JP2009040064A - Inkjet printer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize the stabilization of an ink flow and the facilitation of the discharge of air bubbles while achieving the miniaturization of an apparatus by efficiently integrating a damper action chamber for absorbing the pressure fluctuation of the ink in an inkjet printer apparatus. <P>SOLUTION: A damper device 10 is provided with a damper action chamber 31a having a damper action surface at one side and formed flatly along its damper action surface and having an ink inflow port 53a connected from an ink supply source side and an ink discharge port 42a connected to a recording head 21 side. In this damper action chamber 31a, the ink inflow port 53a and an ink discharge port 42 are arranged at an approximate diagonal position in the damper action chamber 31a. A flexible film 32 is fixed so as to cover the lower surface opening of the damper action chamber 31a, and the flexible film 32 is used as a damper action surface. Two ribs 54 are formed on the ceiling surface of the damper action chamber, and the flow of the ink from the ink inflow port 53a to the ink discharge port 42 is guided. <P>COPYRIGHT: (C)2009,JPO&INPIT

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.

  Conventionally, an ink jet printer of a tube supply type that supplies ink to a recording head mounted on a moving carriage from an ink supply source fixed in an ink jet printer main body via a flexible tube is disclosed in Patent Document 1 and It is known from Patent Document 2 and the like.

  In the configuration of Patent Document 1, an ink flow path to each nozzle and a common ink chamber (damper) are provided so as to have an opening surface on one side surface in the vertical direction of a recording head in which a plurality of nozzle rows are arranged vertically. A working chamber is formed in a recess, and all the ink flow paths are communicated with the common ink chamber. On the other hand, ink is supplied from an ink tank fixed in the printer body to the common ink chamber through a flexible tube. Is supplied. Then, the opening surface in the common ink chamber is sealed with a flexible film (vibration absorbing film).

  By fixing a vibrating body made of a piezoelectric element at a predetermined position of the ink flow path, facing a longitudinal side surface (a surface having an opening surface) of the recording head, and driving the vibrating body, the ink flow Pressure is applied to the ink in the path, and the ink is ejected from the nozzle toward the paper.

  In the configuration of Patent Document 2, a piezo element is fixed to both sides of the front and back in the vertical direction of a recording head in which a plurality of nozzle rows and ink flow paths are arranged vertically, and the piezo element is applied by voltage application. In this configuration, the ink is ejected from the nozzle by the bending that occurs, and a damper member (damper) that introduces ink from an ink tank at a fixed position through a flexible tube and supplies the ink to the ink flow path of the recording head. (Working chamber) is mounted on the carriage. In this damper member, a filter is sandwiched between the first member having one side surface opened in the vertical direction and the second member having both side surfaces opened in the vertical direction, and one side of the second member (the filter The outer surface facing the holding surface in parallel is sealed with a flexible film. A supply pipe connection port communicating with a flexible tube having one end connected to an ink tank at a fixed position is provided at a lower portion of the first member, and an ink flow path of the recording head is provided at a lower portion of the second member. It is disclosed to provide an ink outlet for connection to the printer.

  In any of these prior arts, as the carriage reciprocates, an inertial force acts on the ink in the tube connecting the ink tank and the recording head, particularly at the time of return, and the ink pressure in the direction of the recording head (nozzle) Inadvertent fluctuations are absorbed by the deformation of the flexible film (film) of the damper, and the ink discharge pressure from the nozzles is kept uniform.

  However, according to the configurations of Patent Documents 1 and 2, the damper working chamber is a vertical type, and one side is sealed with a flexible film in the vertical direction, so that a plurality of colors of ink are ejected. When the recording heads are arranged in a plurality of rows, when the damper action chambers for the respective color inks are arranged in parallel, the flexible film is displaced so that there is an appropriate gap between adjacent damper action chambers. In addition, a case for the damper working chamber has to be disposed, which increases the size of the apparatus on the carriage and increases the number of parts, resulting in a high cost.

