JP2011110840A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent diffusion of ink mist produced during maintenance of a nozzle into an image forming apparatus. <P>SOLUTION: The image forming apparatus which forms an image by reciprocating a carriage unit 1 having a recording head 11 for ejecting ink from a nozzle to a recording medium, and performs idle ejection operation of ink from the nozzle toward an idle ejection receiver 5 for the purpose of maintenance of the nozzle, includes a shielding means 13 for shielding a space formed between the nozzle and the idle ejection receiver 5 during idle ejection operation. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus. More specifically, the present invention relates to an image forming apparatus suitable for preventing diffusion of ink mist generated during nozzle maintenance into the apparatus.

  As an image forming apparatus such as a printer, a facsimile machine, a copying machine, or a multifunction machine of these, for example, an apparatus including a recording head composed of a liquid discharging head that discharges liquid droplets of recording liquid (liquid) is used. However, the material is not limited, and a recording medium as a liquid (hereinafter also referred to as ink) is conveyed while conveying a recording medium, a recording medium, a transfer material, and recording paper. There is a so-called ink jet type image forming apparatus (hereinafter referred to as an ink jet image forming apparatus) that performs image formation (hereinafter, recording, printing, printing, and printing are also used synonymously) attached to a sheet.

  In an inkjet image forming apparatus, feed amount control by an encoder sheet is performed in order to accurately control the feed amount in the carriage scanning direction (main scanning direction) and the paper transport direction (sub-scanning direction) which are printing units. Among these, in the main scanning encoder sheet (hereinafter referred to as encoder sheet) arranged in the vicinity of the printing area inside the apparatus, the mist ink (ink mist) ejected from the nozzle surface during printing adheres to the sheet surface. However, there is a problem of accumulation. The light transmission performance of the scale portion on the encoder sheet is reduced due to the accumulation of the ink mist, which causes a reading error of the encoder sheet by the transmission type photo sensor, which causes a deviation in the positional accuracy of the carriage and causes an abnormal image. Become.

  Further, in the inkjet image forming apparatus, a nozzle maintenance operation is performed during the carriage operation in order to prevent clogging due to ink drying at the nozzle opening. Of the maintenance operations, it is known that in the operation of ejecting ink from the nozzles (empty ejection operation), the amount of ink mist generated is larger than the ink ejection during printing as shown in FIG.

  FIG. 13 is a graph showing the relationship between the distance in the main scanning direction (mm) and the output amplitude (V) of the analog sensor (transmission type photosensor), and the initial value (sensor output value before printing) and 1000 sheets after printing. It shows a comparison with the sensor output value. According to FIG. 13, it can be seen that the sensor output values change in the vicinity of the left and right idle ejection areas (maintenance unit side and opposite side) after printing.

  That is, it is considered that the ink mist adheres to the encoder sheet most frequently in the vicinity of the empty ejection area, and it can be said that a sensor reading failure occurs from the vicinity of the empty ejection area. Therefore, it can be said that reducing the adhesion of ink mist to the encoder sheet during the idle ejection operation is effective in maintaining the performance of the image forming apparatus and improving the life of the apparatus.

  With respect to such a problem, Patent Document 1 provides a mist suction pump and a mist suction fan in the ink receiving portion for the purpose of reducing scattering and floating of the ink mist generated during preliminary ejection in the apparatus. An ink jet recording apparatus that sucks ink mist is disclosed.

  In Patent Document 2, when maintenance is performed on an ejection port that ejects ink, a maintenance member (capping unit) that receives ink from the ejection port and a platen are integrally rotated about a rotation axis. Thus, there is disclosed an ink jet printer that performs maintenance by switching the arrangement so that the maintenance member comes to a position facing the discharge port.

  Japanese Patent Laid-Open No. 2004-228688 gives a recording head a drive signal unrelated to printing in a state where the nozzle forming surface of the recording head is sealed by the capping unit during nozzle maintenance, and ejects ink droplets idly. An ink jet recording apparatus is disclosed.

