part; and
a position of said movable part (54, 105) in its thickness direction is regulated by said flange part.
a filter (70) is arranged in an upstream side with respect to said differential pressure valve.
said coil spring (51, 103) is contacted with said movable membrane (54, 105) via a holder (52) having an ink flow hole located to face an ink flow port (54a) of said movable membrane (54, 105).
said valve seat (57c) is formed as a spherical surface protruded toward said movable membrane (54, 105).
a protruded part is formed on a surface of said valve seat (57c) where it is contacted with said movable membrane.
An ink supply unit (3, 90) according to any one of Claims 1 to 18, wherein:
said valve seat (57c) is formed as a protruded part having a planar surface on a side toward said movable valve (54, 105).
said movable valve (54, 105) includes a disc-like movable part made of soft high polymer material and provided at its outer periphery with a thick part, and an annular supporting part made of hard high polymer material and provided at its valve seat side with a flange part; and
said valve seat (57c) is formed as a protruded part defining a planar surface on a movable valve side and having a thickness approximately equal to that of said flange part.
An ink supply unit (3, 90) according to Claim 20, wherein:
An ink supply unit (3, 90) according to any one of Claims 1 to 21, wherein:
said differential pressure valve includes a disc-like movable membrane (54, 105) formed at its center with an ink flow port, a coil spring (51, 103) contacted with said movable membrane (54, 105), and a valve seat (57c) formed as a protruded part defining a planar surface on a movable membrane side and having an outer edge located outside an outer periphery of said coil spring (51, 103).
An ink supply unit (3, 90) according to Claim 22, wherein:
said movable membrane (54, 105) is formed at its valve seat side with a planar surface and at the opposite surface with a protruded part that supports said coil spring (51, 103).
an ink injection port is provided to an upper surface of said container, and communicated with a bottom part of said ink storage chamber via a passage isolated from said ink storage chamber (36, 92).
an ink injection port is provided to an upper surface of said container, and communicated with a bottom part of said ink storage chamber (36, 92) in the vicinity of an upstream side of said differential pressure valve via a passage isolated from said ink storage chamber.
said ink storeroom and an area where said differential pressure valve is accommodated are separated by a wall (33) provided at its bottom part with a communicating hole (21a);
a plurality of electrodes (117, 118, 119) for detecting an ink level are provided in said ink storage chamber (36, 92); and
at least one of said electrodes (117, 118, 119) is disposed above said communicating hole (21a).
said differential pressure valve includes a spherical movable membrane (54, 105) provided at its center with an ink flow port (54a), a coil spring (51, 103) contacted with said movable membrane (54, 105), and a valve seat (57c) having a spherical part protruded toward said movable membrane (54, 105).
An ink supply unit (3, 90) according to Claim 27, wherein:
said valve seat (57c) is formed on a wall forming said ink storage chamber.
said movable membrane (54, 105) and said coil spring (51, 103) are attached to a wall forming said ink storage chamber by a valve fixing frame.
An ink supply unit (3, 90) according to Claim 29, wherein:
said valve fixing frame is formed with a passage communicating with a recording head (4).
An ink supply unit (3, 90) according to Claim 30, wherein:
said passage includes a groove (97) in said valve fixing frame, and an air intercepting film (98) sealing said groove.
a film member having both gas permeability and repellent property is interposed between said capillary and said ink storage chamber (36, 92).
ink level detecting means (118, 119) is arranged in an upstream side with respect to said differential pressure valve.
An ink supply unit (3, 90) according to Claim 15, wherein:
ink level detecting means (118, 119) is arranged in an upstream side with respect to said filter (70).
ink level detecting means (118, 119) is arranged so that said filter (70) is not exposed when an ink end is detected.
EP1016533A1 true EP1016533A1 (en) 2000-07-05
EP1016533B3 true EP1016533B3 (en) 2011-08-31