In order to solve this problem, the present applicant arranges one flat damper working chamber horizontally in a damper device having a plurality of damper working chambers for ejecting a plurality of colors of ink, and the remaining A damper working chamber is formed with a tall narrow width and arranged in parallel on the upper surface of the flat damper working chamber, and the lower surface of the flat damper working chamber and the narrow damper working chamber arranged in parallel are arranged. A structure in which the upper surface is sealed with a flexible film was considered. As a result, in the ink jet head that discharges a plurality of colors, it is possible to absorb ink pressure fluctuations for each ink color while accumulating a plurality of damper working chambers and reducing the overall size.
JP 63-17056 A (refer to FIGS. 1 to 5) Japanese Examined Patent Publication No. 7-121583 (see FIG. 2, FIG. 3, etc.)

  However, in such a structure, the damper action chambers arranged horizontally need to be formed in a flat shape in order to arrange a plurality of narrow damper action chambers on the upper surface thereof. For this reason, in this flat damper working chamber, ink stays in the area outside the ink flow in the shortest path from the ink inlet to the ink outlet in the damper working chamber, or the ink flow is stable. There was a problem of not doing.

  In particular, in a tube supply type ink jet printer, air bubbles easily enter the ink through the tube material. For this reason, if air bubbles flow into the damper working chamber together with the ink, the bubbles will remain in the damper working chamber even if the bubble discharge maintenance operation is performed unless the bubbles can be quickly discharged from the ink outlet. There is also a problem that the ink ejection performance is adversely affected.

  The present invention solves the above-mentioned problems, and in the damper device, the damper working chamber that absorbs ink pressure fluctuations is efficiently integrated to further reduce the overall size, and further stabilize the ink flow and An object of the present invention is to provide an ink jet printer capable of facilitating the discharge of bubbles.

  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 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 has a damper working surface on one side. And a damper working chamber that is formed flat along the damper working surface and has an ink inlet from the ink supply source side and an ink outlet from the recording head side. The damper working surface is provided so as to be substantially horizontal, and the ink inlet and the ink outlet are substantially opposed to each other in the damper working chamber. And it is characterized in that it is arranged at a position.

  According to a second aspect of the present invention, in the ink jet printer according to the first aspect, a rib projects from the inside of the damper working chamber, and the rib guides ink from the ink inlet to the ink outlet. The route is partitioned.

  According to a third aspect of the present invention, in the ink jet printer according to the second aspect, the ink inlet and the ink outlet are both disposed on a surface facing the damper acting surface, and the rib is the damper acting. It protrudes from the surface facing the surface toward the damper acting surface.

  According to a fourth aspect of the present invention, in the ink jet printer according to the third aspect, the damper acting surface is sealed with a flexible film, and a gap is provided between the flexible film and the tip of the rib. It is characterized by being formed.

  According to a fifth aspect of the present invention, in the inkjet printer according to any one of the first to fourth aspects, an opening area of the ink outlet is larger than an opening area of the ink inlet. is there.

  According to a sixth aspect of the present invention, in the ink jet printer according to the fourth aspect, the damper device includes a substantially rigid wall between an upper surface and a peripheral side surface of the damper working chamber, and a lower surface of the damper working chamber. Is sealed with the flexible film, and the rib is formed so as to protrude integrally from the wall constituting the upper surface of the damper working chamber.

  According to the first aspect of the present invention, since the damper working chamber has a damper working surface on one side and is formed flat along the damper working surface, in the ink jet printer that discharges a plurality of ink colors The damper chamber can be easily integrated in a small size. Further, even if the damper working chamber is flat, the ink inlet and the ink outlet are provided at substantially diagonal positions, so that the ink flow inside the damper working chamber is stabilized, and as a result, the ink In addition, bubbles contained in the ink are likely to flow out from the ink outlet.

  According to the second aspect of the present invention, the ink flow from the ink inlet to the ink outlet is further stabilized by the ink path defined by the ribs.

  According to the third aspect of the present invention, since the ink inlet is formed on the surface facing the damper acting surface, the ink flowing from the ink inlet can be directly received by the damper acting surface. The damper effect which absorbs dynamic pressure can be exhibited effectively. In addition, since the ink inlet, the ink outlet, and the rib are formed on the same surface (the surface opposite to the damper action surface), the ink path section by the rib is continuously formed from the ink inlet to the ink outlet. It becomes possible to do.

