JP3870318B2 - Inkjet image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ink jet image forming apparatus such as an ink jet printer.
[0002]
[Prior art]
For example, in a color inkjet printer, recording paper is conveyed in the sub-scanning direction, and a carriage having a plurality of print heads reciprocates in the main scanning direction (width direction of the recording paper), thereby printing an image on the recording paper. (Recording) is to be made. In order to perform maintenance such as cleaning of the print head, a maintenance unit having a cap that covers the print head of the carriage is provided at a predetermined maintenance position outside the range of reciprocation of the carriage during printing. Normally, the maintenance unit is arranged to move up and down below the carriage that has moved to the maintenance position. When the carriage moves, the maintenance unit moves downward and the carriage moves to the maintenance position. When stopped, the cap moves upward and the cap covers the print head.
[0003]
As such a maintenance unit, a cap that covers all the print heads of the carriage is provided, and the cap is connected to a suction pump for cleaning the nozzles of the print head, and the print heads of the carriage one by one. Some caps have the same number of caps as the print heads to cover, and each cap is connected to a suction pump.
[0004]
[Problems to be solved by the invention]
In the former case, since all the print heads are covered with a single cap to clean the nozzles, if the suction pump is operated, ink is also sucked from the nozzles of the print heads that do not require suction, and the ink is wasted. There's a problem.
[0005]
In the latter case, since it is necessary to connect all of the plurality of caps to the suction pump, the structure becomes complicated and the required space increases.
[0006]
In order to solve such a problem, the same number of caps as the carriage print heads are provided, one of which is a cleaning cap that covers one print head, and only that is connected to the suction pump. It is conceivable to perform cleaning by covering each print head in turn with a cleaning cap by moving in the main scanning direction.
[0007]
However, in this case, there is a need for a separate means for moving the maintenance unit in the main scanning direction, and there is a problem that the cap and the print head come into contact when the maintenance unit moves.
[0008]
The object of the present invention is to solve the above-mentioned problems, and to securely cover the print head with the cap, without sucking ink from the print head that does not need to be sucked, the structure of the maintenance unit is simple, and a large space It is an object of the present invention to provide an ink jet image forming apparatus that does not require the above.
[0009]
[Means for Solving the Problems and Effects of the Invention]
  An ink jet image forming apparatus according to the present invention includes a carriage that has a plurality of print heads and moves in the main scanning direction, and a maintenance unit that has a plurality of caps that cover the print head portion of the carriage at the maintenance position.One of the caps of the maintenance unit is a cleaning cap that is connected to a suction pump for cleaning the nozzles of the print head and covers one print headIn an inkjet image forming apparatus, a carriageEach print head positionA positioning recess is formed on the cap, and a positioning projection is formed on the cap to engage the positioning recess.The maintenance unit has a cap support that is fixed at a predetermined cleaning position with respect to the housing at least at the time of nozzle cleaning and capping other than during nozzle cleaning, and a direction in which the maintenance unit approaches and separates from the print head of the carriage. A plurality of caps attached to the cap support so as to move and urged in a direction approaching the print head by an elastic member, and the positioning concave portion and the positioning convex portion are engaged to hold the print head with the cap. When the carriage is moved by the pitch of the print head with respect to the cap support fixed at the cleaning position in the covered state, the cap is pushed by the carriage and moved away from the print head due to the movement of the carriage. When the carriage stops, the cap returns to the direction of approaching the print head by the elastic force of the elastic member. The positioning concave portion and the positioning convex portion are engaged so that the cap covers the print head. In the maintenance position, the carriage is attached to the cap support fixed to the cleaning position. Each print head is covered with a cleaning cap in order to perform cleaning by moving it by the pitch.It is characterized by this.
[0010]
  Normally, the maintenance unit is disposed below the carriage that has moved to the maintenance position. The entire maintenance unit can move in the vertical direction, and the positioning concave portion and the positioning convex portion may be engaged by moving the maintenance unit upward. The maintenance unit does not move up and down.,When the carriage has moved to the maintenance position, the cap is pushed downward by the carriage and moved downward. When the carriage stops at a predetermined position, the cap returns to the upper position due to the biasing force of the elastic member. And the positioning convex portion may be engaged with each other.
[0011]
According to the ink jet image forming apparatus of the present invention, the positioning concave portion of the carriage and the positioning convex portion of the cap engage with each other, so that the cap is accurately positioned with respect to the carriage and the print head is reliably secured with the cap. Can be covered.
