JP3951244B2 - Image forming apparatus and method - Google Patents

Description

  The present invention relates to an image forming apparatus and method, and more particularly to a technique that contributes to the efficiency of replenishment and replacement of a recording medium suitable for a printing system that is required to produce a large number of prints at high speed such as a photo print service.

For example, in a minilab system that provides a photo print service, it is required to print a narrow L size print (127 mm × 89 mm) at high speed. In order to satisfy this printing speed requirement, it has been proposed to transport two narrow-width papers and print them simultaneously. Patent Document 1 discloses a system for printing two rows of roll paper with one shuttle type inkjet head.
JP 2001-347653 A

  In a commercial printer such as a minilab system, it is important to perform print production at high speed, but it is also an important issue that print production is not interrupted. One factor that interrupts print production is roll replacement (paper replenishment) at the paper end. In particular, in a system having a plurality of paper supply units for simultaneous printing of a plurality of rows, it is necessary for the paper supply unit to irregularly change rolls or replenish paper, which is a burden on the operator (operator). It also has a big impact on the efficiency of the entire business.

  The present invention has been made in view of such circumstances, and can control the timing when the recording mediums of a plurality of recording medium supply units are ended so that the replenishment and replacement of the recording medium can be performed systematically. It is an object of the present invention to provide an image forming apparatus and method capable of reducing the above and improving the production efficiency.

In order to achieve the above object, an image forming apparatus according to the present invention is provided with a plurality of recording medium supply units that contain a recording medium and supply the recording medium to an image forming unit, and the plurality of recording medium supply units. Conveying means for conveying the recording medium, image forming means for forming an image on the recording medium provided in the image forming section and conveyed by the conveying means, and recording medium accommodated in each recording medium supply section Based on the remaining amount information of the recording medium supply units obtained by the remaining amount determination unit and the remaining amount information of the plurality of recording medium supply units, the input image is printed. Control means for determining the supply source of the recording medium to be used, means for reserving print processing of an image for each recording medium supply section in the buffer according to the determination, and each buffer for each recording medium supply section Calculating means for calculating a waiting time until printing of the next reserved image is started, wherein the control means is configured such that a difference in remaining amounts of the plurality of recording medium supply units is ½ of a maximum accommodation amount. When the value obtained by subtracting the waiting time of the recording medium supply unit having a large remaining amount from the waiting time of the recording medium supply unit having a smaller remaining amount is smaller than a predetermined criterion value, the plurality of recording media A supply unit with a small remaining amount is determined as a supply source, and a waiting time of a recording medium supply unit with a small remaining amount difference between the plurality of recording medium supply units is less than ½ of the maximum storage capacity. When the value obtained by subtracting the waiting time of the recording medium supply unit having a large remaining amount from the time is larger than the predetermined determination reference value, the supply source having a smaller waiting time among the plurality of recording medium supply units Determine as the supply of the plurality of recording media Of greater than 1/2 of the remaining amount difference accommodate the maximum amount, and, judging from the latency of the remaining amount is large recording medium supply unit, the value of the waiting time by subtracting the remaining amount is small recording medium supply portion of the predetermined If the recording medium supply unit is smaller than the reference value, the remaining one of the plurality of recording medium supply units is determined as the supply source, and the difference in the remaining amount among the plurality of recording medium supply units is larger than ½ of the maximum accommodation amount. When the value obtained by subtracting the waiting time of the recording medium supply unit with a small remaining amount from the waiting time of the recording medium supply unit with a large remaining amount is larger than the predetermined determination reference value, the plurality of recording media One of the supply units having a low waiting time is determined as a supply source.
Another image forming apparatus according to the present invention includes a plurality of recording medium supply units that store a recording medium and supply the recording medium to the image forming unit, and recording media supplied from the plurality of recording medium supply units. A conveying means for conveying; an image forming means for forming an image on a recording medium provided in the image forming section and conveyed by the conveying means; and a remaining amount of the recording medium accommodated in each recording medium supply section. A remaining amount grasping means for grasping, and a recording medium used for printing an input image among the plurality of recording medium supply sections based on the remaining amount information of each recording medium supply section obtained by the remaining amount grasping means A control unit for determining a supply source of the recording medium, a unit for reserving print processing of the corresponding image for each recording medium supply unit in a buffer in accordance with the determination, and a buffer for each recording medium supply unit Calculating means for calculating a waiting time until image printing is started, and the control means is configured such that a difference in remaining amount of the plurality of recording medium supply units is smaller than ½ of the maximum accommodation amount, and When the value obtained by subtracting the waiting time of the recording medium supply unit with a small remaining amount from the waiting time of the recording medium supply unit with a large remaining amount is smaller than a predetermined determination reference value, the remaining one of the plurality of recording medium supply units The remaining amount is determined from the waiting time of the recording medium supply unit having a large amount remaining as the supply source, and the difference between the remaining amounts of the plurality of recording medium supply units being smaller than ½ of the maximum storage capacity. When the value obtained by subtracting the waiting time of the recording medium supply unit with less is larger than the predetermined determination reference value, the one having the low waiting time among the plurality of recording medium supply units is determined as the supply source, Accommodates differences in remaining capacity of multiple recording media supply units When a value obtained by subtracting the waiting time of the recording medium supply unit with a large remaining amount from the waiting time of the recording medium supply unit with a large remaining amount that is larger than ½ and small in the remaining amount is smaller than the predetermined determination reference value , The one having a small remaining amount among the plurality of recording medium supply units is determined as the supply source, and the difference in the remaining amount among the plurality of recording medium supply units is larger than ½ of the maximum accommodation amount and the remaining amount is small. When the value obtained by subtracting the waiting time of the recording medium supply unit with a large remaining amount from the waiting time of the recording medium supply unit is larger than the predetermined determination reference value, the waiting time among the plurality of recording medium supply units It is characterized in that the one with a small amount is determined as the supply source.

  According to the present invention, in an image forming apparatus including a plurality of recording medium supply units, control is performed to appropriately switch the supply source of recording media used for image formation, and the recording media of the plurality of recording medium supply units are ended. