JP4909186B2 - Image forming apparatus and image forming method - Google Patents

Description

  The present invention relates to an image forming apparatus and an image forming method including an ink jet recording apparatus having a printer function and a facsimile (hereinafter referred to as FAX) function.

Conventionally, in an ink jet recording apparatus, for the maintenance of the recording head, empty ejection for ejecting ink at a position outside the paper, suction of ink and bubbles performed by attaching a cap to the head, wiping for wiping the recording head surface, The head recovery process is performed. As an example, there is an “inkjet recording apparatus” described in Patent Document 1. This ink jet recording apparatus is provided with a means for measuring the standby time, and is configured to perform the recovery operation of the recording head when a predetermined standby time elapses. Is possible.
Japanese Patent Laid-Open No. 2-92548

  However, in the above-described prior art, when applied to a multi-function machine composed of a printer, a fax machine, a copying machine, etc., the recording head of the counterpart inkjet printing apparatus can be used at the time of fax transmission (head recovery processing is performed). In other words, there is a possibility that printing cannot be performed by the destination inkjet recording apparatus. For example, in the case of FAX, basically the transmission side does not check the environment on the reception side, and does not check whether the reception side uses an inkjet printer as a multifunction peripheral. As a result, if the sending side receives a notification from the receiving side FAX that the data has been received correctly, the receiving side will receive the data even if the recording head has a problem and printing cannot be performed normally. There are cases where the side thinks that the data is received and printed and output normally.

  As described above, when the receiver uses an inkjet as a multifunction machine, there is a possibility that the head is in a bad state and proper printing cannot be performed. By the way, the head recovery process is performed every time a predetermined time elapses or every time a predetermined print amount is printed. In this case, since the print operation cannot be interrupted to perform the head recovery process, the head recovery process is performed immediately before the start of printing after a predetermined time has elapsed. Alternatively, after the printing of a predetermined printing amount is completed, when the printing is completed for all jobs, the head recovery process is performed before the printing of the next page when the printing page is completed.

  In other words, in the case of a multifunction device, the user can confirm the print quality only when using it as a printer or when using it as a copier. In the case of FAX reception, the sender cannot confirm the print quality. . SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus and an image forming method including an ink jet recording apparatus, which can improve the reliability of print quality in the case of FAX reception in which the sender cannot confirm the print quality. did.

  In order to solve the above problems, an image forming apparatus according to the present invention includes at least a printer function and a facsimile function, and a recording head that performs printing by discharging ink droplets from nozzles, and a start time of the previous recording An elapsed time measuring unit that measures the time from the start to the next recording start, a maintenance unit that performs recovery processing of the recording head, and a head recovery drive control unit that outputs a head recovery processing command to the maintenance unit In an image forming apparatus comprising an ink jet recording apparatus, a function type discriminating means for discriminating which function is requested when print data is input, and an operation interval of a maintenance unit for each function type Threshold that is smaller than the threshold of other functions. Stored in the storage unit, when the print data is input, the function type is determined by the function type determination unit, the time measured by the elapsed time measurement unit after the recording start and the corresponding function type of the storage unit The head recovery drive control unit outputs a head recovery processing command when the measured time exceeds the threshold. In addition, when there are two or more ink types, it is preferable to set different threshold values for each ink type.

  An image forming method according to the present invention includes at least a printer function and a facsimile function, and includes an ink jet recording having a recording head that performs printing by discharging ink droplets from nozzles, and a maintenance unit that performs recovery processing of the recording head. In the image forming method using the apparatus, an elapsed time after recording start time step for measuring the time from the start time of the previous recording to the start of the next recording, and a head recovery processing command are output to the maintenance unit A threshold value that includes a head recovery drive control step and a function type determination step that determines which function is requested when the print data is input, and previously specifies an operation interval of the maintenance unit for each function type The threshold value for the facsimile function is made smaller than the threshold values for other functions in the storage means. When the print data is input, the function type is determined by the function type determination step, and then the time measured by the elapsed time measurement step after the recording start and the threshold value of the corresponding function type in the storage means And a head recovery process command is output by the head recovery drive control step when the measurement time exceeds a threshold value.

  As described above, according to the present invention, in a multi-function peripheral having a FAX function, when printing output by FAX, the recording head recovery process is performed at a shorter interval than in the case of print output by other functions. Therefore, even if the transmission source does not grasp the head state of the ink jet recording apparatus, it is possible to print out more reliably.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an explanatory perspective view of an ink jet recording apparatus as an image forming apparatus according to the present invention as viewed from the front side. The ink jet recording 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. Further, 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 ink cartridges 10k, 10c, 10m, and 10y are configured to be loaded side by side in a vertical state.

