JP2014051006A - Inkjet image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet image forming apparatus which surely moves an inkjet head to the position of a maintenance mechanism even when power supply is suddenly shut-off without increasing the movement load of the inkjet head during printing operation.SOLUTION: When a moving member 81 is moved to a left side board 20a side by being pushed by a carriage 23 while electric power is supplied, the moving member 81 is held on the left side board 20a with an electromagnetic stopper 83. When electric power is shut off, the electromagnetic stopper 83 releases holding of the moving member 81, and the moving member 81 moves to a right side board 20b side due to resilience of a coil spring 85, brought into contact with the carriage 23, and pushes and moves the carriage 23 to a position corresponding to a maintenance-recovery mechanism 46. At the position, the maintenance-recovery mechanism 46 can cover a nozzle of an inkjet head with a cap.

Description

  The present invention relates to an inkjet image forming apparatus that forms an image by ejecting ink droplets from nozzles of an inkjet head.

2. Description of the Related Art Inkjet printers are frequently used as inkjet image forming apparatuses that form images by ejecting ink droplets from nozzles of an inkjet head.
Ink jet printers generally have a maintenance mechanism in order to prevent nozzles from being clogged with dust or the like, and ink discharge performance from deteriorating due to drying and solidification.
In the ink jet printer having the maintenance mechanism, when the print job is completed normally, the ink jet head is moved to the position of the maintenance mechanism by electrical control, and the operation of capping each nozzle by the capping member is performed.

In such an ink jet printer, there is a technique for moving the ink jet head to the position of the maintenance mechanism without using electrical control when power supply is interrupted due to a power failure or the like.
For example, Patent Document 1 discloses an ink jet image forming apparatus in which a moving block is provided in close contact with an ink jet head by a coil spring, and is moved so as to always follow a reciprocating movement in the printing range of the ink jet head. Yes.
In the inkjet image forming apparatus, when the power supply is suddenly interrupted due to a power failure or the like during operation, the moving block pushes the inkjet head to the standby position by the restoring force of the coil spring so that capping can be performed. .

However, in the apparatus described in Patent Document 1, the moving block on which the force to be pulled back by the coil spring is always moved during the printing operation following the reciprocating movement of the inkjet head in the printing range.
Therefore, when the inkjet head moves the moving block in the direction in which the coil spring is stretched, the load on the inkjet head increases, and the load on the motor that moves the inkjet head increases. In addition, since the load increases or decreases depending on the moving direction of the inkjet head, the landing positions of the ink droplets ejected from the nozzles are shifted, and there is a possibility that image quality is deteriorated.

  The present invention has been made in view of the above points, and reliably moves the inkjet head to the position of the maintenance mechanism even when the power supply is suddenly interrupted without increasing the movement load of the inkjet head during the printing operation. The purpose is to enable capping.

In order to achieve the above object, an inkjet image forming apparatus of the present invention is equipped with an inkjet head that ejects ink droplets from nozzles and includes a carriage that reciprocates along a guide member, and one moving end of the carriage. A maintenance / recovery mechanism having a cap for capping at least the nozzles of the inkjet head is provided on the side.
In addition, the moving member that is normally held by the fixed member on the other moving end side of the carriage and moves to the one moving end side contacts the carriage, and the moving member moves to the other moving end side. A moving force accumulating means for accumulating a force for moving the moving member toward the one moving end when moved, and the moving member is pushed by the carriage when the power is supplied. There is also provided holding / release means for holding the moving member on the fixed member when moved to the end side and releasing the holding when the power supply is cut off.
When the power supply is cut off, the moving member is released from the holding / releasing means, and moved to the one moving end side by the force accumulated in the moving force accumulating means, and is moved to the carriage. The carriage moves to a position corresponding to the maintenance / recovery mechanism, and the cap of the maintenance / recovery mechanism enables capping of the nozzles of the inkjet head.

  The inkjet image forming apparatus according to the present invention enables capping by reliably moving the inkjet head to a position where the maintenance mechanism is located even when the power supply is suddenly interrupted without increasing the movement load of the inkjet head during a printing operation. .

1 is a side sectional view showing a mechanism part of an ink jet printer which is an embodiment of an ink jet image forming apparatus according to the present invention. It is a top view which shows the principal part of the mechanism part of the inkjet printer shown in FIG. FIG. 3 is a bottom view showing a nozzle surface of an inkjet head mounted on the carriage shown in FIGS. 1 and 2. It is explanatory drawing which shows typically the wiping state of the maintenance recovery mechanism shown in FIG. It is explanatory drawing which shows the capping state typically similarly. It is a block diagram shown with each part which concerns on the structural example of the control part of the inkjet printer shown in FIG.1 and FIG.2.

FIG. 3 is a schematic plan view of a printing operation state corresponding to FIG. 2 showing the configuration of the embodiment of the characterizing portion of the present invention in the ink jet printer shown in FIGS. 1 and 2. Similarly, it is a schematic plan view of a state immediately after the power supply is shut off. Similarly, it is a schematic plan view of a state where the carriage has been moved to a position corresponding to the maintenance / recovery mechanism. Similarly, it is a schematic plan view of a state immediately after the power supply is started. It is a schematic plan view of the state in which the moving member was similarly hold | maintained at the side plate.

It is a block diagram which shows only a part required for description of other embodiment of this invention in the control part shown in FIG. It is a flowchart which shows an example of the process which memorize | stores the operation information of the power switch by the microcomputer for control shown in FIG. It is a flowchart which shows an example of the process at the time of the power supply interruption | blocking by the control microcomputer shown in FIG. FIG. 9 is a circuit diagram showing a specific example of the electromagnetic stopper drive circuit shown in FIG. 8.

Hereinafter, embodiments for carrying out the present invention will be specifically described with reference to the drawings.
[Mechanical part of inkjet printer embodying the present invention]
FIG. 1 is a side sectional view showing a mechanism part of an ink jet printer which is an embodiment of an ink jet image forming apparatus according to the present invention. The paper feed tray 2 and paper discharge tray 3 are shown only partially broken. FIG. 2 is a plan view showing the main part of the mechanism part of the ink jet printer shown in FIG. FIG. 3 is a bottom view showing the nozzle surface of the inkjet head mounted on the carriage of the inkjet printer.

