JP2012192619A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a suction failure that is caused by buckling and bending of a discharge tube from a suction means, when configured to move a suction means of a maintenance recovery mechanism.SOLUTION: A suction cap 31 and suction pump 37 are mounted on a slide frame 202. The slide frame 202 is reciprocatably arranged between a retreat position where the suction cap 31 is not faced to the recording head 34 and the facing position where the suction cap 31 is faced to the recording head 34. The slide frame 202 has a winding member 231, which is rotatably arranged, and in which the discharge tube 38 from the suction pump 37 is wound around.

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus having a carriage on which image forming means is mounted.

  As an image forming apparatus such as a printer, a facsimile, a copying machine, a plotter, or a complex machine of these, for example, a liquid discharge recording type image forming using a recording head composed of a liquid discharge head (droplet discharge head) that discharges ink droplets. As an apparatus, an ink jet recording apparatus or the like is known. This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a medium). “Ink” is not limited to ink, but is used as a general term for all liquids capable of image formation, such as recording liquid, fixing processing liquid, and liquid. DNA samples, resists, pattern materials, resins and the like are also included. In addition, the “image” is not limited to a planar image, and includes an image given to a three-dimensionally formed image and an image formed by three-dimensionally modeling a solid itself.

  Such a liquid discharge type image forming apparatus includes a maintenance / recovery mechanism for maintaining and recovering the ejection stability of the nozzles of the recording head. The maintenance / recovery mechanism, for example, is a suction cap for capping the nozzle surface to suck and discharge liquid from the nozzle, drying ink in the nozzle, a moisture retention cap for preventing dust from entering the nozzle, and wiping the nozzle surface of the recording head A maintenance / recovery mechanism including a wiper member (also referred to as a wiper blade, a wiping blade, a blade, etc.) that is cleaned by, for example, discharging the thickened ink from the nozzle into the suction cap, and then wiping the nozzle surface. The recovery operation of forming a nozzle meniscus by wiping with a member is performed.

  As a conventional maintenance / recovery mechanism, for example, the recording head is moved to a recovery position facing the suction cap of the maintenance / recovery mechanism to perform a recovery operation, and the entire maintenance / recovery mechanism including the suction cap and the wiper member is moved to move the wiper member. Is known in which the nozzle surface of the recording head at the recovery position is wiped off (Patent Document 1).

JP 2001-212969 A

  By the way, in the maintenance and recovery mechanism described above, a suction means such as a suction pump is connected to the suction cap, and the waste liquid discharged into the suction cap is sucked by a suction means such as a tube pump to accommodate the waste liquid on the apparatus main body side. A member (waste liquid tank) is discharged through a discharge tube made of a flexible tube.

  For this reason, when the maintenance / recovery mechanism itself is movably disposed as described above, a part of the discharge tube downstream of the suction pump cannot be fixed or guided, and as a result, the discharge tube is moved when the maintenance / recovery mechanism is moved. There is a problem that buckling occurs, or the discharge tube is slackened, and is sucked into surrounding parts to cause a suction failure during capping. In this case, if it is attempted to increase the curvature by lengthening the discharge tube in order to prevent buckling, there is a problem that the cost of parts increases and the apparatus becomes large.

  The present invention has been made in view of the above problems, and an object of the present invention is to reduce the occurrence of suction failure by reducing buckling or slack of the discharge tube when a movable maintenance / recovery mechanism is provided.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A recording head having nozzles for discharging droplets;
A maintenance and recovery mechanism for maintaining and recovering the state of the recording head,
The maintenance and recovery mechanism is at least
A suction cap for capping the nozzle surface of the recording head;
A suction means for sucking a sealed space formed in a state where the nozzle surface is capped with the suction cap; and
The suction means is connected to the waste liquid storage means of the apparatus body via a flexible tube,
The suction cap and the suction means are mounted on a slide member,
The slide member is disposed so as to be capable of reciprocating between a retracted position where the suction cap does not face the recording head and an opposing position where the suction cap faces the recording head,
The slide member is configured to be rotatably provided with a winding member around which the tube is wound.

  Here, the winding member can be configured to be tapered in the axial direction.

  Moreover, it can be set as the structure by which the partition part was formed in the outer peripheral surface of the said winding member helically.

  Moreover, it can be set as the structure provided with the urging means which urges | biases the said tube toward the outer peripheral surface of the said winding member.

