HK1055929A - Ink jet printer - Google Patents

Description

Ink-jet printer

Technical area

The present invention relates to an ink jet printer that ejects ink from a print head to form an image on a recording medium, and more particularly, to a serial ink jet printer that forms an image by reciprocating the print head in a width direction of the recording medium and supplying ink to the print head through an ink tube.

Background

In the past, it has been considered that: in an ink jet printer, an ink holding unit for holding ink is provided separately from a print head, and the ink is supplied from the ink holding unit to the print head through an ink tube. In this case, the print head can be more easily downsized than if the ink holding portion and the print head were provided integrally. Further, if such a structure is adopted in the serial type ink jet printer, the load of the carriage motor is reduced due to the miniaturization of the print head, and the miniaturization of the carriage motor can also be achieved.

As a method of mounting the ink tube to the print head when supplying ink from the ink holding portion to the print head through the ink tube as described above, it is conceivable to employ: a method of projecting an ink tube from an upper surface (a surface on the opposite side from the platen) of the print head; and a method of projecting the ink tubes from the end surface on the moving direction side of the print head. When the reduction in the thickness of an ink jet printer is emphasized by the reduction in the size of the external shape of a portable printer, it is preferable to adopt a method in which an ink tube is protruded from an end surface on the side of the moving direction of a print head.

However, when the print head is moved once the ink tube is caused to protrude from the end surface on the moving direction side of the print head, the nozzle tube is bent. On the other hand, a drum for conveying the recording medium in a direction (sub-scanning direction) perpendicular to the moving direction (main scanning direction) of the print head may be disposed near the platen, that is, near the moving range of the print head. In order to suppress the floating of the recording medium, such a platen is disposed as close to the print head as possible.

Therefore, there is a possibility that the curved ink tube comes into contact with the roller. In this case, the ink tube is scraped against a friction member (rubber or coating) on the surface of the roller, and becomes a resistance against the moving direction of the print head, and the roller scratches the surface of the ink tube, thereby damaging the ink tube. Therefore, the ink discharge position cannot be accurately controlled due to a change in the moving speed of the print head, and the ink tube may be broken or ink may leak.

For this reason, it has been thought to cover at least the surface of the roller on the side close to the ink tube with a protective cover. However, when the bent ink tube floats after contacting the protective cover, it also acts as a resistance against the moving direction of the print head. Further, since a positioning mark member such as a code strip may be attached along the moving direction of the print head in the vicinity of the moving range of the print head, the bending of the ink tube must be limited to a certain range. Nevertheless, if a special member is provided in order to restrict the bending of the ink tube, only this hinders the miniaturization.

Disclosure of Invention

The invention aims to provide the following steps: in an ink jet printer which forms an image by supplying ink to a print head through an ink tube while reciprocating the print head in a width direction of a recording medium, the bending of the ink tube is restricted without providing any special member and without increasing a moving resistance of the print head.

An ink jet printer according to the present invention is provided for achieving the above object, the ink jet printer including (i) a print head for ejecting ink droplets to form an image on a recording medium; an ink holding portion provided separately from the printing head and holding the ink supplied to the printing head; guide shaft for guiding the printing head along the width direction of the recording medium; a print head moving mechanism for reciprocating the print head along the guide shaft; an elastic tubular member protruding from an end surface of the print head in the moving direction, the ink holding portion being coupled to the print head over the entire moving range of the print head, the ink being supplied from the ink supply portion to the print head; a roller disposed near the guide shaft and transporting the recording medium in a direction perpendicular to the guide shaft; and a protective cover for preventing the tubular member bent according to the movement of the printing head from contacting the roller by covering the roller, wherein: the protective cover and the guide shaft are provided along a plane substantially perpendicular to the bending direction of the tubular member, and the distance therebetween (the protective cover and the guide shaft) is set to a distance that prevents the tubular member from passing therethrough.

In the present invention thus constituted, the guide shaft for guiding the print head and the protective cover for preventing the tubular member from contacting the platen are arranged so that the end surfaces of the tubular members on the side of the guide shaft are arranged along a plane perpendicular to the direction of bending of the tubular member, and the tubular member is spaced from the protective cover so as not to pass through the protective cover. That is, the tubular member integrally moving with the protective cover and the guide shaft forms a substantially vertical surface that prevents bending thereof.

Therefore, the present invention is not provided with any special member, and can prevent the tubular member from bending beyond the guide shaft and the protective cover. Therefore, if the positioning mark member is provided on the opposite side of the print head with respect to the guide shaft, it is possible to prevent the contamination of the tubular member due to the contact of the positioning mark member with the tubular member. In the present invention, since the surface substantially perpendicular to the direction in which the tubular member is bent is formed by the guide shaft and the protective cover, the ink tube does not float even when the tubular member is prevented from being bent, and therefore the moving resistance to be added to the print head can be small. Thereby, the ejection position of the ink can be further accurately controlled.

