JP4352240B2 - Inkjet printer - Google Patents

Description

The present invention relates to an ink jet printer, and more particularly to an ink jet printer provided with a damper device in the middle of an ink flow path from an ink supply source to a recording head.

  2. Description of the Related Art Conventionally, a tube supply type ink jet printer that supplies ink to a recording head mounted on a moving carriage from an ink supply source fixed in the ink jet printer main body via a flexible tube is known. .

  In the tube supply type ink jet printer, since the tube needs to be displaced according to the movement of the carriage, a flexible tube is used. However, the flexible tube avoids air permeation. I can't. As a result, there is a problem that air is dissolved in the ink in the tube, which becomes bubbles and flows into the recording head side together with the ink, causing ejection failure during recording.

  In a tube supply type ink jet printer, excessive acceleration is also applied to ink in the tube due to acceleration / deceleration of the carriage that reciprocates, and the pressure wave propagates to the ink in the recording head. As a result, the pressure wave has an adverse effect on the meniscus formed in the nozzles of the recording head, and there is a problem that recording quality is impaired.

  Therefore, for example, in Patent Document 1, an air trap (corresponding to a damper device) is mounted on the carriage upstream of the recording head in the ink flow path, and bubbles in the ink are separated by this air trap. A structure that accumulates and absorbs the dynamic pressure applied to the ink is described. The air trap of Patent Document 1 is provided with an ink inlet from an ink supply source and an ink outlet to the recording head on the bottom side. In the air trap, the first chamber on the ink inlet side and the second chamber on the ink outlet side communicate with each other on the ceiling surface side and are partitioned by a metal mesh filter on the bottom surface side. Further, in the first chamber, a bubble reservoir is recessed and opened downward on the ceiling surface which is an extension of the ink inlet. In the manufacture of the air trap of Patent Document 1, the metal film is thermally welded to a member provided with a space serving as a second chamber, and a member provided with the space serving as a first chamber is further ultrasonically welded. It is done.

In the air trap of Patent Document 1 configured as described above, the dynamic pressure of ink flowing from the ink inlet is absorbed (damped) by the bubbles stored in the bubble reservoir in advance. In addition, bubbles contained in the ink rise to the ceiling surface side of the air trap and gradually accumulate. When the amount of bubbles in the air trap exceeds a predetermined amount, suction is performed from the nozzle surface side of the recording head as a purge process, and the bubbles are discharged through the recording head together with ink.
JP 2002-166568 A (see FIGS. 3 and 6)

  As described above, in the air trap of Patent Document 1, the first chamber and the second chamber are partitioned by the filter, and large bubbles are guided to the ceiling surface side without passing through the filter. However, there is a possibility that the fine bubbles pass through the filter on the ink momentum and are supplied to the recording head together with the ink.

  Further, in Patent Document 1, the apparatus can be reduced in size by performing both the dynamic pressure absorption of ink and the storage of bubbles using the same air trap. However, when ink is supplied to the recording head in a larger amount than other color inks because of the high use frequency of the ink, such as black ink, the pressure wave propagating to the ink is also large. It has been desired to realize a structure that can absorb (dump) more reliably and effectively the dynamic pressure.

  Furthermore, since the air trap of Patent Document 1 has a structure in which a member that forms the first chamber and a member that forms the second chamber are joined with the filter interposed therebetween, that is, a combination of three members is joined. It took time and effort. Therefore, an air trap structure that can be manufactured more simply has been demanded.

  The present invention solves the above-described problems, and provides an ink jet printer including a damper device that reliably prevents the inflow of bubbles to the recording head side, is excellent in a damper effect, and is easy to manufacture. It is the purpose.