  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.

  Next, an outline of an internal configuration and a mechanism part of the ink jet recording apparatus will be described with reference to FIGS. 2, 3, 4, and 5. 2 is a schematic side view for explaining the outline of the internal structure, FIG. 3 is a schematic plan view for explaining the same, FIG. 4 is a schematic side view for explaining the overall structure of the mechanism, and FIG. It is principal part plane explanatory drawing of a part. 4 and 5, the carriage 33 is slidably held in the main scanning direction by a guide rod 31 and a stay 32, which are guide members horizontally mounted on the left and right side plates 21A and 21B constituting the frame 21. The main scanning motor 201 (FIG. 3) moves and scans in the arrow direction (carriage main scanning direction) in FIG.

  As described above, the carriage 33 includes a recording head 34 including four droplet discharge heads that discharge ink droplets of yellow (Y), cyan (C), magenta (M), and black (Bk). A plurality of ink ejection openings are arranged in a direction crossing the main scanning direction, and are mounted with the ink droplet ejection direction facing downward. As an inkjet head constituting the recording head 34, 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.

  A driver IC is mounted on the recording head 34 and is connected to a control unit (not shown) via a harness (flexible print cable) 22. Further, the carriage 33 is equipped with a head tank 35 of each color for supplying ink of each color to the recording head 34. As described above, each color head tank 35 is replenished and 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 36 of each color.

  The cartridge loading 4 is provided with a supply pump unit 24 for feeding ink in the ink cartridge 10, and the ink supply tube 36 is engaged with the rear plate 21 </ b> C constituting the frame 21 in the middle of turning. It is held by a stop member 25. On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feeding tray 2, a half-moon roller (feeding) that separates and feeds the papers 42 one by one from the paper stacking unit 41. A separation pad 44 made of a material having a large friction coefficient is provided facing the paper roller 43) and the paper feed roller 43, and the separation pad 44 is urged toward the paper feed roller 43 side.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller. And a 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 34. The transport belt 51 is an endless belt, and is configured to wrap around the transport roller 52 and the tension roller 53 and circulate in the belt transport direction (sub-scanning direction).

  The conveyance belt 51 rotates in the belt conveyance direction of FIG. 4 when the conveyance roller 52 is rotationally driven via the drive belt 204 by the sub-scanning motor 205 (see FIG. 3). Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a paper discharge roller 63 are provided. The paper discharge tray 3 is provided below the paper discharge roller 62. Here, the height from between the paper discharge roller 62 and the paper discharge roller 63 to the paper discharge tray 3 is increased to some extent in order to increase the amount that can be stored in the paper discharge tray 3.

  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. 5, a maintenance / recovery mechanism 81 including a recovery means for maintaining and recovering the state of the nozzles of the recording head 34 is arranged in the non-printing area on one side of the carriage 33 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 34, 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. Then, the waste liquid of the recording liquid generated by the maintenance / recovery operation by the maintenance / recovery mechanism 81, the ink discharged to the cap 82, the ink adhered to the wiper blade 83 and removed by the wiper cleaner 85, and the idle ejection to the idle ejection receiver 84. The discharged ink is discharged and stored in a waste liquid tank (not shown).

  Further, as shown in FIG. 5, in the non-printing area on the other side of the carriage 33 in the scanning direction, idle discharge is performed to discharge liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An empty discharge receiver 88 for receiving the droplets at the time is disposed, and the empty discharge receiver 88 is provided with an opening 89 along the nozzle row direction of the recording head 34. In addition to the above, the maintenance / recovery mechanism is divided into five types depending on the combination of the negative pressure generating portion and the negative pressure generating means as shown in Table 1.

  The negative pressure generation point is whether it is integrated with the ink tank or separated. The negative pressure generation means is an absorber, a bag attached with a spring or the like, or a water head difference is used. However, any of them can be used in the present invention.

Hereinafter, the five types will be described in order.
(1) Type A (Negative pressure generation part and tank are separated / Negative pressure generation is an absorber)
FIG. 6 shows an example of the A type. (A) is sectional drawing which shows the state from which the capillary force generation member storage container and the liquid supply container were removed, (b) is sectional drawing which shows the state in which the capillary force generation member storage container and the liquid supply container were connected is there. The ink tank 1 includes a capillary force generation member storage container 10 as a capillary force generation member storage chamber, and a liquid supply container 30 as an ink storage chamber. The liquid supply container 30 has gas-liquid exchange passages 14a and 14b. It becomes the structure which can be isolate | separated with respect to the capillary force generation member storage container 10 via.