In addition, a flat cable for supplying current to the print head may be attached to a tubular member for supplying ink from the ink holding portion to the print head, and the ink tube and the flat cable may be integrally operated. Further, since a binding member for binding and holding the tubular member and the flat cable is provided and the distance between the protective cover and the guide shaft is smaller than the length of the binding member, the tubular member or the flat cable can be prevented from passing through.

In the above configuration, a binding member is provided for binding and holding the tubular member and the flat cable, and the distance between the protective cover and the guide shaft is smaller than the length of the binding member. Therefore, as described above, the tubular member can be prevented from bending beyond the guide shaft and the protective cover. Further, in the present invention, since the bundling member is brought into contact with the protective cover and the guide shaft to prevent the occurrence of the bending, the space between the protective cover and the guide shaft, the diameter of the ink tube constituting the tubular member, the width of the flat cable, and the like can be set relatively freely, and an effect of further improving the degree of freedom in design can be obtained.

Preferably, the plurality of ink tubes constituting the tubular member are divided into 2 cables, the cables are respectively protruded from both end surfaces in the moving direction of the print head, and a flat cable for energizing the print head is attached to each of the ink tubes protruded from both end surfaces.

In this configuration, the ink tubes for supplying ink to the print head from the ink holding portion provided separately from the print head protrude from both end surfaces in the moving direction of the print head. Flat cables for energizing the print heads are attached to the ink tubes protruding from the end surfaces on both sides. Therefore, since the width of the tubular member and the flat cable can be reduced by half, the present invention can be suitably applied to a case where the reduction in the outer shape of a portable printer is realized and the reduction in the thickness of an ink jet printer is emphasized.

In addition, in the above configuration, the flat cables are divided into two, and the divided flat cables can be well isolated from each other, so that crosstalk is not generated between the flat cables thus divided. Further, since the image is divided into two, it is possible to favorably prevent crosstalk from occurring in the flat cable attached to each ink tube. In addition, the flat cables are attached to the ink tubes, so that the operation thereof can be relatively flat.

To accommodate the bend of the tubular member, a required space can be reduced in the printer housing, and a compact and space-saving tubular member can be handled.

Drawings

Fig. 1 is a perspective view of the internal configuration of an inkjet printer to which an embodiment of the present invention is applied, as viewed from the paper exit side.

Fig. 2 is a perspective view of the foregoing internal configuration as viewed from the paper feed side.

Fig. 3 is a cross-sectional view taken along line a-a of fig. 1.

Fig. 4 is a sectional view taken along line B-B of fig. 3.

Fig. 5 is an enlarged view of a portion C in fig. 3.

Fig. 6A is a plan view showing the manifold structure of the inkjet printer, fig. 6B is a side view showing the manifold structure of the inkjet printer, and fig. 6C is a cross-sectional view taken along line D-D showing the manifold structure of the inkjet printer.

Fig. 7 is an exploded perspective view showing the structure of the ink tube ferrule, the ink tube, the FPC, and the FPC protective film of the ink jet printer.

Fig. 8 is a perspective view showing a manner of folding the FPC near the print head in an analog manner.

Fig. 9 is a top view of the inkjet printer of fig. 1 including the ink cartridge.

Detailed Description

Next, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a perspective view of an internal structure of an ink jet printer to which the present invention is applied, as viewed from a sheet discharging side, that is, from an output side (hereinafter, referred to as a front side) in a recording sheet conveying direction, and fig. 2 is a perspective view of an internal structure thereof, as viewed from a sheet feeding side, that is, from an input side (hereinafter, referred to as a rear side) in the recording sheet conveying direction.

As shown in fig. 2, a paper feed roller 1 is provided at the rear of the inkjet printer, and sheets of recording paper (recording medium) stacked and held on a paper feed tray (not shown) are separated and conveyed page by page. The recording paper fed from the paper feed roller 1 is fed to the platen 5 by the feed roller 3 shown in fig. 1, and after an image is formed by the print head 7, it is discharged to a paper discharge tray, not shown, by the paper discharge roller 9.

As shown in fig. 3, which is a cross-sectional view taken along line a-a of fig. 1, and fig. 4, which is a cross-sectional view taken along line B-B of fig. 3, the print head 7 is mounted on a carriage 11, and the carriage 11 is movably guided in the width direction (main scanning direction) of the recording sheet by a guide shaft 13 or the like. The carriage 11 is connected to an endless belt (endless belt) driven by a carriage motor 15 as a print head moving mechanism, and the platen 5 is moved in the width direction in accordance with the rotation of the carriage motor 15. Further, a code strip 19 is attached to the rear side of the guide shaft 13 in the width direction, and cooperates with an optical sensor, not shown, provided on the carriage 11 to constitute a known linear encoder.

