JP2007098914A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device which copes with a requirement of printing immediately after power turning-on, by shortening a time period necessary for initial operation to a possible minimum extent, and speeding up start-up operation. <P>SOLUTION: According to the operation of the image forming device, in the carriage initial operation, after a carriage 23 is moved in an outgoing direction by setting a carriage speed to a low-speed value, determination is made as to whether a cover 15 of a device main body is opened or closed, based on a detection signal from a cover opening/closing detection circuit 313. If the cover 15 is closed, the carriage speed is set to a high-speed value. On the other hand if the cover 15 is opened, the carriage speed is set to the low-speed value, and thereafter the carriage 23 is moved in a returning direction at a set value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus in which a recording head for ejecting recording liquid droplets is mounted on a carriage.

  As an image forming apparatus such as a printer, a facsimile, a copying apparatus, and a multifunction machine of these, for example, an ink jet recording apparatus is known. The ink jet recording apparatus uses a liquid discharge head as a recording head, and is a recording medium such as recording paper (hereinafter referred to as “paper”, but the material is not limited to paper, and the recording medium, transfer paper, transfer material, Recording is also performed by ejecting ink droplets as a recording liquid (also referred to as image forming, printing, printing, printing, etc.).

  Among such ink jet recording apparatuses, there is a serial type in which a recording head is mounted on a carriage and paper is intermittently sent in the sub-scanning direction to form an image while moving the carriage in the main scanning direction.

In such a serial type image forming apparatus, Japanese Patent Application Laid-Open No. H10-228867 discloses that the recording head moving speed is optimally controlled in relation to the open / closed state of the cover during the recovery operation of the recording head. In order to ensure reliability, convenience, and image reliability, the cover opening / closing state is monitored when the recording head moves for recovery processing, and when the cover opening state is detected, the moving speed of the recording head is adjusted. To ensure safety when the user touches the print head, etc., and when the cover open state is detected, the print head is decelerated and the operating condition of the recovery means of the print head is changed. It is described to do so.
Japanese Patent Application Laid-Open No. 2002-067291

Further, in Patent Document 2, in order to efficiently perform the idle ejection for maintaining the performance of the printer head, when performing the maintenance operation for idle ejection, a predetermined range (for example, three scans in the front and rear directions) sandwiching the maintenance operation timing is used. It is described that the print data position of the print data is determined, and the maintenance operation is performed after scanning the print data closest to the maintenance operation position from the print data position during the printing operation.
JP 2003-94680 A

  By the way, in the image forming apparatus, immediately after the power is turned on, an initial operation for ensuring image and device quality is performed. This initial operation includes a check operation for checking whether or not the recording head maintenance / recovery operation is normal as described in the above-mentioned Patent Document 1, an operation check for checking whether or not the carriage movable range is normal. It is.

  However, for the user, since the initial operation is performed even if the user wants to print immediately after turning on the power, the printing operation is not started until the initial operation time is completed, and the printing speed is slow, Even if it sees in total, the subject that printing time becomes long has arisen.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of quickly starting up after power-on by shortening the initial operation time as much as possible. And

  In order to solve the above-described problems, the image forming apparatus according to the present invention is configured to move the carriage at different speeds in the forward path and the backward path when performing the initial carriage operation.

  Here, it is preferable to determine the return speed of the carriage based on the detection result of the state of the cover that can be opened and closed of the apparatus main body. In this case, it is preferable that the return speed of the carriage is higher than the forward speed when the cover is closed, and the return speed of the carriage is equal to or less than the forward speed when the cover is open. It is preferable.

  According to the image forming apparatus of the present invention, since the carriage is moved at different speeds in the forward path and the backward path when the carriage initial operation is performed, the time required for the initial operation is shortened as much as possible to quickly start up. Can be.

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory perspective view of the image forming apparatus as an example of the image forming apparatus according to the present invention as viewed from the front side.
The image forming apparatus includes an apparatus main body 1, a paper feed tray 2 for loading paper loaded in the apparatus main body 1, and a sheet on which an image is recorded (formed) by being detachably mounted on the apparatus main body 1. A paper discharge tray 3 for stocking is provided. Furthermore, a cartridge loading for loading an ink cartridge that protrudes from the front surface to the front side of the apparatus main body 1 and is lower than the upper surface is provided at one end side of the front surface of the apparatus main body 1 (side of the paper supply / discharge tray section). The cartridge loading unit 4 has an operation / display unit 5 provided with operation buttons and a display.