  The capillary force generation member storage container 10 includes a housing 11 having an ink supply port 12 for supplying ink (including liquid such as a processing liquid) to the outside of a recording head unit or the like that performs recording by discharging liquid from the discharge port. A capillary force generating member 13 made of a mixed fiber such as polypropylene and polyethylene accommodated in the housing 11, and a communication portion opening 18 for contacting the capillary force generating member 13 and introducing a liquid from the liquid supply container 30. It has. The housing 11 further includes an atmosphere communication port 15 for communicating the capillary force generating member 13 accommodated in the interior with the outside air. A rib protruding from the inner surface of the housing 11 is formed in the vicinity of the air communication port 15. A buffer space 16 is provided.

  On the other hand, the liquid supply container 30 stores ink directly in the housing 31, is connected to the communication portion openings 18 a and 18 b of the capillary force generation member storage container 10, and is stored in the housing 31 (liquid storage portion). Ink outlets 32 a and 32 b are provided for leading the liquid to the capillary force generation member storage container 10. In this embodiment, the ink outlets 32 a and 32 b protrude from the housing 31, and the ink inlets 32 a and 32 b are connected to the communication portion openings 18 a and 18 b provided in the capillary force generation member storage container 10. Thus, a communication part between the liquid supply container 30 and the capillary force generation member storage container 10 is formed, and the liquid storage part of the liquid supply container 30 forms a substantially sealed space with respect to the outside air except for this communication part.

  Here, a seal member 37 such as an O-ring is provided at a connection portion between the ink lead-out portions 32a and 32b and the communication portion opening 18 to prevent ink leakage from the connection portion and introduction of the atmosphere. Yes. Further, the ink outlets 32a and 32b serve as sealing means for preventing leakage of ink accommodated inside the ink outlets 32a and 32b before the liquid supply container 30 is connected to the capillary force generating member storage container 10. A film 38 is affixed and can be peeled from the ink outlets 32a and 32b by pulling in the direction F in the drawing.

(2) Type B (negative pressure generation part and tank are integrated / negative pressure generation is an absorber)
FIG. 7 shows an example of the B type. As shown in FIG. 7, a recording element substrate H1100 is provided on one side of the lower surface of the box-shaped recording head H1001. Further, the recording head H1001 is provided with a joint, and an ink flow path H1501 extending toward the recording element substrate 1100 is formed in the joint.

  As an ink flow in such a print head cartridge, an ink tank H1900 for black ink will be described as an example. The ink in the ink tank H1900 is supplied into the recording head H1001 through the ink supply port and the joint. The ink supplied into the recording head H1001 is supplied to the first plate H1200 via the ink flow path H1501, and is further supplied from the first plate H1200 to the ink supply port H1102 of the recording element substrate H1100.

(3) C type (Negative pressure generation part and tank are integrated / Negative pressure generation is a spring)
8 and 9 show an example of C type. As shown in these drawings, the pressure plate 109 is entirely connected to the convex top surface of the sheet 106, so that the shape of the top portion is always kept flat, and this portion is kept on the other surface. A portion having higher rigidity than the portion of the sheet 106 is used. In the ink tank of this embodiment having the spring unit 112, when the ink amount in the ink tank decreases as shown in FIG. 9A, the pressure plate 109 of the spring unit 112 is interposed as shown in FIG. 9B. Accordingly, the movable portion 172 of the sheet 106 whose deformation is not controlled by the entire spring unit 112 starts to be depressed first, and accordingly, the spring 107 of the spring unit 112 starts to gradually contract.

  In this deformation of the sheet 106, since the pressure plate 109 of the spring unit 112 is bonded to the sheet 106, it changes in parallel as shown in FIGS. As shown in d), the state is completely crushed. On the other hand, the type having no spring as shown in FIGS. It is a figure which shows the process in which the ink tank by the sheet | seat single-piece | unit which has a convex shape but does not use a spring unit deform | transforms as the amount of ink decreases.

  In the comparative example shown in FIG. 10, as shown in FIG. 10A, the ink tank composed of the sheet 106 alone and the frame 115 has the largest area of the sheet 106 when the ink in the ink tank is consumed. The flat portions 170 and 180 which are wide portions start to deform. At that time, as shown in FIG. 5B, the plane portions 170 and 180 may change in different shapes or cause a time difference in deformation. When the ink amount in the ink tank further decreases, the ridge line 171 in the convex shape of the sheet 106 remains stiffer than the plane portion of the sheet 106 and remains undeformed as shown in FIG. As shown in FIG. 4D, the ridge line portion 171 falls, and the flat portions 170 and 180 come into contact with each other and are completely crushed.

