Image recording apparatus

An image recording apparatus includes: a first guide member having a first sliding surface; a second guide member having another first sliding surface; and a carriage being supported by the first sliding surfaces of the first and second guide members. The carriage includes first sliding convex parts protruding from a lower surface side thereof and coming in contact with the first sliding surfaces of the first and second guide members, and a coming-out preventing pawl disposed to hold at least one of the first and second guide members in cooperation with the first sliding convex part. At least one of the first and second guide members includes a notch part at a specified position, and the carriage is detachable from the first and second guide members by causing the coming-out preventing pawl to pass through the notch part.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an image recording apparatus of an ink-jet type or the like, and more particularly to a structure of a supporting device of a carriage on which a recording head is mounted.

2. Description of the Related Art

A dominating conventional image recording apparatus is such that for example, as disclosed in JP-A-5-270091 (see FIGS. 1 to 4), in order to support a carriage carrying a recording head in such a manner that it can reciprocate in a main scanning direction, the carriage is slidably supported by a cylindrical guide shaft.

According to the cylindrical guide shaft, because of excellent size accuracy, high rigidity, a variation of a so-called paper gap between the nozzle surface of the recording head and the surface of a recording medium can be made small, and a high quality recording image can be easily obtained, however, the cost is high. Besides, when the carriage is detached from the guide shaft for maintenance, exchange or the like, the guide shaft is first detached from a frame, and further, the carriage must be detached from the guide shaft, while a procedure opposite thereto must be carried out at the time of assembly. Thus, there is a problem that the mounting of the carriage is very difficult.

For the purpose of reducing the cost, in JP-A-2002-254746 (see FIG. 2), a first carriage guide plate having a Z-shaped section is formed by cutting and raising at a halfway part, in the height direction, of a main frame provided to stand in the vertical direction, and a first guide part protruded downward from one lower surface of a carriage is brought into contact with an upper surface of a horizontal first position regulating plate. A third guide part laterally protruded from the lower part of the carriage so as to face the lower surface (sliding surface) of the first guide part is made to face the lower surface of the first position regulating plate.

Besides, at a part protruded downward from a side part of the carriage to have a U shape, a pair of second guide parts are provided to hold both the front and back surfaces of a second position regulating plate obtained by bending the tip of the first position regulating plate vertically upward.

Further, the lower surface (sliding surface) of a fourth guide part protruded downward from the other lower surface of the carriage is brought into contact (slide contact) with a third position regulating surface (upper surface) of the horizontal second carriage guide plate.

SUMMARY OF THE INVENTION

However, in the structure of JP-A-2002-254746, the horizontal first position regulating plate of the first carriage guide plate is sandwiched between the first guide part and the third guide part in the vertical direction, and both the surfaces of the vertical second position regulating plate provided to be coupled with the first position regulating plate is sandwiched between the pair of second guide parts in the horizontal direction. Thus, in order to detach the carriage from the first carriage guide plate, it becomes necessary to perform such an operation as to detach the lower third guide part from the carriage, and there is a problem that the attachment/detachment operation of the carriage relative to the carriage guide plate is difficult.

The present invention provides an image recording apparatus in which a guide shaft is not used, an attachment/detachment operation of a carriage is easy, and manufacturing cost can be reduced.

According to one aspect of the invention, there is provided an image recording apparatus including: a first guide member disposed at an upstream side in a transportation direction of a recording medium, the first guide member having a substantially horizontal upper surface that includes a first sliding surface; a second guide member disposed at a downstream side in the transportation direction, the second guide member having a substantially horizontal upper surface that includes another first sliding surface; and a carriage on which a recording head capable of recording an image on the recording medium is mounted and which reciprocates in a main scanning direction, the carriage being supported by the first sliding surfaces of the first and second guide members which are parallel to a head surface of the recording head, the carriage including first sliding convex parts protruding from a lower surface side thereof and coming in contact with the first sliding surfaces of the first and second guide members, and a coming-out preventing pawl disposed to hold at least one of the first and second guide members in cooperation with the first sliding convex part; wherein at least one of the first and second guide members includes a notch part at a specified position, and the carriage is detachable from the first and second guide members by causing the coming-out preventing pawl to pass through the notch part.

Since the first sliding convex part protruding from the lower surface side of the carriage comes in contact with the first sliding surfaces of the respective upper surfaces of the horizontal first and second guide member, the carriage can be moved in the main scanning direction in a state where it is supported on both of the guide members by only the weight of the carriage. Since the carriage includes the coming-out preventing pawl to hold the back surface (lower surface side) of at least one of the first and second guide members, the carriage is not detached from the guide members at the time of movement. Only at the time when the coming-out preventing pawl is positioned at the notch part provided at the specified position, the carriage can be easily detached from the guide members. Thus, it is unnecessary to remove the coming-out preventing pawl from the carriage, and there is obtained an effect that the structure becomes very simple, and the cost can be reduced.

According to another aspect of the invention, there is provided an image recording apparatus including: a first guide member disposed at an upstream side in a transportation direction of a recording medium which is orthogonal to a main scanning direction, the first guide member having a substantially horizontal upper surface that includes a first sliding surface; a second guide member disposed at a downstream side in the transportation direction, the second guide member having a substantially horizontal upper surface that includes another first sliding surface and a second sliding surface provided to stand substantially orthogonally to the first sliding surface; and a carriage on which a recording head capable of recording an image on the recording medium is mounted and which reciprocates in the main scanning direction, the carriage being supported by the first sliding surfaces of the first and second guide members which are parallel to a head surface of the recording head, the carriage including first sliding convex parts protruding from a lower surface side thereof and coming in contact with the first sliding surfaces of the first and second guide members, coming-out preventing pawls disposed to hold the first and second guide members in cooperation with the respective first sliding convex parts, a second sliding convex part coming in sliding contact with the second sliding surface, a third sliding convex part that is opposite to the second sliding convex part across the second sliding surface, and an elastic member to elastically urge the third sliding convex part toward a direction of the second sliding surface; where in the first and second guide members include, at specified positions, notch parts to enable the respective coming-out preventing pawls to be detached in a direction crossing the main scanning direction of the carriage.