  The cartridge loading unit 4 includes a plurality of recording liquid cartridges that contain recording liquids (inks) of different colors, for example, black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Ink cartridges 10k, 10c, 10m, and 10y (referred to as “ink cartridge 10” when colors are not distinguished) are inserted from the front side to the rear side of the apparatus main body 1 and can be loaded. A front cover (cartridge cover) 6 that is opened when the ink cartridge 10 is attached or detached is provided on the front side of the unit 4 so as to be openable and closable.

  Further, the operation / display unit 5 has the remaining amounts of the ink cartridges 10k, 10c, 10m, and 10y of each color at the arrangement positions corresponding to the mounting positions (arrangement positions) of the ink cartridges 10k, 10c, 10m, and 10y of the respective colors. The remaining amount display portions 11k, 11c, 11m, and 11y for each color for displaying the near end and the end are arranged. Further, the operation / display unit 5 is also provided with a power button 12, a paper feed / print resume button 13, and a cancel button 14.

  A main body cover 15 is mounted on the upper surface of the apparatus main body 1 so as to be opened and closed in the direction of the arrow.

Next, the mechanism of this image forming apparatus will be described with reference to FIGS. FIG. 2 is a schematic configuration diagram for explaining the overall configuration of the mechanism unit, and FIG.
A guide rod 21, which is a guide member placed horizontally between left and right side plates (not shown), and a stay 22 hold the carriage 23 slidably in the main scanning direction, and is driven between the driving pulley 25 and the driven pulley 26 by the main scanning motor 24. 3 moves and scans in the direction indicated by the arrow (carriage scanning direction: main scanning direction) in FIG.

  The carriage 23 has recording heads 31k, 31c, 31m, and 31y (distinguishable) composed of droplet ejection heads that eject ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk). If not, it is referred to as “recording head 31”). A plurality of ink ejection openings are arranged in a direction crossing the main scanning direction, and the ink droplet ejection direction is directed downward.

  As an ink jet head constituting the recording head 31, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. It is possible to use a shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a droplet.

  The carriage 23 is equipped with a sub tank 32 for each color for supplying each color ink to the recording head 31. Each color sub-tank 32 is supplementarily supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4 via the ink supply tube of each color.

  On the other hand, as a sheet feeding unit that is a feeding unit for feeding the sheets 42 stacked on the sheet stacking unit (pressure plate) 41 of the sheet feeding tray 2, the sheets 42 are separated and fed one by one from the sheet stacking unit 41. A half paddle (feed roller) 43 and a separation pad 44 made of a material having a large friction coefficient are provided opposite to the half-moon roller (sheet feed roller) 43, and the separation pad 44 is urged toward the sheet feed roller 43 side.

  In order to feed the sheet 42 fed from the sheet feeding unit to the lower side of the recording head 31, a guide member 45 for guiding the sheet 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a holding belt 48 which is a conveying means for electrostatically attracting the fed paper 42 and conveying it at a position facing the recording head 31.

  The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction). This transport belt 51 is, for example, a surface layer that is a sheet adsorbing surface formed of a pure resin material having a thickness of about 40 μm that is not subjected to resistance control, such as ETFE pure material, and resistance control by carbon with the same material as this surface layer. And a back layer (medium resistance layer, ground layer).

  A charging roller 56 is provided as charging means for charging the surface of the conveyor belt 51. The charging roller 56 is disposed so as to come into contact with the surface layer of the conveyor belt 51 and to be rotated by the rotation of the conveyor belt 51, and applies a predetermined pressing force to both ends of the shaft as a pressing force. The transport roller 52 also functions as an earth roller, and is in contact with the middle resistance layer (back layer) of the transport belt 51 and is grounded.

  In addition, a guide member 57 is disposed on the back side of the conveyance belt 51 so as to correspond to a printing area by the recording head 31. The guide member 57 has an upper surface that protrudes toward the recording head 35 from the tangent line of two rollers (the conveyance roller 52 and the tension roller 53) that support the conveyance belt 51, thereby maintaining high-precision flatness of the conveyance belt 51. Like to do.

  The conveyance belt 51 rotates in the belt conveyance direction (sub-scanning direction) in FIG. 3 when the conveyance roller 52 is rotationally driven by the sub-scanning motor 58 via the drive belt 59 and the pulley 60.

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 31, a separation claw 61 for separating the paper 42 from the conveyance belt 51, a paper discharge roller 62, and a paper discharge roller 63 are provided. The paper discharge tray 3 is provided below the paper discharge roller 62.

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

  Further, as shown in FIG. 3, a maintenance / recovery mechanism 81 including a recovery means for maintaining and recovering the nozzle state of the recording head 31 is arranged in the non-printing area on one side of the carriage 23 in the scanning direction. Yes.