  According to the invention described in claim 4, since the gap is provided between the flexible membrane and the tip of the rib, the flexible membrane side inside the damper working chamber can be used without ink being partitioned. The entire surface of the flexible film can be spread. As a result, the dynamic pressure of the ink flowing from the ink inlet can be absorbed using the entire surface of the flexible film, and the damper effect can be increased.

  According to the fifth aspect of the invention, since the ink outlet is opened larger than the ink inlet, the discharge of bubbles contained in the ink can be improved.

  According to the sixth aspect of the present invention, since the ribs are formed so as to integrally protrude from the wall constituting the upper surface of the damper working chamber, the bubbles that float vertically upward in the damper working chamber can be efficiently removed. Can be guided to.

  Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a perspective view of a recording unit in an ink jet printer according to an embodiment of the present invention, FIG. 2 is a perspective view of a recording head unit, FIG. 3 is an exploded perspective view of the recording head unit, and FIG. 4B is an upper perspective view of the lower case, FIG. 5A is a lower perspective view of the lower case, FIG. 5B is a lower perspective view of the upper case, and FIG. FIG. 6B is an upper perspective view of the upper case, FIG. 7 is a plan view of the recording head unit with the flexible film 43 of the damper device removed, and FIG. 8 is a bottom view of the recording head unit. 9 is a cross-sectional view taken along line IX-IX in FIG. 7 with the flexible membrane 43 of the damper device attached, and FIG. 10 is a plan view of the damper device with the flexible membrane 43 removed, FIG. Is a bottom view of the damper device with the flexible membrane 32 removed, and FIG. 10 is a cross-sectional view taken along line XII-XII in FIG. 10 with the flexible films 32 and 43 attached, and FIG. 13 is a line XIII-XIII in FIG. 10 with the flexible films 32 and 43 of the damper device attached. It is arrow sectional drawing.

  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 unit 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 conveyance direction, the main scanning direction). 4 and the upper surface of the guide rail 3 arranged on the downstream side (in the direction of arrow A in FIG. 1) in the X-axis direction (paper transport direction, sub-scanning direction) in order to reciprocate the recording head unit 4. An arranged timing belt 8 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 an opening of the bottom plate 20c, and the ink supply port 81 and the head connection port 41 of the damper device 10 are rubberized through an opening provided in the reinforcing frame 83. The seal material 82 such as 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 in the damper device 10 includes an upper case 26 having a substantially rectangular shape in plan view, and a substantially box-shaped lower case 27 having a rectangular cylindrical side wall as an outer periphery and having upper and lower surfaces opened. It has. 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. Both the upper case 26 and the lower case 27 are injection-molded with a synthetic resin material and have rigidity, and the joint portions of both cases 26 and 27 are 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 (FIGS. 9, 11, 12 and 12). (See FIG. 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).

  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 in cooperation with the upper case 26.

  In the embodiment, as shown in FIG. 4, two sub-partition walls 36 are arranged to extend over the entire length of the lower case 27 at a distance from each other, and together with the side walls of the lower case 27, cyan ink, Three ink storage chambers 30b to 30d for yellow ink and magenta ink are formed. Each sub partition wall 36 communicates the ink reservoir chambers 30b to 30d with the head connection ports 41b to 41d for each ink color at a position off the upper surface 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 into a substantially triangular shape in plan view together with the side wall of the lower case 27. ing. 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 30 a for black ink is configured by a damper working chamber 31 a and a buffer chamber 39 that are arranged vertically with the main partition wall 35 as a boundary. As shown in FIG. 12, in the buffer chamber 39, the head connection port 41 a provided at a position separated from the main partition wall 35 and the ink outlet 42 formed in the main partition wall 35 are communicated with each other. ing. Further, the ink outlet 42 communicates the damper working chamber 31 a provided on the lower surface side of the main partition wall 35 with the buffer chamber 39 formed on the upper surface side of the main partition wall 35. Therefore, the ink outlet 42 is an inlet to the buffer chamber 39. The buffer chamber 39 is provided so as to temporarily accumulate ink therein, and to gradually accumulate bubbles separated and floated from the ink on the ceiling surface 61 a side formed by the upper case 26. An exhaust port 56a penetrating the upper case 26 is provided in the ceiling surface 61a of the buffer chamber 39 (see FIG. 12).