  Further, the winding member can be configured to be provided on the slide member so as to be movable in the axial direction of the winding member.

  Moreover, it can be set as the structure by which the member which reduces friction is provided between the said winding-up member and the said tube.

  According to the image forming apparatus of the present invention, the suction cap and the suction unit are mounted on the slide member, and the slide member has a retracted position where the suction cap does not face the recording head, and a facing position where the suction cap faces the recording head. Since the slide member is rotatably provided with a winding member around which the tube is wound, the slide member is provided with a movable maintenance / recovery mechanism. The occurrence of poor suction can be suppressed by reducing buckling and slack.

FIG. 3 is a plan view of a main part of a mechanism unit of the image forming apparatus according to the present invention. It is principal part front explanatory drawing of the mechanism part. It is a plane explanatory view when the suction cap of the maintenance recovery mechanism in a 1st embodiment of the present invention exists in a retreat position. It is a plane explanatory view when a suction cap exists in a counter position similarly. It is front explanatory drawing with which it uses for description of a winding means. It is explanatory drawing with which it uses for description of the absorption action of the tube slack at the time of the slide by a winding means. It is front explanatory drawing with which it uses for description of 2nd Embodiment of this invention. It is front sectional explanatory drawing with which it uses for description of the winding means of 3rd Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. An example of an image forming apparatus to which the present invention is applied will be described with reference to FIGS. FIG. 1 is an explanatory plan view of the main part of the mechanism of the image forming apparatus, and FIG. 2 is an explanatory front view of the main part of the mechanism.

  This image forming apparatus is a serial type image forming apparatus, and a main scanning rod 5 is slidably held by a main guide rod 1 and a sub guide member (not shown) horizontally mounted between left and right side plates 100L and 100R. Thus, moving scanning is performed in the main scanning direction via the timing belt 8 passed between the driving pulley 6 and the driven pulley 7.

  The carriage 3 has recording heads 4y, 4m, 4c, 4k (distinguishable) composed of liquid ejection heads for ejecting ink droplets of each color of yellow (Y), magenta (M), cyan (C), and black (K). If not, it is referred to as “recording head 4”.) A nozzle row composed of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ink droplet ejection direction facing downward.

  On the other hand, in order to transport the paper, a transport belt 12 is provided as a transport means for electrostatically attracting the paper and transporting the paper at a position facing the recording head 4. The transport belt 12 is an endless belt, is configured to wrap around the transport roller 13 and the tension roller 14 and circulate in the belt transport direction (sub-scanning direction). 15 is charged (charged).

  Further, the conveyance belt 12 rotates in the sub-scanning direction when the conveyance roller 13 is rotationally driven by the sub-scanning motor 16 via the timing belt 17 and the timing pulley 18.

  Further, a maintenance / recovery mechanism 20 that performs maintenance / recovery of the recording head 4 on the side of the conveyance belt 12 is arranged on one side of the carriage 3 in the main scanning direction, and the recording head 4 is arranged on the side of the conveyance belt 12 on the other side. The empty discharge receptacles 21 for performing empty discharge are respectively disposed.

  The maintenance / recovery mechanism 20 includes, for example, a suction cap 31 and a moisture retaining cap 32 that also serve as a moisture retaining cap for capping the nozzle surface (the surface on which the nozzle is formed) of the recording head 4, a wiper member 33 that wipes the nozzle surface, and an image. An empty discharge receptacle 34 for receiving droplets (empty discharge droplets) that do not contribute to formation is provided.

  An encoder scale 23 having a predetermined pattern (also referred to as a position identification portion, a scale, a slit, etc., hereinafter referred to as “slit”) is stretched between both side plates along the main scanning direction of the carriage 3, and the carriage 23 is provided with an encoder sensor 24 composed of a transmissive photosensor that reads the slit of the encoder scale 23, and the encoder scale 23 and the encoder sensor 24 constitute a linear encoder (main scanning encoder) 27 that detects the movement of the carriage 23. ing.

  Further, an encoder scale (code wheel) 25 is attached to the shaft of the transport roller 13, and an encoder sensor 26 composed of a transmission type photosensor for detecting a pattern (slit) formed on the encoder scale 25 is provided. 25 and the encoder sensor 26 constitute a rotary encoder (sub-scanning encoder) 28 for detecting the moving amount and moving position of the conveyor belt 12.