The print head 7 of this embodiment is a color ink jet print head configured to eject four colors of yellow, red, blue, and black inks. The print head 7 is composed of 4 drive units and nozzle groups, not shown, for each color of ink to be ejected, and the nozzle groups are arranged in the main scanning direction of the print head in the order of y.m.c.bk. The nozzles constituting each nozzle group are opened to the platen 5, and arranged in rows extending in the recording paper transport direction. The print head 7 is connected to 4 ink tubes 31, and ink from the ink holding portion 100, specifically, ink of a color corresponding to each driving portion is supplied to the ink from the ink cartridge through each ink tube 31. The detailed structure of the ink tube 31 will be described later.

Fig. 9 shows an ink holding unit including 4 ink cartridges 100a to 100d, in which black, blue, red, and yellow inks are contained, respectively. The ink holding portion 100 is connected to the print head 7 through a tubular member 31.

As shown in fig. 4, a roller 21 for pressing and nipping the recording paper between the conveying roller 3 and the conveying roller 3 is provided below the conveying roller 3, and the roller 21 is pressed by a spring not shown and is urged upward integrally with a roller clamp 23. Also, a metal sheet protective cover 25 for preventing the feed roller 3 from contacting an ink tube 31 to be described later is provided on the upper outer circumference of the feed roller 3.

As shown in fig. 4, the front end surface of the protective cover 25 and the front end surface of the guide shaft 13 are provided on a vertical surface perpendicular to the platen 5. Various members such as a platen spring 27 for pressing the recording paper against the platen 5 are provided on the platen 5 and elsewhere.

As shown in fig. 5, which is an enlarged view of the portion C of fig. 3, the ink tubes 31 that supply ink to the print head 7 from both end surfaces in the moving direction of the print head 7 protrude in a direction inclined by about 30 degrees from the moving direction of the print head 7 toward the front, i.e., toward the support 51 described later. The ink tubes 31 are arranged in a vertically combined manner, two ink tubes 31 for supplying the red and yellow inks to the print head 7 on one end surface thereof, and two ink tubes 31 for supplying the blue and black inks to the print head 7 on the other end surface thereof. These ink tubes 31 are connected to the print head 7 via the following manifolds 33.

Fig. 6A, 6B, and 6C are a plan view side view and a D-D line sectional view showing the structure of the manifold 33. As shown in fig. 6A, 6B, and 6C, a valve 35 having a diameter of a small cone shape on the insertion side of the cap shape in the protruding direction (mounting direction) of the ink tube 31 and having a diameter of the pipeline 35a smaller than the rear end of the cone portion is protruded from the manifold 33. The ink supplied to the manifold 33 through the valve 35 is supplied from each color supply port 37 to a nozzle, not shown, of the print head 7. Then, a 8-shaped holding member 39 having two hollow portions in which the ink tubes 31 are fitted is fitted and fixed to the manifold 33 so that the valve 35 is provided in the hollow portion. Since the ink tube 31 must be pressed to the valve 35, the holding member 39 is made of a material harder than the ink tube 31, and is attached so as to be pressed into the holding member 39 in a state where the ink tube 31 is inserted into the valve 35. In the manifold 33 thus constructed, the outer circumference of the ink tube 31 is pressed from the holding member 39, the inner circumference from the valve 35, respectively, so that the ink tube 31 can be securely fixed.

The two ink tubes 31 are bundled at respective positions of an FPC43 (corresponding to a flat cable, or an FFC) and an FPC cover (hereinafter referred to simply as a cover) 45 by an ink tube ferrule 41 as a bundling member shown in fig. 7.

The ink tube band 41 is made of an elastic material such as rubber or elastic synthetic resin, and as shown in fig. 7, a pair of grooves 47 and one groove 49 are provided. The grooves 47 constitute anti-slip members on the inner surface to fix the ink tubes 31 so as not to move. On the other hand, the groove 49 provides the pull-out stop portion 60 while slowly embedding the FPC43 and the protective film 45, and keeps it movable in the longitudinal direction. The FPC43 is disposed between the pair of ink tubes 31 and the protective film 45, and is protected by the protective film 45. The protective film 45 has rectangular cutouts at both end edges of the mounting portion to the tube band 41, and the protective film 45 is held movably in the longitudinal direction within the range of the cutouts 45 a.

A slope 48 is formed in a portion of the tube holder 41 facing the pull-out stopper 60, and a protrusion 61 is formed at the tip of the pull-out stopper 60. The length of the groove 49 in the longitudinal direction (vertical direction) is longer than the width of the portion of the FPC43 or the protective film 45 where the cutout 45a is formed, and shorter than the width of the protective film 45 where the cutout 45a is not formed. The protective film 45 and the FPC43 are guided to the inclined surface 48 provided on the ink tube band 41, guided into the groove 49 while being bent, and released from the bending when the entire width enters the groove 49. (of course, at this time, the pull-out stopper 60 of the tube band 41 can be temporarily retracted against the elasticity of the tube band 41.) the pull-out stopper 60 and the protrusion 61 prevent the FPC43 and the protective film 45 from being moved to the slope 48 side and from being pulled out of the groove 49.