When the carriage is moved along the first and second guide members, the carriage does not float and can be accurately moved with reference to the second sliding surface. Even if the first sliding surface and the second sliding surface orthogonal to each other exist on the second guide member, there is obtained an effect that the carriage can be easily detached from the guide members at the specified position and can be exchanged without removing the coming-out preventing pawl provided on the carriage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, an embodiment of the invention will be described.

An image recording apparatus1of this embodiment is a multi function device (MFD) having a printer function, a copy function, a scanner function and a facsimile function, to which the invention is applied. As shown inFIG. 1, at a bottom part of a recording apparatus main body2made of synthetic resin, a paper feed cassette3is disposed which can be inserted through an opening part2aat the front side (left side inFIG. 1) of the recording apparatus main body2.

In this embodiment, the paper feed cassette3is made to have such a form that plural sheets P, each of which is a recording medium and is cut into, for example, A4 size, letter size, legal size, postcard size or the like, can be stacked (deposited) and contained in such a manner that its short side extends in a direction (direction orthogonal to the surface of the sheet ofFIG. 1, main scanning direction, or Y-axis direction) orthogonal to a sheet transporting direction (sub-scanning direction or X-axis direction). An auxiliary support member3ato support the rear end part of the long sheet P of legal size or the like is mounted at the front end of the paper feed cassette3in such a manner that it can be moved in the X-axis direction. AlthoughFIG. 1shows a state in which the auxiliary support member3ais disposed at a position where it protrudes toward the outside from the main body2, in the case where the sheet P of A4 size or the like which can be contained in the paper feed cassette3(which does not protrude toward the outside from the opening part2a) is used, the auxiliary support member3acan be housed in a housing part3bin such a manner that it does not block the paper feed.

A bank part8for sheet separation is disposed at the depth side (right side inFIG. 1) of the paper feed cassette3. Besides, an arm6awhose lower end part can swing in the vertical direction is mounted at the side of the recording apparatus main body2, and the sheet P as the recording medium stacked (deposited) on the paper feed cassette3is separated and transported one by one by a paper feed roller6provided at the lower end of the arm6aand the bank part8. The separated sheet P is fed to a recording part7provided at an upper side (high position) behind the paper feed cassette3through a U-turn path (feed path)9directed upward. As described later in detail, the recording part7includes a carriage5on which an ink-jet recording head4to realize the printer function and the like is mounted and which can reciprocate.

A paper discharge part10to which the sheet P recorded in the recording part7is discharged while its recording surface is turned upward, is formed above the paper feed cassette3, and a paper discharge port10acommunicating with the paper discharge part10is opened toward the front of the recording apparatus main body2.

An image reading device12for reading a document in the copy function and the facsimile function is disposed at an upper part of the recording apparatus main body2. A bottom wall11of the image reading device12is constructed to overlap from above an upper cover body30substantially without a gap. The image reading device12is constructed to be capable of opening/closing/swinging vertically with respect to one side end of the recording apparatus main body2through a not-shown pivot part. Further, a rear end of a document cover body13covering an upper surface of the image reading device12is mounted to a rear end of the image reading device12so that it can vertically swing about a pivot shaft12a.

An operation panel part14including various operation buttons, a liquid crystal display part and the like is provided at the upper side of the recording apparatus main body2and in front of the image reading device12. The recording part7, the paper discharge part10and an ink storage part15provided at one side of this paper discharge part10are disposed to be positioned in a projection area of the image reading device12and the operation panel part14when viewed on a plane. In the state where the auxiliary support member3ais housed in the housing part3b, the length of the paper feed cassette3in the X-axis direction is almost equal to the length of the image reading device12plus the length of the operation panel part14in the X-axis direction. Accordingly, since this image recording apparatus1becomes a substantially rectangular parallelepiped having a substantially square shape when viewed on a plane, packing becomes easy at a packing time when it is shipped as a product, and a box for the packing can be miniaturized.

A placement glass plate16on which a document can be placed after the document cover body13is opened upward, is provided on the upper surface of the image reading device12, and at its lower side, an image scanner device (CIS: Contact Image Sensor)17for document reading is provided to be capable of reciprocating in the direction (main scanning direction or Y-axis direction inFIGS. 2 to 6) orthogonal to the paper plane ofFIG. 1.

The ink storage part15is opened toward an upper part of the recording apparatus main body2, and the ink storage part15is constructed such that ink cartridges19(cartridges for individual colors, that is, black (BK), cyan (C), magenta (M) and yellow (Y) are denoted by19ato19d, seeFIGS. 2 to 4) which respectively contain four color inks for full-color recording, have small areas when viewed on a plane, have high height sizes, and have substantially rectangular box shapes can be housed along the X-axis direction, and can be detachably attached from above.

The inks are supplied from the respective ink cartridges19(individually denoted by19ato19d) to the ink-jet recording head4through plural (four in this embodiment) ink supply tubes (ink tubes)20(individually denoted by20ato20d, seeFIG. 7). Incidentally, in the case where ink colors more than four colors are used (six colors to eight colors, etc.), the structure has only to be modified such that the ink cartridges the number of which corresponds to the number of the ink colors can be housed in the ink storage part15, and the number of the ink supply tubes20are also increased according to the number of the ink cartridges.