  In this image forming apparatus configured as described above, the sheet 10 is fed from the sheet feeding tray (not shown) onto the charged conveying belt 12 and sucked, and the sheet 10 is moved in the sub-scanning direction by the circular movement of the conveying belt 12. Be transported. Therefore, by driving the recording head 4 according to the image signal while moving the carriage 3 in the main scanning direction, ink droplets are ejected onto the stopped paper 10 to record one line, and the paper 10 is placed in place. After the quantitative transport, record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 10 has reached the recording area, the recording operation is finished and the paper 10 is discharged onto the paper discharge tray 103.

Next, details of the maintenance and recovery mechanism 20 according to the first embodiment of the present invention will be described with reference to FIGS. 3 is an explanatory plan view when the suction cap of the maintenance / recovery mechanism is in the retracted position, and FIG. 4 is an explanatory plan view when the suction cap is also in the facing position.
In the maintenance / recovery mechanism 20, a slide frame 202, which is a slide member, is disposed on a maintenance frame 201 so as to be movable in the sub-scanning direction. On the slide frame 202, a suction pump 37 including a suction cap 31, a wiper member 33, an empty discharge receptacle 34 including a wiper cleaner 36, a wiper cleaner 35, a tubing pump as suction means connected to the suction cap 31, and the like. And a discharge tube 38 made of a flexible tube of the suction pump 37 is connected to a waste liquid storage container (waste liquid tank) (not shown) on the apparatus main body side.

  Then, the slide frame 202 is moved along the guide rail 203 disposed in the sub-scanning direction on the maintenance frame 201 and the retraction position shown in FIG. It is moved between the facing positions shown in FIG. 4 facing (possibly facing) the head 4. The suction cap 31 is held by the cap holder and advanced / retracted (in this example, moved up and down) by the advance / retreat mechanism, and the wiper member 33 is held by the wiper holder and advanced / retreated (in this example, moved up / down).

  In addition, three moisturizing caps 32 are mounted on the maintenance frame 201. The moisturizing cap 32 is held by the cap holder and is advanced and retracted (in this example, moved up and down) by the advance and retract mechanism.

  The movement of the slide frame 202 and the forward / backward movement (lifting / lowering operation) of the moisturizing cap 32 are performed by forward / reverse rotation of the motor 210 and switching of driving using two one-way clutches. Here, the movement of the slide frame 202 and the raising / lowering operation of the cap 32 convert the rotational motion into the horizontal motion using the eccentric cams 211a and 211b and the arms 212a and 212, respectively.

  Further, the advancing and retreating of the suction cap 31 (in this example, raising and lowering) and the driving of the suction pump 37 are also performed by forward / reverse rotation of the motor 220 and switching of driving using a one-way clutch.

  Therefore, when the recovery operation of the recording head 4 is performed, the recording head 4 that performs the recovery operation is moved to a position where it can be capped by the suction cap 31 (opposite position) in the main scanning direction, and the slide frame 202 is recorded from the retracted position. After moving to a position facing the head 34, the suction cap 31 is raised to cap the nozzle surface of the recording head 4.

  The slide frame 202 is rotatably provided with a winding means 230 around which the discharge tube 38 is wound, so that the winding amount of the winding means 230 changes according to the movement of the slide frame 202. .

Next, details of the winding means will be described with reference to FIG. FIG. 5 is an explanatory front view for explaining the winding means.
As described above, the guide rail 203 is disposed on the maintenance frame 201 in the sub-scanning direction, the slide frame 202 is slidably engaged with the guide rail 203, and the slide frame 202 slides relative to the maintenance frame 201. To do. The slide frame 202 is driven (moved) by converting the rotational movement of the motor 210 into a linear reciprocating movement by the eccentric cam 211a and the arm (lever) 212a. However, the motor rotation switching control by the rack and pinion and the sensor is used. It can also be made to reciprocate.

  One end of a winding member 231 constituting the tube winding means 230 is rotatably mounted on the slide frame 202 by a snap fit 232. At the other end of the winding member 231, a pinion gear 234 that meshes with a rack gear 233 arranged in the sub-scanning direction on the maintenance frame 201 is provided. Accordingly, the winding member 231 rotates in conjunction with the slide frame 202 reciprocating relative to the maintenance frame 201.

  The winding member 231 has a spiral partition portion 242 formed on the outer peripheral surface of a tapered portion 241 that is tapered in the axial direction. A discharge tube 38 that is a flexible tube extending from the outlet of the suction pump 37 is wound around the outer peripheral surface of the tapered portion 241 along the spiral partition portion 242.