[0013]
  Also,Only one of the plurality of caps may be connected to the suction pump as a cleaning cap, the structure of the maintenance unit is simple, and a large space is not required. In addition, since the cleaning cap covers one print head, even if the suction pump is operated for cleaning, ink is not sucked from the print head that does not require suction, and the ink is wasted. There is nothing.
[0018]
  The cap support of the maintenance unit may always be fixed at the cleaning position or when cleaning the nozzle.And capping except during nozzle cleaningIt may be fixed in the cleaning position only occasionally.
[0019]
In this case, since the cap support is fixed at the cleaning position at the time of nozzle cleaning, even if the carriage moves, the cap support and the cap supported thereby do not move together. When the carriage is moved by the pitch of the print head with the cap support fixed at the cleaning position and covering the print head with the cleaning cap, the cap is pushed by the carriage by the movement of the carriage. When the carriage stops and the carriage stops, the cap returns to the upper position due to the urging force of the elastic member, and the positioning recess of the carriage engages with the positioning protrusion of the cap. Cover the head.
[0020]
  The present inventionAccording toWith the cap support fixed to the cleaning position with respect to the housing,CarriageFor each print head pitch relative to the cap supportAll the print heads can be moved with one cleaning cap just by moving it.In orderThe print head can be cleaned by covering.
[0021]
  The present inventionIn the inkjet image forming apparatus, for example, when the maintenance unit is cleaning the nozzleWhen capping other than nozzle cleaningOnly a cap means is provided for locking the cap support in the cleaning position.
[0022]
  In this case, cleaning the nozzleAnd cappingWhen not performing, the cap support body of the maintenance unit can be located at a position other than the cleaning position.
[0023]
  According to this, cleaning the nozzleAnd cappingWhen the operation is not performed, the cap support of the maintenance unit can be positioned at a position other than the cleaning position so that the movement of the carriage is not hindered.
[0024]
In the above-described ink jet image forming apparatus, for example, when the carriage moves to the extreme position of the maintenance position, the lock unit fixes the cap support in the cleaning position, and the carriage moves in the reverse direction until the cap is removed from the print head. By moving, the locking means releases the cap support.
[0025]
  According to this, the lock means can be operated or the operation of the lock means can be released by the movement of the carriage, and an extra mechanism for that is unnecessary.
  In the above-described ink jet image forming apparatus, for example,The maintenance position is provided on the right side in the main scanning direction, the right side of the maintenance position is the extreme position, the maintenance unit is arranged below the carriage that has moved to the maintenance position, and the carriage support is on the lower left side Is supported by the housing so as to be able to move diagonally between the standby position and the upper right position, and is biased diagonally to the left by an elastic member, and the locking means is located on the right side of the maintenance position. A lock arm that is fixed to the body, extends to the left, and protrudes upward at the left end, and a cap that extends in the left-right direction and the left and right ends turn up and down. The locking hook portion that is attached to the support body and is urged by the elastic member so that the right end portion rotates downward is engageable with the locking hook portion of the lock arm. A lock lever formed at the left end of the lock release pressing portion that can be brought into contact with the carriage, and a stopper that contacts the lock lever and restricts the rotation of the lock lever. When it is located to the left of the maintenance position, the cap support is stopped at the standby position,
  When the carriage moves to the right, the carriage hits the cap support with the print head of the carriage positioned above the corresponding cap, and the carriage further moves to the right, so that the carriage support is moved to the carriage. When moving to the right together with the cap, the cap positioning projection engages the carriage positioning recess, the cap covers the print head, and the carriage moves further to the extreme position. The lock hook part of the lock engages with the lock hook part of the lock arm, the cap support is fixed in the cleaning position, and the carriage is moved to the left with the cap support fixed in the cleaning position. The carriage moves away from the maintenance unit, and the carriage moves further to the left. The carriage hits the lock release part of the lock lever and pushes it down. As a result, the lock hook part of the lock lever pivots upward and disengages from the lock hook part of the lock arm. The cap support is released and returned to the standby position by the elastic force of the elastic member.
[0026]
  The present inventionIn the inkjet image forming apparatus, for example, the carriage includes three or more print heads, the maintenance unit includes the same number of caps as the carriage print head, and one cap covers one print head. Yes.
[0027]
According to this, each print head can be reliably covered one by one with the same number of caps as the print heads of the carriage.
[0028]
In the above-described ink jet image forming apparatus, for example, each cap is attached to the cap support so as to move individually.
