INK JET RECORDING HEAD AND INK JET RECORDER

Abstract: An open exhaust port is secured on the side of the end in a direction in which a cleaning blade and a recording head are relatively moved in the vicinity of a nozzle aperture in a nozzle plate and a protective layer for regulating so that the cleaning blade comes in contact with the vicinity of a nozzle aperture when the cleaning blade is pressed is formed.

Description: FIELD OF THE INVENTION The present invention relates to an ink-jet recording head for jetting ink pressurized in a pressure generating chamber by pressurizing means from a nozzle aperture as an ink droplet, and in more detail, relates to an ink-jet recording head in which a nozzle aperture can be prevented from being clogged by a wiping member. RELATED ART An ink-jet recording head is provided with a nozzle plate wherein nozzle apertures are made at predetermined pitch in a thin plate, a pressure generating chamber communicating with each nozzle aperture and a reservoir for supplying ink to a pressure generating chamber as well-known, and is constituted so that an ink droplet is jetted from a nozzle aperture by pressurizing ink in a pressure generating chamber by a piezoelectric vibrator, a heater element and others. As dust on recording paper and the leavings of ink adhere to a nozzle aperture and the vicinity and the nozzle aperture is often clogged because an ink-jet recording head executes printing at an interval to the extent that the ink-jet recording head almost comes in contact with recording paper and ink including a solid component such as dye is used, a nozzle plate is wiped by a blade of a rubber plate every predetermined time to remove dust on recording paper and the leavings of ink. In the meantime, as described above, as an interval between a nozzle plate and recording paper is extremely small, the recording paper comes in contact with a nozzle aperture and an ink-repellent layer provided around the nozzle aperture may be worn. Therefore, as shown in Fig. 21A, a measure to prevent recording paper from coming in contact with a protective layer in the vicinity of each nozzle aperture N by forming the protective layer composed of a metallic layer 1 to 30 µm thick in an area apart by approximately 100 to 150 µm from each nozzle aperture N of a nozzle plate P so that a concave portion C is formed around each nozzle aperture N is taken. See for instance JP-A-08 025 630. As the width of a concave portion C between adjacent nozzle apertures in the same column is extremely small to form an independent concave portion C every nozzle aperture as described above in case recently, pitch at which nozzle apertures are arranged is 180 dpi per column and extremely small to enhance printing quality, it is very difficult to form such a concave portion. Therefore, as shown in Fig. 21B, a rectangular common concave portion C' is formed around nozzle apertures N in one column. A recording head H provided with the nozzle plate P constituted as described above is relatively moved in the direction D or D' of a blade B as shown as II and II' after the blade B is lifted on the side of the recording head H with the recording head located on the upstream side of the blade B arranged on a path of movement as shown in Fig. 22 (I) which is cleaning means, hereby, the blade B is elastically touched to the recording head H as shown as III and III' and hereby, cleaning is executed. At this time, as the most area of the blade B is dropped in the concave portion C', comes in contact with and rubs an ink-repellent layer F with strong pressure, there is a problem that the ink-repellent layer F is worn, scratched leavings of ink are accumulated particularly along a wall W2 on the downstream side out of walls W1 and W2 partitioning the concave portion C' as shown in Figs. 23A and 23B and recording paper is dirtied, a direction in which an ink droplet is jetted varies, or the like. DISCLOSURE OF THE INVENTION An ink-jet recording head according to the present invention comprises plural pressure generating chambers arranged at predetermined pitch linearly in one or more columns for pressurizing ink by pressurizing means and a nozzle plate in which plural nozzle apertures each of which communicates with each pressure generating chamber are formed and a protective layer for regulating so that a part of a blade comes in contact with a nozzle aperture when the blade is pressed on the nozzle plate is formed in the vicinity of the above nozzle aperture in a state in which an open exhaust port is secured on the side of the end of the protective layer in a direction in which the blade for cleaning is moved. Therefore, a first object of the present invention is to provide an ink-jet recording head wherein ink which adheres to the nozzle plate, the leavings of ink and dust on paper can be securely exhausted in an area which has no effect upon jetting an ink droplet without wearing an ink-repellent layer and further, the ink-repellent layer can be prevented from being worn or broken by contact between the ink-repellent layer and recording paper. A second object of the present invention is to provide an ink-jet recording apparatus provided with cleaning means suitable for the above recording head. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective drawing showing an embodiment of a recording apparatus using an ink-jet recording head according to the present invention; Figs. 2A and 2B are a side view and a top view respectively showing the structure in the vicinity of a cleaning device; Fig. 3 is a sectional view showing an embodiment of the ink-jet recording head according to the present invention; Figs. 4 show an embodiment of a nozzle plate of the above recording head, Fig. 4A is a front view, Fig. 4B shows the section viewed along a line A-A; Fig. 5 shows a state in which a blade is in contact with the nozzle plate for cleaning; Fig. 6 is a front view showing the structure of a nozzle plate equivalent to another embodiment of the present invention; Figs. 7 show the structure of a nozzle plate equivalent to further another embodiment of the present invention, Fig. 7A is a front view and Fig. 7B shows the sectional structure viewed along a line B-B; Fig. 8 is a front view showing the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention; Figs. 9 show the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention, Fig. 9A is a front view, Fig. 9B shows the sectional structure viewed along a line C-C; Fig. 10 shows a state in which a blade is in contact with the nozzle plate for cleaning; Figs. 11 show the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention, Fig. 11A is a front view and Fig. 11B shows the sectional structure viewed along a line D-D; Figs. 12 show the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention, Fig. 12A is a front view and Fig. 12B shows the sectional structure viewed along a line E-E; Figs. 13A and 13B are respectively front views showing the structure of nozzle plates equivalent to furthermore another embodiment of the present invention; Figs. 14 show the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention, Fig. 14A is a front view and Fig. 14B shows the sectional structure viewed along a line F-F; Figs. 15 show the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention, Fig. 15A is a front view and Fig. 15B shows the sectional structure viewed along a line G-G; Figs. 16 show the structure of a nozzle plate equivalent to the other embodiment of the present invention, Fig. 16A is a front view and Fig. 16B shows the sectional structure viewed along a line H-H; Figs. 17 to 20 respectively show a cleaning state of the nozzle plate shown in Figs. 16; Figs. 21A and 21B respectively show conventional type examples of nozzle plates of an ink-jet recording head used for a recording apparatus; Figs. 22 (I) to (III') are explanatory drawings for explaining wiping operation by a blade and further; and Figs. 23A and 23B are a front view and a sectional view respectively showing a state of cleaning. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments showing the details of the present invention in the drawings will be described below. Fig. 1 shows an embodiment of a recording apparatus using an ink-jet recording head according to the present invention, a carriage 1 is connected to a pulse motor 3 via a timing belt 2, the carriage is constituted so that it is guided by a guide member 4 and reciprocated in the direction of the width of recording paper 5 and ink-jet recording heads 6 and 7 described later are attached to the surface opposite to the recording paper 5, the lower surface in this embodiment. The ink-jet recording heads 6 and 7 are respectively supplied with ink by ink cartridges 8 and 9 mounted on the carriage 1, respectively jet an ink droplet on the recording paper 5 as the carriage 1 is moved, respectively form one or plural dots per one pixel and respectively print images and characters on the recording paper 5. A capping device 10 is provided in a non-printing area, seals nozzle apertures of the recording heads 6 and 7 during rest to prevent the nozzle apertures from being dry and in the meantime, also functions as a receptacle for receiving an ink droplet jetted from the recording heads 6 and 7 by flushing operation executed during printing. A cleaning device 11 is provided in the vicinity