The ink tube band 41 described above, if too much is provided, will rather prevent the ink tube from smoothly bending, so an excessive arrangement is not recommended. It is preferable that the area in contact with the ink tube guide 53 or the area in contact with the guide shaft 13 and the protective cover 25 be as small as possible. This is because the impact sound and the like due to the abutment described later do not adversely affect the ink tube 31. However, it is preferable to bundle the ink tubes with the ink tube bands 41 because the deformation and displacement of the ink tubes 31, the FPC43, and the protective film 45 are likely to increase in the connection portion between the print head 7 and the ink tubes 31, the support portion 51, and the portion near the substantially center of the ink tubes 31 connected to the support portion 51 and the print head 7.

As shown in fig. 5, the FPC43 and the protective film 45 are guided to the rear end face of the print head 7, and the FPC43 is folded over the rear end face to be guided to the print head 7 and the optical sensor, and the protective film 45 is directly passed through the opposite side of the rear end face. The above folding of FPC43 is shown in phantom in fig. 8, to which reference is made. In addition, the FPC43 is originally configured such that the FPC43 bundles four drive signal lines to the drive unit and four photosensor output lines in one on the print head 7. The bundled FPC43 is divided into three bundles at one end thereof: a driving signal wire harness of the yellow and red driving parts at the left end; a centrally located photosensor output beam; and a driving signal harness of blue and black driving parts at a right end.

Next, as shown in fig. 1 to 3, a pair of columnar support portions 51 are provided in front of the platen 5 at substantially the center in the main scanning direction, and plate-like ink tube guides 53 for preventing the ink tubes 31 from bulging from the front are provided in association with each other on the left and right sides thereof. As described above, the ink tubes 31, the FPC43, and the protective film 45 protruding from both end surfaces in the moving direction of the carriage 11 are bundled at each location by the ink tube band 41, are guided to the support 51, are folded at the support 51, are fixed along the front surface of the ink tube guide 53, and are guided in the left-right direction. The ink tube 31 is guided to the ink cartridge (ink holding portion 100) provided below the platen 5 via the left and right guide pieces 55, and the FPC43 is guided to a control circuit (not shown) provided below the platen 5 via the guide groove 57.

The ink tube guide 53 extends from the pair of support portions 51 to the end portions in the left-right main scanning direction, and the rear wall of the ink tube guide 53 is gradually positioned forward as it approaches the end portions.

A sponge as a buffer is attached to the surface of the ink tube guide 53 that contacts the ink tube 31. Therefore, the impact sound of the bundle of ink tubes 31 and the ink tube guide 53, particularly the impact sound of the ink tube band 41 and the ink tube guide 53, can be reduced, and the effect of reducing noise can be obtained. Further, the sponge deforms with the load, and the impact on the ink tube 31 is alleviated, and the durability of the ink tube 31 is extended. In addition, the impact on the ink in the ink tube 31 can be alleviated, and the effect of improving the ejection performance can be produced.

In the ink jet printer of the present embodiment thus configured, since the print head 7 moves together with the carriage 11, the ink tube 31 bends as shown by the broken line in fig. 3. At this time, as described above, the forward bending of the ink tube 31 is restricted by the rear surface of the ink tube guide 53. The protective film 45 or the ink tube band 41 abuts against the guide shaft 31 and the protective cover 25 to restrict the backward bending of the ink tube 31.

Here, on a vertical plane perpendicular to the platen 5 as shown in fig. 4, the front end surface of the protective cover 25 and the front end surface of the guide shaft 13 are provided at a distance narrower than the width of the protective film 45. That is, the protective cover 25 and the guide shaft 13 form vertical surfaces that prevent the ink tubes 31, the FPC43, and the protective film 45, which are bundled by the ink tube band 41, from being bent.

More specifically, as shown in fig. 4, the transport roller 3 and the guide shaft 13 are disposed with a slight shift in the sheet transport direction, and the front end surface of the protective cover 25 covering the transport roller 3 and the front end surface of the guide shaft 13 are arranged along a plane perpendicular to the platen 5 at the position in the sheet transport direction. The interval between the protective cover 25 and the guide shaft 13 is also set smaller than the width of the protective film 45 or the width of the tube band 41.

Therefore, in the present embodiment, the ink tube 31 can be prevented from being bent beyond the guide shaft 13 and the protective cover 25 without providing any special member. So that the encoder strip 19 can be well prevented from being stained in contact with the ink tubes 31. In the present embodiment, since the guide shaft 13 and the protective cover 25 form a plane perpendicular to the direction in which the ink tube 31 is bent, the ink tube 31 does not float when the bending of the ink tube 31 is prevented, and the moving resistance added to the print head 7 can be made small. Thus, the ink discharge position can be controlled more accurately.