[0029]
According to this, since each cap can be moved individually, the print head can be surely covered with each cap even if there is an error in attaching the cap to the cap support.
[0030]
In the above-described ink jet image forming apparatus, for example, a plurality of caps other than the cleaning cap are integrally formed.
[0031]
According to this, a plurality of caps formed integrally can be moved along a common guide and urged by a common elastic member, and the structure of the maintenance unit is simplified.
[0032]
  The present inventionIn the inkjet image forming apparatus, for example, the maintenance unit includes one cleaning cap that covers one print head and a cap that covers the remaining plurality of print heads.
[0033]
According to this, the number of caps is only two, the number of guides for guiding the caps and the number of elastic members for biasing the caps can be reduced, and the structure of the maintenance unit is simplified.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0035]
1 to 4 show a first embodiment. FIG. 1 is a perspective view showing the carriage (1) and the maintenance unit (2) in the vicinity of the maintenance position of the ink jet image forming apparatus, and FIGS. 2 and 3 show the carriage (1) and the maintenance unit (2) in the maintenance position. FIG. 4 is a front view showing two different states, and FIG. 4 is an explanatory view showing the operation during nozzle cleaning. In the following description, the downstream side (the front side of the paper surface in FIGS. 2 and 3) of the printing unit provided with the carriage (1) is the front side, and the upstream side (the back side of the paper surface in the figure) is the rear side. The left and right when looking from the front to the rear, that is, the left and right in FIGS.
[0036]
As shown in FIGS. 1 to 3, the printing unit of the image forming apparatus is provided with a guide bar (4) that is fixed to the housing (3) and extends in the left-right direction that is the main scanning direction. The carriage (1) is attached to the guide bar (4) and is moved in the left-right direction along the guide bar (4) by an appropriate driving means (not shown).
[0037]
The recording paper is conveyed in a portion with a predetermined printing width on the left side of the maintenance position shown in FIGS. 2 and 3, and when performing printing, the carriage (1) is reciprocated in the left-right direction. . In this example, in the reciprocating movement range of the carriage (1), the right outer portion of the print width portion is the maintenance position, and the maintenance unit is positioned below the carriage (1) at the maintenance position. (2) is arranged.
[0038]
On the lower surface of the carriage (1), a plurality (three in this example) of print heads (5a) (5b) (5c) are provided at equal pitches in the main scanning direction. The print heads are collectively referred to by reference numeral (5), and when it is necessary to distinguish them, the first print head (5a), the second print head (5b), and the second print head (5c) are called in order from the left one. I will decide. Although not shown in detail, each print head (5) is provided with a plurality of ink ejection nozzles. Further, arc-shaped positioning recesses (6a), (6b), and (6c) are provided before and after the position of each print head (5) of the carriage (1). The positioning recesses are collectively referred to by reference numeral (6), and when it is necessary to distinguish them, the first recess (6a), the second recess (6b), and the third recess (6c) are called in order from the left one. To do. A front overhanging portion (9) is integrally formed at the lower right end of the front surface of the carriage (1).
[0039]
The maintenance unit (2) corresponds to the cap support (7) and the recess (6) of the carriage (1), and the print head (7) attached to the support (7) at regular intervals in the main scanning direction. The number of caps (8a), (8b) and (8c) is the same as 5). The caps are collectively referred to by reference numeral (8), and when it is necessary to distinguish them, they are referred to as a first cap (8a), a second cap (8b), and a third cap (8c) in order from the left one.
[0040]
Although not shown in detail, the cap support (7) is supported by the housing (3) so that it can move in the left-right direction and the up-down direction while maintaining the same posture as shown in FIGS. ing. The support (7) includes a plate-like horizontal portion (10) that is long in the left-right direction, and a plate-like vertical portion (11) that rises vertically upward from the right end of the horizontal portion (10). Guide holes (12) extending diagonally from the lower left to the upper right are formed in the front and rear housing (3) portions of the support (7), and the horizontal (10) and vertical ( 11) The front and rear guide pins (13) fixed in a protruding manner on both front and rear sides near the boundary with 11) are fitted into the corresponding guide holes (12), and the support (7) is aligned with the guide holes (12). To move.