  Further, an elastic member 244 is wound around the outer periphery of the discharge tube 38 around the discharge tube 38 around which the winding member 231 is wound. Yes.

Next, the absorption action of the tube slack at the time of sliding by the winding means configured as described above will be described with reference to FIG.
First, FIG. 8A shows a winding state when the slide frame 202 is in the retracted position, and FIG. 8B shows a winding state when the slide frame 202 is moved to the facing position. The slide frame 202 moves from the retracted position to the facing position by a distance (sliding amount) ΔL. At this time, the deflection ΔL of the discharge tube 38 due to the slide amount has a relationship of approximately ΔL = πD2−πD1 with respect to the winding diameters D1 and D2 of the winding member 231 before and after the slide. Absorbs slack.

  Further, since the discharge tube 38 is biased inward by the elastic member 244, even if the winding member 231 rotates in the direction of loosening the discharge tube 38, the discharge tube 38 is guided to the spiral partition 242 and tapered. It will be loosened uniformly along the outer peripheral shape of 241, and it is possible to reliably prevent the slackness from concentrating at one place and causing problems such as buckling in the discharge tube 38.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 7 is an explanatory front view for explaining the embodiment.
In the present embodiment, a shaft member 251 whose outer peripheral surface is threaded is extended on the slide frame 202 in the main scanning direction, and a winding member 231 having a threaded hole is supported on the shaft member 251. Yes.

  With this configuration, when the slide frame 202 slides and the winding member 231 rotates in the winding and loosening direction of the discharge tube 38, the winding member 231 moves in the thrust direction (axial direction of the rotation shaft). The amount of movement in the thrust direction when the winding diameter of the discharge tube 38 changes is offset.

  Thereby, the deviation of the tube outlet and the inlet position in the thrust direction before and after the slide of the slide frame 202 can be suppressed, and buckling and deflection of the discharge tube can be more stably prevented.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 8 is an explanatory front sectional view for explaining the winding means of the embodiment.
In the present embodiment, a sheet member 261 having a low friction coefficient is sandwiched between the outer peripheral surface of the winding member 231 and the discharge tube 38.

  With this configuration, when the winding member 231 rotates, the discharge tube 38 can move along with the spiral partitioning portion 242 together with the sheet material 261, and the winding member 231 can be rotated. Torque can be reduced, stable winding can be performed, and durability is improved.

  In the above embodiment, the present invention has been described with reference to an example in which the present invention is applied to a serial type image forming apparatus. However, the present invention can also be applied to a line type image forming apparatus.

DESCRIPTION OF SYMBOLS 1 Guide rod 3 Carriage 4, 4k, 4c, 4m, 4y Recording head 5 Main scanning motor 16 Sub scanning motor 20 Maintenance recovery mechanism 31 Suction cap 32 Moisturizing cap 33 Wiper member 34 Empty discharge receptacle 37 Suction pump 38 Ejection tube 201 Maintenance frame 202 Slide frame 203 Guide rail 230 Winding means 231 Winding member 241 Taper 242 Spiral partition 244 Elastic member

Claims (6)

A recording head having nozzles for discharging droplets;
A maintenance and recovery mechanism for maintaining and recovering the state of the recording head,
The maintenance and recovery mechanism is at least
A suction cap for capping the nozzle surface of the recording head;
A suction means for sucking a sealed space formed in a state where the nozzle surface is capped with the suction cap; and
The suction means is connected to the waste liquid storage means of the apparatus body via a flexible tube,
The suction cap and the suction means are mounted on a slide member,
The slide member is disposed so as to be capable of reciprocating between a retracted position where the suction cap does not face the recording head and an opposing position where the suction cap faces the recording head,
The image forming apparatus, wherein the slide member is rotatably provided with a winding member around which the tube is wound.   The image forming apparatus according to claim 1, wherein the winding member is tapered in the axial direction.   The image forming apparatus according to claim 1, wherein a partition portion is spirally formed on an outer peripheral surface of the winding member.   The image forming apparatus according to claim 1, further comprising an urging unit that urges the tube toward an outer peripheral surface of the winding member.   The image forming apparatus according to claim 1, wherein the winding member is provided on the slide member so as to be movable in an axial direction of the winding member.   The image forming apparatus according to claim 1, wherein a member that reduces friction is provided between the winding member and the tube.

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