  The mechanism of the inkjet printer 1 holds a carriage 23 with a guide rod 21 fixed between a left side plate 20a and a right side plate 20b constituting the frame 20 shown in FIG. 2, and a stay 22 shown in FIG. doing. The carriage 23 is moved and scanned in the main scanning direction indicated by an arrow X in FIG. 2 by a main scanning motor and a timing belt mechanism which will be described later.

  Two ink jet heads 24 a and 24 b are mounted on the carriage 23. Each of the inkjet heads 24a and 24b has two nozzle rows in which a large number of nozzles are arranged along a direction (sub-scanning direction) orthogonal to the main scanning direction, with an interval in the main scanning direction. . Each nozzle has its ink droplet ejection direction directed downward.

For example, as shown in FIG. 3, the one inkjet head 24a includes a nozzle row 60k that ejects black (K) ink droplets and a nozzle row 60c that ejects cyan (C) ink droplets. ing. In FIG. 3, a part of the nozzle row 60k is shown in an enlarged manner, and 60n is a discharge port of each nozzle.
The other inkjet head 24b includes a nozzle row 60m that ejects magenta (M) ink droplets and a nozzle row 60y that ejects yellow (Y) ink droplets. The inkjet heads 24a and 24b are collectively referred to as “inkjet head 24”. The nozzle rows 60k, 60c, 60m, and 60y are collectively referred to as “nozzle row 60”.

As the inkjet head 24, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor, and a shape memory alloy actuator that uses a metal phase change caused by a temperature change In addition, an electrostatic actuator using an electrostatic force or the like provided as energy generating means for discharging ink can be used.
The configuration of the inkjet head 24 is not limited to the above-described example, and is configured using one or a plurality of recording heads having one or a plurality of nozzle rows that eject ink droplets of one or a plurality of colors. can do.

A driver IC is mounted on the inkjet head 24. Although not shown in FIGS. 1 and 2, the harness (flexible print cable) shown in FIG. 2 is connected to the print control microcomputer shown in FIG. 25 is connected so that data can be exchanged.
In addition, the carriage 23 is equipped with a sub tank 26 that holds ink of each color for supplying ink of each color to the inkjet head 24.
For example, as shown in FIG. 2, the sub tank 26 includes a black (K) ink sub tank 26k, a cyan (C) ink sub tank 26c, a magenta (M) ink sub tank 26m, and a yellow (Y) ink sub tank 26y. It is comprised from these four. When the colors are not distinguished, they are collectively referred to as “sub tank 26”.

Each color sub-tank 26 includes ink cartridges 9k, 9c, 9m, and 9y (collectively referred to as “ink cartridge 9”) that hold the inks of the respective colors mounted in the cartridge loading unit 7 shown in FIG. The inks of the respective colors are replenished and supplied through the ink supply tube 27 for use.
The cartridge loading unit 7 is provided with a supply pump unit 28 for feeding ink in each ink cartridge 9. The ink supply tube 27 is fixed and held on the rear plate 20c constituting the frame 20 using a holder 29 in the middle of scooping. Further, the ink supply tube 27 is also fixed on the carriage 23 using the fixing rib 30.

  On the other hand, the sheet feeding unit for feeding the sheets P stacked on the sheet stacking unit (lifting plate) 31 of the sheet feeding tray 2 shown in FIG. A paper feed roller (half moon roller) 32 for feeding P one by one is provided. A separation pad 33 made of a member having a large friction coefficient is provided facing the paper feed roller 32 and is pressed against the paper feed roller 32 side.

The sheet P separated and fed from the sheet feeding unit is fed to the lower part of the inkjet head 24, and the sheet P is electrostatically adsorbed to a position facing the inkjet head 24. A transport belt 34 is provided for transporting the transport.
Further, the counter roller 36 for transporting the paper P sent from the paper feed section via the guide 35 between the transport belt 34 and the paper P fed substantially vertically upward in FIG. A conveyance guide 37 for changing the direction so as to follow the conveyance belt 34 and a tip pressing roller 39 pressed against the conveyance belt 34 by a pressing member 38 are also provided.

In addition, a charging roller 40 for charging the surface of the conveyor belt 34 is provided.
The conveyor belt 34 is endless and is stretched between the conveyor roller 41 and the tension roller 42. Then, the conveyance roller 41 is rotated in the direction indicated by the arrow by a sub-scanning motor (not shown), and thus moves in the sub-scanning direction indicated by arrow Y in FIG. 2 (hereinafter referred to as “rotation”).
The transport belt 34 is, for example, a surface layer serving as a sheet adsorbing surface formed of a pure resin material having a thickness of about 40 μm that is not subjected to resistance control, for example, ETFE (thermoplastic fluororesin) pure material, and the same surface layer. It has a back layer (for example, a medium resistance layer or a ground layer) that is made of carbon and controlled in resistance.

On the other hand, the charging roller 40 shown in FIG. 1 is a charging unit for charging the surface of the conveyance belt 34, contacts the surface layer of the conveyance belt 34, and rotates along with the rotation of the conveyance belt 34 (driven rotation). . Further, a predetermined pressing force is applied to both ends of the shaft so as to apply pressure to the conveyor belt 34.
Further, the transport roller 41 also serves as an earth roller, and is in contact with the middle resistance layer (back layer) of the transport belt 34 and grounds it.

Further, a guide member 43 is disposed on the back side of the conveyance belt 34 so as to correspond to a printing area by the inkjet head 24.
The upper surface of the guide member 43 protrudes closer to the inkjet head 24 than the external tangent common to the two rollers (the conveyance roller 41 and the tension roller 42) that support the conveyance belt 34. Thereby, since the conveyance belt 34 is pushed up and guided by the upper surface of the guide member 43 in the printing region, high-precision flatness is maintained.

Further, as a paper discharge unit for discharging the paper P recorded by the inkjet head 24, a separation claw 52 for separating the paper P from the transport belt 34, a paper discharge roller 53, and a paper discharge roller 54 are provided. The paper discharge tray 3 is provided below the paper discharge roller 53.
Here, the height from the sheet discharge roller 53 and the sheet discharge roller 54 to the sheet discharge tray 3 is increased to some extent in order to increase the amount that can be stored in the sheet discharge tray 3.