  Patent Document 4 discloses an ink jet recording apparatus that ejects ink droplets for preventing clogging after a shielding member is raised and brought close to a recording head when the recording paper is not in a printing position.

  However, in the technique described in Patent Document 1, it is possible to prevent scattering of ink mist that floats inside the empty discharge receiver among the ink mist generated during the empty discharge operation. There is a problem that ink mist generated outside is not collected and floats in the apparatus as it is.

  Further, the shielding member referred to in the technique described in Patent Document 4 corresponds to a blank discharge receiver. Even when blank discharge is performed by bringing the shielding member close to the recording head during the blank discharge operation, Patent Document 1 is used. Similarly to the above, there is a problem that ink mist generated outside the shielding member is not collected and floats in the apparatus as it is. Further, the technique described in Patent Document 4 relates to an ink jet recording apparatus having a stationary recording head that does not scan the recording head. Therefore, the linear encoder mechanism for position detection is not included in the apparatus, and There is no problem of poor encoder reading caused by ink mist diffusion into the ink.

  Further, as in the techniques described in Patent Documents 2 and 3, according to the configuration in which the nozzle is sealed by operating the capping unit during nozzle maintenance, the ink mist is not diffused into the apparatus, but the capping unit is not used. Since the maintenance operation to be operated takes time, there is a problem that the maintenance time becomes long. In addition, the control mechanism for moving the capping unit and the arrangement relationship with other members become complicated, which increases the cost of the image forming apparatus.

  Therefore, nozzle maintenance by empty ink discharge to the empty discharge receiver, or nozzle maintenance by empty ink discharge to the empty discharge receiver and nozzle maintenance by capping means and nozzle maintenance by empty ink discharge to the empty discharge receiver are used in combination. It is desirable to shorten the maintenance time.

  Accordingly, the present invention forms an image by reciprocating a carriage unit having a recording head that discharges ink from a nozzle onto a recording medium, and for the purpose of nozzle maintenance, the ink is discharged from the nozzle toward the empty discharge receiver. An image forming apparatus that performs a discharge operation includes a shielding unit that blocks a space formed between the nozzle and the empty discharge receiver during the idle discharge operation, thereby performing a maintenance operation that activates the capping unit during the nozzle maintenance operation. Without performing the operation, the ink empty discharge operation is performed toward the fixedly arranged empty discharge receiver, and at this time, the floating and diffusion of the ink mist that may occur inside and outside of the empty discharge receiver in the apparatus can be prevented. An image forming apparatus is provided.

  In order to achieve this object, an image forming apparatus according to claim 1 forms an image by reciprocating a carriage unit having a recording head for ejecting ink from a nozzle onto a recording medium, and performs maintenance of the nozzle. For the purpose, an image forming apparatus that performs an idle ejection operation of ink from a nozzle toward an idle ejection receiver includes a shielding unit that shields a space formed between the nozzle and the idle ejection receiver during the idle ejection operation.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the shielding means is provided in the carriage unit or the idle discharge receiver, and descends in the direction of the idle discharge receiver from the carriage unit during the idle discharge operation. Or, it moves upward from the idle discharge receiver in the direction of the carriage unit.

  According to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the shielding means has a convex member, and when the carriage unit moves to the upper position of the idle discharge receiver, the convex member is located inside the apparatus. It is pressed against the pressing member, and the shielding means is raised or lowered.

  According to a fourth aspect of the present invention, in the image forming apparatus according to the second aspect of the present invention, a driving unit is provided in the carriage unit or the idle discharge receiver, and the shielding unit is raised or lowered by the driving unit.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, it is determined whether or not the lifting / lowering operation of the shielding means is executed based on the set print mode. To do.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the shielding means includes an absorber inside the wall surface.

  According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the first to sixth aspects, the shielding means and / or the idle discharge receiver are connected to the ink mist collecting means.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the seventh aspect, the ink mist collecting means collects the ink mist with a fan.

  According to a ninth aspect of the present invention, in the image forming apparatus according to the eighth aspect, the air volume and / or driving time of the fan is switched based on the set print mode.

  According to the present invention, it is possible to prevent floating and diffusion of ink mist that may occur inside and outside the idle ejection receiver.