of the capping device in the non-printing area and arranged so that a blade 12 for touching the nozzle plates of the recording heads 6 and 7 as shown in Figs. 2 has a gradient of an angle  with a direction perpendicular to a direction in which nozzle apertures are arranged, that is, a direction in which the carriage 1 is moved. Fig. 3 shows an embodiment of the above recording head and pressure generating means, a piezoelectric vibrator 13 in this embodiment and a passage unit 14 to which displacement from the above piezoelectric vibrator is applied are fixed to a holder 15. The passage unit 14 is constituted by laminating an elastic plate 16 which is in contact with the end of the piezoelectric vibrator 13 and to which elastic deformation is applied, a spacer 20 partitioning a pressure generating chamber 17, an ink supply port 18 and a reservoir 19, and a nozzle plate 22 provided with a nozzle aperture 21 communicating with the pressure generating chamber 17. The nozzle plate 22 is provided with two columns of nozzle apertures 21 each of which is formed at predetermined pitch as shown in Figs. 4, and long and narrow protective layers 23 extended in parallel with a wiping direction at the same pitch as pitch between adjacent nozzle apertures 21 so that at least the protective layer is opposite to the nozzle aperture 21 are discretely formed in each column of nozzle apertures 21. The height H of the protective layer 23 is set to approximately 2 to 10 µm and is formed so that the length L is at least larger than the diameter d of the nozzle aperture 21. These protective layers 23 can be formed by etching a substrate to be the nozzle plate 23, electroforming metallic material on the nozzle plate 22 in a shape equivalent to the protective layer 23 or sticking a thin piece formed beforehand as another member. In this embodiment, when the end of the blade 12 is touched to the nozzle plate 22 and wiping is executed if an ink droplet is not jetted from the nozzle aperture 21, the central area between the protective layers 23 elastically comes in contact with the face of the nozzle aperture 21 with weak strength suitable for removing the leavings of ink and dust on paper because the surface of the blade 12 elastically comes in contact with the protective layer 23 as shown in Fig. 5. In this state, when the blade 12 is relatively moved in a direction in which the protective layer 23 is extended, the leavings of ink and dust on paper in the vicinity of the nozzle aperture 21 and further, ink which adheres to the blade 12 are swept into an area not related to jetting an ink droplet from a clear aperture O open at the other end of the protective layer 23 on the downstream side in a direction in which the blade 12 is moved without rubbing an ink-repellent layer formed around the nozzle aperture 21 with strong strength uselessly. In the above embodiment, the protective layer 23 is formed at the same pitch as pitch between adjacent nozzle apertures, however, one protective layer 23 per plural nozzle apertures 21 may be also formed as shown in Fig. 6. Figs. 7A and 7B respectively show a second embodiment of the present invention and in this embodiment, a band 24 is formed by connecting the side of the admission port of a blade 12 of each protective layer 23 so that the downstream side of each protective layer 23 in a direction in which the blade 12 is moved is open. According to this embodiment, as recording paper can be lifted up to the height of the protective layer 23 owing to the band 24 even if the end of recording paper is in contact with the nozzle plates 10 of the recording heads 6 and 7 due to a jam of recording paper and others, an accident that strong strength is uselessly applied to the protective layer 23 by the end of the recording paper and the protective layer is lost can be prevented beforehand. In the above embodiment, a direction perpendicular to a direction in which nozzle apertures 21 are arranged is a horizontal direction, however, as shown in Fig. 8, if the protective layer 23 is tilted by the approximately similar angle ' in case the blade 12 is tilted by an angle  with a direction in which nozzle apertures are arranged, the leavings of ink, dust on paper and ink can be efficiently exhausted into an area not related to jetting an ink droplet without reducing rejection ratio. Figs. 9 show the structure of a nozzle plate equivalent to further another embodiment of the present invention, a protective layer 30 is formed between nozzle apertures 21 formed at predetermined pitch in a nozzle plate 22. The protective layer 30 comprises the body 30a parallel to a direction in which recording heads 6 and 7 are moved and a wider