A double-sided paper feeding unit 44 is detachably mounted on the back surface of the inkjet printer 1. The double-sided paper feeding unit 44 has a function of taking in paper that is returned by reverse rotation of the conveying belt 34 and inverting it during double-sided printing, and feeding the paper again between the tip pressure roller 39 and the conveying belt 34.
Further, a manual paper feed unit 45 for feeding manual paper is provided on the upper surface of the double-sided paper feed unit 44.

On the other hand, as shown in FIG. 2, in the non-printing region on one moving end side (right side in this example) of the carriage 23 in the scanning direction, the state of the nozzles of the inkjet head 24 is maintained and recovered for recovery. A mechanism 46 is arranged.
The maintenance / recovery mechanism 46 includes caps 47a and 47b for capping the nozzle surfaces of the inkjet head 24 (collectively referred to as “cap 47” when not distinguished), and wipes (wipes) the nozzle surfaces. For example, a wiper blade 48 which is a blade member is provided.
The maintenance / recovery mechanism 46 may also be provided with an empty discharge receptacle for discharging ink droplets that do not contribute to recording in order to discharge the thickened ink.

Then, the ink waste liquid generated by the maintenance and recovery operation by the maintenance and recovery mechanism 46, the ink discharged to the cap 47, the ink attached to the wiper blade 48 and removed by the wiper cleaner (not shown), and the empty discharge receptacle are empty. The discharged ink is discharged and stored in a waste liquid tank (not shown).
In addition, ink droplets that do not contribute to recording are ejected to the non-printing region on the other moving end side (left side in FIG. 2) of the carriage 23 in order to discharge ink that has been thickened during recording or the like. An empty discharge receiver 50 is disposed. The idle discharge receiver 50 is provided with two openings 51 along the nozzle arrangement direction of the inkjet head 24.

  Further, a communication circuit unit (interface) such as a USB for transmitting / receiving data to / from the host computer, and a control microcomputer (FIG. 2) that controls the entire inkjet printer are provided on the rear side of the inkjet printer 1. A control circuit board is provided which is described in FIG.

In the ink jet printer 1, the paper P is separated and fed one by one from the paper feed tray 2 shown in FIG. 1, and the paper P is guided substantially vertically upward in the figure by a guide 35. It is sandwiched between the counter roller 36 and conveyed.
Thereafter, the front end of the paper P is guided by the transport guide 37 and pressed against the transport belt 34 by the front end pressure roller 39, and the transport direction is changed by approximately 90 °.

  At this time, an alternating voltage in which a positive voltage and a negative voltage are alternately repeated is applied from the AC bias supply unit to the charging roller 40 by a control microcomputer described later with reference to FIG. Thereby, the surface of the conveyor belt 34 is charged with an alternating charging pattern. That is, charging is performed such that positive and negative charges are alternately generated in a band shape with a predetermined width in the sub-scanning direction, which is the rotation direction of the transport belt 34.

  When the paper P is fed onto the conveyance belt 34 that is alternately charged positively and negatively, the paper P is also alternately charged positively and negatively with the opposite polarity to the charged polarity of the conveyor belt 34 by electrostatic induction. Occurs. Therefore, the paper P is attracted to the transport belt 34 by electrostatic attraction, and the paper P is accurately transported in the sub-scanning direction by the rotation of the transport belt 34 without causing a relative positional shift.

Therefore, by driving the inkjet head 24 according to the image signal while moving the carriage 23 in the main scanning direction, the ink droplets are ejected onto the stopped paper P, and a plurality of lines corresponding to the number of nozzles are discharged. After the image is recorded and the paper P is conveyed by a predetermined amount, the next plural lines are recorded.
Then, upon receiving a recording end signal or a signal indicating that the trailing edge of the paper P has reached the sub-scanning edge of the recording area, the recording operation is finished and the paper P is discharged onto the paper discharge tray 3.

During printing (recording) standby, the carriage 23 is moved to the maintenance / recovery mechanism 46 side, and the inkjet head 24 is capped by the cap 47 to keep the nozzles moist, thereby preventing ink ejection failure due to ink drying. To prevent.
Further, in a state where the inkjet head 24 is capped with the cap 47, ink is sucked from the nozzle by a suction pump (not shown) (this is referred to as “nozzle suction” or “head suction”), and the thickened ink and bubbles are removed. Perform recovery action to eject.
In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. By these, the stable discharge performance of the inkjet head 24 is maintained.

[Example of maintenance and recovery mechanism]
Next, a configuration example of the maintenance / recovery mechanism 46 will be described with reference to FIGS.
4 and 5 are explanatory diagrams schematically showing a wiping state and a capping state of the maintenance / recovery mechanism 46 shown in FIG. 2, respectively.
The maintenance / recovery mechanism 46 includes one cap holder 49, and two caps 47 a and 47 b are held on the upper surface of the cap holder 49. The caps 47a and 47b are dedicated caps for capping the inkjet heads 24a and 24b on the nozzle surface 23a of the carriage 23, respectively. A wiper blade 48 for wiping (cleaning) the nozzle surface 23a of the carriage 23 is also provided.

Further, in order to move the cap holder 49 and the wiper blade 48 up and down, a maintenance / recovery mechanism driving motor 61 is provided, and a coaxial cam shaft 62 is provided on the rotating shaft thereof. A cap cam 63 and a wiper cam 64 are fixed to the cam shaft 62 at an interval in the axial direction.
According to this maintenance / recovery mechanism 46, every time the camshaft 62 is half-rotated in the direction indicated by arrow C by the maintenance / recovery mechanism driving motor 61, the rotation of the wiper cam 64 and the cap cam 63 shifted by 180 ° phase One of the wiper blade 48 and the cap holder 49 can be raised and the other can be lowered.

When removing ink and impurities adhering to the nozzle surface 23a of the carriage 23, the cam shaft 62 is rotated so as to be in the state shown in FIG. Thereby, the wiper blade 48 is raised in the direction approaching the carriage 23 as indicated by arrow B by the rotation of the wiper cam 64. At this time, the cap holder 49 is lowered as indicated by an arrow A.
In this state, by moving the carriage 23 in the main scanning direction indicated by the arrow X, the wiper blade 48 wipes the inkjet heads 24a and 24b on the nozzle surface 23a of the carriage 23 to wipe away impurities and the like. .