As shown inFIGS. 3 to 6, the recording part7includes laterally long plate-shaped guide members22and23which are supported by pair of right and left side plates21aof a main frame21and extend in the Y-axis direction (main scanning direction), a carriage5which extends over both of the guide members22and23, is slidably supported (mounted) and is constructed to be capable of reciprocating, a timing belt24which is disposed on and in parallel to an upper surface of the guide member23disposed at the downstream side in the sheet transporting direction (direction of an arrow A) in order to reciprocate the carriage5on which the recording head4is mounted, a CR (carriage) motor25(although it is a DC motor in this embodiment, it may be another motor such as a stepping motor) to drive the timing belt24, a plate-shaped platen26to support the transported sheet P at the lower surface side of the recording head4, an encoder strip47which is disposed to extend in the main scanning direction and is for detecting the Y-axis direction (main scanning direction) position of the carriage5, and the like. The band-shaped encoder strip47is disposed such that a check surface (formation surface of slits disposed at regular intervals in the Y-axis direction) extends in the vertical direction.

Besides, a pair of registration rollers27are disposed at both sides of the platen26and at the upstream side in the transporting direction, and the sheet P is fed to the lower surface of the recording head4. A spur (not shown) coming in contact with the upper surface of the sheet P and a paper discharge roller28at the lower surface side are disposed at the downstream side of the platen26, and the recorded sheet P is transported to the paper discharge part10.

Besides, at the outside relative to the width (short side of the sheet P) of the sheet P to be transported, an ink receiving part (not shown) is disposed at one end side (in the embodiment, a part near the left side plate21ainFIG. 3), and a maintenance unit50is disposed at the other end side (a part near the right side plate21ainFIGS. 3 and 5). By this, the recording head4periodically performs an ink discharge to prevent clogging of a nozzle at a flashing position provided in the ink receiving part during a recording operation, and ink is received by the ink receiving part. In the portion of the maintenance unit50, the carriage5is at a standby position, and cleaning of the nozzle surface of the recording head4is performed, and further, ink is selectively sucked for each color, and a recovery processing for removing bubbles in a not-shown buffer tank on the recording head4is performed.

A partition plate (lower cover body)29is disposed which covers an upper part of the discharge part10between the lower surface of the guide member23at the downstream side in the sheet transporting direction and the paper discharge port10aat the front end of the recording apparatus main body2. Further, an upper cover body30is disposed above this partition plate (lower cover body)29to be spaced apart therefrom by a suitable distance and to cover the carriage5and an upper part of its reciprocal movement passage. Incidentally, a rectangular window hole31through which the reciprocal movement passage of the carriage5can be seen from above is provided at the halfway part of the upper cover body30(seeFIG. 2). In the case where the sheet P causes a paper jam in the recording part7, the user swings the image reading device12from the recording apparatus main body2and can remove the sheet P through this window hole31. In this case, since the ink supply tube20is not routed on the platen26, the removal of the sheet P becomes easy.

The guide member22at the upstream side in the sheet transporting direction and the guide member23at the downstream side are substantially in the horizontal state, and first sliding surfaces51and52parallel to the lower surface (head surface on which nozzles are formed) of the recording head4in the carriage5are formed on the upper surfaces of both of the guide members22and23at the side close to the arrangement of the carriage5. Besides, a second sliding surface54directed to the downstream side in the sheet transportation is formed on an almost perpendicular (vertical) guide piece53obtained by bending the upstream side, in the sheet transporting direction, of the downstream side guide member23(seeFIGS. 5 and 6).

The carriage5includes first sliding convex parts55aand55bwhich protrude from its lower surface side and come in contact with the first sliding surfaces51and52of the guide members22and23, and plural coming-out preventing pawls56aand56bdisposed to hold the first and second guide members22and23in cooperation with the first sliding convex parts55aand55b.

In this embodiment, the one first sliding convex part55acoming in contact with the first sliding surface51of the first guide member22is disposed almost at the center of the carriage5in the lateral direction (main scanning direction). The two first sliding convex parts55bcoming in contact with the first sliding surface52of the second guide member23and disposed to be spaced apart from each other by a suitable distance in the lateral direction (main scanning direction), and the two right and left coming-out preventing pawls56aand56bopposite to the lower surface of each of the first and second guide members22and23are respectively provided at the sides close to the right and left side pieces of the carriage5when viewed on a plane (seeFIGS. 5,9and10).

The three first sliding convex parts55a,55band55bare disposed at the respective apexes of a triangle (isosceles triangle is preferable) of the carriage5when viewed on a plane, so that the carriage5is stably supported relative to the first and second guide members22and23. In order to lightly slide the first sliding convex parts55aand55bwhile receiving the weight of the carriage5against both of the guide members22and23, plural concave recesses58long in the X-axis direction and for holding lubricating grease are formed on the lower surfaces (support surfaces or sliding surfaces) of the first sliding convex parts55aand55bin the main scanning direction (Y-axis direction) at suitable intervals (seeFIG. 9).

On the other hand, as shown inFIG. 5, plural (two at each of the right and left) notch parts57aand57bare formed in the first guide member22and the second guide member23at positions outside the recording area relative to the sheet P in the main scanning direction (Y-axis direction). The positions are close to the maintenance unit50and are specified positions deviated by a distance Y3. By this, an operation position where the carriage5is detached from the guide members22and23can be made close to a standby position of the carriage5, and a movement distance of the carriage5can be decreased.

A distance Y4between the two notch parts57aof the first guide member22and a distance Y4between the two notch parts57bof the second guide member23are respectively set to be equal to arrangement intervals between the two right and left coming-out preventing pawls56aand56b(seeFIGS. 5 and 10).

The notch part57aof the first guide member22is formed such that the downstream side edge of the first guide member22is opened and its shape is substantially rectangular when viewed on a plane. The notch part57bof the second guide member23is formed such that a corner part lying astride an upstream side edge of the second guide member23and the upward guide piece53is opened to have an L-shaped side section (seeFIG. 6,FIGS. 14A to 14B,FIGS. 15A to 15B). Besides, a closing member90to prevent the coming-out preventing pawl56bfrom coming out at a normal use time is fitted in the one notch part57b. The closing member90is made of, for example, synthetic resin and is formed to have a C-shape side section. As shown inFIG. 18AandFIG. 18B, although the closing member90is fitted to the notch part57bof the second guide member23from an outer angle side, it is constructed to be removable by the hand of an operator.