  The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a to 82d (hereinafter referred to as “caps 82” when not distinguished from each other) for capping the nozzle surfaces of the recording head 31, and nozzle surfaces. A wiper blade 83 that is a blade member for wiping the ink, and an empty discharge receiver 84 that receives liquid droplets when performing empty discharge for discharging liquid droplets that do not contribute to recording in order to discharge the thickened recording liquid. ing. Here, the cap 82a is a suction and moisture retention cap, and the other caps 82b to 82d are moisture retention caps.

  Further, in the non-printing area on the other side of the carriage 23 in the scanning direction, there is an empty space for receiving a liquid droplet when performing an empty discharge for discharging a liquid droplet that does not contribute to recording in order to discharge the recording liquid thickened during recording or the like. A discharge receiver 88 is arranged, and the idle discharge receiver 88 is provided with openings 89 a to 89 d along the nozzle row direction of the recording head 31.

  In the ink jet recording apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feeding tray 2, and the sheet 42 fed substantially vertically upward is guided by the guide 45, and the transport belt 51 and the counter roller 46, and the leading end is guided by the conveying guide 37 and pressed against the conveying belt 51 by the tip pressing roller 49, and the conveying direction is changed by approximately 90 °.

  At this time, a charging voltage pattern in which a positive voltage and a negative output are alternately repeated from the AC bias supply unit to the charging roller 56 by a control unit (not shown), that is, an alternating voltage is applied, and the conveying belt 51 alternates. That is, plus and minus are alternately charged in a band shape with a predetermined width in the sub-scanning direction which is the circumferential direction. When the paper 42 is fed onto the conveyance belt 51 charged alternately with plus and minus, the paper 42 is attracted to the conveyance belt 51, and the paper 42 is conveyed in the sub-scanning direction by the circular movement of the conveyance belt 51.

  Therefore, by driving the recording head 31 according to the image signal while moving the carriage 23, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  During printing (recording) standby, the carriage 23 is moved to the maintenance / recovery mechanism 81 side, the recording head 31 is capped by the cap 82, and the nozzles are kept in a wet state to prevent ejection failure due to ink drying. . Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) with the recording head 31 capped by the cap 82 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. Thereby, the stable ejection performance of the recording head 31 is maintained.

Here, an example of the maintenance and recovery mechanism 81 will be described with reference to FIG. FIG. 4 is a schematic front view of the maintenance / recovery mechanism.
The frame 200 of the maintenance / recovery mechanism 81 includes a cap holder 201A for holding caps 82a and 82b for capping the nozzle surfaces 31a of the recording heads 31 described above, a cap holder 201B for holding caps 82c and 82d, and a nozzle surface. A wiper blade 83 which is a wiping member for wiping (wiping) 31a to be cleaned, an idle discharge receiver 84, and a carriage lock member (not shown) are held so as to be movable up and down. Here, the cap 82 is urged upward (capping direction) by an elastic member 202 provided between the cap holders 201A and 201B, and the cap elastic member 202 contracts when contacting the nozzle surface 31 of the recording head 31. A cap 82 is brought into close contact with the nozzle surface 31a.

  A cam shaft 205 is rotatably disposed on the frame 200 below the cap holders 201A and 201B (referred to as “cap holder 201” when not distinguished from each other). The cam shaft 205 is connected to a gear 206 by a drive motor (not shown). Is rotated. The camshaft 205 includes cap cams 211A and 211B for raising and lowering the cap holders 201A and 201B (referred to as “cap cam 211” when not distinguished), a wiper cam 212 for raising and lowering the wiper blade 83, and a carriage. A carriage lock cam (not shown) for raising and lowering the lock member 87 is provided.

  Therefore, by rotating the cam shaft 205, the cap cam 211 rotates, the cap holder 201 rises with the cap 82, and abuts against the nozzle surface 31a of the recording head 31 by the cap 82 to perform capping. The contact / separation operation in which 201 is lowered with the cap 82 and separated from the nozzle surface 31 a of the recording head 31 by the cap 82 can be performed.

  Further, a suction pump 207 such as a tube pump driven by a drive motor (not shown) for rotating the camshaft 205 is provided, the tube 207 is connected to the suction cap 82a, and the nozzle surface 31a of the recording head 31 is attached to the cap 82a. When the suction pump 207 is driven in the capped state, the recording liquid is forcibly sucked from the nozzles of the recording head 31 (nozzle suction), and the waste liquid of the recording liquid discharged into the cap 82a passes through the tube 208 from the suction pump 207. Through a waste liquid tank (not shown) below. Further, the waste liquid of the recording liquid discharged to the empty discharge receiver 84 by the empty discharge operation is also dropped into the lower waste liquid tank as it is.