[0041]
  A support pin (14) protruding in the front-rear direction is fixed to the front surface of the lower portion of the vertical portion (11) of the support (7).Left and rightLock lever (15) extending in the directionrightThe side portion is pivotally attached to the support pin (14). Lock lever (15)rightAt the end, a locking hook part (16) protruding downward is formed integrally, and the locking lever (15)leftThe end protrudes upwardrightAn unlocking pressing portion (17) having an arcuate side is integrally formed. Further, a torsion coil spring (18), which is an elastic member that urges the lock lever (15) in the clockwise direction when viewed from the front, is attached to the support pin (14). On the right side of the support vertical part (11), there is a stopper (19) that contacts the lower surface of the lock lever (15) slightly to the right of the support pin (14) and holds the lock lever (15) in a substantially horizontal position. Is provided. Preferably, the support pin (14), the lock lever (15), the spring (18) and the stopper (19) in the maintenance unit (2) are provided symmetrically on the front and rear of the support (7), and in the carriage (1). The overhanging portion (9) is also provided symmetrically in the front-rear direction, but only the front side is shown in the drawing.
[0042]
The lock arm (20) that extends to the left side is fixed to the right case (3) of the maintenance unit (2), and the hook of the lock lever (15) is attached to the left end of the lock arm (20). A locking hook portion (21) protruding upward that engages with (16) is integrally formed.
[0043]
The lock lever (15), the spring (18), the stopper (19), and the lock arm (20) constitute lock means for fixing the support (7) to a cleaning position to be described later.
[0044]
Elasticity that biases the support (7) diagonally downward to the left between the lower surface of the horizontal part (10) of the support (7) of the maintenance unit (2) and the lower part of the housing (3) A tension coil spring (22) as a member is provided.
[0045]
Each cap (8) is integrally formed with a horizontal plate-like elevating member (23), and is supported so as to be individually movable up and down with respect to the support (7) as follows. Although not shown in detail, a rubber seal is provided on the upper end surface of each cap (8).
[0046]
Guide members (25) having guide holes (24) extending up and down are fixed in front of and behind three portions in the left-right direction of the support horizontal portion (10). The front and rear guide pins (26) are fixed to the front and rear end faces of the elevating member (23) constituting each cap (8), and the front and rear guide pins (26) of each cap (8) correspond to the front and rear. Each of the caps (24) can be moved up and down along the guide hole (24) by being fitted into the guide hole (24) of the guide member (25). A compression coil spring (27), which is an elastic member that urges the cap (8) upward, is provided between the lower surface of each cap (8) and the support horizontal portion (10) below the cap (8). Yes.
[0047]
The three caps (8) are arranged at the same pitch as the print head (5) in the left-right direction. Positioning convex portions (28a) (28b) (28c) corresponding to the positioning concave portions (6) of the carriage (1) are integrated with the front and rear end portions of the upper surface of the elevating member (23) constituting each cap (8). Is formed. The positioning convex portions are collectively referred to by reference numeral (28). When it is necessary to distinguish, the first convex portion (28a), the second convex portion (28b), and the first convex portion (28a) are arranged in order from the left first cap (8a). It will be called a 3rd convex part (28c).
[0048]
Of the three caps (8), the first cap (8a) on the leftmost side, that is, the print width portion side, is connected to a suction pump (29) for cleaning the print head (5), so that one It is a cleaning cap that covers the print head (5).
[0049]
A wiper (30) and a purge (31) are arranged in the left casing (3) of the maintenance unit (2).
[0050]
When the carriage (1) moves away from the maintenance unit (2) at the right end of the lower surface of the carriage (1), the lower right end of the carriage (1) is the left side of the cap (8a). A notch (33) is formed to prevent contact with the.
[0051]
Next, operations of the carriage (1) and the maintenance unit (2) during nozzle cleaning will be described mainly with reference to FIG.
[0052]
When printing is performed, as described above, the carriage (1) reciprocates the portion of the print width that is separated to the left from the maintenance unit (2). When the carriage (1) is thus separated from the maintenance unit (2), the guide of the cap support (7) is applied by the biasing force of the spring (22) as shown in FIGS. 2 and 4 (a). The pin (13) is positioned at the lower left end of the guide hole (12), and the support (7) is stopped at the standby position at the lowermost left end. At this time, due to the biasing force of the spring (27), the guide pin (26) of each cap (8) is positioned at the upper end of the guide hole (24), and each cap (8) is positioned at the upper end position. Further, the upper end of the positioning convex portion (28) in each cap (8) is located at a position lower than the lower surface of the carriage (1).