The carriage50is provided with two second sliding convex parts59and60which are brought into contact with the second sliding surface54of the second guide member23. The one second sliding convex part59is formed integrally with a holder case61of the carriage5and is disposed such that the vertical guide piece53is sandwiched between a holding piece62and the second sliding convex part59. A space between the holding piece62and the second sliding convex part59is opened in the main scanning direction and downward (seeFIGS. 9 and 10).

The other second sliding convex part60and a holding piece63are provided through a posture adjustment unit64to adjust the mount posture of the carriage5relative to the vertical guide piece53of the second guide member23, and the second sliding convex part60is provided at a position (position spaced much apart from the one second sliding convex part59) close to the other side of the carriage5. In this embodiment, as shown inFIG. 7,FIGS. 11 to 13,FIG. 16andFIG. 17, an adjusting body block65integrally provided with the second sliding convex part60and the holding piece63comes in slide contact with one side surface61aof the holder case61, is supported by an upper and a lower guide blocks66aand66bprovided to protrude at an upper and a lower parts of the one side surface61aof the holder case61, and is disposed to be slidable in the X-axis direction (seeFIG. 17). Besides, a pair of contact surfaces67aand67bopposite to each other are formed in a space of an inner diameter part of the adjusting body block65. An eccentric round shaft70is formed integrally with the back surface of a dial plate69having an adjustment knob68on its surface, and a shaft hole72in which a round spindle71protruding from the one side surface61aof the holder case61is fitted is formed in the eccentric round shaft70.

When the eccentric round shaft70of the dial plate69is fitted over the round spindle71, the outer peripheral surface (diameter part) of the eccentric round shaft70is always in contact with the pair of contact surfaces67aand67b. Concave grooves (notch grooves)73used also as graduations are formed, in the circumstantial direction and at suitable intervals, in the portion of the surface of the dial plate69close to the outer periphery. The center part of a plate spring body74having a C-shaped section and covering the surface side of the dial plate69is cut out, and the adjustment knob68and the concave grooves (notch grooves)73can be exposed. A press part75which can be engaged/disengaged with/from the concave groove (notch groove)73, presses it, and has a lateral V-shaped section, is formed by bending at a halfway part, in the vertical direction, of each of a pair of elastic pieces74aof the plate spring body74(seeFIGS. 11 and 17). Attachment holes77engaged with engagement pawls76provided to protrude from the outer surfaces of the upper and lower guide blocks66aand66bof the holder case61are formed to penetrate an upper and a lower attachment pieces74bof the plate spring body74(seeFIG. 17). The adjusting body block65is moved in the X-axis direction according to the adjustment knob68and the rotation position of the dial plate69, the protrusion amount of the second sliding convex part60relative to the guide piece53can be adjusted, and the posture of the carriage5when viewed on a plane can be adjusted around the place where the sliding surface of the one first sliding convex part59is in contact with the guide piece53.

Incidentally, the hole78(seeFIGS. 11,12and16) provided in the surface of the adjustment knob68is a tool set hole for setting such a state that the rotation position of the dial plate69, and the position of the adjusting body block65in the X-axis direction is located at a reference position (the reference position is such that a nozzle line of the recording head4is disposed to be orthogonal to the vertical guide piece53of the second guide member23).

Besides, an urging unit79to always press and urge the vertical guide piece53of the second guide member toward the sliding surfaces of the pair of second sliding convex parts59and60is provided between the pair of second sliding convex parts59and60in the Y-axis direction. In this embodiment, as shown inFIGS. 9,10and19, a support part80having a C shape when viewed on a plane is integrally formed downward at the lower surface side of the holder case61. A spring receiving part83of a press body81having a third sliding convex part82at one side and having a C-shaped side section is disposed in the inside of the support part80to be movable in the X-axis direction. Both ends of a plate spring84as an elastic member having a bow shape when viewed on a plane is supported by the inner surface of the support part80, and the center part of the plate spring84presses the spring receiving part83, and by this, the third sliding convex part82elastically urges the guide piece53toward the sliding surface direction of the pair of second sliding convex parts59and60and always enables slide contact.

Each of the sliding surfaces of the first sliding convex parts55aand55b, the second sliding convex parts59and60, and the third sliding convex part82is formed into a convex curved shape in the main scanning direction (Y-axis direction). That is, these sliding surfaces come in line contact with the first sliding surfaces51and52and the second sliding surface54in the X-axis direction.

The carriage5is provided with a light transmission sensor (photo-coupler)85for detecting its position. A guide groove86which is opened downward and through which the encoder strip47can pass is formed in the vicinity of a root part between the holder case61of the carriage5and an after-mentioned coupling piece34. The photo-coupler85is disposed at a position adjacent to the guide groove86and at both sides of the front and back surfaces of the encoder strip47(seeFIGS. 9 and 13, etc.). The photo-coupler85is also opened in the Y-axis direction and downward.

Further, an attachment part87for coupling and fixing a part of the timing belt24is provided in the vicinity of the root part between the holder case61of the carriage5and the coupling piece34. Since the attachment part87is provided at a position slightly higher than height positions of winding parts (pulley parts24aand24b) of both ends of the timing belt24, by the tensile force of the timing belt24, the carriage5always receives a force to press it toward the upper surface of the downstream side guide member23.

A lid cover body41to cover the upper surface of the holder case61is detachably attached to the upper surface of the carriage5. A control board (not shown) which receives a signal from an after-mentioned flexible flat cable40and outputs a specified drive signal to the recording head4is disposed on the lower surface side of the lid cover body41. The detachment/attachment of the lid cover body41is necessary for maintenance such as exchange of the control board. A blocking pawl39to face the lower surface of the upstream side guide member22is formed integrally downward in the lid cover body41(seeFIGS. 5,9and10). The blocking pawl39is disposed substantially at the same height as the coming-out preventing pawl56a, and is located at a position spaced apart from the one coming-out preventing pawl56aby Y5(<Y4, seeFIG. 5) in the main scanning direction.