1 is a schematic configuration diagram of a mechanism unit of an image forming apparatus according to the present invention. 1 is a schematic top view of an image forming apparatus. It is a figure which shows the mode of the ink mist generation | occurrence | production at the time of idling operation. It is a schematic diagram which shows an example of the shielding means provided with the convex member. It is a schematic diagram which shows the other example of the shielding means provided with the convex member. It is a schematic diagram which shows the example which provided the raising / lowering means in the carriage unit. It is a schematic diagram which shows the example which provided the raising / lowering means in the empty discharge receptacle. It is a control flowchart of the motor of a raising / lowering means. It is a schematic diagram which shows an example of the shielding means which provided the absorber. It is a schematic diagram of an ink mist collecting means for collecting ink mist. It is an air volume control flowchart of the fan which collects ink mist. It is an operation time control flowchart of the fan which collects ink mist. It is an example of the graph explaining the fall of the sensor output value by printing.

  Hereinafter, a configuration according to the present invention will be described in detail based on the embodiment shown in FIGS.

(Image forming apparatus configuration)
The image forming apparatus of the present embodiment forms an image by reciprocating a carriage unit having a recording head that discharges ink from a nozzle to a recording medium, and is directed from the nozzle to an empty discharge receiver for the purpose of nozzle maintenance. An image forming apparatus that performs an idle ink ejection operation includes a shielding unit that shields a space formed between the nozzle and the idle ejection receptacle during the idle ejection operation. With this configuration, as will be described in detail below, the ink mist generated by shielding the space around the nozzle by the shielding member is prevented from floating and diffusing in the apparatus.

  FIG. 1 shows an example of a mechanism part configuration of an inkjet image forming apparatus which is an embodiment of an image forming apparatus according to the present invention. Reference numeral 1 denotes a printing unit, and a head portion having a sub tank for storing ink supplied from a replaceable main ink tank (ink cartridge) 2 through an ink tube 3 and a nozzle for discharging ink is provided inside. A mounted carriage unit (printing mechanism) 1 reciprocates in the main scanning direction, which is the paper width direction.

  In addition, paper feeding means (paper feeding mechanism) is provided as means for conveying paper in the sub-scanning direction orthogonal to the main scanning direction, and the operation of the printing mechanism and paper feeding mechanism is controlled by the control unit. The image is formed on the paper.

  Further, in the example shown in FIG. 1, by providing the maintenance unit 4 and the empty discharge receiver (left empty discharge receiver) 5 on both sides of the paper width, ink discharge generated due to ink thickening, solidification, or bubble mixing, etc. Has a function to solve the problem.

  An encoder sheet is stretched along the main scanning direction of the carriage unit 1, and the carriage unit 1 includes a transmissive photosensor (encoder sensor) that detects a slit of the linear scale.

  FIG. 2 is a schematic top view of the inkjet image forming apparatus shown in FIG. The carriage unit 1 stands by at the position of the maintenance unit 4 (upward in the vertical direction) as an initial position. The maintenance unit 4 includes a right discharge receptacle 7, a suction cap 8, and a moisture retention cap 9. The suction cap 8 and the moisture retention cap 9 seal the nozzle surface on the head so that the ink in the nozzles is dried. To prevent. Reference numeral 6 denotes a paper transport unit.

  Further, during the nozzle maintenance operation, nozzle maintenance is performed by discharging ink (empty discharge) from the nozzle toward the right empty discharge receiver 7. The right empty discharge receptacle 7 has a wiper blade 10 built therein, and wipes the nozzle surface that has become dirty due to nozzle suction and empty discharge. Further, a left empty discharge receiver 5 is installed on the opposite side of the maintenance unit 4 and is configured to perform an empty discharge operation in the same manner as the right empty discharge receiver 7.