In addition, since the distance between the feed roller 3 and the guide shaft 13 is set to be narrow so as not to pass the protective film 45 or the ink tube guide 41, the thickness (height) of the entire apparatus can be reduced.

As described above, in the present embodiment, the projecting direction of the ink tubes 31 is inclined by 30 ° from the moving direction (main scanning direction) of the print head 7 toward the support 51 side. The angle is set in accordance with the results of simulation and experiment for the purpose of improving durability, and is at least 15 to 45 degrees, preferably 25 to 35 degrees. The appropriate angle varies depending on the material and diameter of the ink tube 31 and the allowable bending space, and when a polyethylene material is used, and the outer shape of the ink tube 31 is 3mm and the distance (bending space) from the valve 35 to the ink tube guide 53 is about 60mm, the inclination of 30 ° is most suitable in view of the durability against bending of the ink tube 31.

Therefore, as shown by the solid line in fig. 3, when the ink tube 31 is pulled in the direction of the support portion 51, the resistance can be suppressed from acting on the movement of the print head 7, and as shown by the broken line in fig. 3, when the ink tube 31 is bent between the support portion 51 and the print head 7, the ink tube 31 can be smoothly bent in the direction of the support portion 51. Therefore, when the print head moves, the increase of the resistance by the ink tube 31 can be suppressed well.

As shown in the right ink tube 31 indicated by the solid line in fig. 3, when the printhead 7 moves to the end of the ink tube 31 on the projecting side, the ink tube 31 also bends smoothly in the direction of the support 51. Therefore, in the present embodiment, the flow path area of the ink in the ink tube 31 can be ensured well, the supply of the ink is not hindered, and the housing of the ink jet printer can be designed to be small in the width direction of the recording paper.

The bending of the ink tube 31 in the front-rear direction is controlled by the contact with the rear surface of the ink tube guide 53, the guide shaft 13, and the protective cover 25 as described above, and is positioned forward as the rear surface of the ink tube guide 53 moves to the end as described above, so that the bending of the ink tube 31 is easily deviated, and the ink tube 31 can be bent more smoothly. Further, the resistance to the movement of the print head 7 becomes smaller.

In addition, because of the above-described structure of the inclined tube guide 53 and the projecting angle of the ink tube from the print head 7, the bending of the ink tube 31 is generated near the eye side (the output side in the recording paper conveying direction, the tube guide side), so that the ink tube 31 is less likely to contact the guide shaft 13 or the conveying roller 3 (the protective cover 25). Unlike the ink tube guide 53, since the guide shaft 13 cannot be provided with a buffer such as sponge, impact sound or the like due to contact between the guide shaft 13 and the ink tube 31 cannot be alleviated. Therefore, contact is avoided by avoiding the contact as much as possible.

In the present embodiment, the support portion 51 is provided at a substantially central position of the scanning area of the print head 7, and therefore the length of the ink tube 31 required to couple the print head 7 and the support portion 51 can be controlled to a minimum. Since the length of the ink tube 31 can be reduced, the bending amount of the ink tube 31 is reduced, and the resistance of the print head moving process is reduced.

Further, in the present embodiment, the ink tubes 31 are bundled together with the FPC43 and the protective film 45 by the ink tube band 41, and the FPC43 and the protective film 45 are held movably in the longitudinal direction with respect to the ink tube band 41. Therefore, even if the curvature of the ink tube 31 differs from that of the FPC43 and the protective film 45, the bend portion of the ink tube 31 does not twist. Thus, increase in the movement resistance of the print head 7 can be suppressed more effectively. Further, the movement range of the protective film 45 is restricted by the cutout portion 45a, and therefore, even if the FPC43 and the protective film 45 move in the longitudinal direction as described above, the reset is easy.

Since the ink tube band 41 fixes the pair of ink tubes 31 to the pair of grooves 47, respectively, the occurrence of twisting or the like can be prevented more effectively if the fixation is performed as follows. That is, the pair of ink tubes 31 may be fixed straight and in parallel by a jig or the like, and the ink tube band 41 may be fixed to the fixed ink tubes 31. Thus, the twist of the pair of ink tubes 31 can be prevented, and the increase of the moving resistance of the print head 7 can be controlled well. In addition, since the FPC43 and the protective film 45 are inserted into the groove 49 of the ink tube band 41 from above, these may be inserted at the end of mounting.

Since the protective film 45 has a width direction perpendicular to the platen 5, the ink tube 31 can be prevented from being bent in the recording paper direction. Therefore, in the present embodiment, it is possible to prevent the ink tube 31 from being contaminated by the contact with the recording medium, to make the curved trajectory of the ink tube 31 smoother, and to further control the ink tube 31 to increase the moving resistance of the print head 7. By reducing the load of the carriage motor 15 well, the ejection position of the ink can be controlled more accurately.