[0053]
When cleaning the nozzles, the carriage (1) moves from the print width portion to the rightmost maintenance position. When the carriage (1) moves to the right to some extent, the right end of the carriage (1) hits the support vertical part (11), but until then, the support (7) is located at the lowest standby position. The protruding portion (9) of the carriage (1) does not interfere with the pressing portion (17) of the lock lever (15).
[0054]
Even after the carriage (1) hits the support vertical part (11), the carriage (1) moves to the right together with the carriage (1), and the guide pin (13) is guided. By being guided by the hole (12), the support (7) moves vertically upward with respect to the carriage (1). When the support (7) moves to some extent upward with respect to the carriage (1), the projections (28) of the three caps (8) fit into the corresponding recesses (6) of the carriage (1), and the three caps (8) abuts on the lower surface of the carriage (1) by the biasing force of the spring (27) and completely covers the three print heads (5). When the carriage (1) further moves to the extreme right position, the guide pin (13) of the support (7) moves to the upper right end of the guide hole (12) as shown in FIGS. 3 and 4 (b). The support (7) moves to the uppermost rightmost cleaning position. Then, when the hook portion (16) of the lock lever (15) is engaged with the hook portion (21) of the lock arm (20), the support (7) is fixed at the cleaning position. At this time, as described above, the first cap (8a) is the first print head (5a), the second cap (8b) is the second print head (5b), and the third cap (8c) is the third print. Each head (5c) is covered.
[0055]
In this way, the pump (29) is operated with the three caps (8) covering the three print heads (5). Thereby, the nozzles of the first print head (5a) covered by the first cap (8a) connected to the pump (29) are cleaned.
[0056]
When the cleaning of the first print head (5a) is completed, the carriage (1) moves to the left by one pitch of the print head (5). Even if the carriage (1) moves to the left, the engagement of the lock lever (15) and the lock arm (20) is maintained by the biasing force of the spring (18), so the support (7) It is fixed in position and does not move with the carriage (1). Then, by moving only the carriage (1) to the left side, the convex portion (28) of each cap (8) is disengaged from the concave portion (6) of the print head (5) that has been engaged so far, and the carriage ( 1) The caps (8) are pushed downward to come into contact with portions other than the concave portion (6) on the lower surface, and are separated downward from the print head (5). Therefore, the print head (5) is not rubbed by the cap (8). When the carriage (1) moves and stops by one pitch of the print head (5), the cap (8) moves upward by the biasing force of the spring (27), and the convex portion (28) of the cap (8). Engages with the recess (6) of the print head (5), and as shown in FIG. 4 (c), the first cap (8a) is the second print head (5b) and the second cap (8b) is the second. Each of the three print heads (5c) is covered.
[0057]
By operating the pump (29) in a state where the two print heads (5b) and (5c) are covered with the two caps (8a) and (8b) in this way, the first cap (8a) is the same as described above. The nozzles of the second print head (5b) covered with are cleaned.
[0058]
When the cleaning of the second print head (5b) is completed, the carriage (1) further moves to the left by one pitch of the print head (5). As a result, the third print head (5c) is covered with the first cap (8a) as shown in FIG. Then, in this state, the pump (29) is operated to clean the nozzles of the third print head (5c).
[0059]
When the cleaning of the third print head (5c) is completed, the carriage (1) further moves to the left and leaves the maintenance unit (2).
[0060]
When the carriage (1) moves away from the maintenance unit (2), the overhang (9) of the carriage (1) is pressed against the lock lever (15) of the support (7) located at the upper cleaning position. The lock lever (15) is rotated counterclockwise when viewed from the front against the urging force of the spring (18) in order to hit the part (17) and push it down. As a result, the hook portion (16) of the lock lever (15) is disengaged from the hook portion (21) of the lock arm (20), and the support (7) is in the standby position at the lower left end by the biasing force of the spring (22). Move to.
[0061]
When the carriage (1) is in a standby state where printing is not being performed or the apparatus is not turned on, the carriage (1) stops at the extreme position on the right as shown in FIG. 4 (b). The support (7) of the maintenance unit (2) is fixed at the cleaning position, and the three caps (8) cover the three print heads (8).
[0062]
FIG. 5 is a perspective view corresponding to FIG. 1 showing the second embodiment.
[0063]
2nd Embodiment is the same as 1st Embodiment except the structure of the part of the cap mentioned later, In FIG. 5, the part corresponding to FIG. 1 is attached | subjected the same code | symbol.
[0064]
In the case of the second embodiment, the first cap (8a) is a cleaning cap having the same configuration as in the case of the first embodiment.