Next, a detailed description will be given to an arrangement structure of the ink supply tubes20which always couple the respective ink cartridges19contained in the ink storage part15to the recording head4of the recording part7and have flexibility.

In this embodiment, the respective ink supply tubes20ato20dare tube bodies independent of each other, and the lengths of all the ink supply tubes20bto20dare made equal to each other and are used.

As shown inFIGS. 3 and 4, root parts of the plural (four in this embodiment) ink supply tubes20are bundled at a portion of one end part15aof the ink storage part15, and are extended on the upper surface of the lower cover body29from its one side end part (right end part inFIG. 3) to the other end part (left end part inFIG. 3) in the Y-axis direction. At this time, the root parts of all the ink supply tubes20ato20dare arranged in one lateral line along the upper surface of the substantially horizontal lower cover body29. At least a part (halfway part etc.) of this ink supply tube20is supported by the upper surface of the lower cover body29.

Next, all the ink supply tubes20ato20dare twisted such that their halfway parts extend along one longitudinal surface (almost vertical surface) of a laterally long longitudinal partition plate32of the lower cover body29, and the halfway parts of all the ink supply tubes20ato20dare arranged in one longitudinal line and are fixed (held or sandwiched) between the longitudinal partition plate and a vertical plate-shaped fixing body33made of synthetic resin and fixed by screws or the like to face the one longitudinal surface of the longitudinal partition plate32. A portion where all the ink supply tubes20ato20dare fixed (held) by the fixing body33and the one longitudinal surface of the longitudinal partition plate32becomes an intermediate fixing part. Incidentally, the intermediate fixing part may has such a structure that the halfway parts of all the ink supply tubes20ato20dare arranged in one vertical line and are fixed (held or sandwiched) by, for example, a downward U-shaped or an upward U-shaped fixing body (not shown).

The carriage5is provided with the coupling piece34extending substantially horizontally in the sheet transporting downstream direction (direction of the arrow A), and tip parts of all the ink supply tubes20ato20dare connected in an arrangement of one substantially horizontal lateral line to a coupling part (connecting part)35provided at the left end of the coupling piece34inFIG. 3. The directions of all the ink supply tubes20ato20dare changed from left to right between the place of the intermediate fixing part (fixing body33) and the coupling part (connecting part)35, and the ink supply tubes are twisted such that the phase of the lines (arrangement) of all the ink supply tubes20ato20dvaries from the substantially vertical direction at the intermediate fixing part (fixing body33) side to the substantially horizontal direction at the coupling part (connecting part)35side. In other words, the halfway parts of the four ink supply tubes20ato20dare curved and arranged so that the direction is changed by 180 degrees when viewed on a plane between the movement passage of the carriage5and the intermediate fixing part (fixing body33). In this curved halfway part, the ink supply tubes are routed such that the phase of the arrangement directions of the four ink supply tubes20ato20dextending toward the intermediate fixing part side is made different from the phase of the arrangement directions of the four ink supply tubes20ato20dextending toward the coupling part35side of the ink supply tube20ato20din the carriage5. It is of course that all the ink supply tubes20ato20dare independently separate from each other between the place of the intermediate fixing part (fixing body33) and the coupling part (connecting part)35.

As stated above, in the halfway part (from the place of the intermediate fixing part (fixing body33) to the coupling part (connecting part)35, or non-bundled or non-restricted area), curving (inverting) is performed so that the direction of extension toward the intermediate fixing part (fixing body33) side is different from the direction of extension toward the coupling part35side of the carriage5by 180 degrees. Further, in the curved halfway part, twisting is performed so that the phase of the arrangement directions of the ink supply tubes20ato20dextending toward the intermediate fixing part (fixing body33) side is different from the phase of the arrangement directions of the ink supply tubes20ato20dextending toward the coupling part35side of the carriage5. Then, although the respective ink supply tubes20ato20dare curved independently of each other, all the ink supply tubes20ato20dbecome easy to bundle. Especially, in the case where the arrangement of the ink supply tubes20ato20dat the intermediate fixing part (fixing body33) side is in the longitudinal direction (vertical direction) and the arrangement at the coupling part35side is in the horizontal direction, the arrangement of the ink supply tubes20ato20dduring the movement becomes less disordered (disturbed) in the vertical direction at the curved halfway part, and the posture of the ink supply tubes20ato20dduring the movement becomes stable.

As a result, the space height of the area (movable area, or non-bundled or non-restricted area) through which the ink supply tubes20ato20dpass in the case where the carriage5reciprocates in the Y-axis direction (main scanning direction) can be made small, and the height of the recording apparatus main body2can be made compact. Besides, when the arrangement of the ink supply tubes20ato20dat the coupling part35side is in the horizontal direction, interference with other tightly-packed parts at the carriage5side can be made less, and the height size at the carriage5portion can be made low. Further, even if all the ink supply tubes20ato20dare independent of each other, since the posture during the movement becomes stable, it becomes unnecessary to separately provide a tube bundling device, the assembling quality is improved, and the cost can be reduced.

This embodiment will be described in more detail. The inner diameter of the ink supply tube20ato supply black (BK) ink is 1.6 mm, and its outer diameter is 2.4 mm. The inner diameter of each of the three ink supply tubes of the ink supply tube20bto supply cyan (C) ink, the ink supply tube20cto supply magenta (M) ink and the ink supply tube20dto supply yellow (Y) ink is 1.2 mm and the outer diameter is 2.0 mm. Accordingly, the flexural rigidity (geometrical moment of inertia) relating to the axial line of the ink supply tube20ais 1.91 times as high as the flexural rigidity of each of the ink supply tubes20bto20dfor color inks of cyan and the like. In this embodiment, the inner diameter of the ink supply tube20afor black (BK) ink is made large as compared with the case of the other color ink. This is because, in order to make the recording speed in the case of monochrome recording higher than that of color recording, the number of nozzles for black (BK) ink in the recording head4is made more than the number of nozzles for the other color ink (substantially, the nozzle line is doubled), so that the ink supply amount per unit time must be increased.