Next, an outline of the control unit of the image forming apparatus will be described with reference to FIG. This figure is an overall block diagram of the control unit.
The control unit controls the entire image forming apparatus, and the main control unit 301 configured by a microcomputer also serving as a means for controlling the initial operation according to the present invention, and the printing configured by the microcomputer that controls the print control. And a control unit 302.

  Then, the main control unit 301 uses the main scanning motor 24 and the sub-scanning motor 58 as described above in order to form an image on the paper 42 based on the print processing information input from the communication circuit 300. Drive control is performed via the drive circuit 303 and the sub-scanning motor 304, and control such as sending print data to the print control unit 302 is performed.

  The main control unit 301 receives a detection signal from a carriage position detection circuit 305 that detects the position of the carriage 23, and the main control unit 301 controls the movement position and movement speed of the carriage 23 based on the detection signal. To do. The carriage position detection circuit 305 detects the position of the carriage 23 by, for example, reading and counting the number of slits of an encoder sheet arranged in the scanning direction of the carriage 23 with a photosensor mounted on the carriage 23. The main scanning motor drive circuit 303 rotates the main scanning motor 24 according to the carriage movement amount input from the main control unit 301 to move the carriage 23 to a predetermined position at a predetermined speed.

  Further, the main control unit 301 receives a detection signal from a conveyance amount detection circuit 306 that detects the movement amount of the conveyance belt 51, and the main control unit 301 moves the movement amount and movement speed of the conveyance belt 51 based on the detection signal. To control. The conveyance amount detection circuit 306 detects the conveyance amount by, for example, reading and counting the number of slits of the rotary encoder sheet attached to the rotation shaft of the conveyance roller 52 with a photo sensor. The sub-scanning motor driving circuit 304 rotates the sub-scanning motor 58 in accordance with the conveyance amount input from the main control unit 301 to rotate the conveyance roller 52 to move the conveyance belt 51 to a predetermined position at a predetermined speed. Move with.

  The main control unit 301 rotates the sheet feeding roller 43 once by giving a sheet feeding roller driving command to the sheet feeding roller driving circuit 307. The main control unit 301 rotates the above-described motor (not shown) of the maintenance / recovery mechanism 81 via the maintenance / recovery mechanism drive motor drive circuit 308 to move the cap 82 up and down, the wiper blade 83 up and down, and the suction pump 207. Drive it.

  The main control unit 301 drives and controls an ink supply motor for driving the pump of the supply unit via the ink supply motor drive circuit 311, and ink is supplied from the ink cartridge 10 loaded in the cartridge loading unit 4 to the sub tank 42. Replenish supply. At this time, the main control unit 301 controls replenishment supply based on a detection signal from the sub tank full tank sensor 312 that detects that the sub tank 42 is full.

  The main control unit 301 also stores information stored in the non-volatile memories 115k, 115c, 115m, and 115y that are storage units provided in the ink cartridges 10 attached to the cartridge loading unit 4 through the cartridge communication circuit 314. The data is taken in, required processing is performed, and the data is stored and held in a non-volatile memory (for example, EEPROM) 315 which is a main body storage unit.

  The print control unit 302 generates pressure for ejecting droplets of the recording head 41 based on the signal from the main control unit 301 and the carriage position and conveyance amount from the carriage position detection circuit 305 and the conveyance amount detection circuit 306. Data for driving the means is generated and supplied to the head drive circuit 310.

  The head drive circuit 310 drives the pressure generating means (piezoelectric element in the case of a piezo head) of the recording head 31 based on the print data from the print control unit 302 to discharge droplets from the required nozzles.

  The main control unit 301 receives a detection signal from a cover opening / closing detection circuit 313 that detects opening / closing of the cover 15 of the apparatus main body 1, and in the initial operation based on this detection signal, as will be described below. The speed of the carriage 23 is controlled. The cover open / close detection circuit 313 can be composed of a convex portion provided on the cover 15 and a transmission type photosensor into which the convex portion enters, or a push-type switch that is pushed when the cover 15 is closed. .

Accordingly, processing related to the initial operation (initial operation) performed by the main control unit 301 will be described with reference to FIG.
First, when the power is turned on, the main control unit 301 starts the initial operation of each unit, and drives the cam shaft 205 and the suction pump 207 of the maintenance / recovery mechanism 81 via the maintenance / recovery mechanism motor drive circuit 308. The initial operation is performed to determine whether or not the maintenance / recovery system is abnormal. If the abnormality is abnormal, the subsequent operation is disabled.