[0065]
The second cap (8b) and the third cap (8c) are integrally formed on one common horizontal plate-like lifting member (32). A pair of front and rear guides (25) and one spring (27) are provided for the elevating member (32), and the second cap (8b) and the third cap (8c) together with the elevating member (32). , Move up and down together. The elevating member (32) includes a pair of front and rear positioning protrusions (28b) corresponding to the second cap (8b) and a pair of front and rear positioning protrusions (28c) corresponding to the third cap (8c). And are integrally formed.
[0066]
Others are the same as those in the first embodiment.
[0067]
FIG. 6 is a perspective view corresponding to FIG. 1 showing the third embodiment.
[0068]
The third embodiment is also the same as the first embodiment except for the configuration of the cap portion described later. In FIG. 6, the same reference numerals are given to the portions corresponding to FIG.
[0069]
In the case of the third embodiment, the maintenance unit (2) is provided with two caps, that is, a first cap (8a) and a second cap (8d).
[0070]
The first cap (8a) is a cleaning cap having the same configuration as in the first and second embodiments.
[0071]
The second cap (8d) is formed integrally with a horizontal plate-like lifting member (33) similar to the lifting member (32) of the second embodiment. As in the case of the second embodiment, the elevating member (33) has a pair of front and rear second positioning projections (28b) and a pair of front and rear third positioning projections (28c) integrally formed. Is formed. The second cap (8d) has a size that covers the two print heads (5) simultaneously. When the carriage (1) moves to the extreme right position and the cap support (7) is fixed at the cleaning position, the second cap (8d) is moved to the second print head of the carriage (1). (5b) and the third print head (5c) are covered at the same time.
[0072]
Others are the same as those in the first embodiment.
[0073]
7 to 9 show a fourth embodiment. 7 and 8 are a perspective view and a front view showing the carriage (40) and the maintenance unit (41) in the vicinity of the maintenance position of the ink jet image forming apparatus, and FIG. 9 is an explanatory view showing the operation during nozzle cleaning. . 7 to 9 showing the fourth embodiment, portions corresponding to those in FIGS. 1 to 4 showing the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. .
[0074]
In the fourth embodiment, the overall configuration of the image forming apparatus is the same as that of the first embodiment. The carriage (40) is the same as that of the first embodiment except that the front overhanging portion (9) in the first embodiment is not formed.
[0075]
The maintenance unit (41) includes a carriage support (42) and three caps (8a) (8b) (8c) attached to the carriage support (42). The carriage support (42) has a horizontal plate shape, and its right end is fixed to the housing (3), and is always located at the cleaning position. The method of attaching the cap (8) to the carriage support (42) is the same as the method of attaching the cap (8) to the horizontal portion (10) of the cap support (7) in the first embodiment. The configuration of other parts of the maintenance unit (41) is the same as that in the first embodiment.
[0076]
In the case of the fourth embodiment, the notch (33) in the carriage (1) is such that the lower right end of the carriage (1) is a cap when the carriage (1) moves to the maintenance position and leaves the maintenance unit (2). It is provided to prevent contact with the left part of (8a).
[0077]
Next, operations of the carriage (40) and the maintenance unit (41) during nozzle cleaning will be described mainly with reference to FIG.
[0078]
When the carriage (40) is separated from the maintenance unit (41) to the left, such as during printing, as shown in FIGS. 7 and 9 (a), the biasing force of the spring (27) The guide pin (26) of each cap (8) is located at the upper end of the guide hole (24), and each cap (8) is located at the upper end position. At this time, the upper end of the positioning convex portion (28) in each cap (8) is located at the same height as or slightly higher than the upper end of the positioning concave portion (6) in the carriage (40). Yes. The upper surface of each cap (8) is positioned slightly higher than the lower surface of the carriage (40), and the upper surface of the elevating member (23) of each cap (8) is slightly higher than the lower surface of the carriage (40). Located in a low position.
[0079]
When cleaning the nozzles, the carriage (40) moves from the print width portion to the rightmost maintenance position. When the carriage (40) moves to the right side to some extent, the carriage (40) hits the positioning projection (28) of the cap (8) in order from the left, and thereafter the carriage (40) is as shown in FIG. Then, the cap (8) moves to the right while pushing downward against the urging force of the spring (27). Then, when the carriage (40) moves to the extreme position of the maintenance position, as shown in FIG. 9 (b), the three print heads (7) of the carriage (40) and the three caps of the maintenance unit (41) ( 8) The corresponding positions of the corresponding ones in the left-right direction coincide with each other, and the urging force of the spring (27) causes the convex portions (28) of the three caps (8) to correspond to the corresponding concave portions (6) of the carriage (40). The three caps (8) come into contact with the lower surface of the carriage (1) and completely cover the corresponding three print heads (5).