  If the nozzles of the ink jet heads 24a and 24b are left exposed to the outside air, the ink inside the nozzles dries and becomes thickened and fixed, thereby deteriorating the ink ejection performance. Therefore, in order to prevent this, the carriage 23 is moved to a position where the tip of each nozzle of the ink jet heads 24a, 24b can be capped by the caps 47a, 47b of the maintenance / recovery mechanism 46.

  Thereafter, the cam shaft 62 is rotated so as to be in the state shown in FIG. Thereby, the cap holder 49 is raised as indicated by an arrow D by the rotation of the cap cam 63. As the cap holder 49 is raised, the caps 47a and 47b cap and cover the tip portions of the nozzles of the inkjet heads 24a and 24b, so that drying of the nozzles can be suppressed. At this time, the wiper blade 48 is lowered as indicated by an arrow E.

  Then, the wiper blade 48 and the cap holder 49 can both be lowered by rotating the maintenance / recovery mechanism driving motor 61 by 1/4 from the state shown in FIG. As a result, the wiper blade 48 and the caps 47a and 47b are both separated from the nozzle surface 23a, the carriage 23 can be scanned, and preparations for printing start are made.

[Configuration example of control unit]
Next, a configuration example of the control unit of the inkjet printer 1 will be described.
FIG. 6 is a block diagram showing the configuration of the control unit of the ink jet printer together with related units.
The control unit includes a control microcomputer 100 configured by a microcomputer that controls the entire inkjet printer, and a print control microcomputer 108 configured by a microcomputer that controls printing.
When there is a print command from the user through the application 90 of the host computer connected to the inkjet printer, the OS (GDI) 92 of the host computer transmits image data output by the inkjet printer to the printer driver 94.

Here, a GDI (Graphic Device Interface) implemented in a Windows (registered trademark) OS such as Windows (registered trademark) XP is taken as an example.
The printer driver 94 converts the image data transmitted from the application 90 into print image data in a format that can be processed by the ink jet printer, and inputs the image data to the control microcomputer 100 of the ink jet printer via the communication circuit 96.
The control microcomputer 100 includes a carriage drive motor and a carry motor, which will be described later, a carriage drive motor drive circuit 103 and a carry motor drive circuit in order to form an image on a sheet based on the printed image data input from the communication circuit 96. Drive control is performed via 105. Further, control such as sending print data to the print control microcomputer 108 is performed.

The control microcomputer 100 receives a detection signal from the carriage position detection circuit 102 that detects the position of the carriage 23 described above, and controls the movement position and movement speed of the carriage 23 based on the detection signal.
The carriage position detection circuit 102 detects the position of the carriage 23 by counting the pulse signals detected by the photosensor attached to the carriage 23 with the slits of the encoder sheet fixedly arranged along the main scanning direction of the carriage 23. To do.
The carriage drive motor drive circuit 103 rotates the carriage drive motor according to the carriage movement amount input from the control microcomputer 100 to move the carriage 23 to a predetermined position at a predetermined speed.

The control microcomputer 100 receives a detection signal from the conveyance amount detection circuit 104 that detects the movement amount of the conveyance belt 34 shown in FIGS. 1 and 2, and the movement amount and movement of the conveyance belt 34 based on the detection signal. Control the speed.
The conveyance amount detection circuit 104 counts the pulse signal generated by the rotary encoder attached to the rotation shaft of the conveyance roller 41 shown in FIG. 1 and FIG. The amount of movement is detected.

The transport motor drive circuit 105 rotates the transport motor in accordance with the transport amount input from the control microcomputer 100 and rotates the transport roller 41 to move the transport belt 34 to a predetermined position at a predetermined speed. .
The control microcomputer 100 rotates the sheet feeding roller 32 shown in FIG. 1 once by giving a sheet feeding roller driving command to the sheet feeding roller driving circuit 110.
Further, the control microcomputer 100 rotates and drives the above-described maintenance / recovery mechanism drive motor 61 via the maintenance / recovery mechanism drive motor drive circuit 111, and the caps 47a and 47b and the wipers shown in FIGS. The blade 48 is raised and lowered.

Further, the control microcomputer 100 drives and controls the ink supply motor for driving the pump of the supply pump unit 28 shown in FIG. 2 via the ink supply motor drive circuit 112, and the ink loaded in the cartridge loading unit 7. Ink is supplied from the cartridge 9 to the sub tank 26.
The control microcomputer 100 also receives a detection signal from the sub tank liquid level sensor 113 that detects the liquid level of the sub tank 26, a detection signal from the cartridge cover sensor 114 that detects opening and closing of the front cover of the cartridge loading unit 7, and the like. Entered.

Further, each ink cartridge 9 attached to the cartridge loading unit 7 shown in FIG. 2 is provided with a nonvolatile memory. Therefore, the control microcomputer 100 takes in information stored in each nonvolatile memory of each ink cartridge 9 through the cartridge communication circuit 115, performs a necessary process, and then performs an internal nonvolatile memory (for example, (EEPROM) 116 is stored and held.
Further, various information is displayed on an operation panel 117 having various keys and a display, and information by a user's key operation is input.

On the other hand, the print control microcomputer 108 drives pressure generation means for discharging ink droplets from the nozzles of the carriage 23 based on the carriage position information from the control microcomputer 100 and the information on the conveyance amount by the conveyance belt. Is generated and applied to the head drive circuit 109.
The head drive circuit 109 drives the pressure generating means (a piezoelectric element in the case of a piezo-type head) of the carriage 23 based on the print data from the print control microcomputer 108 to eject ink droplets from the required nozzles.

The control microcomputer 100 detects the size of the paper being passed from the paper size sensor 106 and determines whether the input image data can be arranged on the paper, and if there is image data outside the paper, The print control microcomputer 108 can be set to perform trimming and drawing.
As a method for detecting the paper size, a reflective sensor is arranged on the side of the carriage 23, and the paper width is detected by detecting the difference in reflectance between the paper and the conveyance path when the carriage 23 scans. it can. In addition, the sheet width can also be detected by arranging a line sensor on the sheet conveyance path so as to go straight in the conveyance direction. As for the sheet length in the conveyance direction, a reflection type sensor can be similarly arranged on the conveyance path, and the sheet length can be detected based on the conveyance amount after the leading edge of the sheet is detected.