In order to solve the above-described problem, an ink jet printer according to an embodiment of the present invention includes a recording head that performs recording by discharging ink onto a recording medium, and an ink supply that stores ink supplied to the recording head. In the ink jet printer having a light source, an ink flow path from the ink supply source to the recording head, and a damper device formed in the middle of the ink flow path, the damper device includes ink flowing from the ink supply source A damper working chamber that absorbs the dynamic pressure of the ink, and an ink reservoir chamber that has a bubble trapping region in the upper part for storing bubbles contained in the ink that has passed through the damper working chamber. An ink outlet for supplying ink in the provided ink reservoir chamber to the recording head, and An ink inlet into which ink from the par action chamber flows, and a rib protruding from the lower side toward the upper bubble trap region between the ink outlet and the ink inlet; The damper working chamber is formed in a flat shape extending in the horizontal direction, and is connected to the ink inlet at one end of the upper surface thereof, and a flexible film whose lower surface extends in the horizontal direction. The flexible film extends to a region overlapping with the ink inlet as viewed from above and below, and seals the lower part of the damper working chamber and the lower part of the ink inlet. It is a feature.

According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the damper working chamber has a surface parallel to the direction in which the damper working chamber extends in the horizontal direction sealed with a flexible film. It is characterized by being.

According to a third aspect of the present invention, in the ink jet printer according to the first or second aspect, the damper device includes an upper case that forms a ceiling surface of the bubble trap region, and a lower case that includes the ink outlet. The main body case is provided, and the rib protrudes from the lower case.

According to the first aspect of the present invention, the rib protruding from the lower side toward the upper bubble trapping region is provided between the ink inlet port from the damper working chamber and the ink outlet port to the bubble trapping region. However, since the rib is spaced from the ceiling surface, the bubbles contained in the ink flow around the rib in a detour regardless of the size. That is, since bubbles are prevented from flowing directly from the downstream end of the damper working chamber to the outlet of the buffer chamber, it is possible to prevent bubbles from entering the recording head side.

Further, even if the linear distance between the downstream end of the ink flow in the damper working chamber and the ink outlet in the ink reservoir chamber is short, a substantial ink flow path can be obtained by forming a bypass by the rib. it can. Therefore, the bubbles in the ink are easily separated and floated, and the accumulation in the bubble trap region is promoted.

Further, in the damper device, the ink passes through the damper working chamber and then passes over the rib to the ink outlet of the ink reservoir chamber having the bubble trapping region . In other words, the damper working chamber is formed separately from the bubble trapping region. Therefore, the structure of the damper working chamber can be formed so as to obtain a high damper effect without being restricted by other structures.

According to the second aspect of the present invention, the damper working chamber has a wide area using the surface because the damper working chamber is sealed with a flexible film in a plane parallel to the direction in which the damper working chamber extends in the horizontal direction. The flexible film can be used, and a large dynamic pressure absorbing effect can be exerted on the ink.

According to the third aspect of the present invention, since the rib protrudes from the lower case, the damper device having the rib inside can be easily formed only by combining the upper case and the lower case.

  Next, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the ink jet printer of the present invention includes a recording unit 1 that records ink by ejecting ink onto a paper that is a recording medium, inside a main body frame (not shown). The ink jet printer is applied as a printer function of a multi-function device (MFD) having a copy function, a scanner function, a facsimile function, and the like.

  The recording unit 1 is a recording head that constitutes a carriage that reciprocally moves across a horizontally long plate-shaped guide rails 2 and 3 that extend in the Y direction (a direction orthogonal to the paper transport direction X, the main scanning direction). A unit 4, a timing belt 8 disposed in parallel with the upper surface of the guide rail 3 for reciprocating the recording head unit 4, and a CR (carriage) motor 6 for driving the timing belt 8 are provided. .

  As shown in FIGS. 2 and 3, the recording head unit 4 includes a substantially box-shaped main body portion 20a, and a connecting support piece 20b protruding from the main body portion 20a toward the downstream side in the paper conveyance direction (the direction of arrow A in FIG. 1). A head holder 20, an ink jet recording head 21 fixed to the lower surface side of the bottom plate 20c of the head holder 20, and a damper device 10 and an exhaust valve means 11 fixed to the upper side of the bottom plate 20c. Yes.

  The damper device 10 is provided with a connecting piece 13 that extends substantially horizontally on the downstream side of the paper conveyance (in the direction of arrow A in FIG. 1) and is supported by being overlapped with the connecting support piece 20b. (Tube) 14 can be connected at the tip. This ink jet printer has individual ink tanks (not shown) of yellow ink (Y), magenta ink (M), cyan ink (C), and black ink (Bk) as ink supply sources for full color recording. The ink supply pipe 14 is connected to the base end of each ink tank. An ink flow path for supplying ink from the ink tank to the recording head 21 via the ink supply pipe 14 and the damper device 10 is formed. In this embodiment, since the ink colors are four colors of black ink (BK), cyan ink (C), yellow ink (Y), and magenta ink (M), there are four ink supply tubes 14, but the ink colors The type of ink and the number of ink supply pipes are not limited to this.