branch 30b than the width of the body which is perpendicular to the direction in which the recording heads 6 and 7 are moved and in the center of which the end of the body 30a is located. The height H of the protective layer 30 is set to approximately 2 to 10 µm, and the body 30a and the branch 30b are formed so that each length La and Lb is at least larger than the diameter of the nozzle aperture 21. These protective layers 30 are arranged at predetermined pitch, at the same pitch as the nozzle aperture 21 in this embodiment so that an interval Lc is made between the end of the body 30a and the branch 30b of adjacent protective layers 30 to open at least a direction in which a blade 12 is moved. These protective layers 30 can be readily formed by etching a substrate to be the nozzle plate 22 in a desired shape, forming them on the nozzle plate 22 by electroforming metallic material such as nickel in a shape equivalent to the protective layer 30 or forming a thin piece in a shape equivalent to the protective layer as another member and bonding the thin piece to the nozzle plate 22 as in the case of the above protective layer 23. A reference number 31 denotes an ink-repellent layer and the ink-repellent layer is formed by coating or electrolytic plating ink-repellent material a few hundred nm to a few µm thick formed around the nozzle aperture 21 such as fluoropolymers. In this embodiment, when the end of the wiper blade 12 is touched to the nozzle plate 22 and wiping is executed, the end of the blade 12 elastically comes in contact with a part between the bodies 30a of the protective layers 30 as shown in Fig. 10 when the blade passes the nozzle aperture 21. When the wiper blade 12 is relatively moved in the axial direction of the body 30a in this state, the leavings of ink and dust on paper in the vicinity of the nozzle aperture 21 are removed, preventing the ink-repellent layer 31 from being worn or deteriorated because the ink-repellent layer 31 formed around the nozzle aperture 21 is never rubbed with strong contact force. Ink and dust on paper at the nozzle aperture 21 and in the vicinity which are wiped by the wiper blade 12 as described above are swept in an area not related to jetting an ink droplet from an exhaust port located on the downstream side of the adjacent protective layers 30 and never remain around the nozzle aperture 21. Further, as the blade 12 comes in contact with the branch 30b of the protective layer 30 formed in the following vicinity when the recording heads 6 and 7 and the blade 12 are relatively moved and reach the vicinity of the next column of nozzle apertures, ink and dust on paper which respectively adhere immediately before are rubbed by the branch 30b formed in an area not related to jetting an ink droplet and the blade 12 is refreshed. Therefore, even if plural columns of nozzle apertures are continuously wiped by the blade 12, ink, the leavings of ink and dust on paper at the nozzle aperture 21 immediately before can be possibly prevented from adhering to the nozzle aperture 21 in the next column and the vicinity. Ink and dust on paper which are rubbed by the branch 30b of the protective layer 30 and adhere to another branch 30b are flushed when the recording heads 6 and 7 are sealed by a capping device 10 and ink is forcedly exhausted from the recording heads 6 and 7 by a suction pump 16. According to this embodiment, as the body 30a and the branch 30b approximately surround the nozzle aperture 21, recording paper can be securely prevented from coming in contact with the ink-repellent layer 31 in the vicinity of the nozzle aperture 21 due to a paper jam, or the like. Figs. 11 show furthermore another embodiment of the present invention and in this embodiment, the branch 30b' of a protective layer 30 is extended so that it is twice or more as long as pitch between adjacent nozzle apertures 21 and the bodies 30a are arranged at an interval twice or more as long as pitch between adjacent nozzle apertures 21. According to this embodiment, the refresh rate of the wiper blade 12 is enhanced by quantity in which the length of the branch 30b is longer than that in the above embodiment shown in Figs. 9. Figs. 12 show furthermore another embodiment of the present invention, a protective layer 30 is constituted so that branches 30b longer than pitch between adjacent nozzle apertures 21 are formed at both ends of the body 30a with the body located in the center of the protective layer 30 and the protective layers are arranged at pitch twice as long as the pitch between adjacent nozzle apertures 21 in each column so that they are zigzag. In the above embodiment, the body and the branch are arranged