JP2015168077A - Image forming device and maintenance recovery unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that creep deformation of a member supporting a cap causes pressing force of the cap to decrease so that deterioration in image quality due to viscosity rise or the like occurs.SOLUTION: An image forming device comprises a slider member 302 that supports a cap 82 capping a nozzle face and is movably provided, and a lever member 400 that moves the slider member 302 between a capping position and a retreat position. The lever member 400 has a first arm 400a and a second arm 400b in a direction crossing the first arm 400a and is supported to be rotatable with an intersection point part of the first arm 400a and the second arm 400b as a rotation supporting point. A tip part of the first arm 400a is movably connected to the slider member 302, and the connection point thereof to the slider member 302 and the rotation supporting point are lined along a capping direction in a capping state.

Description

  The present invention relates to an image forming apparatus and a maintenance / recovery unit.

  As an image forming apparatus such as a printer, a facsimile, a copying apparatus, a plotter, and a complex machine of these, for example, a liquid discharge recording type image forming apparatus using a recording head composed of a liquid discharge head (droplet discharge head) for discharging droplets Inkjet recording apparatuses are known.

  Such an image forming apparatus includes a maintenance / recovery mechanism (maintenance / recovery unit) that maintains and recovers the state of the nozzles of the liquid discharge head serving as the recording head. This maintenance / recovery mechanism is known to include a cap for capping the nozzle surface of the head when the apparatus is not performing a printing operation to prevent dust from adhering and increasing the viscosity in the nozzle (Patent Document 1).

Japanese Patent No. 4663289

  By the way, in the conventional maintenance / recovery mechanism, the capping state is maintained by always pressing the cap against the nozzle surface of the head with a certain force with an elastic member such as a spring during non-printing.

  As a result, the resin parts that support the head and the cap gradually creep, particularly under high-temperature environments, and the sealing force (moisturizing properties) of the cap cannot be maintained due to a gradually insufficient pressing force. There is a problem that the quality deteriorates.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to suppress creep deformation of a member supporting a cap and to ensure print quality after being left for a long time.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A cap for capping the nozzle surface of the head having a nozzle for discharging droplets;
A cap support member that supports the cap and is movably provided;
A lever member that moves the cap support member between a capping position where the cap capping the nozzle surface and a retracted position where the cap is separated from the nozzle surface;
The lever member is
A first arm and a second arm in a direction intersecting the first arm;
The intersection of the first arm and the second arm is supported rotatably about a rotation fulcrum,
A distal end portion of the first arm is movably connected to the cap support member;
In a state where the nozzle surface is capped with the cap, the connection point with the cap support member and the rotation fulcrum are arranged along the capping direction.

  According to the present invention, creep deformation of a member supporting a cap can be suppressed, and printing quality after being left for a long time can be secured.

FIG. 3 is a side explanatory view illustrating a mechanism unit of an example of an image forming apparatus according to the present invention. It is principal part plane explanatory drawing of the mechanism part. It is explanatory drawing of the cap holding | maintenance mechanism in 1st Embodiment of this invention. It is explanatory drawing with which it uses for description of the generation | occurrence | production principle of the cap press shortage by creep deformation | transformation. It is explanatory drawing with which it uses for description of the generation | occurrence | production principle of the cap press shortage by creep deformation | transformation similarly. It is explanatory drawing with which it uses for description of arrangement | positioning and reaction force of an action point and a fulcrum in the embodiment. It is explanatory drawing with which it uses for description of arrangement | positioning and reaction force of an action point and a fulcrum in a comparative example. It is explanatory drawing of the cap holding | maintenance mechanism in 2nd Embodiment of this invention. It is explanatory drawing of the cap holding | maintenance mechanism in 3rd Embodiment of this invention. It is explanatory drawing of the cap holding | maintenance mechanism in 4th Embodiment of this invention. It is explanatory drawing of the slider member in 5th Embodiment of this invention. It is explanatory drawing of the cap holding | maintenance mechanism in the embodiment. It is explanatory drawing of the cap holding | maintenance mechanism in 6th Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an example of an image forming apparatus according to the present invention will be described with reference to FIGS. FIG. 1 is an explanatory side view for explaining the overall configuration of the image forming apparatus, and FIG. 2 is an explanatory plan view of a main part of the apparatus.