Further, the upper surfaces of the damper device 10 and the exhaust valve means 11 and the upper surface of the connecting piece 13 of the damper device 10 are covered with lid cover bodies 12 and 13a, respectively (see FIG. 1).

  A number of nozzles 22 are provided on the lower surface of the recording head 21, and in FIG. 8 (view of the recording head 21 seen from the lower surface), a nozzle row 22a for black ink (BK) and a cyan ink (C) are shown from the left side. The nozzle row 22b of yellow, the nozzle row 22c for yellow ink (Y), and the nozzle row 22d for magenta ink (M) are long in the direction orthogonal to the moving direction (Y direction, main scanning direction) of the carriage 5. Is formed. Each nozzle 22 is exposed downward so as to face the upper surface of the sheet.

  The recording head 21 has an ink supply port 81 for each ink color on one side of the upper surface, similar to those known in JP-A-2002-67312, JP-A-2001-219560, and the like. Ink is distributed to a number of pressure chambers via ink supply channels (manifolds) extending from the supply port 81, and ink is ejected from the nozzles 22 by driving actuators 23 such as piezoelectric elements corresponding to the pressure chambers. is there. As shown in FIG. 3, a flexible flat cable 24 that applies a voltage to the actuator 23 is fixed to the upper surface of the actuator 23. The recording head 21 is attached to the lower surface side of the bottom plate 20c of the head holder 20, and a reinforcing frame 83 is interposed between the recording head 21 and the bottom plate 20c in order to prevent the recording head 21 from being bent at the time of attachment. . A head connection port 41 (described later) of the damper device 10 is inserted into the opening of the bottom plate 20c, and the ink supply port 81 and the head connection port 41 of the damper device 10 are connected through an opening provided in the reinforcing frame 83. The seal material 82 such as rubber packing is sandwiched and communicated. In addition, a U-shaped front frame 84 is attached to the nozzle surface (lower surface) side of the recording head 21 to eliminate a step difference in the nozzle surface.

  Next, the configuration of the damper device 10 will be described with reference to FIGS.

  The damper device 10 includes a plurality of ink reservoir chambers 30 that are independent for each ink color, divided by a main partition wall 35 and sub-partition walls 36 and 37 that intersect the main partition wall 35. In the embodiment, a damper working chamber 31 a which is a part of a black ink (BK) ink reservoir chamber 30 is disposed below the main partition wall 35, and the black ink ink reservoir chamber 30 is disposed on the main partition wall 35. The buffer chamber 39, the cyan ink reservoir 30b, the yellow ink reservoir 30c, and the magenta ink reservoir 30d, which are other parts, are arranged in a two-layer structure as a whole. Has been.

Specifically, the main body case 25 of the damper device 10 has an upper case 26 (corresponding to an upper housing in claims) having an approximately rectangular and flat shape in plan view, and a rectangular cylindrical side wall as an outer periphery. An open substantially box-shaped lower case (corresponding to a lower casing in claims) 27 is provided. The upper and lower cases are fixed so that the upper case 26 covers the upper surface of the lower case 27. One end in the longitudinal direction of the upper surface portion of the upper case 26 is extended outward to form the connecting piece 13 for connection with the ink supply pipe 14. The upper case 26 and the lower case 27 are both injection-molded with a synthetic resin material and have rigidity. The joint between the cases 26 and 27 is liquid-tight by ultrasonic welding or the like. (See FIGS. 3, 4, 5, and 6).

  The lower case 27 is provided with an opening on the lower surface thereof that opens most of the area of the lower surface, and the main partition wall 35 is disposed at a position spaced in parallel from the opening and the upper surface of the lower case 27. Is formed. The opening on the lower surface is sealed with a damper flexible film (made of synthetic resin and impermeable to air and liquid) 32. Specifically, the outer peripheral edge of the flexible film 32 is bonded to the lower end surface of the outer peripheral wall 33 that defines the outer periphery of the opening on the lower surface by bonding or ultrasonic welding (see FIGS. 9, 12, and 13). ).