so that they are in the shape of a letter H, however, the similar action is produced even if as shown in Fig. 13A, the body 30a is arranged so that it is located between nozzle apertures and branches 30b are arranged on the same side, on the upper side in Fig. 13A in this embodiment so that an interval can be formed between the bodies 30a of adjacent protective layers 30 and as shown in Fig. 13B, the branches 30b are formed in reverse directions in the shape of a key. Figs. 14 show furthermore another embodiment of the present invention and a protective layer 35 is formed approximately in the shape of a triangle symmetrical in a direction in which a linear part 35a which is approximately perpendicular to a path on which the blade is moved on the side opposite to a direction in which the blade 12 is moved and which is longer than pitch between adjacent nozzle apertures 21 and a curved part 35b forming a vertex 35b tapered from the linear part to the side of the nozzle aperture on the side opposite to the nozzle aperture 21 are perpendicular to a direction in which nozzle apertures are arranged. Pitch between the adjacent protective layers 35 is equal to pitch between the adjacent nozzle apertures 21 and the protective layers are arranged with them alternately inverted so that the side of the vertex is located on the side of the nozzle aperture. Figs. 15 show furthermore another embodiment of the present invention and a protective layer 36 is formed so that a linear part 36a which is approximately perpendicular to a path on which a blade is moved on the side opposite to a direction in which the blade 12 is moved and which is longer than pitch between adjacent nozzle apertures 21 and a curved part the center of which is the narrowest part are both symmetrical in a direction in which the nozzle apertures are arranged and a direction perpendicular to the direction. These protective layers 36 are arranged at pitch twice as long as pitch between adjacent nozzle apertures 21 so that the narrowest part is opposite to the nozzle aperture. In this embodiment, as the blade is also elastically touched to the nozzle aperture with elastic pressure regulated by an interval in a concave portion after the blade is cleaned and refreshed by the linear part, ink, the leavings of ink, dust on paper and others in the vicinity of the nozzle aperture can be removed, preventing an ink-repellent layer from being worn possibly. Figs. 16 show the structure of a nozzle plate equivalent to furthermore another embodiment of the present invention and rectangular concave portions 40 and 40' respectively surrounding nozzle apertures 21 and nozzle apertures 21' in the respective columns and provided with open parts 40a and 40a' at the end of a nozzle plate 22 (the lower end in Fig. 16A) are formed. These concave portions 40 and 40' are connected by a concave portion 41 formed in a boundary between them. These concave portions 40 and 40' and the concave portion 41 are constituted by providing a protective layer 43 made of metal and others with the thickness of approximately 5 to 30 µm by sputtering, electroless plating, electrolytic plating and others and an ink-repellent layer 44 is formed by material provided with ink repellency inside at least the concave portions 40 and 407. Walls 40b and 40b' on the respective sides (on the sides of the upper end in Fig. 16) on which the concave portions 40 and 40' are closed, a wall 41a regulating the concave portion 41 and a wall 40c' on the downstream side are formed as a slant face the downstream side in a direction in which a blade 12 is moved of which is disconnected. In this embodiment, as recording paper is supported by the surface of the protective layer 43 in case the recording paper comes in contact with the surface of the nozzle plate 22 in printing, the recording paper crosses the concave portions 40 and 40', does not come in contact with the ink-repellent layer 44 which has a great effect upon ink jetting performance in the concave portions 40 and 40' and therefore, does not peel the ink-repellent layer. As the blade 12 has an angle  with a direction in which nozzle apertures 21 are arranged when the blade 12 is elastically touched to the nozzle plates 22 of recording heads 6 and 7 and the blade 12 or the recording head 6 is relatively moved in a direction shown by an arrow D in Fig. 17 if cleaning is required because of long-time printing, the most of the blade 12 is supported by the surface of the protective layer 43, only a part enters the concave portions 40 and 40' and is elastically touched to the ink-repellent layer 44 with light force as shown in Fig. 17. When the recording head 6 is further relatively