  This image forming apparatus is a serial type ink jet recording apparatus. The carriage 33 is slidably held in the main scanning direction by main and slave guide rods 31 and 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B of the apparatus main body 1, and a timing belt is interposed by a main scanning motor which will be described later. To move and scan in the carriage main scanning direction.

  The carriage 33 is provided with recording heads 34a and 34b composed of liquid ejection heads for ejecting ink droplets of yellow (Y), cyan (C), magenta (M), and black (K). "Recording head 34"). The recording head 34 is mounted with a nozzle row composed of a plurality of nozzles arranged in the sub-scanning direction orthogonal to the main scanning direction and the droplet discharge direction facing downward.

  The recording head 34 has two nozzle rows in which a plurality of nozzles that discharge droplets are arranged.

  One nozzle row of the recording head 34a is a monochrome nozzle row that discharges black (K) droplets, and the other nozzle row is a color nozzle row that discharges cyan (C) droplets.

  One nozzle row of the recording head 34b is a color nozzle row that ejects magenta (M) droplets, and the other nozzle row is a color nozzle row that ejects yellow (Y) droplets.

  Further, the carriage 33 is equipped with head tanks 35a and 35b (referred to as “head tank 35” when not distinguished) for supplying ink of each color corresponding to the nozzle rows of the recording head 34.

  In the head tank 35, ink cartridges 10y, 10m, 10c, and 10k, which are main tanks of the respective colors that are detachably attached to the cartridge loading unit 4, are supplied from the ink pumps 24 through the supply tubes 36 of the respective colors. Of ink is replenished.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the papers 42 one by one from the paper stacking unit 41. And a separation pad 44 facing the paper feed roller 43.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a pressing member 48 having 49. Further, a transport belt 51 is provided as a transport unit for electrostatically attracting the fed paper 42 and transporting the paper 42 at a position facing the recording head 34.

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction).

  Further, a charging roller 56 that is a charging unit for charging the surface of the transport belt 51 is provided. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51. The transport belt 51 rotates in the belt transport direction when the transport roller 52 is rotationally driven through timing by a sub-scanning motor described later.

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a spur 63 that is a paper discharge roller. And a paper discharge tray 3 below the paper discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the conveyor belt 51, reverses it, and feeds it again between the counter roller 46 and the conveyor belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, a maintenance / recovery mechanism (a maintenance / recovery unit) 81 for maintaining and recovering the state of the nozzles of the recording head 34 is disposed in a non-printing area on one side in the scanning direction of the carriage 33.

  The maintenance / recovery mechanism 81 is provided with a suction cap 82a and a moisture retention cap 82b (also referred to as “cap 82” when not distinguished from each other) that serve as both suction and moisture retention for capping each nozzle surface of the recording head 34.

  The maintenance / recovery mechanism 81 includes a wiper member (wiper blade) 83 for wiping the nozzle surface. Further, the maintenance / recovery mechanism 81 includes an empty discharge receiver 84 that receives droplets when performing empty discharge for discharging droplets that do not contribute to recording in order to discharge the thickened recording liquid, and a carriage lock that locks the carriage 33. 87 and the like.

  Here, an absorption member (absorber) 90 for absorbing the discharged liquid waste liquid is disposed in the suction cap 82a. Further, suction means such as a suction pump (not shown) is connected to the suction cap 82a.

  A waste liquid tank 100 for storing waste liquid generated by the maintenance recovery operation is mounted on the lower side of the head maintenance recovery mechanism 81 in a replaceable manner with respect to the apparatus main body.

  Further, in the non-printing area on the other side of the carriage 33 in the scanning direction, there is an empty space for receiving liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. A discharge receiver 88 is disposed. The idle discharge receiver 88 is provided with an opening 89 along the nozzle row direction of the recording head 34.

  In the image forming apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feed tray 2, and the sheets 42 fed substantially vertically upward are guided by the guide member 45, It is sandwiched between the counter roller 46 and conveyed. Further, the front end of the paper 42 is guided by the transport guide 37 and pressed against the transport belt 51 by the front end pressure roller 49, and the transport direction is changed by approximately 90 °.

  When the paper 42 is fed onto the charged transport belt 51, the paper 42 is attracted to the transport belt 51, and the paper 42 is transported in the sub-scanning direction by the circular movement of the transport belt 51.

  Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  When performing the maintenance recovery of the nozzles of the recording head 34, the carriage 33 is moved to a position facing the maintenance recovery mechanism 81 which is the home position.

  Here, nozzle suction (suction / discharge operation, also referred to as “cleaning operation” hereinafter) is performed by capping the nozzle surface by the suction cap 82a to suck and discharge ink from the nozzle, and does not contribute to image formation toward the suction cap 82a. By performing a maintenance and recovery operation such as an idle discharge operation for discharging droplets, it is possible to perform image formation by stable droplet discharge.

  Next, a first embodiment of the present invention will be described with reference to FIG. 3A and 3B are explanatory views of the cap holding mechanism in the embodiment, where FIG. 3A is an explanatory view of a capping state, and FIG. 3B is an explanatory view of a decapping state.

  The cap 82 is held by the cap holder 212 via a spring (elastic member) 301.

  The cap holder 212 is held by a slider member 302 that is a cap support member. The slider member 302 is disposed on the frame member 211 of the maintenance / recovery mechanism 81 so as to be movable in the vertical direction.

  Below the slider member 302, a cap is supported between a capping position shown in FIG. 3A where the cap 82 capping the nozzle surface and a retracting position shown in FIG. 3B where the cap 82 is separated from the nozzle surface. A lever member 400 for moving the slider member 302 as a member is disposed.

  The lever member 400 includes a first arm 400a and a second arm 400b that intersects the first arm 400a.

  The lever member 400 is supported by the support portion 303 of the frame member 211 so as to be rotatable about a shaft 403 with the intersection portion of the first arm 400a and the second arm 400b as a rotation fulcrum.

  In addition, a pin member 401 is provided at the distal end portion of the first arm 400 a of the lever member 400, and the pin member 401 is fitted in a connecting groove 302 formed in the slider member 302 so as to be movable. Thereby, the front-end | tip part of the 1st arm 400a of the lever member 400 is connected with the slider member 302 so that a movement is possible.

  Here, in a state where the nozzle surface is capped with the cap 82, the pin member 401, which is a connection point with the slider member 302, which is the cap support member of the lever member 400, and the shaft 403, which is the rotation fulcrum, are aligned along the capping direction. It is out.

  Since it comprised in this way, the lever member 400 rotates by lowering | hanging the front-end | tip part of the 2nd arm 400a of the lever member 400 from the capping state shown to Fig.3 (a) to an arrow direction, and it shows in FIG.3 (b). Thus, the slider member 302 is lowered with the cap 82, and the cap 82 is decapped from the nozzle surface of the head 34.

  Here, the principle of occurrence of insufficient cap pressurization due to creep deformation will be described with reference to FIGS.

  Creep deformation appears particularly prominently in resin parts, and is a phenomenon in which deformation progresses over time when stress is always applied. As shown in FIGS. 4 and 5, this creep deformation is characterized in that the stress is larger and the progress is accelerated as the temperature is higher.

  The cap 82 that presses the head is always pressed against the head 34 by the spring 301 when the apparatus is not used (during non-printing), and conversely, the cap support member that supports the cap 82 (described above) The slider member 302) always receives a reaction force of the same magnitude.

  As a result, as shown in FIGS. 4 and 5, the cap support member is deformed in a direction away from the head as time passes, and the pressing force of the cap 82 by the spring 301 is reduced, so that the pressure applied to the cap 82 is reduced. Will decrease.

  Further, when creep deformation progresses in this way, the pressing force against the nozzle surface of the cap 82 is insufficient, and a gap is generated between the nip portion of the cap 82 and the nozzle surface, whereby moisture evaporation from the nozzle is accelerated, When left unattended after printing, image defects such as missing nozzles are likely to occur.

  Therefore, in the present embodiment, as described above, the lever member 400 that moves the slider member 302 is provided. In the capping state, the lever member 400 has a pin member 401 supporting the slider member 302 and a shaft 403 supported by the frame member 211 arranged side by side along the capping direction.

  Thus, the rotation fulcrum (point supported by the frame member 211: the shaft 403) and the action point (point supporting the pi-slider member 302: pin member 401) are arranged along the capping direction (the same direction as the capping direction). As shown in FIG. 6, a capping reaction force 405 is applied to the action point and a reaction force 406 from the frame 211 having the same magnitude as the capping reaction force is applied to the fulcrum as shown in FIG.