In the portion of the one end part15aof the ink storage part15, the ink supply tube20afor black (BK) ink is disposed at the most upstream side in the sheet transportation, and next, at the downstream side thereof, the ink supply tube20bfor cyan (C) ink, the ink supply tube20cfor magenta (M) ink, and the ink supply tube20dfor yellow (Y) ink are arranged in sequence. In the embodiment ofFIGS. 3 and 7, at the place of the intermediate fixing part (fixing body33), the ink supply tubes20a,20b,20cand20dare arranged in sequence from above in the vertical direction.

Accordingly, at the curved halfway part, the radius R of curvature of the ink supply tube20afor black (BK) ink is largest, and the radius of curvature becomes small in the sequence of the ink supply tube20bfor cyan (C) ink, the ink supply tube20cfor magenta (M) ink, and the ink supply tube20dfor yellow (Y) ink.

As stated above, the radius R of curvature of the ink supply tube for black (BK) ink with the large flexural rigidity is made larger than that of each of the ink supply tubes20bto20dhaving low flexural rigidity, so that with respect to bending, the load of the ink supply tube20afor black (BK) ink due to bending deformation can be decreased, and the durabilities of all the ink supply tubes20ato20dcan be made substantially uniform.

At the intermediate fixing part by the fixing body33, when setting is made such that the arrangement height position of the ink supply tube20ahaving high flexural rigidity becomes a position higher than the horizontal height position passing (connecting) the center lines of all the ink supply tubes20ato20dat the position of the coupling part35, an acting force is exerted such that the ink supply tube20ais routed downward toward the coupling part35. In the case where the carriage5is mounted from above on the guide members22and23at the sheet transportation upstream side and the downstream side, it is possible to certainly prevent the carriage5from floating above both the guide members22and23by the downward acting force, and the reciprocal movement in the main scanning direction (Y direction) can be stabilized.

In this embodiment, the flexible flat cable40for transmitting an instruction signal to discharge an ink droplet selectively from a nozzle of the recording head4mounted on the carriage5from a not-shown control part provided at the recording apparatus main body2side, is disposed in the area (movable area, or non-bundled or non-restricted area) through which the ink supply tubes20ato20dpass in the case where the carriage5reciprocates in the Y-axis direction (main scanning direction) and substantially in parallel to the direction in which the ink supply tube20extends (seeFIGS. 3 and 4).

The convex curved direction of the curved halfway part of the ink supply tube20and the convex curved direction of the curved halfway part of the flexible flat cable40are set to be opposite to each other with respect to the reciprocal movement direction of the carriage. In other words, the direction in which the ink supply tube20extends relative to the coupling part35of the carriage5is set to be opposite to the direction in which the flexible flat cable40extends relative to the carriage5. Besides, in the space between the upper and the lower cover bodies30and29, curving formation is performed so that inversion in the vertical direction occurs at a halfway part40aof the flexible flat cable40.

By adopting the structure as stated above, the ink supply tubes20and the flexible flat cable40can be arranged substantially at the same height (substantially the same horizontal plane), and as a result, the whole image recording apparatus1can be made thin.

By the above structure, at the normal recording operation time, as shown inFIG. 13, the sliding surface of the one first sliding convex part55aof the carriage5comes in slide contact with the first sliding surface51of the upstream side first guide member22, and the other two first sliding convex parts55bcome in slide contact with the first sliding surface52of the second guide member23. The vertical guide piece53of the second guide member23is sandwiched between the right and left second sliding convex parts59and60and the corresponding holding pieces62and63. The third sliding convex part82presses the upstream side surface of the guide piece53by the urging force of the plate spring84, so that the right and left second sliding convex parts59and60come in slide contact with the second sliding surface54at the downstream side of the guide piece53.

In this state, the respective coming-out preventing pawls56aand the blocking pawl39are positioned at the lower surface side of the first guide member22, the respective coming-out preventing pawls56bare positioned at the lower surface side of the downstream side second guide member23, and the carriage5cannot be detached upward from both the guide member22and23. The encoder strip47parallel to the guide piece53is positioned in the check groove85aof the photo-coupler85.

The plane on which the carriage5is stable with respect to the first sliding surfaces51and52as the horizontal planes of both the guide members22and23is determined by the first sliding convex parts55a,55band55bat the three apex positions of the triangle, and can be made the reference height position of the nozzle plane of the recording head4in the carriage5. The vertical direction guide piece53is sandwiched between the right and left second sliding convex parts59and60and the third sliding convex part82therebetween, so that the second sliding surface54acts as a reference for the reciprocal movement of not only the carriage5but also the recording head4in the main scanning direction.

Further, by the posture adjustment unit64, the nozzle line of the recording head4is disposed to be orthogonal to the vertical guide piece53of the second guide member23and the reference position can be set. Besides, since the guide piece53is disposed at a part close to a place where the tip end parts of the ink supply tubes20connected to the coupling part35of the coupling piece34of the carriage5are curved, the action to press the second sliding convex parts59and60of the carriage5to the second sliding surface54of the guide piece53occurs by the reaction force due to the curve of the ink supply tube20, and the stability of the posture of the carriage5at the time of movement can be further improved.

Next, in order to detach the carriage5from the first and second guide members22and23for the operation of exchanging the recording head4together with the carriage5, first, it is necessary to detach the lid cover body41from the carriage5and both the guide members22and23. For that purpose, the carriage5is moved rightward to the vicinity of the maintenance unit50inFIG. 5, and the blocking pawl39is made to be aligned with the place of the left notch part57aof the first guide member22. In this state, since the positions of the four coming-out preventing pawls56aand56bare not coincident with the positions of the four notch parts57aand57b, the holder case61cannot be detached from both the guide members22and23. Then, the blocking pawl39is pulled out upward through the notch part57a, and the lid cover body41is detached from the holder case61. Next, the closing member90is removed from the one notch part57b, the carriage5is further moved rightward, and the four coming-out preventing pawls56aand56bare stopped at the position where they are aligned with the four notch parts57aand57b(seeFIG. 14A).