moved to the blade 12, the leavings K of ink are gathered on a wall on the downstream side of the concave portion 40 and as the blade 12 is moved, the leavings of ink are moved in a direction shown by an arrow E in Fig. 18, that is, on the side of the open port 40a as shown in Fig. 18. The leavings of ink are exhausted out of the nozzle plate 22 via the open port 40a. In the other concave portion 40', the leavings K of ink are also gathered on a wall on the downstream side, are moved to the open port 40a' of the concave portion 40' as described above as shown in Fig. 19, are guided to outside along the slope of the wall 40c' regulating the end of the concave portion 40' and are exhausted as shown in Fig. 20. If the blade 12 is formed so that at least the open ports 40a and 40a' in an area in which the blade and the nozzle plate 22 are in contact are located outside the end of the nozzle apertures 21 (on the side of the lower end in Fig. 20), the leavings K' of ink can be guided in an area not related to jetting an ink droplet, further, if the blade is extended up to the end of the nozzle plate 22, the leavings of ink can be exhausted in an area with which the blade 12 is not in contact and the leavings of ink can be prevented from adhering to the blade 12 again in cleaning. In the above embodiments, the ink-jet recording head of a type that a pressure generating chamber is pressurized by a piezoelectric vibrator is described as an example, however, it is clear that the similar action can be produced even if the present invention is applied to a nozzle plate of a bubble-jet recording head wherein a heater element is sealed in a pressure generating chamber and ink is jetted by thermal energy. UTILIZATION FOR INDUSTRIAL FIELD As described above, according to the present invention, if recording paper comes in contact with the nozzle plate, it can be prevented from coming in contact with the ink-repellent layer in an area in the vicinity of a nozzle aperture owing to the protective layer, in cleaning the ink-repellent layer is prevented from being worn by regulating an area with which the blade comes in contact by the protective layer and elastically touching the blade with light force enough to clean the face of an nozzle aperture and further, ink, the leavings of ink and dust on paper respectively gathered by the blade can be exhausted in an area not related to jetting an ink droplet via the open port.

Claims: An ink jet recording apparatus, comprising: a blade (12) for cleaning constituted by an elastic member; an ink jet recording head (6, 7), comprising plural pressure generating chambers (17) arranged at predetermined pitch in one or plural columns for pressurizing ink by pressurizing means (13); a nozzle plate (22) in which plural nozzle apertures (21) are formed, each of which communicates with one of said pressurizing chambers (17); and a protective layer (23; 30; 35) formed in a vicinity of said nozzle apertures (21), and adapted to regulate contact of said cleaning blade (12) with said nozzle apertures (21), wherein said cleaning blade (12) is elastically touched to said nozzle plate (22) on a path on which said recording head (6, 7) is moved in cleaning, wherein said blade (12) is pressed on said nozzle plate (22), such that said blade (12) and said recording head (6, 7) move relatively to one another in a movement direction (D); characterized in that said protective layer (23; 30; 35) comprises clear apertures (O) so that leavings of ink and dust at the nozzle apertures (21) and in their vicinity are swept by the cleaning blade (12) through said clear apertures (0) into an area (15a, 16a; 40a, 40a') not related to jetting an ink droplet, wherein said area (15a, 16a; 40a, 40a') is located on the downstream side of the adjacent protective layers (23; 30; 35) with respect to the movement direction (D) of the cleaning blade or the movement direction (E) of the leavings of ink. The ink-jet recording apparatus according to Claim 1, wherein said pressurizing means is a piezoelectric vibrator or heating means provided to said pressure generating chamber. The ink-jet recording apparatus according to Claim 1, wherein an ink-repellent layer is formed at least in the vicinity of said nozzle aperture. The ink-jet recording apparatus according to Claim 1, wherein said protective layer is 2 to 30 µm thick. The ink-jet recording apparatus according to Claim 1, wherein said protective layer is formed by means for forming a film on said nozzle plate. The ink-jet recording apparatus according to Claim 1, wherein said protective layer is formed by laminating another member. The ink-jet recording apparatus according to Claim 1, wherein