  Thereby, in the capping state, the reaction force of the capping is not transmitted to the force point of the lever member 400 (the tip of the second arm 400a), and excessive stress applied to the inside of the lever member 400 can be reduced, and crepe deformation is suppressed. Can do.

  On the other hand, as in the comparative example shown in FIG. 7, the rotation fulcrum (point supported by the frame member 211: shaft 403) and the action point (point supporting the slider slider 302: pin member 401) are in the capping direction. If they are not lined up (arranged in a direction different from the capping direction), the force 407 acts on the force point (the tip of the second arm 400a) by the moment balance in addition to the force balance.

  Therefore, in the configuration of the comparative example, the force applied to the lever member 400 increases and causes creep deformation, and the operational effects of this embodiment cannot be obtained.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is an explanatory diagram of a cap holding mechanism in the same embodiment.

  In the lever member 400 of the present embodiment, an angle on the small side formed by the first arm 400a and the second arm 400b is an obtuse angle.

  As in the first embodiment, the lever member 400 is in the capping state, and the pin member 401 supporting the slider member 302 and the shaft 403 supported by the frame member 211 are aligned along the capping direction. Is arranged in.

  As a result, like the first embodiment, creep deformation can be suppressed and deterioration of image quality after being left for a long time can be suppressed.

  However, the tip of the second arm 400b is closer to the frame member 211 than when the angle on the small side formed by the first arm 400a and the second arm 400b is less than a right angle as in the first embodiment. . For this reason, in order to ensure the required amount of movement of the cap 82, the point supported by the frame member 211 may have to be increased.

  Next, a third embodiment of the present invention will be described with reference to FIG. FIGS. 9A and 9B are explanatory views of the cap holding mechanism in the embodiment, where FIG. 9A is a capping state and FIG. 9B is an explanatory view of the decapping state.

  In the present embodiment, a guide member 408 is provided on the slider member 302, and a hook 409 is provided on the first arm 400 a side of the lever member 400, thereby connecting the first arm 400 a of the lever member 400 and the slider member 302.

  Next, a fourth embodiment of the present invention will be described with reference to FIG. FIGS. 10A and 10B are explanatory views of the cap holding mechanism in the embodiment, where FIG. 10A is a capping state, and FIG. 10B is an explanatory view of a decapping state.

  In the present embodiment, two arc-shaped rack gears 410 and 411 centering on the rotation fulcrum (shaft 403) are arranged on the second arm 400b of the lever member 400 so as to face each other at different distances from the rotation fulcrum. Is provided.

  A missing gear 412 that meshes with one rack gear at different timings is rotatably disposed between the two rack gears 410 and 411.

  With this configuration, when the missing gear 412 rotates in the arrow direction from the capping state shown in FIG. 10A, the missing gear 412 meshes with the inner rack gear 410 and the lever member 400 rotates in the arrow direction. To do. As a result, the slider member 302 is lowered and the cap 82 is decapped as shown in FIG.

  On the other hand, when the missing gear 412 rotates in the arrow direction from the decap state shown in FIG. 10B, the missing gear 412 meshes with the outer rack gear 411 and the lever member 400 rotates in the arrow direction. As a result, the slider member 302 is raised and the cap 82 is capped as shown in FIG.

  By rotating the lever member in this manner, the stroke area for contact / retraction is not required as in the operation with the cam, and a compact configuration can be achieved by driving in one direction.

  Next, a fifth embodiment of the present invention will be described with reference to FIGS. FIG. 11 is an explanatory view of a slider member in the same embodiment, and FIG. 12 is an explanatory view of a cap holding mechanism in the same embodiment.

  In this embodiment, the connecting groove 302 of the slider member 302 is formed in an arc-shaped portion 420 around the capping position with the rotation fulcrum of the lever member 400 as the center.

  With this configuration, when the lever member 400 is used for driving, even if the stop angle of the lever member 400 slightly deviates, such as the position A or the position B in FIG. Therefore, the amount of displacement is absorbed, and the height of the slider member 302 is kept constant.

  Thereby, the capping force with respect to the nozzle surface of the head 34 can be made constant.

  Next, a sixth embodiment of the present invention will be described with reference to FIG. FIG. 13 is an explanatory diagram of a cap holding mechanism in the same embodiment.