  Here, the ink discharge operation during the nozzle maintenance operation other than during printing has three patterns: (i) right empty discharge, (ii) empty discharge in the cap, and (iii) left empty discharge. The empty discharge operation is performed by the receiver 7, the suction cap 8, and the left empty discharge receiver 5. Here, (ii) empty discharge in the cap can realize powerful nozzle maintenance by forcibly sucking with a pump while discharging the ink with the head surface sealed with a suction cap. It takes a lot of time. On the other hand, (i) right-empty discharge and (iii) left-empty discharge discharge ink directly from the nozzle toward the opening of each empty discharge receiver, and therefore (ii) operate more efficiently than in-cap empty discharge. Less time is required. Such a plurality of patterns of idle ejection operations are appropriately combined according to the state of the nozzles to perform control to prevent a decrease in printing speed caused by the maintenance operation. In this embodiment, (i) right empty discharge and (i) right empty discharge, (ii) empty discharge in the cap, and (iii) left empty discharge, (i) right empty discharge and (Iii) Left empty discharge will be described, but (ii) a configuration for executing empty discharge inside the cap (suction cap 8, moisturizing cap 9, etc.) is not provided (i) right empty discharge and (iii) left empty discharge Of course, the image forming apparatus can be executed only.

  Among these empty discharge operations, (i) right empty discharge and (iii) left empty discharge do not capping the head surface, so when ink is discharged from the nozzle, a mist-like ink mist is generated. , There is a problem of scattering in the device.

  FIG. 3 shows how ink mist is generated when (iii) left-empty ejection is performed. (Iii) In the left empty discharge, ink is discharged from the nozzle of the head unit 11 mounted on the carriage unit 1 toward the left empty discharge receiver 5, but at the moment when the ink is discharged, a mist-like ink mist is generated. appear.

  That is, when ink is ejected from the nozzle toward the opening 12 of the left empty discharge receiver 5, the ink mist floats inside the left empty discharge receiver 5 and outside the left discharge receiver around the opening 12. Among these, the ink mist floating outside is further diffused in the image forming apparatus, which causes a problem.

(Shielding means configuration)
Therefore, the ink jet image forming apparatus according to the present embodiment includes a shielding unit for preventing diffusion of ink mist generated in the vicinity of the idle ejection receiver during the idle ejection operation. Hereinafter, details of the shielding means will be described.

<First Embodiment>
FIG. 4 shows a first embodiment of the shielding means. As shown in FIG. 4A, the shielding means 13 of the present embodiment is a quadrangular prism-shaped cylindrical body, and is provided on the carriage unit 1 so as to cover the entire periphery of the carriage unit 1. The shielding means 13 has a structure that moves up and down in the vertical direction.

  FIG. 4B shows details of the shielding means 13 shown in FIG. The shielding means 13 is held on the carriage unit 1 by locking means (for example, a spring 14). A pressing member 17 is provided on the side plate 16 of the image forming apparatus. Further, the upper side of one side surface of the shielding means 13 provided with the pressing member 17 has a convex shape. In the present embodiment, the convex member 15 is provided on the shielding means 13.

  Here, when the carriage unit 1 moves in the main scanning direction (in the direction of the arrow in FIG. 4B) and moves to the upper position of the left empty discharge receiver 5, the convex member 15 of the shielding means 13 is pressed against the pressing member 17. So that it receives a load in the downward direction. Thereby, the shielding means 13 can be lowered by the height of the convex member 15 as the carriage unit 1 scans.

  FIG. 4B is a diagram showing a state in the middle of the descent. When the shielding means 13 descends in this way, the circumferential direction in the vicinity of the head portion 11 is shielded, and a shielded space is formed. When the idle discharge operation is completed and the carriage unit 1 moves rightward from the left empty discharge position, the urging force by the convex shape 15 is released, and the shielding means 13 is lifted by the spring 14 and held by the spring 14. Return to the initial height position.

<Second Embodiment>
Next, FIG. 5 shows a second embodiment of the shielding means. The shielding means 13 of this embodiment has the same shape as the shielding means shown in FIG. 4, but is provided on the left empty discharge receiver 5 so as to cover the entire periphery of the left empty discharge receiver 5. The shielding means 13 has a structure that moves up and down in the vertical direction.