[0080]
In this way, the pump (29) is operated with the three caps (8) covering the three print heads (5). Thereby, the nozzles of the first print head (5a) covered by the first cap (8a) connected to the pump (29) are cleaned.
[0081]
When cleaning of the first print head (5a) is completed, the carriage (40) moves to the left by one pitch of the print head (5). As the carriage (40) moves to the left side, the convex portion (28) of each cap (8) is disengaged from the concave portion (6) of the print head (5) that has been engaged so far, and the lower surface of the carriage (1) The caps (8) are pushed down and separated from the print head (5) in order to come into contact with portions other than the recesses (6). Therefore, the print head (5) is not rubbed by the cap (8). When the carriage (40) moves by one pitch of the print head (5) and stops, the cap (8) moves upward by the biasing force of the spring (27), and the convex portion (28) of the cap (8). Engages with the recess (6) of the print head (5), and as shown in FIG. 9 (c), the first cap (8a) is the second print head (5b) and the second cap (8b) is the second. Each of the three print heads (5c) is covered.
[0082]
By operating the pump (29) in a state where the two print heads (5b) and (5c) are covered with the two caps (8a) and (8b) in this way, the first cap (8a) is the same as described above. The nozzles of the second print head (5b) covered with are cleaned.
[0083]
When the cleaning of the second print head (5b) is completed, the carriage (1) further moves to the left by one pitch of the print head (5). Accordingly, as described above, as shown in FIG. 9D, the third print head 5c is covered with the first cap 8a. Then, in this state, the pump (29) is operated to clean the nozzles of the third print head (5c).
[0084]
When the cleaning of the third print head (5c) is completed, the carriage (40) further moves to the left and leaves the maintenance unit (41). As described above, each time the carriage (40) moves to the left by one pitch of the print head (5) from the right extreme position, the cap (8) returns to the upper end position one by one from the right one, and the carriage ( When 40) moves away from the maintenance unit (41), all three caps (8) return to the upper end position.
[0085]
Also in the case of the fourth embodiment, when the carriage (40) is in a standby state where printing is not being performed and the apparatus is not turned on, the carriage (40) is positioned on the right side as shown in FIG. 9 (b). The three caps (8) cover the three print heads (8).
[0086]
In the case of the fourth embodiment, the cap support (42) is fixed to the housing (3), and the maintenance unit (41) is always fixed to the cleaning position. Therefore, as in the case of the first embodiment. A mechanism for supporting the cap support so that it can be moved vertically and horizontally and a mechanism for locking the cap support at the cleaning position are not required, and the structure of the maintenance unit is further simplified.
[0087]
Also in the fourth embodiment, the configuration of the cap covering the three print heads (5) can be the same as the second embodiment shown in FIG. 5 or the third embodiment shown in FIG. .
[Brief description of the drawings]
FIG. 1 is a perspective view of a carriage and a maintenance unit in an image forming apparatus showing a first embodiment of the present invention.
FIG. 2 is a front view of the carriage and maintenance unit portion of FIG. 1;
FIG. 3 is a front view corresponding to FIG. 2 and showing a state different from FIG. 2;
FIG. 4 is an explanatory diagram illustrating operations of a carriage and a maintenance unit during nozzle cleaning in the first embodiment.
FIG. 5 is a perspective view of portions of a carriage and a maintenance unit in an image forming apparatus showing a second embodiment of the present invention.
FIG. 6 is a perspective view of portions of a carriage and a maintenance unit in an image forming apparatus showing a third embodiment of the present invention.
FIG. 7 is a perspective view of portions of a carriage and a maintenance unit in an image forming apparatus showing a third embodiment of the present invention.
FIG. 8 is a front view of the carriage and maintenance unit portion of FIG. 7;
FIG. 9 is an explanatory diagram showing the operation of the carriage and the maintenance unit during nozzle cleaning in the fourth embodiment.