  Since the moisture retaining cap 82b of the cap 82 is the same as the suction cap 82a, the suction tube connection port on the bottom surface is an atmosphere opening port portion 82c opened to the atmosphere.

  Therefore, in this embodiment, the first arm 400a of the lever member 400 is provided with a wiping member 430 for wiping the atmosphere communication opening 82c, and the wiping member 430 is released to the atmosphere during the capping operation using the rotation operation of the lever member 400. The mouth portion 82c is wiped away.

  The wiping member 430 may be a wiper such as an ink absorber or rubber, or a brush.

  If the ink 440 drips onto the moisture retention cap 82b and adheres to the atmosphere opening port 82c, the pressure inside the cap 82b becomes negative during the decap operation, and the meniscus of the nozzle may be destroyed, resulting in nozzle missing.

  As in this embodiment, the air communication port 82c is wiped by the wiping member 430 every time the cap is moved up and down, the ink 440 is removed, and the air release port 82c is not clogged, thereby preventing the nozzle from being removed.

  In the present application, “paper” is not limited to paper, but includes OHP, cloth, glass, a substrate, and the like, and can be attached to ink droplets and other liquids. This includes recording media, recording media, recording paper, recording paper, and the like. In addition, image formation, recording, printing, printing, and printing are all synonymous.

  The “image forming apparatus” means an apparatus that forms an image by discharging a liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics or the like. In addition, “image formation” not only applies an image having a meaning such as a character or a figure to a medium but also applies an image having no meaning such as a pattern to the medium (simply applying a droplet to the medium). It also means to land on.

  The “ink” is not limited to an ink unless otherwise specified, but includes any liquid that can form an image, such as a recording liquid, a fixing processing liquid, or a liquid. Used generically. For example, 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.

  Further, the image forming apparatus includes both a serial type image forming apparatus and a line type image forming apparatus, unless otherwise limited.

10 Ink cartridge (main tank)
33 Carriage 34, 34a, 34b Recording head (liquid ejection head)
35 Head tank 81 Maintenance and recovery mechanism 82a Cap (for suction and moisture retention)
82b Cap (for moisturizing)
302 Slider member (cap support member)
400 Lever member 400a First arm 400b Second arm

Claims (5)

A cap for capping the nozzle surface of the head having a nozzle for discharging droplets;
A cap support member that supports the cap and is movably provided;
A lever member that moves the cap support member between a capping position where the cap capping the nozzle surface and a retracted position where the cap is separated from the nozzle surface;
The lever member is
A first arm and a second arm in a direction intersecting the first arm;
The intersection of the first arm and the second arm is supported rotatably about a rotation fulcrum,
A distal end portion of the first arm is movably connected to the cap support member;
In the state where the nozzle surface is capped with the cap, the connection point with the cap support member and the rotation fulcrum are arranged along the capping direction. The second arm of the lever member is provided with two arc-shaped rack gears centered on the rotation fulcrum at different distances from the rotation fulcrum in directions facing each other.
The image forming apparatus according to claim 1, wherein a missing gear that meshes with one rack gear at different timing is rotatably disposed between the two rack gears. The cap support member is provided with a connection groove,
The first arm of the lever member is provided with a pin member movably fitted in the connecting groove,
The image forming apparatus according to claim 1, wherein the connection groove is formed in an arc shape in the vicinity of a capping position with the rotation fulcrum as a center. The cap has an air opening at the bottom,
4. The image forming apparatus according to claim 1, wherein the first arm of the lever member is provided with a wiping member for wiping the air opening portion. 5. A maintenance and recovery unit for maintaining and recovering the state of a nozzle of a head having a nozzle for discharging droplets,
A cap for capping the nozzle surface of the head;
A cap support member that supports the cap and is movably provided;
A lever member that moves the cap support member between a capping position where the cap capping the nozzle surface and a retracted position where the cap is separated from the nozzle surface;
The lever member is
A first arm and a second arm in a direction intersecting the first arm;
The intersection of the first arm and the second arm is supported rotatably about a rotation fulcrum,
A distal end portion of the first arm is movably connected to the cap support member;
In a state where the nozzle surface is capped with the cap, the connection point with the cap support member and the rotation fulcrum are arranged along the capping direction.

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