  The control microcomputer 100 can detect the position of the paper in the machine from a plurality of paper position sensors 107 arranged on the conveyance path. If the paper is in an unintended position during printing, the control microcomputer 100 can jam. (Paper jam) can be detected and the user can be notified of the abnormality. The location where the abnormality has occurred can also be indicated.

[Embodiments of features of the present invention]
Next, referring to FIGS. 7A to 7E, the configuration and operation of the embodiment of the characterizing portion of the present invention in the above-described ink jet printer will be described.
7A to 7E correspond to FIG. 2 for explaining the mechanism for moving the carriage 23 to the position corresponding to the maintenance / recovery mechanism 46 when the power supply in the above-described inkjet printer is cut off, and the operation thereof. It is a schematic plan view to do.
7A is a printing operation state, FIG. 7B is a state immediately after the power supply is cut off, FIG. 7C is a state where the carriage is moved to a position corresponding to the maintenance / recovery mechanism, and FIG. 7D is a state immediately after the power supply is started. FIG. 7E shows a state where the moving member is pushed back to the left end position and held on the side plate.

In these drawings, the same parts as those shown in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.
First, the components not shown in FIG. 2 will be described with reference to FIG. 7A.
The carriage 23 penetrates the guide rod 21 and is provided so as to be able to reciprocate between the left side plate 20 a and the right side plate 20 b along the guide rod 21. Near the inner side of the left side plate 20a, a main scanning motor 70 having a drive pulley 71 fixed to the rotating shaft is fixed by a bracket (not shown). Further, a driven pulley 72 is rotatably supported by a support member (not shown) near the inside of the right side plate 20b.

A timing belt 73 is stretched between the drive pulley 71 and the driven pulley 72 and is arranged in parallel near the guide rod 21. A belt clamping portion 23 b provided at the rear end portion of the carriage 23 is fixed with a part of the upper portion of the timing belt 73 interposed therebetween.
The main scanning motor 70 can rotate in the forward and reverse directions. When the driving pulley 71 is rotated by the forward or reverse rotation, the timing belt 73 rotates (referred to as rotation) to move the carriage 23 in the direction indicated by the arrow X (see FIG. It can be reciprocated in the main scanning direction.

During the printing operation, the carriage 23 reciprocates in a printing area within the width of the sheet conveyed by the conveying belt 34.
Further, in a normal state, when a series of printing (print job) is completed, the carriage 23 is moved to a position corresponding to the maintenance / recovery mechanism 46 by the rotation of the electrically controlled main scanning motor 70. Wait after the above-mentioned capping is performed.
These are configurations also provided in a conventional inkjet printer.

Members newly provided in the embodiment of the present invention are a moving member 81, an electromagnetic stopper 83, and a coil spring 85.
The moving member 81 is a flat plate member that is penetrated by the guide rod 21 and can reciprocate along the guide rod 21, and has a pressing portion 81 a on the surface facing the side surface of the carriage 23 and an end near the timing belt 73. The part is provided with a spring hook 81b. Further, the moving member 81 has an inverted L-shaped hook portion 81c that extends outward from a surface opposite to the pressing portion 81a and protrudes backward at a tip portion parallel to the left side plate 20a. ing. The hook portion 81c can protrude to the outside of the left side plate 20a through an opening 20h (see FIG. 7B) formed in the left side plate 20a.

Then, both ends of the coil spring 85 are attached to the spring hooking portion 81b and the right side plate 20b of the moving member 81.
Further, an electromagnetic stopper 83 is fixed at a position facing the opening 20h on the outer surface of the left side plate 20a, which is a fixed member, and the movable piece 83a of the electromagnetic stopper 83 always protrudes into the opening 20h. The tip of the movable piece 83a is formed on an inclined surface that increases the amount of protrusion into the opening 20h with respect to the moving direction in which the hook portion 81c of the moving member 81 protrudes from the opening 20h.

  The electromagnetic stopper 83 used in this embodiment incorporates a small electromagnet and a spring, and gives an elastic force in a direction in which the movable piece 83a is retracted by the spring. However, when the power is supplied, the electromagnet opposes the force of the spring and causes the movable piece 83a, at least part of which is made of a magnetic material, to protrude by a repulsive force or an attractive force. When the power supply is cut off, the movable piece 83a is retracted by the spring force. Therefore, when the power is supplied, the electromagnetic stopper 83 is always energized, but the power consumption is very small.

When the moving member 81 is pushed by the carriage 23 and moved to a position where it comes into contact with the left side plate 20a, the hook portion 81c protrudes from the opening 20h, and the bent tip portion is the tip portion of the movable piece 83a of the electromagnetic stopper 83. Move by sliding on the slope. At that time, the movable piece 83a can be retracted against the force of the electromagnet, and the movable piece 83a protrudes again immediately after the passage, and the hook portion 81c is prevented from being caught by the movable piece 83a and returning to the right. The
Thereby, as shown in FIG. 7A, the moving member 81 is held by the left side plate 20a which is the left side fixing member by the electromagnetic stopper 83. In this state, the coil spring 85 is greatly extended, and a force for moving the moving member 81 toward the right side plate 20b is stored.

  During a normal printing operation, in the state shown in FIG. 7A, the timing belt 73 is rotated by forward and reverse rotation of the main scanning motor 70 that is electrically controlled by the control microcomputer 100 shown in FIG. As a result, the carriage 23 reciprocates in the direction indicated by the arrow X in the required printing area along the guide rod 21, and forms an image on the sheet conveyed in the sub-scanning direction by the conveying belt 34. At this time, since the moving member 81 is held by the left side plate 20 a, no load is applied to the reciprocating movement of the carriage 23.

If the power supply to the inkjet printer is interrupted due to a power failure or the power plug being unintentionally pulled out during this printing operation, the power supply to the main scanning motor 70 is interrupted and the carriage 23 is indefinite. Stop at the position.
For example, as shown in FIG. 7A, it is assumed that the carriage 23 stops in the middle of the reciprocating range. In this case, in order to move the carriage 23 with the driving force of the main scanning motor 70, a relatively large amount of electric power is required, so the main scanning motor 70 cannot move the carriage 23 to a position corresponding to the maintenance / recovery mechanism 46. .