In the present embodiment, FPCs 43 are attached to the ink tubes 31 protruding from the end surfaces on both sides in the moving direction of the print head 7. Therefore, the FPC43 is divided into two pieces, and the divided FPC43 can be well separated. The FPC43 includes a signal line for transmitting a driving signal to the print head 7 and a signal line for transmitting a signal from an optical sensor, not shown, and is divided equally into two in the present embodiment. The ink tubes 31 are 4 in total, and ink of 4 colors is supplied, and the assignment of these ink tubes 31 and the combination of signal lines output to the respective color portions corresponding to the print head 7 are substantially free. However, in the present invention, when the ink colors to be dispensed using the ink tubes 31 and the signal lines of the FPC43 are combined, there is an advantage that the cause is easily found when a failure occurs. Between the FPCs 43 separated in this manner, crosstalk does not occur because the FPCs 43 do not overlap with each other. Further, since the image is divided into two parts, it is also possible to excellently prevent crosstalk from being generated on the FPC43 added to each ink tube 31. Since each FPC43 is attached to the ink tube 31 by the ink tube ferrule 41, the operation thereof can be stabilized as in the case of the ink tube 31.

Therefore, in the present embodiment, crosstalk can be prevented without increasing the size of the apparatus. That is, the bending property is ensured by maintaining the cross-sectional area of each FPC43 small, and crosstalk can be prevented without using a large capacitor. In addition, as described above, since the FPC43 operates stably, the durability thereof can be improved well, and the load on the carriage motor 15 can be reduced. Therefore, the present ink jet printer can form a very accurate image.

The present invention is not limited to the above-described embodiments, and can be implemented in various ways without departing from the scope of the present invention. For example: the direction in which the ink tube 31 projects from the print head 7 can also produce the aforementioned action and effect to some extent if it is slightly inclined forward from the direction of movement of the print head 7. However, it is proposed to incline the projection direction by 15 ° to 45 °, preferably by 25 ° to 35 °, from the direction of movement of the print head 7. In particular, in order to miniaturize the ink jet printer in the width direction of the recording paper, it is recommended that the projecting direction be inclined by 30 °.

Although the sponge is attached to the surface of the tube guide 53 that contacts the ink tube 31, the sponge is not attached to the entire contact surface, and may be attached only to the portion of the tube guide 53 that contacts the tube band 41. In particular, the present invention is useful in a configuration in which the tube band 41 has a thickness, only the tube band 41 abuts against the tube guide 53, and the protective film 45 does not directly abut against the tube guide 53.

As another configuration, when the ink tubes 31 are bundled together with the FPC43 and the protective film 45 as in the above-described embodiment, a recessed portion as a relief portion of the ink tube band 41 may be formed in a portion of the ink tube guide 53 which is in contact with the ink tube band 41 without sticking a sponge. In the above embodiment, the FPC43 and the protective film 45 are slidably bundled, and are disposed on the outer side of the bend of the ink tube 31 so as not to be in close contact with the ink tube 31. In particular, it is apparent at a portion where the tube band 41 is not provided. Then, in the portion where the ink tube band 41 is not present, the ink tube 31 is not directly abutted against the ink tube guide 53 but is contacted through the FPC43 and the protective film 45, and at this time, the FPC43 and the protective film 45 function as buffers, and the contact impact is reduced. On the other hand, at the portion where the tube band 41 is provided, since the impact due to the collision with the tube guide 53 is transmitted to the ink tube 31, the aforementioned recessed portion is necessary in order not to generate the collision or to reduce the impact.

In the above embodiment, the FPC43 is also arranged so that the width direction thereof is directed in the direction perpendicular to the platen 5, similarly to the protective film 45, and therefore, the effect of suppressing the bending of the ink tube 31 in the recording paper direction can be expected. If the FPC43 has sufficient strength and durability, the FPC43 can also function as the protective film 45, and the protective film 45 may be omitted.

The front end surface of the protective cover 25 may be shifted slightly forward from the front end surface of the guide shaft 13 and from a plane perpendicular to the platen. The ink tube 31 is deformed in a drooping direction by its own weight, and the front end surface of the protective cover 25 is moved forward, whereby the downward deformation is prevented and the contact with the recording paper is also prevented. That is, since the ink tubes 31 are shifted so that the bending direction thereof becomes more vertical, the ink tubes 31 are less likely to be deviated.

In the above-described embodiment, the protective cover 25 is designed to cover the transport roller 3 over the entire possible range in which the print head can record, and as shown in fig. 3, unlike the side on which the tube guide 53 is provided, the portion where the tube 31 abuts against the transport roller 3 is not limited, and therefore, the protective cover 25 may be designed to cover only the abutting portion.