  Further, in the case of the ink tank of the comparative example configured by the sheet 106 alone and the frame 115, the shape stability is relatively low when the change in the tank pressure due to the ink consumption and vice versa is repeated. That is, since the repeatability of the method of crushing the tank is poor, the negative pressure changes every time even when the amount of ink consumed is the same. Moreover, it can be said that it is easy to be influenced by environmental temperature, the material of a sheet, and molding.

(4) D type (negative pressure generation part and tank are separated / negative pressure generation is spring)
FIG. 11 shows an example of the D type. An ink jet head 1 that performs recording by ejecting ink from an ink ejection port 2 and an ink tank 30 for supplying ink to the ink jet head 1 are connected via a negative pressure generating container 10 so that ink can flow. The route is configured. The negative pressure generating container 10 includes a housing 11 and an inner bag 12 that is located inside the housing 11 and can be peeled off from the housing 11.

  The negative pressure generating container 10 is provided with an ink supply port 15 for supplying ink to the inkjet head 1 and an ink suction port 14 for sucking the ink 19 in the ink tank 30 into the negative pressure generating container 10. ing. That is, the negative pressure generating container 10 is connected to the ink jet head 1 via the ink supply port 15 and is connected to the ink tank 30 via the ink suction port 14 and an ink supply pipe 34 described later. Ink 19 is stored in the inner bag 12. A part of the casing 11 is provided with an atmosphere communication port 13 for communicating the space between the casing 11 and the inner bag 12 with the atmosphere.

  The negative pressure generating container 10 is a substantially polygonal hollow container having a negative pressure generating function. The negative pressure generating container 10 includes a housing 11 and an inner bag 12, and the housing 11 and the inner bag 12 can be separated from each other. The inner bag 12 has flexibility, and the inner bag 12 can be deformed as the ink stored therein is led out. An air communication port 13 is provided, and air can be introduced between the inner bag 12 and the housing 11 through the air communication port 13. The inner bag 12 is composed of three layers of a liquid contact layer having ink resistance, an elastic modulus dominating layer, and a gas barrier layer excellent in gas barrier properties in order from the inside, and each layer is functionally separated in a bonded state. ing.

  The elastic modulus dominating layer is one in which the elastic modulus of the elastic modulus dominating layer is kept almost constant within the operating temperature range of the negative pressure generating container 10, that is, the inner bag within the operating temperature range of the negative pressure generating container 10. The elastic modulus of 12 is kept almost constant by the elastic modulus dominating layer. In the inner bag 12, the intermediate layer and the outer layer may be interchanged, the elastic modulus dominating layer may be the outermost layer, and the gas barrier layer may be the intermediate layer. By configuring the inner bag 12 in this way, it becomes possible for the inner bag 12 to fully perform the functions of the respective layers with a small number of layers such as an ink-resistant layer, an elastic modulus dominant layer, and a gas barrier layer. The influence on the temperature change such as the elastic modulus of the bag 12 is reduced.

  Further, the inner bag 12 has an elastic modulus suitable for controlling the negative pressure of the negative pressure generating container 10 within the operating temperature range. It has a buffer function. In the present embodiment, polypropylene or polyethylene is used as the material of the innermost liquid contact layer constituting the inner bag 12, cyclic olefin copolymer is used as the intermediate elastic modulus dominating layer, and EVOH (EVA (ethylene acetate) is used as the material of the outermost gas barrier layer. Vinyl saponified resin) is used.

Here, by including a functional adhesive resin material in the elastic modulus dominating layer, it is not necessary to specially provide an adhesive layer between the layers, so that the thickness of the inner bag 12 can be reduced, which is preferable. As the material of the housing 11, the same polypropylene as the innermost layer of the inner bag 12 is used. An ink tank 30 is detachably connected to the ink suction port 14 via an ink supply pipe 34. The ink tank 30 contains the ink 19 inside, and an air communication port 33 for communicating the inside of the ink tank 30 with the atmosphere is provided in the upper part of the casing 31 of the ink tank 30. The ink tank 30 is disposed at a position where the liquid level of the ink 19 is lowered in the use state with respect to the negative pressure generating container 10. The tip of the ink supply pipe 34 is disposed on the bottom surface of the ink tank 30.