In this state, first, as shown inFIG. 14B, the carriage5is raised substantially in the horizontal state up to the upper edge (height size H1) of the notch part57bof the second guide member23at the guide piece53side. By this rising movement, the coming-out preventing pawl56ais pulled out (passes) upward through the notch part57aof the first guide member22, and the carriage rises up to the position where the coming-out preventing pawl56bnearly comes in contact with the upper edge of the notch part57bat the guide piece53side. At the same time, the upper edge of the vertical guide piece53also comes out of the lower ends of the second sliding convex parts59and60and the holding pieces62and63. At the same time, the upper edge of the guide piece comes out of the third sliding convex part82as well. Similarly, the almost upper edge of the encoder strip47comes out of the place of the photo-coupler85downward. Next, as shown inFIG. 15A, the whole carriage5is substantially horizontally moved toward the second guide member23side (downstream side in the transporting direction). The movement distance is slightly larger than a size W1of the notch part57bto the depth side edge of the second guide member23. Incidentally, a gap91is formed such that at the time of the horizontal movement, the upper edge of the guide piece53do not interfere with the lower surfaces of the second sliding convex parts59and60and the third sliding convex part82and the side surface of the first sliding convex part55b. The coming-out preventing pawl56bcompletely comes out of (passes) the notch part57bof the vertical guide piece53by this horizontal movement. Thus, when the whole carriage5is raised as it is (seeFIG. 15B), the trouble to remove the coming-out preventing pawl56bfrom the carriage5is saved, and the carriage5can be easily detached (separated) from the second guide member23having the L-shaped side section. Besides, the carriage5can be easily detached from both the guide members22and23without detaching the encoder strip47in the vertical state from the second guide member23. Incidentally, the timing belt24can be detached from the attachment part87in the middle of the operation or after the operation.

On the other hand, the carriage5is made to face the maintenance unit50, the nozzle surface of the recording head4is covered with a cap (not shown) from below, and ink is selectively sucked from the nozzle for each color, or the restoring processing to remove bubbles in a not-shown buffer tank above the recording head4is performed. In that case, the carriage5is moved to the aligned position with the cap part of the maintenance unit50when viewed on a plane. When the cap is raised in this state, the carriage5is made not to be detached from both the guide members22and23. As an embodiment for that, inFIG. 5, the carriage5is moved rightward by Y3from the pair of notch parts57aof the first guide member22and the pair of notch parts57bof the second guide member23, and is stopped at the position. When a bent corner part at the place between the second guide member23and the vertical guide piece53at the transportation direction upstream side is slightly rounded in the side section, there is a fear that the tip end of the coming-out preventing pawl56bpasses through the bent corner part upward by the force when the carriage5is pressed upward. In order to prevent that, as shown inFIGS. 18A to 18C, an outer edge93of a horizontal piece of the second guide member23at the transportation direction upstream side is formed to be coincident with the outer surface of the guide piece53. By this, the rising tip edge of the coming-out preventing pawl56binterferes with the outer edge93of the horizontal piece of the second guide member23at the transportation direction upstream side, and detachment can be made impossible.

Besides, in the case where the recording head4is disposed to deviate rightward or leftward with respect to the barycentric position of the carriage5in the Y-axis direction (right and left direction), when the recording head4is pressed up from below so that the cap covers the recording head, the moment to rotate the carriage5in the right or left direction is exerted thereon. Also at such a state, in order to prevent the carriage5from detaching from both the guide members22and23, the pair of coming-out preventing pawls56aand56bare disposed at side parts (positions significantly spaced apart from each other at both sides of the barycentric position of the carriage5in the Y-axis direction (right and left direction)) of the carriage5in the right and left direction of the recording head4when viewed on a plane, so that it is possible to certainly prevent only one side of the carriage5from detaching from both the guide members22and23.

When material for formation of at least one of or all of the sliding surfaces of the first sliding convex parts55aand55b, the second sliding convex parts56aand56band the third sliding convex part82is made a material (synthetic resin such as nylon) having a small friction coefficient or wear resistance, after the base parts of these sliding convex parts are primarily molded (injection molded) integrally with the holder case61requested to have strength, a material having a small friction coefficient or wear resistance is secondarily molded (outsert molded) for the parts to form the sliding surfaces of the sliding convex parts, so that a product can be easily formed of two kinds of materials to satisfy different design requests.

As described above, in the image recording apparatus1, one guide member of the first guide member22and the second guide member23includes a second sliding surface54provided to stand substantially orthogonally to the first sliding surface51,52, and the carriage5includes a second sliding convex part which comes in contact with the second sliding surface and is slidable, and an elastic member to elastically urge a third sliding convex part, which is opposite to the second sliding convex part across the second sliding surface, toward a direction of the second sliding surface.

Thus, it is possible to certainly ensure that the carriage5mounted on both the guide members22,23is linearly moved along the second sliding surface.

In the image recording apparatus1, ink is supplied from an ink storage part provided at a stationary position of a main body of the image recording apparatus through a flexible ink supply tube connected to the carriage5, and the second guide member23close to a place where the ink supply tube is coupled to the carriage includes the second sliding surface.

Accordingly, since the one guide member on which an influence of the connection of the ink supply tube to the carriage is easily exerted is provided with the second sliding surface54, there is obtained an effect that the contact state of the second sliding convex part to the second sliding surface can be ensured.

Further, the coming-out preventing pawl is disposed outside of a recording range of the recording head with respect to the recording medium P.

Therefore, the operation position where the carriage5is detached from both the guide members is made close to the standby position of the carriage, and the movement distance of the carriage5can be made small.