  However, when the power supply is cut off, power is not supplied to the electromagnetic stopper 83, and the movable piece 83a is retracted by the force of the spring, so that it is detached from the hook portion 81c of the moving member 81. Therefore, the moving member 81 is released from being held on the left side plate 20 a and becomes free, and by the restoring force stored in the coil spring 85. As shown by the arrow X1 in FIG. 7B, it moves in the direction approaching the right side plate 20b.

The moving member 81 comes into contact with the carriage 23 during the movement, and the pressing portion 81 a hits the side surface of the carriage 23. Thereafter, the moving member 81 moves as shown by an arrow X2 in FIG. 7C while pushing the carriage 23, moves the carriage 23 to a position corresponding to the maintenance / recovery mechanism 46, and stops.
In this state, the maintenance / recovery mechanism driving motor 61 shown in FIGS. 4 and 5 is driven by a small amount of electric power remaining in the capacitor of the power supply circuit, and the camshaft 62 is rotated by ¼, thereby maintaining / recovering mechanism. The cap holder 49 of 46 is raised, and the inkjet heads 24a and 24b can be capped by the caps 47a and 47b, respectively.

Thereafter, when the power supply to the ink jet printer is resumed, the electromagnetic stopper 83 is also supplied with power, so that the movable piece 83a protrudes as shown in FIG. 7D. Then, the rotation of the main scanning motor 70 electrically controlled by the control microcomputer 100 shown in FIG. 6 moves the carriage 23 in a direction approaching the left side plate 20a as indicated by an arrow X3 in FIG. 7D.
As a result, the moving member 81 is pushed by the carriage 23 and is moved until it contacts the left side plate 20a as shown by an arrow X4 in FIG. And the hook part 81c of the moving member 81 is hooked on the movable piece 83a of the electromagnetic stopper 83, and the moving member 81 is hold | maintained at the left side board 20a.

  At this time, if there is a print job, the carriage 23 can be moved back and forth in the print area as it is to start printing. If there is no print job, the carriage 23 is moved again to a position corresponding to the maintenance / recovery mechanism 46, and each nozzle is capped and placed on standby.

In this embodiment, the moving member 81 is always the left side plate 20a which is a fixed member on the other moving end side with respect to the moving end (one moving end) side on which the maintenance / recovery mechanism 46 of the carriage 23 is provided. And is brought into contact with the carriage 23 by moving toward the one moving end side.
The coil spring 85 is a moving force accumulating unit that stores a force for moving the moving member 81 toward the one moving end when the moving member 81 is moved toward the other moving end.
When the moving member 81 is pushed by the carriage 23 and moved to the other moving end side when power is supplied, the electromagnetic stopper 83 holds the moving member 81 on the left side plate 20a that is a fixed member. And holding / releasing means for releasing the holding when the power supply is cut off.

  When the power supply is cut off, the moving member 81 is released from the holding by the electromagnetic stopper 83 as holding / release means, and the one moving end is moved by the force accumulated in the coil spring 85 as moving force accumulation means. Move to the side. Accordingly, the moving member 81 contacts the carriage 23 to move the carriage 23 to a position corresponding to the maintenance / recovery mechanism 46, and the nozzles of the inkjet heads 24 a and 24 b are moved by the caps 47 a and 47 b of the maintenance and recovery mechanism 46. Enable capping.

  Further, in this embodiment, the extension coil spring is used as the moving force accumulating means. However, instead of this, a compression coil spring may be used and attached between the left side plate 20a and the moving member 81. . A coil spring is preferable because it is relatively inexpensive and has little deterioration over time. However, when the moving member 81 is moved to the left side plate 20a, which is the other moving end, the force that moves the moving member 81 to the right side plate 20b, which is one moving end, is elastically deformed and stored. If it is a member which has, members other than a coil spring may be sufficient. For example, rubber, a winding spring or a small air cylinder can be used.

According to the above-described embodiment, when the power supply is interrupted without affecting the load of the reciprocating movement of the carriage 23 during the printing operation, no control is required and the restoring force of the coil spring is not required. Thus, the ink jet head 24 can be moved to a position corresponding to the maintenance / recovery mechanism 46 and the ink jet head 24 can be capped.
However, this is not limited to a case where the power supply is cut off due to a power failure or the power plug of the inkjet printer being unexpectedly disconnected during the printing operation, and the movable member 81 is always unlocked when the power is turned off. 81 moves toward the right side plate 20b.

That is, when the printing operation is completed and the carriage 23 is already waiting at a position corresponding to the maintenance / recovery mechanism 46 (for example, when the power switch is turned off), an extra operation is performed. Become. Even in that case, when the power supply is resumed after that, it is necessary to move the carriage 23 to the vicinity of the left side plate, push the moving member 81 back while stretching the coil spring 85, and hold it on the left side plate 20a by the electromagnetic stopper 83. is there.
However, since the moving member 81 is held by the left side plate 20a during the printing operation, the movement load of the inkjet head is increased during the normal printing operation as in the apparatus described in Patent Document 1. There is no. Therefore, the increase in power consumption is only small when the power supply is resumed, and the load on the inkjet head does not change depending on the moving direction, so there is no risk of image quality deterioration.

[Other Embodiments of the Invention]
By the way, only when it is really necessary, the carriage is moved to a position corresponding to the maintenance / recovery mechanism by the moving member, and the electromagnetic stopper is not energized at all times to minimize power consumption. The embodiment will be described with reference to FIGS.
FIG. 8 is a block diagram showing only a part necessary for explaining the embodiment of the control unit shown in FIG.

  The ink jet printer of this embodiment has an operation panel 117 provided with a power switch, like a normal ink jet printer. Further, when the power supply is shut off by operating the power switch, if the carriage is not in a position corresponding to the maintenance / recovery mechanism, the carriage is moved to a position corresponding to the maintenance / recovery mechanism, and the cap of the maintenance / recovery mechanism is Therefore, the nozzle of the inkjet head is capped.

  Then, the control microcomputer 100 shown in FIG. 8 monitors the state of the power switch of the operation panel 117 and the nonvolatile memory 116 that stores the state, and when the power supply is cut off, the factor is the power switch. It is determined whether or not it is due to the operation of. Then, only when it is determined that the cause of the interruption of the power supply is not due to the operation of the power switch, the electromagnetic stopper drive circuit 118 is controlled to hold the moving member 81 by the electromagnetic stopper as a holding / release means. Release it. The control microcomputer 100 is backed up by a battery so that the minimum necessary operation can be continued for a while even if the power supply is cut off.