(5) Type E (Negative pressure generation part and tank are separated / Negative pressure generation is water head difference)
FIG. 12 shows an example of the E type.
The ink supply device is arranged vertically downward, and stores an ink tank 22 that stores ink, an ink supply pipe 17 that is a pipe-like first connecting portion that supplies ink from the ink tank 22 to the recording head 11, and an ink tank. 22 has an air release pipe 26 which is a pipe-like second connecting portion for introducing the atmosphere.

  The ink tank 22 is made of, for example, a highly rigid housing that is formed of polyethylene, polypropylene, noryl, or the like having a thickness of 0.5 mm or more and does not easily deform. The ink supply pipe 17 includes a pipe-shaped needle portion 24 made of stainless steel or the like. The needle portion 24 penetrates through a rubber plug 25 that closes a hole provided in the bottom surface of the ink tank 22, and the ink tank 22. Can be inserted into the inside. Similarly, the air release pipe 26 includes a pipe-like needle portion 30 made of stainless steel or the like, and this needle portion 30 penetrates through a rubber plug 31 that closes a hole provided in the bottom surface of the ink tank 22. The ink tank 22 can be inserted.

  Further, the ink supply pipe 17 is bent in the horizontal direction at the lower end of the needle portion 24 standing vertically, and is bent upward again to be connected to the inside of the head from the side wall near the bottom surface of the sub tank 12 of the recording head 11. On the other hand, the air release pipe 26 is bent in the horizontal direction at the lower end of the needle part 30 standing vertically, and is bent upward again. The hole provided in the bottom surface of the ink tank 22 is opened as an injection port when ink is injected into the unused ink tank 22, and is closed by the rubber plugs 25 and 31 after ink injection. As shown in FIG. 6, when the recording apparatus main body is mounted, the needle portions 24 and 30 are inserted into the ink tank 22 through the rubber plugs 25 and 31, respectively.

  As a result, the ink tank 22 and the recording head 11 communicate with each other via the ink supply pipe 17 (first connection part) including the needle part 24, and the atmosphere release pipe 26 (second connection part) including the needle part 30. The inside of the ink tank 22 is open to the atmosphere via Before the ink tank 22 is attached to the recording apparatus main body or after the ink tank 22 is removed from the recording apparatus main body, the rubber plugs 25 and 31 close the holes, so that the ink does not flow out of the ink tank 22. At this time, even if the holes are opened by the needle portions 24 and 30, the needle portions 24 are pulled out by the elasticity of the rubber plugs 25 and 31, and the holes are closed at the same time.

  In addition, the ink supply tank of the present invention can include an element that wirelessly notifies the state in the tank. An example of the element includes a detection sensor that detects the state of ink, an electronic circuit that converts information into a radio signal, and a transmitter that transmits radio waves. The surface of the element is preferably coated with a resin or the like so that it does not corrode even in contact with ink.

  Further, as shown in FIG. 2 and FIG. 3, communication such as a USB for sending / receiving data to / from the host and a modular jack for sending / receiving data to / from another FAX on the inner rear side of the apparatus main body 1. A circuit unit (interface) 101 is provided, and a control circuit board 102 constituting a control unit that controls the entire image forming apparatus is provided. 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 47 and pressed against the conveying belt 51 by the leading end pressing roller 49, and the conveying direction is changed by approximately 90 °.

  When the paper 42 is fed onto the transport belt 51, the paper 42 is transported in the sub-scanning direction by the circular movement of the transport belt 51. Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, ink droplets are ejected onto the stopped paper 42 to record one line, and after the paper 42 is conveyed by a predetermined amount, Record the next line. Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.

  Further, during printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the recording head 34 is capped by the cap 82 to keep the nozzles in a wet state, thereby preventing 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 34 capped by the cap 82 (referred to as “nozzle suction” or “head suction”) to discharge the thickened recording liquid or bubbles. Do. In addition, an idle ejection operation for ejecting ink not related to recording is performed before the start of recording or during recording. As a result, the stable ejection performance of the recording head 34 is maintained.

  Next, another example of the head configuration of the recording head will be described with reference to FIG. FIG. 13 is an explanatory view of the recording head as viewed from the nozzle surface side. The recording head 134 includes four nozzle rows composed of a plurality of nozzles 134n for ejecting droplets of each color of black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. It is a head in which 134k, 134c, 134m, and 134y (hereinafter referred to as “nozzle row 134N” when not distinguished) are formed on one nozzle surface 134a.