  FIG. 5B shows details of the shielding means 13 shown in FIG. The shielding means 13 is held on the left empty discharge receptacle 5 by a locking means (for example, a spring 14). A pressing member 17 is provided on the side plate 16 of the image forming apparatus. Moreover, the lower side of one side surface of the shielding means 13 provided with the pressing member 17 is convex. In the present embodiment, the convex member 15 is provided on the shielding means 13.

  Here, when the carriage unit 1 moves in the main scanning direction (the arrow direction in FIG. 5B) and moves to the upper position of the left empty discharge receiver 5, the pressing member 17 is driven by a driving means (not shown). The pressing member 17 according to the present embodiment is provided so as to be extendable and contractable in the main scanning direction. By extending the pressing member 17 in the main scanning direction, the pressing member 17 is brought into contact with the convex member 15 of the shielding unit 13 to be shielded. The means 13 receives the load in the upward direction. Thereby, the shielding means 13 can be raised by the height of the convex member 15 at the maximum.

  FIG. 5B is a diagram showing a state in the middle of ascending. As the shielding means 13 ascends in this way, the circumferential direction in the vicinity of the head portion 11 is shielded and a shielding space is formed. Further, when the idle discharge operation is completed, the pressing member 17 is contracted to release the contact with the convex shape 15, and the shielding means 13 is lowered by the spring 14, and the initial height position held by the spring 14. Return to.

<Third Embodiment>
Next, FIG. 6 shows a third embodiment of the shielding means. As shown in FIG. 6, the shielding means 13 of the present embodiment is a quadrangular columnar cylindrical body, and is provided in the carriage unit 1 so as to cover the entire periphery of the carriage unit 1. The shielding means 13 is held on the carriage unit 1 by a locking means (for example, a spring 14).

  In this embodiment, the carriage unit 1 is provided with lifting means including a motor 18, a gear 19, a gear 20, and a cam 21. The motor 18 of the elevating means is controlled by the control unit, and the cam 21 is rotated via the gear 19 and the gear 20 by driving the motor 18. The cam 21 is in contact with the upper end of one side surface of the shielding means 13.

  Here, when the carriage unit 1 moves in the main scanning direction (the arrow direction in FIG. 6) and moves to the upper position of the left empty discharge receiver 5, the motor 18 is rotated by a predetermined amount to rotate the cam 21. The shielding means 13 receives a load in the downward direction by the cam 21 and performs a lowering operation, thereby shielding the circumferential direction in the vicinity of the head portion 11 and forming a shielding space. When the idle discharge operation is completed and the carriage unit 1 moves from the left empty discharge position, the motor 1 is further rotated by a predetermined amount to release the bias by the cam 21, and the shielding means 13 is raised by the spring 14. Return to the initial height position held by the spring 14.

<Fourth Embodiment>
Next, FIG. 7 shows a fourth embodiment of the shielding means. As shown in FIG. 7, the shielding means 13 of the present embodiment is a quadrangular cylindrical body, and is provided in the left empty discharge receiver 5 so as to cover the entire periphery of the carriage unit 1. The shielding means 13 is held by the left empty discharge receptacle 5 by a locking means (for example, a spring 14).

  In the present embodiment, the left empty discharge receiver 5 is provided with lifting means including a motor 18, a gear 19, a gear 20 and a cam 21. The motor 18 of the elevating means is controlled by the control unit, and the cam 21 is rotated via the gear 19 and the gear 20 by driving the motor 18. The cam 21 is in contact with the lower end of one side surface of the shielding means 13.

  Here, when the carriage unit 1 moves in the main scanning direction (in the direction of the arrow in FIG. 7) and moves to the upper position of the left empty discharge receiver 5, the motor 18 is rotated by a predetermined amount to rotate the cam 21. The shielding means 13 receives a load in the upward direction by the cam 21 and moves upward, thereby shielding the circumferential direction in the vicinity of the head portion 11 and forming a shielding space. Further, when the idle discharge operation is completed and the carriage unit 1 moves from the left empty discharge position, the motor 1 is further rotated by a predetermined amount to release the urging by the cam 21 and the shielding means 13 is lowered by the spring 14. Return to the initial height position held by the spring 14.