Also, the carriage5includes an adjustment unit to adjust a protrusion amount of the second sliding convex part.

Thus, there is obtained an effect that the adjustment of the posture of the carriage5to optimize the picture quality of recording can be carried out in the state where the carriage is fitted to both the guide members22,23, and the adjustment operation becomes easy.

In addition, the sliding surface of at least one of the first and second sliding convex parts includes a concave groove58for holding lubricating grease.

Therefore, there is obtained an effect that the friction resistance of the guide member to the sliding surface can be decreased, the occurrence of an abnormal sound and the consumption energy for movement of the carriage can be reduced, and the carriage5can be lightly slid while it does not apply a forcible force to the guide member.

Further, the first sliding convex parts are disposed at respective apexes of a triangle extending over the first and second guide members22,23.

Since the carriage is supported on both the guide members22,23through the so-called three-point support, there is obtained an effect that the posture of the carriage5can be stabilized.

Additionally, when the carriage5comes in slide contact with the first and second guide members22,23, the coming-out preventing pawl is out of contact with the first and second guide members.

Since the coming-out preventing pawl is out of contact with both the guide members22,23at the time of the movement of the carriage, there is obtained an effect that a forcible force is not applied to the guide members, and the carriage5can be slid further lightly.

Also, the coming-out preventing pawl is disposed at a position where the coming-out preventing pawl can come in contact with the first and second guide members22,23when the carriage5receives an external force from a surface side of the recording head.

Therefore, even if an external force is applied to the recording head at the time of a maintenance operation, there is no such fear that the carriage5is tilted, and there is obtained an effect that the maintenance operation can be carried out without fail.

Further, the sliding surfaces of the first and second sliding convex parts are formed to be convex curved surfaces in the main scanning direction of the carriage5.

Thus, the first and second sliding convex parts come in line contact with the first and second sliding surfaces, and the carriage5can be lightly moved. Further, even when the protrusion amount of the one second sliding convex part is changed and the posture of the carriage is adjusted, the two second sliding convex parts can come in contact with the second sliding surface without fail, and there is obtained an effect that the posture adjustment of the carriage5can be accurately performed.

In the image recording apparatus1, after the carriage5is primarily molded of synthetic resin material, portions where the sliding surfaces of the first and second sliding convex parts are formed are outsert-molded.

Therefore, it is possible to easily select materials which meet design requirements for the strength of the carriage5itself, deformation prevention and the like, and different demands for wear resistance requested in the sliding convex part, small friction coefficient and the like, and there is obtained an effect that the durability of the carriage is improved, and the improvement of the quality of the image recording apparatus can be easily attained.

Also, the sliding surfaces of the first and second sliding convex parts of the carriage are set to act as a reference of a nozzle surface at a time when the recording head is fitted to the carriage5, as a frame reference, and as a reference at a time of scanning.

Since the reference position or the reference surface having a direct influence on the quality of image recording can be regulated by the first and second sliding convex parts provided on the carriage, there is obtained an effect that the assembly of the image recording apparatus1can be improved and simplified.

Also, an attachment position of a belt to move the carriage5in the main scanning direction is set to be higher than a height position of both ends of the belt in the main scanning direction.

When the carriage5is moved in the main scanning direction, it is possible to certainly prevent the carriage from floating above both the guide members, and there is obtained an effect that the quality of a recording image can be kept constant.

In the image recording apparatus1, at least the two coming-out preventing pawls are disposed to be spaced suitably apart from each other along the main scanning direction of the carriage, and the notch parts whose number and arrangement interval are equal to the number and the arrangement interval of the coming-out preventing pawls are provided in the first and second guide members22,23so that when the carriage5is detached in the direction crossing the main scanning direction, all the coming-out preventing pawls can be simultaneously detached from the first and second guide members.

Since at least the two coming-out preventing pawls prevent the carriage5from floating relative to the main scanning direction of the respective guide members22,23, the posture of the carriage is not carelessly changed, and especially, even if an external force is applied from below at the time of maintenance, there does not occur such a disadvantage that the carriage is tilted. Besides, when the carriage is detached from both the guide members, the detachment of the carriage5and the mounting posture can be regulated so that all the coming-out preventing pawls come out from all the notch parts at the same time, and it is possible to certainly prevent the respective parts of the image recording apparatus from being carelessly damaged or broken at the time of an exchange operation of the carriage.

Further, a closing member to prevent the coming-out preventing pawl from coming off in a detaching direction of the carriage5is detachably attached to at least one of the notch parts.

Thus, the carriage5does not carelessly detach from the guide member at the normal operation time other than the exchange operation of the carriage.

Also, an encoder strip long along the movement direction of the carriage5is disposed such that its detected surface is parallel to the second sliding surface of the second guide member, the respective notch parts of the second guide member are formed to lie astride the first sliding surface and the second sliding surface, and the coming-out preventing pawl is set to be positioned at a height position of the notch part on a side of the second sliding surface at a time when the carriage moves in the detaching direction and in a state where the encoder strip comes out of the carriage5.

Since the exchange operation of the carriage5can be carried out without detaching the encoder strip, there is obtained an effect that the operation can be easily performed. Besides, since the encoder strip is not detached, a subsequent adjustment operation of a movement position of the carriage becomes unnecessary.

Furthermore, a detachable/attachable lid cover body is provided on an upper surface of the carriage5, and the lid cover body includes, at a place different from the coming-out preventing pawl, a blocking pawl to prevent the lid cover body from detaching from one guide member of the first and second guide members at a time when the carriage is moved in a detaching direction.

Thus, the lid cover body has a function to press the upper side of the flexible flat cable, the carriage cannot be detached/attached at the position where the lid cover can be detached/attached, and the lid cover body cannot be detached/attached at the position where the carriage can be detached/attached. Thus, there is obtained an effect that it is possible to prevent the carriage5from being easily detached/attached from/to the guide member.