By making the ink tube ferrule 41 of a slightly elastic and hard plastic material, the rigidity of the pull-out stop portion 60 can be increased, and the relative positions of the protective film 45, the FPC43, and the ink tube 31 can be more accurately maintained. Further, by making the diameter of the groove 47 of the ink tube band 41 smaller than the diameter of the ink tube 31, it is possible to eliminate the formation of the anti-slip member, thereby improving the productivity of the ink tube band 41.

In the above embodiment, the total number of the ink tubes 31 is 4, and the bundling is performed by 2, as an example, but the number is not limited. When the ink tubes 31 bundled respectively are distributed, it is recommended to divide them into the same number as the number of the ink tubes 31 bundled respectively, in view of the thinning of the print head 7 and the fact that the moving resistance does not change in the reciprocating scanning of the print head 7.

In the above embodiment, the guide shaft 13 and the protective cover 25 are provided on the input side in the recording paper conveyance direction, and the tube guide 53 is provided on the output side in the recording paper conveyance direction. In this case, the conveyance roller 3 serves as a sheet delivery roller, and the sheet delivery roller functions as a conveyance roller.

Claims (24)

1. An ink jet printer having the following structure:

a print head that ejects ink droplets and forms an image on a recording medium;

an ink holding portion provided separately from the printing head and holding the ink supplied to the printing head;

a guide shaft for guiding the print head in a width direction of the recording medium;

a print head moving mechanism for reciprocating the print head along the guide shaft;

an elastic tubular member protruding from an end surface of the print head in a moving direction, the ink holding portion being coupled to the print head over an entire moving range of the print head, the tubular member supplying ink from the ink supply portion to the print head;

a roller disposed near the guide shaft and transporting the recording medium in a direction orthogonal to the guide shaft; and

a protective cover for preventing the tubular component bending along with the movement of the printing head from contacting the roller by covering the roller, characterized in that,

the protective cover and the guide shaft are provided along a plane substantially perpendicular to the bending direction of the tubular member, and the distance between the protective cover and the guide shaft (the protective cover and the guide shaft) is set to a distance that prevents the tubular member from passing through.

2. The ink jet printer according to claim 1,

the print head is provided with a plurality of divided driving portions, the tubular member is composed of a plurality of ink tubes, and the plurality of ink tubes are connected so as to correspond to the driving portions, respectively, and can independently supply ink,

the aforementioned tubular member is provided with a first ink tube group composed of a plurality of ink tubes protruding from a first side face portion of the print head,

the plurality of ink tubes in the first ink tube group are juxtaposed in a direction (up and down) perpendicular to the recording medium so as to extend in a direction substantially parallel to the recording medium,

the first ink tube group is provided with a connecting part for fixedly maintaining the arrangement position relationship of the plurality of ink tubes.

3. The inkjet printer according to claim 2, wherein:

the connecting part is composed of a bundling component for fixedly bundling and holding a plurality of ink tubes,

the distance between the protective cover and the guide shaft is narrower than the dimension of the first ink tube group in the direction of the arrangement of the ink tubes or the dimension of the bundling member in the direction of the arrangement, thereby preventing the tubular member from passing through.

4. The ink jet printer according to claim 2, wherein the print head is a color print head capable of ejecting ink of a plurality of colors, and a plurality of driving portions divided by the colors of the respective ejected inks are provided, and the individual ink tubes of the respective colors are connected to the respective driving portions.

5. The ink jet printer according to claim 1, further comprising a protective film attached to the tubular member and formed in a band shape having a width that is widened in a direction perpendicular to the recording medium, thereby suppressing the tubular member from being bent in the perpendicular direction.

6. The ink jet printer according to claim 5, wherein the protective film is attached so as to be positioned on one side (on a side where bending is performed) in a bending direction of the tubular member in accordance with movement of the print head.

7. The ink jet printer according to claim 6, wherein a width of the protective film is larger than an interval between the protective cover and the guide shaft.

8. The ink jet printer according to claim 1, further comprising a flat cable attached to the tubular member so as to widen a width thereof in a direction perpendicular to the recording medium, and integrally operating with the tubular member to apply a drive signal to the print head.

9. The ink jet printer according to claim 8, wherein the flat cable is attached so as to be positioned on one side (on a side where bending is performed) in a bending direction of the tubular member in accordance with movement of the print head.

10. An ink-jet printer having a structure in which,

a print head that ejects ink droplets and forms an image on a recording medium;

an ink holding portion provided separately from the printing head and holding the ink supplied to the printing head;

a guide shaft for guiding the print head in a width direction of the recording medium;

a print head moving mechanism for reciprocating the print head along the guide shaft;

an elastic tubular member protruding from an end surface of the print head in a moving direction, the ink holding portion being coupled to the print head over an entire moving range of the print head, the tubular member supplying ink from the ink supply portion to the print head;

sixthly, a flat cable attached to the tubular member, integrally operating with the tubular member, and applying a driving signal to the print head;

a roller disposed near the guide shaft and configured to convey the recording medium in a direction perpendicular to the guide shaft; and

a protective cover for preventing the tubular member bent according to the movement of the print head from contacting the drum by covering the drum, wherein,

the protective cover and the guide shaft are provided along a plane substantially perpendicular to a bending direction of the tubular member moving together with the print head, and an interval between the protective cover and the guide shaft is set to an interval that prevents the passage of the ink tube or the flat cable.