  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 (see FIGS. 5 and 5).

  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 (see FIG. 9). 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 ink reservoir chamber 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 air 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 (a film made of synthetic resin and impermeable to air and liquid) 43 defines the outer periphery thereof. It joins to the upper end surface of the outer peripheral wall which adhere | attaches 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. Communication holes 49b to 49d, second concave 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. 4B 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, the ink supplied to the recording head 21 is temporarily stored, and the air bubbles separated and floated from the ink are gradually accumulated on the ceiling surface 61a side. Then, black ink is supplied from the head connection port 41 a provided at the bottom of the buffer chamber 39 to the ink supply port 81 for black ink 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.

  Thus, in the above configuration, the damper working chamber 31a for black ink is formed flat on the lower surface side of the main partition wall 35, and three dampers for cyan ink, yellow ink, and magenta ink are formed on the upper surface side. Since the working chambers 31b to 31d are arranged in parallel and the flexible films 32 and 43 are arranged on the upper and lower surfaces facing the main partition wall 35, even when a plurality of damper working chambers are required for color recording, It can be integrated in a small size as a whole.

  In the damper working chamber 31a that must be formed flat, the ink inlet 53a and the ink outlet 42 are arranged at substantially diagonal positions, so that the ink flow is stabilized, and the damper working chamber 31a has an inner flow. The retention of ink and bubbles could be greatly reduced.

  Further, in the damper working chamber 31a, the ribs 54 divide the ink path so as to guide the ink from the ink inlet 53a to the ink outlet 42, so that the ink and bubbles can be more quickly removed from the ink outlet 42. Can be discharged. In particular, due to the characteristics of gas, the bubbles rise to the ceiling (vertically upward) side, but the guide ribs 54 are formed on the ceiling, so that the bubbles are reliably guided to the ink outlet 42 side. The structure is such that bubbles are easily discharged from the damper working chamber 31 a and accumulated in the buffer chamber 39. Therefore, when bubbles are exhausted for maintenance or the like, the bubbles can be surely removed from the buffer chamber 39, so that the bubbles can be prevented from being mixed into the recording head 21 and adversely affecting the discharge performance.

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 the lower case, and (b) is an upper perspective view of the upper case. It is a top view of the state recording head unit except the flexible film | membrane 43 of a damper apparatus. 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 excluded 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 56 Exhaust port 57 Exhaust passage 60 Bubble trap chamber 81 Ink supply port

Claims (6)

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 has a damper acting surface on one side, is formed flat along the damper acting surface, and has an ink inlet from the ink supply source side and an ink outlet to the recording head side. A damper working chamber having
In this damper working chamber, the ink jet working surface is provided so that the damper working surface is substantially horizontal, and the ink inlet and the ink outlet are disposed at substantially diagonal positions in the damper working chamber. Printer.   2. The ink jet printer according to claim 1, wherein a rib projects from the inside of the damper working chamber, and an ink path for guiding ink from the ink inlet to the ink outlet is defined by the rib. .   The ink inflow port and the ink outflow port are both disposed on a surface facing the damper acting surface, and the rib protrudes from the surface facing the damper acting surface toward the damper acting surface. The inkjet printer according to claim 2, wherein   4. The ink jet printer according to claim 3, wherein the damper working surface is sealed with a flexible film, and a gap is formed between the flexible film and the tip of the rib.   The inkjet printer according to claim 1, wherein an opening area of the ink outlet is larger than an opening area of the ink inlet.   In the damper device, an upper surface and a peripheral side surface of the damper working chamber are configured by a substantially rigid wall, a lower surface of the damper working chamber is sealed by the flexible film, and the ribs of the damper working chamber are sealed. The inkjet printer according to claim 4, wherein the inkjet printer is formed so as to protrude integrally from a wall constituting the upper surface.

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