  According to the shielding means 13 of the first to fourth embodiments described above, the head surface and the idle discharge receptacle are connected by a separate member and sealed by shielding the periphery of the head portion 11 of the carriage unit 1 during the idle discharge operation. Without using a complicated and expensive mechanism, it is possible to increase the recovery efficiency of the ink mist generated during the idle ejection operation and prevent the ink mist from diffusing into the apparatus, and is provided in the vicinity of the carriage unit 1. Ink mist adhesion to the encoder sheet 26 can be prevented. Needless to say, the mechanism for moving the shielding means 13 up and down is not limited to the above example.

  It should be noted that the control using the shielding means 13 can be similarly performed during the right empty discharge to the right discharge receiver 7. In the case of the said 1st-2nd embodiment, it can raise / lower similarly by providing the convex member 15 also in a symmetrical position, for example.

(Elevating means control)
Next, control of the motor 18 of the lifting / lowering means of the shielding means 13 of the third and fourth embodiments will be described with reference to the flowchart shown in FIG.

  First, the control unit of the image forming apparatus detects the set print mode (S1). The print mode can be set from the operation panel of the image forming apparatus or an information processing apparatus (such as a personal computer) connected to the image forming apparatus, and the setting contents are temporarily stored in the RAM or the like of the image forming apparatus. ing.

  In the present embodiment, when the set print mode is any one of (i) clean mode, (ii) high image quality mode, and (iii) envelope mode (S1: Yes), as described below. Operation control of the shielding means is performed (to S2). On the other hand, when the printing mode does not correspond to any of the above modes (i) to (iii) (S1: No), the lifting / lowering operation of the shielding means is not performed (S8). This is because, in modes other than the above (i) to (iii), a relatively small amount of ink mist is generated. However, the combination of modes for controlling the operation of the shielding means is not limited to the above example, and it is needless to say that the operation control of the shielding means may be performed in all printing modes. Further, it may be possible to set whether or not to perform the operation of the shielding unit without making a determination based on the print mode.

  Next, when the carriage detects an idle discharge operation, that is, stops at the idle discharge position for a certain time (S2), the motor 18 is operated (rotated by a certain amount) (S3), and the shielding means is moved up and down to A shielded space is formed between the empty discharge receptacles 5.

  In this state, the idle ejection operation starts from the nozzles provided in the head 11 (S4). After detecting the end of the idle ejection operation (S5), it is detected that a preset time t (the time when there is no ink mist floating around the idle ejection port and the head surface) has passed (S6), and the shielding means is raised and lowered. The motor is actuated (rotated by a certain amount) to release the shielding state (S7). Thereafter, the scanning of the carriage starts again. The above is the flow of raising and lowering the shielding unit.

(Other embodiments)
Moreover, it is preferable to provide the absorber 22 which can adsorb | suck ink mist inside the shielding means 13 (inner wall). FIG. 9 shows an example of shielding means provided with the absorber 22.

In the example shown in FIG. 9, the shielding unit 13 is held by the carriage unit 1, and the shielding unit 13 moves up and down in the direction of the arrow to shield the space between the head unit 11 and the left empty discharge receiver 5. And the generated ink mist is confined. Further, an absorber 22 is affixed to the inside of the shielding means 13 so that ink mist can be adsorbed. Here, as the absorber 22, for example,
A fiber material such as felt can be used. Further, the absorber 22 is not necessarily provided on the entire inner surface (four surfaces) of the shielding means 13. It is also preferable that the absorber 22 can be replaced.

  By providing the absorber 22 in the shielding means 13 in this way, it is possible to increase the ink mist adsorption efficiency and more effectively reduce the diffusion of the ink mist into the apparatus.

  It is also preferable to provide an ink mist collecting means for collecting ink mist generated during idle ejection. FIG. 10 shows an example of an ink mist collection means comprising a duct 23, a fan (mist fan) 24, and a collection container 25.