  Next, a maintenance / recovery mechanism using the recording head 134 having the head configuration shown in FIG. 13 will be described with reference to FIGS. 14 and 15 are schematic explanatory views showing different states of the maintenance and recovery mechanism. This maintenance / recovery mechanism 81 includes dedicated caps 182k, 182c, 182m, and 182y for capping the nozzle rows 134k, 134c, 134m, and 134y on the nozzle surface 134a of the recording head 134, and these caps 182k, 182c, and 182m. , 182y are held by one cap holder 185.

  In addition, a wiper blade 183 for wiping (cleaning) the nozzle surface 134a of the recording head 134 is provided. In order to move the cap holder 185 and the wiper blade 183 up and down, a maintenance and recovery mechanism drive motor 191, a cam shaft 192 rotated by the motor 191, a cap cam 193 and a wiper cam 194 attached to the cam shaft 192, It has.

  In this maintenance / recovery mechanism, when removing ink or impurities adhering to the nozzle surface 134a of the recording head 134, the maintenance / recovery mechanism drive motor 191 is rotated, and the wiper blade 194 is wiped through the wiper cam 194 as shown in FIG. Raise 183. In this state, by moving the carriage 33 in the main scanning direction, the wiper blade 183 wipes the nozzle surface 134a of the recording head 134 to wipe away impurities and the like.

  In addition, if the nozzle 134n of the recording head 134 is left exposed to the outside air, the ink in the inside dries out, thickens and adheres, and the ink ejection performance deteriorates. To prevent this, the recording head When the nozzle surface 134a of 134 is covered with the cap 182, the maintenance / recovery mechanism driving motor 191 is rotated to raise the cap 182 via the cap cam 193 as shown in FIG. Thereby, the cap 182 of each color can cover the nozzle row 134N of the corresponding nozzle surface 134a, and the drying of the nozzle 134n can be suppressed. Furthermore, by rotating the maintenance / recovery mechanism driving motor 191 by 1/4 from the state shown in FIGS. 14 and 15, the carriage 33 can be scanned, and preparation for printing start can be made. This maintenance / recovery mechanism can be similarly applied to the above-described multi-head configuration.

  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 300 controls the entire image forming apparatus, and includes a main control unit 301 configured by a microcomputer that also functions as a measurement unit, a determination unit, a recovery drive operation control unit, and the like according to the present invention. And a print control unit 302 configured by a microcomputer. Then, as described above, the main control unit 301 uses the main scanning motor 201 and the sub-scanning motor 205 to form an image on the paper 42 based on the print processing information input from the communication circuit 101. 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 33, and the main control unit 301 controls the movement position and movement speed of the carriage 33 based on the detection signal. To do. The carriage position detection circuit 305 detects the position of the carriage 33 by, for example, reading and counting the number of slits of an encoder sheet arranged in the scanning direction of the carriage 33 with a photosensor mounted on the carriage 33. The main scanning motor drive circuit 303 rotates the main scanning motor 201 according to the carriage movement amount input from the main control unit 301 to move the carriage 33 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 205 in accordance with the conveyance amount input from the main control unit 301 and rotationally drives 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 motor 191 via the maintenance / recovery mechanism driving motor drive circuit 308 to move the cap 182 (cap 82) up and down and the wiper blade 183 (wiper blade 83) up and down. The main control unit 301 drives and controls the ink supply motor for driving the pump of the supply unit 24 via the ink supply motor drive circuit 311, and the ink cartridge 10 loaded in the cartridge loading unit 4 controls the sub tank 35. Supply ink.

  The main control unit 301 includes a detection signal from the sub tank full sensor 312 that detects that the sub tank 35 is full, a detection signal from the cartridge cover sensor 313 that detects opening and closing of the front cover 6 of the cartridge loading unit 4, and the like. Is entered. The print control unit 302 ejects droplets of the recording head 34 (recording head 134) 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 pressure generating means is generated and applied to the head drive circuit 310.

  The head drive circuit 310 drives the pressure generating means (a piezoelectric element in the case of a piezo head) of the recording head 34 (recording head 134) based on the print data from the print control unit 302, and drops liquid droplets from a required nozzle. To discharge.

  Next, a printing process in the image forming apparatus configured as described above will be described with reference to FIG. This flowchart is a print processing program stored in the main control unit 301 and executed when a print request is received via the communication circuit 101. First, the cap 82 is lowered (uncapped) to prepare for printing. Thereafter, the carriage 33 is moved to the printing position, and at the same time, the driving of the transport motor 205 is started. In this state, the sheet feeding roller 43 is activated to feed the sheet in the sheet feeding tray 2 and move along the conveyance path.