  If there is no abnormality in the maintenance / recovery system, the sub-scanning motor 58 is driven via the sub-scanning motor drive circuit 304 to determine whether or not there is any abnormality in the conveyance drive system while moving the conveyance belt 51 in an orbit. If there is, processing for disabling the subsequent operation is performed.

  If there is no abnormality in the conveyance drive system, is the carriage (main scanning drive system) abnormal while driving the main scanning motor 24 via the main scanning motor drive circuit 303 to move the carriage 23 back and forth (forward path and return path)? If it is abnormal, a process for disabling the subsequent operation is performed. If there is no abnormality, the initial operation process is terminated.

  In this way, the initial operation of the maintenance / recovery mechanism motor, the initial transport drive operation, and the initial carriage drive operation are performed to detect an abnormality and confirm the operation of the equipment quality.

An example of the initial carriage operation of the image forming apparatus according to the present invention will be described with reference to FIG.
First, when the carriage initial operation is started, the carriage speed is set to a low speed, an instruction to move the carriage 23 in the forward direction is given, and it is determined whether or not the movement of the carriage 23 is completed.

  When the movement of the carriage 23 in the forward direction is completed, the open / close state of the cover 15 of the apparatus main body is determined based on the detection signal from the cover open / close detection circuit 313. At this time, if the cover 15 is closed, the carriage speed is set to a high speed. If the cover 15 is open, the carriage speed is set to a low speed, and then the carriage 23 is set in the backward direction at the set speed. An instruction to move is issued, it is determined whether or not the movement of the carriage 23 is finished, and the carriage initial operation process is finished when the movement is finished.

  In other words, in this carriage initial operation process, the carriage 23 is moved in the forward direction, and after the forward movement is completed, it is moved in the backward direction to check whether or not there is any abnormality in the carriage movable range. At this time, considering the shortening of the initial operation time and the safety of the user, the carriage speed is set to be different between the forward path and the return path.

  As described above, when the cover 15 of the device body that can be opened and closed is provided, for example, when the cover 15 is opened, it can be used by moving at different carriage speeds in the forward path and the return path. In consideration of the safety of the user, the carriage 23 is moved slowly. When the cover 15 is closed, the safety of the user is ensured, so that the carriage 23 can be moved quickly. Thereby, it is possible to shorten the initial operation time as much as possible while ensuring the safety of the user, and to quickly start up the apparatus (become ready to print).

  Specifically, when the cover is closed based on the determination of the cover open / close state, the safety of the user can be ensured, so that the initial operation time is shortened. That is, if the carriage speed is high in the forward path movement, the carriage 23 may be damaged when there is an abnormality. For example, the carriage 23 is moved at a speed of 100 mm / sec. Since it is an operation, it is moved at a maximum speed of 1200 mm / sec, for example.

  On the other hand, when determining whether the cover is open or not, it is necessary to consider the safety of the user when the cover is open. Therefore, as described above, for example, the forward path is moved at 100 mm / sec, and the backward path is also moved at 100 mm / sec.

1 is a perspective view illustrating an example of an image forming apparatus according to the present invention as viewed from the front side. 2 is a configuration diagram illustrating an outline of a mechanism unit of the image forming apparatus. FIG. It is principal part plane explanatory drawing of the mechanism part. FIG. 2 is a schematic front explanatory view of a maintenance / recovery mechanism of the image forming apparatus. FIG. 2 is a block explanatory diagram illustrating an overview of a control unit of the image forming apparatus. It is a flowchart with which it uses for description of the initial operation process by the main control part. FIG. 10 is a flowchart for explaining an example of a carriage initial operation process in the initial operation process.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Ink cartridge 15 ... Cover 23 ... Carriage 24 ... Main scanning motor 31 ... Recording head 58 ... Sub scanning motor 81 ... Maintenance recovery mechanism 313 ... Cover opening / closing detection circuit

Claims (4)

  An image forming apparatus for intermittently transporting a recording medium in the sub-scanning direction while moving a carriage mounted with a recording head for discharging recording liquid droplets in the main scanning direction to form an image on the recording medium The image forming apparatus according to claim 1, wherein the carriage is moved at different speeds in the forward path and the backward path when the carriage initial operation is performed.   2. The image forming apparatus according to claim 1, wherein a return speed of the carriage is determined based on a detection result of a state of an openable / closable cover of the apparatus main body.   3. The image forming apparatus according to claim 2, wherein when the cover is in a closed state, the return speed of the carriage is higher than the forward speed. 4. The image forming apparatus according to claim 2, wherein when the cover is in an open state, the return speed of the carriage is equal to or less than the forward speed.

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