  In FIG. 10, the shielding unit 13 is held in the carriage unit 1, and a shielded space is formed between the left empty discharge receiver 5 and the head unit 11 to confine the generated ink mist. Further, the shielding means 13 and the left empty discharge receptacle 5 are provided with a vent hole, and a bifurcated duct 23 is installed so as to be connected thereto. A fan 24 is attached to the opposite side of the air vent of the duct 23 to suck the ink mist around the head portion 11 and the ink mist in the left empty discharge receptacle 5, and the ink mist sucked by the fan 24 is separately provided. It is stored as waste liquid in the installed collection container 25.

  In the example shown in FIG. 10, the duct 23 is connected to the vent holes provided in both the shielding means 13 and the left empty discharge receptacle 5, but may be provided only in one of them. Further, ink mist collection means (duct 23, fan 24, collection container 25) may be provided on both the shielding means 13 and the left empty discharge receptacle 5 respectively.

  In this way, by providing a vent hole in the shielding means 13 and / or the idle discharge receptacle and collecting the ink mist by the collecting means such as the fan 24, the ink mist collecting efficiency can be further increased. Diffusion into the device can be more effectively reduced.

(Fan air volume control)
It is also preferable to switch the fan airflow based on the set print mode. Hereinafter, an example of air volume control of the fan 24 of the ink mist collecting means will be described with reference to the flowchart shown in FIG.

  First, the set print mode is detected (S1). The print mode can be set from an operation panel of the image forming apparatus or an information processing apparatus (such as a personal computer) connected to the image forming apparatus, and the setting contents are stored in the image forming apparatus.

  In the present embodiment, when the set print mode is any one of (i) clean mode, (ii) high image quality mode, and (iii) envelope mode (S1: Yes), as described below. Operation control of the fan 24 is performed (to S2). On the other hand, when the printing mode does not correspond to any of the above modes (i) to (iii) (S1: No), the operation control of the fan 24 and the elevation control of the shielding means (see FIG. 8) are not performed. (S10). This is because, in modes other than the above (i) to (iii), a relatively small amount of ink mist is generated. However, the combination of modes for controlling the operation of the fan 24 is not limited to the above example, and it goes without saying that the operation control of the fan 24 may be performed in all printing modes. Further, it may be possible to set whether or not to execute the operation control of the fan 24 without determining based on the print mode.

  Next, when the carriage detects an idle discharge operation, that is, stops at the idle discharge position for a certain time (S2), the motor 18 is operated (rotated by a certain amount) (S3), and the shielding means is moved up and down to A shielded space is formed between the empty discharge receptacles 5.

  In this state, the fan 24 is operated. At this time, according to the printing mode detected in S1, the fan 24 is operated in three kinds of air volume modes by controlling the current value. In the present embodiment, since the amount of ink mist generated increases in accordance with (i) clean mode, (ii) high image quality mode, and (iii) envelope mode, the fan air volume is reduced in (i) clean mode. (Ii) Control is made in the air volume in the high image quality mode, and (iii) Air volume is increased in the envelope mode (S4).

  Next, after the idle ejection operation is started from the nozzle unit 11 (S5) and the end of the idle ejection operation is detected (S6), a preset time t (the ink mist floating around the idle ejection port and the head surface is detected). (S7), the fan 24 is stopped (S8). After the above operation is completed, the shielding means raising / lowering motor 18 is operated (rotated by a certain amount) (S9), and after the shielding state is released, the carriage scanning is started again. The above is the fan air flow control flow.

(Fan driving time control)
It is also preferable to switch the fan drive time based on the set print mode. Hereinafter, an example of operation time control of the fan 24 of the ink mist collecting means will be described with reference to the flowchart shown in FIG.

  First, the set print mode is detected (S1). The print mode can be set from an operation panel of the image forming apparatus or an information processing apparatus (such as a personal computer) connected to the image forming apparatus, and the setting contents are stored in the image forming apparatus.