A damper working chamber 31a, which is a part of the ink reservoir 30a for black ink, is formed flat between the flexible film 32 and the main partition wall 35, and faces the main partition wall 35. That is, the surface sealed with the flexible film 32 is a damper acting surface. Further, as shown in FIG. 9, the damper device 10 is secured between the flexible film 32 and the bottom plate 20c of the head holder 20 with a gap for the deformation of the flexible film 32 secured. The holder 20 is installed so that the damper action surface (flexible film 32) of the black ink damper action chamber 31a is substantially horizontal. The head connection ports 41 a to 41 d connected to the ink supply ports 81 of the recording head 21 are positioned side by side on the lower surface of the lower case 27 so as to face the four ink supply ports 81, and are flexible films. In the position extended below 36, it opens downward (refer FIG.5 and FIG.9). The recording head 21 is arranged with a row of nozzles 22 extending substantially parallel to the main partition wall 35.

  In the damper working chamber 31a for black ink, an ink inlet 53a to the damper working chamber 31a and an ink outlet 42 from the damper working chamber 31a are formed in the main partition wall 35. Are arranged at positions substantially diagonal in a plan view in the damper working chamber 31a having a substantially rectangular shape in a plan view. The ink outlet 42 has a larger opening area than the ink inlet 53a (see FIGS. 5, 6, and 11).

  A rib 54 projects from the inside of the damper working chamber 31a, and an ink path for guiding ink from the ink inlet 53a to the ink outlet 42 is defined. In the embodiment, the rib 54 has two parallel linear shapes that are integrally projected on the lower surface of the main partition wall 35 and extend in the diagonal direction of the damper working chamber 31a (between the two ribs 54 ( An ink inlet 53a and an ink outlet 42 are arranged on the inner side. Since the hanging length of the rib 54 is formed so as not to reach the flexible film 32, a gap is provided between the tip of the rib 54 and the flexible film 32. Therefore, in the vicinity of the main partition wall 35 serving as the ceiling portion of the damper working chamber 31a, the rib 54 hangs down from the ceiling portion, but in the vicinity of the flexible film 32 serving as the bottom portion of the damper working chamber 31a, the bottom portion Ink is spread throughout (see FIGS. 12 and 13).

  On the upper surface of the main partition wall 35, the sub-partition walls 36 and 37 are formed so as to rise integrally with the main partition wall 35, and a portion above the main partition wall 35 in the lower case 27 is formed. A plurality of ink reservoirs are formed together with the upper case 26.

  In the embodiment, as shown in FIG. 4, two sub-partition walls 36 are disposed so as to extend over the entire length of the lower case 27 with a space therebetween, and together with the side walls of the lower case 27, cyan ink, yellow ink, and Three ink reservoirs 30b to 30d for magenta ink are formed. Each sub partition wall 36 communicates the ink reservoirs 30b-30d with the head connection ports 41b-41d for each ink color at the end position of the main partition wall 35 (see FIG. 9).

On the other hand, as shown in FIG. 4, the sub partition wall 37 is provided so as to partition the corner portion of the lower case 27 in the vicinity of the head connection port 41 a together with the side wall of the lower case 27 into a substantially triangular shape in plan view. A buffer chamber 39, which is a part of the ink reservoir 30a for black ink, is formed between the sub partition wall 37 and the side wall of the lower case 27. That is, the ink reservoir chamber 30 a for black ink is constituted by a damper working chamber 31 a and a buffer chamber 39 that are arranged above and below the main partition wall 35, and the damper working chamber 31 a is an ink supply path to the buffer chamber 39. It is also. The area of the buffer chamber 39 in plan view is smaller than the area of the damper working chamber 31a in plan view, but a part of the buffer chamber 39 is disposed so as to overlap with the damper working chamber 31a in plan view. As shown in FIG. 12, the ink outlet 42 of the damper working chamber 31a formed in the main partition wall 35 becomes an ink inlet to the buffer chamber 39 (corresponding to the buffer chamber inlet in the claims). ing. In the buffer chamber 39, a head connection port 41a provided at the end position of the main partition wall 35 is an ink outlet (corresponding to the buffer chamber outlet in the claims). As described above, in the buffer chamber 39, the buffer chamber outlet (head connection port 41 a) and the buffer chamber inlet (ink outlet 42) are both provided on the bottom side, which is one surface of the buffer chamber 39.