  Therefore, the control microcomputer 100 stores the first state in the non-volatile memory 116 as the storage unit when the power is supplied when the power switch is operated, and the second state when the power supply is cut off. Let If the nonvolatile memory 116 stores the first state when the power supply is cut off, it is determined that the interruption factor is not due to the operation of the power switch, and the nonvolatile memory 116 If the state is stored, it is determined that the interruption factor is due to the operation of the power switch. This is a function as a cutoff factor determination means by the control microcomputer 100.

  FIG. 9 is a flowchart illustrating an example of a process for storing operation information of the power switch in the nonvolatile memory 116 by the control microcomputer 100 illustrated in FIG. 8. FIG. 10 is a flowchart showing an example of processing at the time of power supply interruption by the control microcomputer 100. In these figures, each step is indicated by “S”.

The control microcomputer 100 always performs the processing shown in FIG. 9. In step (S) 1, it is determined whether or not the power switch is operated. If the power switch is not operated (in the case of N), step 1 is executed. Wait until the operation is repeated. However, since it is usually necessary to perform other treatments in parallel, the determination in step 1 may be performed at a short regular timing.
If it is determined in step 1 that the power switch has been operated (in the case of Y), the process proceeds to step 2 to determine whether or not the power supply is started, and in the case where the power supply is started (when turned on). In step 3, “1” indicating the first state is stored in the nonvolatile memory, and this process is terminated.

If it is determined in step 2 that the power supply is not started (turned off), “0” indicating the second state is stored in the nonvolatile memory in step 4 and the process is terminated.
Thus, if power is supplied when the power switch is operated, “1” is set as the first state in the nonvolatile memory 116 as the first state, and “0” is set as the second state when the power supply is cut off. Remember.

  Further, the control microcomputer 100 always performs the processing shown in FIG. 10. In step 11, it is determined whether or not the power supply is interrupted. If it is determined that the power supply is not interrupted (in the case of N), The determination in step 11 is repeated until the power supply is cut off. However, in this case as well, since it is usually necessary to perform other treatments in parallel, the determination in step 11 may be performed at a short periodic timing.

If it is determined in step 11 that the power supply is cut off (in the case of Y), the process proceeds to step 12 to determine whether or not the data stored in the nonvolatile memory is “1”. If the data in the nonvolatile memory is not “1” (in the case of “0”) in the determination of step 12, it is determined that the power switch is turned off and the power is shut off, and this process is terminated without doing anything.
However, if the data in the nonvolatile memory is “1” in Step 12 (Y), the power supply is cut off even though the power switch is ON. Therefore, it is determined that the power supply cutoff factor is not due to the operation of the power switch, and in step 13, the moving member 81 is unlocked by an electromagnetic stopper, which will be described later, and the process ends.

  Accordingly, the moving member 81 described above with reference to FIGS. 7A to 7E is moved by the restoring force of the coil spring 85 and pushes the carriage 23 to a position corresponding to the maintenance and recovery mechanism 46. Accordingly, the maintenance / recovery mechanism 46 can cap the nozzles of the inkjet head 24 mounted on the carriage 23 by the cap.

FIG. 11 is a diagram illustrating a configuration example of the electromagnetic stopper driving circuit 118 illustrated in FIG. 8, and controls the electromagnetic stopper 84.
The electromagnetic stopper 84 is slightly different from the electromagnetic stopper 83 described with reference to FIGS. 7A to 7E.
The electromagnetic stopper 84 also includes a small electromagnet 84b and a coil spring 84c. However, normally, the movable piece 84a is projected to the maximum by the restoring force of the coil spring 84c interposed between the movable piece 84a and the iron core of the electromagnet 84b. The movable piece 84a is formed of a magnetic material at least at a portion facing the electromagnet 84b, and is retracted in the direction (indicated by arrow F) by the attractive force of the electromagnet 84b only when the coil L of the electromagnet 84b is energized. Moving.

The electromagnetic stopper drive circuit 118 shown in FIG. 11 includes two transmission gates 121 and 122, an inverting circuit (inverter) 123, a capacitor C1, and two resistors R1 and R2.
When a low level signal “0” is input to the signal input terminal 124, the transmission gate 121 is turned on and the transmission gate 122 is turned off. Therefore, if power is supplied to the power supply terminal 125, a charging current flows to the capacitor C1 through the resistor R1 and the transmission gate 121 to charge the capacitor C1. When the charging is completed, no more current flows, so the power consumption is negligible.

When a high level signal “1” is input to the signal input terminal 124, the transmission gate 122 is turned on and the transmission gate 121 is turned off. Therefore, a discharge current flows to the coil L of the electromagnet 84b of the electromagnetic stopper 84 through the transmission gate 122 and the resistor R2 due to the electric charge charged in the capacitor C1.
As a result, the electromagnet 84b is excited only for a short time, and the movable piece 84a moves against the force of the coil spring 84c by the attraction force and moves in the retracting direction.

Therefore, if the control microcomputer 100 in FIG. 8 inputs the signal “1” to the signal input terminal 124 in the electromagnetic stopper drive circuit 118 in FIG. 11 only when the processing in step 13 in FIG. The movable piece 84a of 84 can be moved in the direction of arrow F, and the lock of the moving member 81 described with reference to FIGS. 7A to 7E can be released.
Accordingly, the moving member 81 is moved by the restoring force of the coil spring 85 and pushes the carriage 23 to move to a position corresponding to the maintenance / recovery mechanism 46, thereby enabling capping of the inkjet head.

As described above, the ink jet printer according to this embodiment unlocks the moving member 81 only when the power supply is suddenly interrupted due to a factor other than the power switch being turned OFF. Therefore, when the power switch is turned off and the power supply is normally cut off, no extra operation is performed. Therefore, when the power switch is turned on and power supply is resumed, the operation of moving the moving member 81 to the lock position becomes unnecessary, and unnecessary power consumption is eliminated.
In addition, the electromagnetic stopper 84 does not need to be energized all the time, and only needs to be energized for a short time only when the lock of the moving member 81 is released.