[Explanation of symbols]
(1) (40) Carriage
(2) (41) Maintenance unit
(5a) (5b) (5c) Print head
(6a) (6b) (6c) Positioning recess
(7) (42) Cap support
(8a) (8b) (8c) (8d) Cap
(15) Lock lever
(18) Spring
(19) Stopper
(20) Lock arm
(27) Spring
(28a) (28b) (28c) Positioning projection
(29) Suction pump

Claims (8)

A carriage that has a plurality of print heads and moves in the main scanning direction; and a maintenance unit that has a plurality of caps that cover the print head portion of the carriage at the maintenance position, and one of the plurality of caps of the maintenance unit includes : In an inkjet image forming apparatus that is a cleaning cap connected to a suction pump for cleaning the nozzles of a print head and covering one print head ,
A positioning recess is formed at each print head position of the carriage , and a positioning projection is formed on the cap to engage with the positioning recess .
The maintenance unit moves in a direction in which the cap support is fixed to a predetermined cleaning position with respect to the housing at the time of capping other than at the time of nozzle cleaning and nozzle cleaning, and a direction in which the carriage print head approaches / separates. A plurality of caps attached to the cap support and biased in the direction of approaching the print head by an elastic member,
When the positioning concave portion and the positioning convex portion are engaged and the print head is covered with the cap, the carriage is moved by the print head pitch relative to the cap support fixed at the cleaning position. The cap is pushed by the carriage to move away from the print head, and when the carriage stops, the cap returns to the direction approaching the print head due to the elastic force of the elastic member. The projection is engaged, and the cap covers the print head.
At the maintenance position, the carriage is moved by the pitch of the print head with respect to the cap support fixed at the cleaning position, so that each print head is covered with the cleaning cap in order for cleaning. An ink jet image forming apparatus. 2. The ink jet image forming apparatus according to claim 1 , wherein the maintenance unit includes a lock unit that fixes the cap support to the cleaning position only during nozzle cleaning and capping other than during nozzle cleaning . When the carriage moves to the extreme position of the maintenance position, the locking means fixes the cap support in the cleaning position, and the carriage moves in the reverse direction until the cap is removed from the print head, so that the locking means is the cap support. The inkjet image forming apparatus according to claim 2 , wherein the fixing of the ink jet is released. The maintenance position is provided on the right side in the main scanning direction, and the right side of the maintenance position is the extreme position.
The maintenance unit is located below the carriage that has moved to the maintenance position,
The carriage support is supported by the housing so as to be able to move diagonally between the lower left standby position and the upper right position, and is urged diagonally downward left by the elastic member,
The locking means
A lock arm fixed to the right housing part of the maintenance position, extending to the left side, and formed with a lock hook portion protruding upward at the left end;
  It is attached to the cap support so that the left and right ends turn in the up and down direction, and it is urged by the elastic member so that the right end turns down. A lock lever formed on the right end, and a lock release portion formed on the left end that can be brought into contact with the carriage;
A stopper that contacts the lock lever and regulates the rotation of the lock lever,
When the carriage is located to the left of the maintenance position, the cap support is stopped at the standby position,
When the carriage moves to the right, the cap that the carriage print head corresponds to When the carriage hits the cap support in the state of being positioned above, and the carriage further moves to the right, the carriage support moves to the right together with the carriage and moves upward, and the cap positioning protrusion The part engages with the positioning recess of the carriage, and the cap covers the print head,
When the carriage further moves to the extreme position, the lock hook portion of the lock lever engages with the lock hook portion of the lock arm, and the cap support is fixed at the cleaning position.
With the cap support fixed at the cleaning position, the carriage moves to the left, the carriage moves away from the maintenance unit, and the carriage moves further to the left, causing the carriage to unlock the lock lever. The lock hook part of the lock lever is pivoted upward and is released from the lock hook part of the lock arm, the lock of the cap support is released, and the cap support is released. 4. The ink jet image forming apparatus according to claim 3, wherein the ink jet image forming apparatus is returned to the standby position by the elastic force of the elastic member. The carriage includes three or more print heads, the maintenance unit includes the same number of caps as the carriage print head, and one cap covers one print head . 5. The inkjet image forming apparatus according to any one of 4 above. 6. The ink jet image forming apparatus according to claim 5 , wherein each cap is attached to the cap support so as to move individually. 6. The ink jet image forming apparatus according to claim 5 , wherein a plurality of caps other than the cleaning cap are integrally formed. The inkjet image according to any one of claims 1 to 4 , wherein the maintenance unit includes one cleaning cap that covers one print head and a cap that covers the remaining plurality of print heads. Forming equipment.

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