  The buffer chamber 39 is provided so as to temporarily store ink therein, and the ceiling surface 61a side formed by the upper case 26 serves as a bubble trapping region so as to gradually accumulate bubbles separated and floated from the ink. . And the exhaust port 56a which penetrates the upper case 26 is provided in the ceiling surface 61a of the buffer chamber 39 (refer FIG. 12). Further, the main partition wall 35 serving as the bottom surface (bottom wall) of the buffer chamber 39 is provided with ink in the buffer chamber 39 between the ink outlet 42 (buffer chamber inlet) and the head connection port (buffer chamber outlet) 41a. A rib 55 is provided projecting from the outlet 42 (buffer chamber inlet) side and the head connection port (buffer chamber outlet) 41a side (see FIG. 12). The rib 55 has a protruding length that does not reach the ceiling surface 61a of the buffer chamber 39, and a width dimension that completely separates the ink outlet 42 side and the head connection port 41a side in the buffer chamber 39 on the bottom surface side (see FIG. Therefore, the ink that has flowed into the buffer chamber 39 from the ink outlet port 42 always flows along the rib 55 so as to detour upward, and then flows into the head connection port 41. To reach.

  The upper case 26 is formed with a plurality of recesses on the upper and lower surfaces thereof, and at the position near the connecting piece 13, three ribs 38 that are continuous in a rectangular ring shape project toward the lower case 27, and this rib 38 The three independent regions are surrounded by

  The three regions surrounded by the ribs 38 are formed in a substantially rectangular shape in plan view and open up and down. When the upper case 26 and the lower case 27 are joined, the regions are formed in the lower case 27, respectively. The three ink reservoirs 30b to 30d are accommodated inside. The hanging length of the rib 38 is formed so as not to reach the main partition wall 35, and a gap is formed between the tip of the rib 38 and the bottom of each of the ink reservoir chambers 30 b to 30 d, that is, the main partition wall 35. It is comprised so that. The region surrounded by the ribs 38 is a damper that stores a certain amount of bubbles in advance in the ink reservoir chambers 30b to 30d for cyan ink, yellow ink, and magenta ink before the start of use of the ink jet printer. The working chambers 31b to 31d are formed. Since the bubbles stored in the damper working chambers 31b to 31d are separated from the surroundings by the drooping of the ribs 38, they are not exhausted from the exhaust ports 56b to 56d, which will be described later. The amount specified by the drooping length) is reliably stored. In addition, in order to seal the upper open surfaces of these three regions in common, a single flexible film for damper (synthetic resin air and liquid impermeable film) 43 is disposed around the outer periphery thereof. It joins to the upper end surface of the outer peripheral wall to define by adhesion | attachment or ultrasonic welding.

  Further, in the ink reservoir chambers 30b to 30d for cyan ink, yellow ink, and magenta ink, the regions on the downstream side of the damper working chambers 31b to 31d (sides close to the head connection ports 41b to 41d) are respectively Bubble trapping chambers 60b to 60d are provided so as to gradually accumulate bubbles that have separated and floated from the ink. The ceiling surfaces 61b to 61d of the bubble trap chambers 60b to 60d are constituted by the upper case 26, and exhaust ports 56b to 56d penetrating the upper case 26 are formed in the ceiling surfaces 61b to 61d (FIGS. 6 and 6). 13).

  As described above, the end of the upper case 26 in the direction of the arrow A is the connecting piece 13, but on one side edge side of the connecting piece 13, the supply pipe connecting port 47 ( In the embodiment, four supply pipe connection ports for black ink, cyan ink, yellow ink, and magenta ink are provided as 47a, 47b, 47c, and 47d, respectively (see FIG. 2 and FIG. 2). 7, FIG. 10 and FIG. 12).