Further, when the control microcomputer 100 in FIG. 8 determines whether or not the carriage is at the standby position corresponding to the maintenance / recovery mechanism 46 before executing the process of step 13 in FIG. It is more preferable that the process of step 13 is executed only for the above.
Then, even when the power supply is cut off due to a power failure or the like, if the print job is completed and the carriage is in the standby position, the movement member 81 is not unlocked and unnecessary operations are not performed.

Although the description of the embodiment has been completed above, in the present invention, the specific configuration of each unit, the content of processing, the data format, and the like are not limited to those described in the embodiment.
In the above-described embodiment, an example in which the present invention is applied to an ink jet printer has been described. However, the present invention is similarly applied to other image forming apparatuses such as a facsimile machine, a copier, and a multi-function machine having an ink jet type image forming unit. Applicable. The present invention can be applied not only to a color image forming apparatus but also to an image forming apparatus that forms a monochrome image.
In addition, the configuration of each of the above-described embodiments can be added, changed, or omitted as appropriate within the scope defined by the claims, and can of course be implemented in any combination within a range that does not contradict each other. .

1: Inkjet printer 2: Paper feed tray 3: Paper output tray
7: Cartridge loading unit 9, 9k, 9c, 9m, 9y: Ink cartridge 20: Frame 20a: Left side plate 20b: Right side plate 20c: Rear plate
20h: Opening 21: Guide rod 22: Stay 23: Carriage
23a: Nozzle surface 23b: Belt clamping part
24, 24a, 24b: inkjet head 25: harness 26, 26k, 26c, 26m, 26y: sub tank 27: ink supply tube 28: supply pump unit 29: holder 30: fixing rib 31: paper stacking unit
32: Feed roller 33: Separation pad 34: Conveyor belt 35: Guide
36: Counter roller 37: Transport guide 38: Holding member
39: tip pressure roller 40: charging roller 41: transport roller

42: Tension roller 43: Guide member 44: Double-sided paper feed unit 45: Manual paper feed unit 46: Maintenance / recovery mechanism 47a, 47b: Cap 48: Wiper blade 49: Cap holder 50: Empty discharge receptacle
51: Opening of empty discharge receptacle 52: Separation claw 53: Paper discharge roller 54: Paper discharge roller
60, 60k to 60y: Nozzle row 60n: Nozzle outlet
61: Maintenance / recovery mechanism drive motor 62: Cam shaft 63: Cap cam
64: wiper cam 70: main scanning motor 71: driving pulley 72: driven pulley 73: timing belt 81: moving member 81a: pressing portion 81b: spring hook portion 81c: hook portion 83, 84: electromagnetic stopper 83a, 84a: movable Fragment
84b: Electromagnet 84c, 85: Coil spring

90: Application 92: OS (GDI) 94: Printer driver
96: communication circuit 100: control microcomputer 102: carriage position detection circuit 103: carriage drive motor drive circuit 104: carry amount detection circuit 105: carry motor drive circuit 106: paper size sensor 107: paper position sensor
108: Print control microcomputer 109: Head drive circuit 110: Paper feed roller drive circuit 111: Maintenance / recovery mechanism drive motor drive circuit 112: Ink supply motor drive circuit 113: Sub tank liquid level sensor 114: Cartridge cover sensor 115: Cartridge Communication circuit 116: Non-volatile memory 117: Operation panel
118: Electromagnetic stopper drive circuit 121, 122: Transmission gate
123: Inversion circuit 124: Signal input terminal 125: Power supply terminal

JP 2006-192649 A

Claims (6)

An inkjet head that ejects ink droplets from nozzles is mounted, a carriage that reciprocates along a guide member is provided, and at least one cap on the moving end side of the carriage has a cap that caps at least the nozzles of the inkjet head. In an inkjet image forming apparatus provided with a mechanism,
A moving member that is normally held by a fixed member on the other moving end side of the carriage and contacts the carriage by moving to the one moving end side;
A moving force accumulating means for storing a force for moving the moving member toward the one moving end when the moving member is moved toward the other moving end;
When the moving member is pushed by the carriage and moved to the other moving end side when power is supplied, the moving member is held by the fixed member, and when the power supply is cut off, A holding / release means for releasing the holding;
When the power supply is cut off, the moving member is released from holding by the holding / release means, moves to the one moving end side by the force accumulated in the moving force accumulation means, and contacts the carriage. The carriage is moved to a position corresponding to the maintenance / recovery mechanism, and the nozzle of the inkjet head can be capped by the cap of the maintenance / recovery mechanism.   The moving force accumulating means is a member having an elastic force for accumulating the force for moving the moving member toward the one moving end when the moving member is moved toward the other moving end. The inkjet image forming apparatus according to claim 1, wherein the inkjet image forming apparatus is provided.   3. The member having elastic force is a coil spring having one end connected to the moving member and the other end connected to a fixed member on the one moving end side of the carriage. The inkjet image forming apparatus described. In the inkjet image forming apparatus according to any one of claims 1 to 3,
A power switch, and when the power supply is shut off by operating the power switch, when the carriage is not in a position corresponding to the maintenance / recovery mechanism, the carriage is moved to a position corresponding to the maintenance / recovery mechanism, Having a function of capping the nozzle of the inkjet head by the cap of the maintenance and recovery mechanism;
When the power supply is cut off, there is provided a cutoff factor judgment means for judging whether the factor is due to the operation of the power switch,
The ink-jet printer is characterized in that the holding / releasing means releases the holding of the moving member only when the shut-off factor determining means determines that the cause of the power supply being cut off is not due to the operation of the power switch. Image forming apparatus.   The shut-off factor determining means is a storage means for storing the first state when power is supplied when the power switch is operated, and the second state when the power supply is shut off, and the power supply is shut off. 5. The determination unit according to claim 4, further comprising: a determination unit that determines that the factor is not caused by an operation of a power switch if the storage unit stores the first state when the operation is performed. Inkjet image forming apparatus.     The shut-off factor determining means, when it is determined that the factor that shuts off the power supply is not due to the operation of a power switch, only when the carriage is not in the standby position corresponding to the maintenance / recovery mechanism, The inkjet image forming apparatus according to claim 4, wherein a release unit releases the holding of the moving member.

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