  When the paper reaches the printing position, the conveyance motor 205 is stopped. At this time, a recovery operation starting process 408 described later is executed, and a recovery operation is executed as necessary. Thereafter, the image data received via the communication circuit 101 is set in the print control microcomputer 302 to prepare for drawing. When the carriage 33 is scanned in this state, ink discharge is started. When the scanning of the carriage 33 is completed, it is determined whether or not printing within the page has been completed. If the printing has not been completed yet, the sheet is conveyed again and the determination of reaching the printing position (406) is repeated.

  When printing is finished, the paper is conveyed toward the paper discharge tray 3. If there is an unprocessed page, the process is repeated from the paper feed (405), and when the printing of all the pages is completed, the conveyance motor 205 is stopped to complete the printing, and capping is performed.

  Next, the head recovery operation starting process 408 executed in the printing process will be described with reference to FIG. First, the remaining amount of ink in the head tank 35 is detected, and notification is given when the remaining amount is insufficient (step 502). Next, it is determined whether or not the print data is FAX reception data (step 503). If it is FAX data (step 503 Yes), Athresh is substituted for Clth of the value to be compared with the time PrTime from the previous print start described later, and otherwise (No in step 503), Bthreth is substituted for Clth. The relationship between Athresh and Bthresh is Athresh <Bthresh.

  Next, this Clth is compared with the above-mentioned PrTime (step 506). If PrTime is larger than Clth (step 506 Yes), printing is stopped. If PrTime is not larger than Clth (step 506 No), a determination process between pages (step 507) is executed. In the processing after the determination processing 507, printing is stopped between the Nth pages (step 508). Here, the number N of detections between pages is N = 1 if the size of the head tank 35 can store ink for one page, and N> 2 if ink for two pages or more can be stored. Can be set.

  While printing is stopped, the head recovery operation 509 is executed, and the resumption of printing is permitted. In this head recovery operation, ink is supplied from the cartridge according to the remaining amount determined by detecting the remaining amount of the head tank, which will be described later, in addition to idle ejection, wiping, and head suction as described above. Also, depending on the type of ink used, if the PrTime is greater than Clth, printing is stopped and the recovery operation is limited to a specific ink, and printing is stopped between the Nth page and the recovery operation is performed. Of ink. This type of ink is due to the fact been decided what component at design time, or whether easy to dry is only restored in advance what ink because should know in advance the good idea determined by experiments or the like. Depending on the components, all may be performed.

  Next, processing started by the head tank remaining amount detection 501 will be described with reference to FIG. First, a method for detecting the remaining amount of ink in the head tank 35 based on the accumulated discharge amount will be described with reference to FIG. The accumulated ink consumption value is subtracted from the predetermined ink capacity of the head tank 35, in which the ink amount ejected at each ink ejection 412 shown in FIG. By doing so, the amount of ink remaining in the head tank 35 can be calculated. Note that the ink consumption cumulative value used at this time is reset to 0 every time ink is supplied to the head tank 35 and full in the recovery operation 509 shown in FIG.

  Next, a method for detecting the remaining amount of ink in the head tank 35 using the electrode sensor 312 will be described with reference to FIG. The inter-electrode resistance value obtained by the electrode sensor 312 disposed inside the head tank 35 is detected in a stepwise manner, and the remaining amount of ink in the head tank is full level, medium level (print continuation possible level), small level ( It is detected whether the level is (printing continuation impossible level). Here, the value of the interelectrode resistance value Rb is determined by determining an amount corresponding to a constant value M in the head tank ink remaining amount determination processing 502 in FIG. The result of the ink remaining amount detection at can be used as it is in the determination processing 503.

  According to an embodiment of the present invention, in an inkjet recording apparatus equipped with at least a printer function and a FAX function, even if the sender cannot know the printing state like FAX, the head recovery is automatically performed according to the function. Therefore, reliable printing can be performed. Further, the amount of waste liquid by the head recovery process can be reduced as much as possible.

  The information processing program executed by the image forming apparatus according to the present embodiment is an installable or executable file in a CD-ROM, flexible disk (FD), CD-R, DVD (Digital Versatile Disk). And the like recorded on a computer-readable recording medium.

  The information processing program executed by the image forming apparatus according to the present embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. The information processing program executed by the image forming apparatus according to the present embodiment may be provided or distributed via a network such as the Internet. The information processing program executed by the image forming apparatus according to the present embodiment may be provided by being incorporated in advance in a ROM or the like.