  The ink supply pipes 14 are connected to the supply pipe connection ports 47 through joint members 45 having flow paths for the respective ink colors. Each supply pipe connection port 47 communicates with each ink reservoir chamber 30 through passages provided in the upper case 26 and the lower case 27 (see FIGS. 4, 5, and 6).

  In this embodiment, as shown in FIG. 12, as the ink flow path for black ink, first, the connection piece 13 has a supply pipe connection port 47 a at one end and is opened downward on the lower surface of the connection piece 13. The first concave passage 48a formed in a straight line, the first communication hole 49a formed through the upper and lower surfaces of the connecting piece 13 at the other end of the first concave passage 48a, and the first communication hole 49a A second concave passage 50a formed at the end and opened upward on the upper surface of the connecting piece 13 and formed in an L shape, and the other end of the second concave passage 50a is formed through the upper and lower surfaces of the upper case 26. The second communication hole 51a is provided. On the other hand, as shown in FIG. 4, in the lower case 27, a third communication hole 52 is formed through the corner portion adjacent to the ink reservoir 30d for magenta ink and far from the head connection port 41d. . The lower opening of the third communication hole 52 is provided in the main partition wall 35, and this opening serves as the ink inlet 53a to the above-described black ink damper working chamber 31a. When the upper case 26 and the lower case 27 are joined, the upper end surface of the third passage hole 52 and the lower end surface of the second passage hole 51a are in close contact with each other, whereby the black ink supply pipe is joined. The connection port 47a is connected to the damper working chamber 31a (ink reservoir chamber 30a).

  Further, as shown in FIG. 13, as the ink flow paths for cyan ink, yellow ink, and magenta ink, the connecting piece 13 has supply pipe connection ports 47 b to 47 d at one end, respectively. First concave passages 48b to 48d formed in an L shape by opening downward on the lower surface of 13 and a first through hole formed on the upper and lower surfaces of connecting piece 13 at the other end of first concave passages 48b to 48d. The communication holes 49b to 49d, the second recess passages 50b to 50d each having the first communication holes 49b to 49d at one end and opened upward on the upper surface of the connecting piece 13, and the second recesses Second communication holes 51b to 51d formed through the upper and lower surfaces of the upper case 26 are provided at the other ends of the passages 50b to 50d. The second communication holes 51 b to 51 d are provided integrally with the rib 38 and protrude downward slightly longer than the protruding length of the rib 38. The lower openings of the second communication holes 51b to 51d are ink inlets 53b to 53d to the ink reservoirs 30b to 30d, respectively (see FIGS. 5 and 6). Accordingly, the supply pipe connection ports 47b to 47d for cyan ink, yellow ink, and magenta ink are connected to the respective ink reservoirs 30b to 30d.

  Further, as described above, the upper case 26 is formed with exhaust ports 56a to 56d communicating with the buffer chamber 39 and the bubble trap chambers 60b to 60d, and the upper ends of the exhaust ports 56a to 56d are formed in the upper case. 26 are respectively connected to a plurality of exhaust passages 57a to 57d which are recessed independently of each other. The exhaust passages 57 a to 57 d extend while being bent in a direction perpendicular to the longitudinal direction of the upper case 26, and the other end is connected to the exhaust valve means 11.

  The first concave passages 48a to 48d formed on the lower surface of the connecting piece 13 are commonly covered by a single film material 44 bonded to the lower end of the outer peripheral wall defining the outer periphery thereof by bonding or ultrasonic welding. Each is formed as a flow path. Further, the second concave passages 50a to 50d and the exhaust passages 57a to 57d are extended portions of the damper flexible film 43, and are commonly covered by the same method and formed as flow paths.

  Next, the exhaust valve means 11 will be described. As shown in FIGS. 4A and 5B, the storage portion 70 integrally provided on one side of the lower case 27 has an ink color for each ink color. Four passage holes 71 are formed so as to be long in the vertical direction and open vertically. The side edge of the upper case 26 is extended to a position that covers the upper end of the storage portion 70, and the openings 58 at the other ends of the exhaust passages 57 a to 57 d are individually communicated with the upper ends of the passage holes 71. . A valve body (not shown) is accommodated in each passage hole 71 and is driven so as to open and close the lower end opening of the passage hole 71. When the carriage 5 moves to the position of a maintenance unit (not shown) in the ink jet printer, the valve body is driven to open the lower end opening of the passage hole 71 and the lower end opening is sucked by the suction pump. As a result, the bubbles in the ink reservoirs 30 a to 30 d can be exhausted through the exhaust ports 56 a to 56 d and the exhaust passage 57.