11. The ink jet printer according to claim 10,

a binding member for binding and holding the tubular member and the flat cable is provided,

the distance between the protective cover and the guide shaft is narrower than the dimension of the bundling member in the bundling direction, thereby preventing the tubular member or the flat cable from passing through.

12. The ink jet printer according to claim 11, wherein the binding member holds either the tubular member or the flat cable movably in a longitudinal direction thereof, and a binding position determined by the binding member of the tubular member or the flat cable is changeable.

13. The ink jet printer according to claim 10, further comprising a protective film attached to the tubular member and having a strip shape with a width that is widened in a direction perpendicular to the recording medium, the protective film being configured to prevent the tubular member from being bent in the perpendicular direction, the protective film covering and protecting the flat cable from a side opposite to the tubular member.

14. The ink jet printer according to claim 13, wherein a width of the protective film is wider than a gap between the protective cover and the guide shaft.

15. The ink jet printer according to claim 13,

a binding member for binding and holding the flat cable, the tubular member and the protective film,

the binding member holds either the flat cable, the protective film, or the tubular member so as to be movable in the longitudinal direction thereof, and the binding position determined by the binding member of the flat cable, the protective film, or the tubular member can be changed.

16. The ink jet printer according to claim 15,

the protective film has a width wider than that of the flat cable, and is formed with a cut portion having a partial width equal to that of the flat cable and being narrowed.

The binding member is composed of: a fixing groove for fixedly holding the tubular member; a sliding groove having a width larger than the width of the flat cable and slidably holding the flat cable and the notch of the protective film.

17. The printhead according to claim 10, wherein a support portion that fixedly supports a central portion of the tubular member that connects the printhead to the ink holding portion is provided at a position shifted from a substantially center of a movement range of the printhead in a transport direction of the recording medium.

18. The ink jet printer according to claim 17,

a guide surface formed by a surface extending from the support portion along the movement range of the print head is provided,

the displacement of the tubular member in the transport direction of the recording medium, which is bent in accordance with the movement of the print head and displaced, is restricted by the guide surface, the protective cover, and the guide shaft.

19. The ink jet printer according to claim 18, wherein the guide surface is formed in a shape in which a distance from the guide shaft is at least partially increased from the support portion to an end of a moving range of the print head.

20. The ink jet printer according to claim 10,

the print head is provided with a plurality of divided driving portions, the tubular member is composed of a plurality of ink tubes, and the plurality of ink tubes are connected so as to correspond to the driving portions, respectively, and can independently supply ink,

the ink tubes have a first ink tube group protruding from a first side portion of the print head, and a second ink tube group protruding from a second side portion of the print head,

a first flat cable for applying a drive signal to a drive unit for supplying ink from the first ink tube group is attached to the first ink tube group,

a second flat cable for applying a drive signal to a drive unit for supplying ink from the second ink tube group is attached to the second ink tube group,

the distance between the protective cover and the guide shaft is set to a distance that prevents any one of the first ink tube group, the second ink tube group, the first flat cable, and the second flat cable from passing through.

21. The ink jet printer according to claim 1, wherein:

the tubular member is disposed between the print head and the ink holding portion when the print head is scanned along the guide shaft so that a curved loop is dynamically formed on the tubular member,

the space occupied by the movement of the tubular member and the ring substantially coincides with the space occupied by the movement of the print head.

22. The ink jet printer of claim 21,

and a support portion supporting a central portion of the tubular member to which the ink protection portion is coupled, at a position shifted from a moving range of the print head in a transport direction of the recording medium perpendicular to (in) a width direction of the recording medium.

The tubular member protrudes from an end surface on the side of the moving direction of the print head, bends in the moving range of the print head, and extends to the support portion in a direction substantially parallel to the recording medium.

23. The ink jet printer according to claim 10,

the tubular member is disposed between the print head and the ink holding portion while the print head scans along the guide shaft, so that a curved loop is dynamically formed on the tubular member,

the space occupied by the movement of the tubular member and the ring substantially coincides with the space occupied by the movement of the print head.

24. The ink jet printer according to claim 23,

and ninthly, a support part which supports and connects the central part of the tubular component of the ink protection part at a position which is deviated from the conveying direction of the recording medium which is vertical (direction) to the width direction of the recording medium from the moving range of the printing head.

The tubular member protrudes from an end surface on the side of the moving direction of the print head, bends in the moving range of the print head, and extends to the support portion in a direction substantially parallel to the recording medium.