FIG. 2 is a perspective explanatory view of an ink jet recording apparatus as an image forming apparatus according to the present invention as viewed from the front side. FIG. 2 is an explanatory side view showing an outline of the internal configuration of the ink jet recording apparatus according to the present invention. 2 is an explanatory plan view illustrating an outline of an internal configuration of the ink jet recording apparatus according to the present invention. FIG. It is a side schematic structure figure showing the whole structure of the mechanism part of the ink-jet recording device concerning the present invention. It is principal part plane explanatory drawing of the mechanism part of the inkjet recording device which concerns on this invention. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. It is explanatory drawing of the negative pressure generation mechanism in an ink tank. FIG. 3 is an explanatory view of the recording head as viewed from the nozzle surface side. FIG. 6 is a schematic explanatory view showing different states of a recording head maintenance / recovery mechanism. FIG. 6 is a schematic explanatory view showing different states of a recording head maintenance / recovery mechanism. 2 is a block diagram illustrating an overall configuration of a control unit of the image forming apparatus. FIG. 5 is a flowchart illustrating a printing process of the image forming apparatus. 6 is a flowchart illustrating a head recovery operation start process of the image forming apparatus. 4 is a flowchart illustrating a remaining head tank detection process of the image forming apparatus. 4 is a flowchart illustrating a remaining head tank detection process of the image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper feed tray 3 Paper discharge tray 4 Cartridge loading part 5 Operation / display part 6 Front cover (cartridge cover)
10, 10k, 10c, 10m, 10y Ink cartridge 11k, 11c, 11m, 11y Remaining amount display portion 12 Power button 13 Paper feed / print resume button 14 Cancel button 21 Frame 21A, 21B, 21C Side plate 22 Harness (flexible print cable)
25 Locking member 31 Guide rod 32 Stay 33 Carriage 34 Recording head 35 Head tank 36 Ink supply tube 41 Paper stacking section (pressure plate)
42 paper 43 half moon roller (paper roller)
44 Separating pad 45 Guide member 46 Counter roller 47 Conveying guide member 48 Holding member 49 Tip pressure roller 51 Conveying belt 52 Conveying roller 53 Tension roller 61 Separation claw 62 Discharging roller 63 Discharging roller 71 Duplex unit 72 Manual tray 81 Maintenance recovery Mechanism 82, 82a to 82d Cap member (cap)
83 Wiper blade 84 Empty discharge receiver 85 Wiper cleaner 88 Empty discharge receiver 89 Opening 201 Main scanning motor 202 Timing belt 205 Sub-scanning motor 204 Drive belt

Claims (3)

A recording head that has at least a printer function and a facsimile function, and that prints by ejecting ink droplets from the nozzles, and an elapsed time measurement after the start of recording that measures the time from the start time of the previous recording to the start of the next recording In an image forming apparatus comprising: an inkjet recording apparatus comprising: a means; a maintenance unit that performs recovery processing of the recording head; and a head recovery drive control unit that outputs a head recovery processing command to the maintenance unit.
A function type discriminating means for discriminating which function is requested when the print data is inputted;
Storage means for storing a threshold value that designates an operation interval of the maintenance unit for each function type and that has a threshold value of the facsimile function smaller than that of other functions;
With
When print data is input, the function type is determined by the function type determination unit, the time measured by the elapsed time measurement unit after the start of recording is compared with the threshold value of the corresponding function type in the storage unit, and the measurement time The image forming apparatus according to claim 1, wherein the head recovery drive control unit outputs a head recovery processing command when the value exceeds a threshold value. The image forming apparatus according to claim 1 ,
An image forming apparatus, wherein a different threshold is set for each ink type when there are two or more ink types. A recording head that has at least a printer function and a facsimile function, ejects ink droplets from nozzles to perform printing, a maintenance unit that performs recovery processing of the recording head, and
An image forming method using an inkjet recording apparatus having
An elapsed time measurement step after the start of recording that measures the time from the start time of the previous recording to the start of the next recording;
A head recovery drive control step for outputting a head recovery processing command to the maintenance unit;
A function type determining step for determining which function is requested when the print data is input;
With
A threshold value that designates the operation interval of the maintenance unit for each function type and that is smaller than the threshold value of the facsimile function is stored in the storage means in advance, and when print data is input, When the function type is discriminated by the function type discriminating step, the time measured by the elapsed time measurement after the recording start is compared with the threshold value of the corresponding function type in the storage means, and the measured time exceeds the threshold value A head recovery process command is output in the head recovery drive control step.

Images