  According to the above configuration, first, ink in an ink tank (not shown) is supplied to the damper device 10 from the supply pipe connection port 47 through the ink supply pipe 14. As shown in FIG. 12, the black ink passes from the supply pipe connection port 47a through the first concave passage 48a and the second concave passage 50a of the connecting piece 13 to the lower surface side of the main partition wall 35 from the ink inlet 53a. It flows into the damper working chamber 31a. The ink flowing in from the ink inflow port 53a directly hits the flexible film 32 (damper action surface) opposite to the ink inlet 53a. At this time, the ink spreads over the entire bottom of the damper action chamber 31a, so that the dynamic pressure of the ink is reduced. Absorb securely (damping) over a large area. Then, the black ink, along with the bubbles, is guided to the ink outlet 42 by the ribs 54 suspended from the ceiling of the damper working chamber 31a, and is quickly discharged from the ink outlet 42 having a large opening area.

  The black ink flowing out from the ink outlet 42 flows into a buffer chamber 39 formed on the upper side of the main partition wall 35. Since the buffer chamber 39 is disposed above the damper working chamber 31a, the bubbles rise without flowing and flow into the buffer chamber 39. In the buffer chamber 39, ink is collected and supplied to the recording head 21 side. The ink flowing from the bottom side of the buffer chamber 39 passes over the rib 55 and reaches the head connection port 41a also provided on the bottom side. Bubbles separated and floated from the ink in the meantime are gradually accumulated in the bubble trap region on the ceiling surface 61a side. Then, the black ink is supplied from the head connection port 41 a to the black ink supply port 81 of the recording head 21.

  On the other hand, as shown in FIG. 13, the cyan ink, the yellow ink, and the magenta ink flow from the supply pipe connection ports 47b to 47d through the first concave passages 48b to 48d and the second concave passages 50b to 50d, respectively. The ink flows into the ink reservoirs 30b to 30d from the inlets 53b to 53d. In the ink reservoir chambers 30 b to 30 d, damper action chambers 31 b to 31 d in which a certain amount of bubbles are stored in advance and the ceiling portion is covered with the flexible film 43 are arranged on the upstream side in the ink reservoir chambers 30 b to 30 d. The dynamic pressure of the ink that has flowed in is absorbed (damped) by the flexible film 43 and the bubbles. The bubbles separated and floated from the ink stored in the ink reservoirs 30b to 30d are gradually accumulated in the bubble trap chambers 60b to 60d.

  When the carriage 5 moves to the maintenance position and the exhaust valve means 11 is connected to the suction pump as a bubble removal maintenance operation, the bubbles accumulated in the buffer chamber 39 and the bubble trap chambers 60b to 60d are respectively The exhaust ports 56a to 56d are exhausted to the outside through the exhaust passages 57a to 57d and the exhaust valve means 11.

  As described above, in the above configuration, the rib 55 is protruded upward from the bottom surface of the buffer chamber 39, and the buffer chamber inflow port (ink outflow port 42) side and the buffer chamber outflow port (head connection port 41a) side. And is partitioned. Since the rib 55 has a wall shape and does not have a mesh like a filter, the ink flowing from the buffer chamber inlet (ink outlet 42) provided on the bottom surface side of the buffer chamber 39 always passes through the rib 55. If it does not go through the route to get over, it cannot reach the buffer chamber outlet (head connection port 41a) provided on the bottom side. Therefore, regardless of the size of the bubbles contained in the ink, the bubbles are prevented from flowing directly to the head connection port 41a with the momentum of inflow. Since the bubbles once rise along the rib 55 together with the ink, the bubbles easily separate and float in the bubble trap region provided on the ceiling surface 61a side of the buffer chamber 39. As a result, ejection failure due to bubbles in the recording head 21 can be reliably prevented.