  In the present embodiment, when the set print mode is any one of (i) clean mode, (ii) high image quality mode, and (iii) envelope mode (S1: Yes), as described below. Operation control of the fan 24 is performed (to S2). On the other hand, when the printing mode does not correspond to any of the above modes (i) to (iii) (S1: No), the operation control of the fan 24 and the elevation control of the shielding means (see FIG. 8) are not performed. (S10). This is because, in modes other than the above (i) to (iii), a relatively small amount of ink mist is generated. However, the combination of modes for controlling the operation of the fan 24 is not limited to the above example, and it goes without saying that the operation control of the fan 24 may be performed in all printing modes. Further, it may be possible to set whether or not to execute the operation control of the fan 24 without making a determination based on the print mode.

  Next, when the carriage detects an idle discharge operation, that is, stops at the idle discharge position for a certain time (S2), the motor 18 is operated (rotated by a certain amount) (S3), and the shielding means is moved up and down to A shielded space is formed between the empty discharge receptacles 5.

  In this state, the fan 24 is operated (S4). At this time, the idle discharge operation is started from the nozzle unit 11 (S5), and after the end of the idle discharge operation is detected (S6), a preset time t It is detected that the time (no time for the ink mist floating around the empty ejection port and the head surface to disappear) has passed (S7), and the fan 24 stops (S8).

  The time t set at this time is determined according to the print mode detected in S1. In the present embodiment, since the amount of ink mist generated increases as (i) clean mode, (ii) high image quality mode, and (iii) envelope mode, the fan operating time is set to (i) clean mode time. Short (ii) high time mode is controlled during the time, and (iii) envelope mode is controlled as the time length (S8).

  Next, after the above operation is completed, the motor 18 is actuated (rotated by a certain amount) (S9), and after the shielding state is released, the scanning of the carriage is started again. The above is the operation time control flow of the fan 24.

  The above-described embodiment is a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention.

1 Carriage unit 2 Main ink tank (ink cartridge)
3 Ink tube 4 Maintenance unit 5 Empty discharge receptacle (left empty discharge receptacle)
6 Paper transport unit 7 Right empty discharge receptacle 8 Absorption cap 9 Moisturizing cap 10 Wiper blade 11 Head (head)
12 Opening portion 13 Shielding means 14 Spring 15 Convex member 16 Side plate 17 Holding member 18 Motor 19, 20 Gear 21 Cam 22 Absorber 23 Duct 24 Fan 25 Collection container 26 Encoder sheet

JP 2008-149538 A Japanese Patent Laid-Open No. 2004-9513 JP 2001-322296 A Japanese Patent Laid-Open No. 9-300658

Claims (9)

A carriage unit having a recording head for discharging ink from the nozzles to the recording medium reciprocates to form an image, and for the purpose of maintenance of the nozzles, the ink is discharged from the nozzles toward the empty discharge receiver. In the image forming apparatus to perform,
An image forming apparatus comprising: a shielding unit configured to shield a space formed between the nozzle and the idle discharge receptacle during an idle discharge operation.   The shielding means is provided in the carriage unit or the idle discharge receiver, and is moved downward from the carriage unit toward the idle discharge receiver during the idle discharge operation, or raised from the idle discharge receiver to the carriage unit. The image forming apparatus according to claim 1. The shielding means has a convex member,
3. The image forming apparatus according to claim 2, wherein when the carriage unit moves to an upper position of the idle discharge receiver, the convex member is pressed against a pressing member in the apparatus, and the shielding unit is raised or lowered. . Drive means is provided in the carriage unit or the idle discharge receiver,
The image forming apparatus according to claim 2, wherein the shielding unit is raised or lowered by the driving unit.   5. The image forming apparatus according to claim 1, wherein the image forming apparatus determines whether or not the lifting / lowering operation of the shielding unit is executed based on a set print mode.   The image forming apparatus according to claim 1, wherein the shielding unit includes an absorber inside the wall surface.   The image forming apparatus according to claim 1, wherein the shielding unit and / or the idle discharge receiver are connected to an ink mist collecting unit.   The image forming apparatus according to claim 7, wherein the ink mist collecting unit collects the ink mist with a fan.   The image forming apparatus according to claim 8, wherein the air volume and / or driving time of the fan is switched based on a set print mode.