said protective layer is formed discretely approximately in parallel with a path on which the blade is moved and between said nozzle apertures at pitch longer than pitch between adjacent nozzle apertures. The ink-jet recording apparatus according to Claim 7, wherein said protective layer is formed so that it is longer than a diameter of said nozzle aperture. The ink-jet recording apparatus according to Claim 7, wherein said protective layers are arranged at least on one side of said nozzle aperture. The ink-jet recording apparatus according to Claim 7, wherein a branch (30b) of said protective layer perpendicular to said path on which the blade is moved is formed at least at one end of said protective layer. The ink-jet recording apparatus according to Claim 10, wherein said branch is formed so that it is at least longer than the pitch between adjacent nozzle apertures. The ink-jet recording apparatus according to Claim 10, wherein said branch is formed so that it is wider than a width of said protective layer. The ink-jet recording apparatus according to Claim 10, wherein clearance from which ink can be exhausted is secured between said branch and adjacent another protective layer. The ink-jet recording apparatus according to Claim 10, wherein said branches (30b) are arranged with said branch (30b) put between adjacent said protective layers (23). The ink-jet recording apparatus according to Claim 10, wherein said branches are formed on the same side at both ends of said protective layer. The ink-jet recording apparatus according to Claim 10, wherein said branches are formed on opposite sides at both ends of said protective layer. The ink-jet recording apparatus according to Claim 7, wherein said protective layer is provided with a linear part (35a, 36a) approximately perpendicular to said path on which said blade is moved on a side opposite to a direction in which said blade is moved and longer than the pitch between adjacent nozzle apertures and a curved part (36c, 36b) on a side opposite to said nozzle aperture. The ink-jet recording apparatus according to Claim 17, wherein said protective layer is provided with a vertex (35b) tapered from said linear part (35a). The ink-jet recording apparatus according to Claim 18, wherein said protective layers are arranged so that said vertices are opposite. The ink-jet recording apparatus according to Claim 18, wherein said protective layers are symmetrical in a direction perpendicular to a direction in which said nozzle apertures are arranged. The ink-jet recording apparatus according to Claim 19, wherein said protective layers are arranged at the same pitch as pitch between adjacent nozzle apertures. The ink-jet recording apparatus according to Claim 17, wherein said protective layer is formed so that a center is the narrowest. The ink-jet recording apparatus according to Claim 22, wherein said protective layers are symmetrical both in a direction in which said nozzle apertures are arranged and a direction perpendicular to said direction. The ink-jet recording apparatus according to Claim 22, wherein said protective layers are arranged so that said narrowest part is opposite to said nozzle aperture. The ink-jet recording apparatus according to Claim 21, wherein said protective layers are arranged at pitch twice as long as pitch between adjacent nozzle apertures. The ink-jet recording apparatus according to Claim 7, wherein said protective layer surrounds all said nozzle apertures in the same column; and a concave portion (40) provided with an open port (40a) at an end on a downstream side in a direction in which said blade is moved is formed. The ink-jet recording apparatus according to Claim 26, wherein a wall (41a) for regulating an open port (40a) of said concave portion is tilted in a direction in which said blade exhausts. The ink-jet recording apparatus according to Claim 26, wherein a boundary between adjacent said concave portions is connected by a wall (41a) tilted in a direction in which said blade exhausts. The ink-jet recording apparatus according to Claim 26, wherein said open port is formed outside said nozzle aperture located at least at an end of the nozzle plate. The ink-jet recording apparatus according to Claim 26, wherein said open port is formed at an end of said nozzle plate. The ink-jet recording apparatus according to one of the preceding claims, wherein said blade is provided with a gradient to a perpendicular to said path on which said blade is moved.

Inventors: KITAHARA TSUYOSHI, MORIKOSHI KOJI, KITAHARA, TSUYOSHI, MORIKOSHI, KOJI
Applicants: SEIKO EPSON CORP, SEIKO EPSON CORPORATION
Application year: 1998
Main classification: B41J2
IPC codes: B41J2