  In the black ink flow path, the damper working chamber 31a for absorbing the dynamic pressure of the ink is configured separately from the buffer chamber 39 for accumulating bubbles in the ink. In the case of black ink, the frequency of use is higher and the amount of ink supplied is larger than other color inks, so the pressure wave transmitted to the ink is also large. However, by making the damper working chamber 31a independent, high dynamic pressure absorption is achieved for the ink. It can be set as the structure which exhibits an effect.

  Further, even if the damper working chamber 31a and the buffer chamber 39 are formed separately, they share the main partition wall 35 and are arranged vertically so as to overlap in plan view, so that the overall configuration is small. Can do.

  Further, the rib 55 projecting upward from the bottom wall (bottom surface) side of the buffer chamber 39 is provided integrally with the lower case 27 constituting the bottom wall side of the buffer chamber 39, so that the upper case is simply provided. The buffer chamber 39 (damper device 10) having the ribs 55 inside can be easily formed simply by overlapping the upper case 26 and the lower case 27 together.

FIG. 3 is a perspective view of a recording unit in the ink jet printer according to the embodiment of the present invention. It is a perspective view of a recording head unit. FIG. 3 is an exploded perspective view of a recording head unit. (A) is an upper perspective view of an upper case, (b) is an upper perspective view of a lower case. (A) is a lower perspective view of the lower case, (b) is a lower perspective view of the upper case, (A) is a lower perspective view of a lower case, (b) is a lower perspective view of an upper case. 4 is a plan view of the recording head unit in a state where a flexible film 43 of the damper device is removed. FIG. It is a bottom view of the recording head unit. It is the IX-IX arrow directional cross-sectional view of FIG. 7 in the state which attached the flexible film | membrane 43 of the damper apparatus. It is a top view of the state which removed the flexible film | membrane 43 of the damper apparatus. It is a bottom view of the state which removed the flexible film | membrane 32 of the damper apparatus. FIG. 11 is a cross-sectional view taken along line XII-XII in FIG. 10 with the flexible films 32 and 43 of the damper device attached. FIG. 11 is a cross-sectional view taken along line XIII-XIII in FIG. 10 with the flexible films 32 and 43 of the damper device attached.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Recording part 4 Recording head unit 10 Damper apparatus 11 Exhaust valve means 14 Ink supply pipe 20 Head holder 21 Recording head 22 Nozzle 23 Actuator 24 Flexible flat cable 26 Upper case 27 Lower case 30 Ink reservoir chamber 31 Damper action chamber 32 Flexibility Membrane 35 Main partition wall 36 Subpartition wall 37 Subpartition wall 38 Rib 39 Buffer chamber 41 Head connection port 43 Flexible membrane 47 Supply pipe connection port 54 Rib 55 Rib 56 Exhaust port 57 Exhaust passage 60 Bubble trap chamber 81 Ink supply port

Claims (3)

A recording head that performs recording by discharging ink to a recording medium, an ink supply source that stores ink supplied to the recording head, an ink flow path from the ink supply source to the recording head, and the ink In an inkjet printer having a damper device formed in the middle of a flow path,
The damper device includes a damper working chamber that absorbs the dynamic pressure of ink flowing from the ink supply source, and an ink reservoir chamber that has a bubble trapping area for accumulating bubbles contained in the ink that has passed through the damper working chamber. And
The ink reservoir chamber includes an ink outlet for supplying ink in the ink reservoir chamber provided below to the recording head, and an ink inlet for receiving ink from the damper working chamber also provided below. A rib protruding from the lower side toward the upper bubble trap region between the ink outlet and the ink inlet;
The damper working chamber is formed in a flat shape extending in the horizontal direction, and is connected to the ink inlet at one end of the upper surface thereof, and a flexible film whose lower surface extends in the horizontal direction. Is sealed by
The ink jet printer, wherein the flexible film extends to a region overlapping with the ink inlet when viewed from above and below, and seals a lower portion of the ink inlet together with a lower surface of the damper working chamber.   2. The ink jet printer according to claim 1, wherein a surface of the damper working chamber parallel to a direction in which the damper working chamber extends in the horizontal direction is sealed with a flexible film. The damper device has a main body case including an upper case constituting a ceiling surface of the bubble trap region and a lower case having the ink outlet , and the rib protrudes from the lower case. An ink jet printer according to claim 1 or 2.

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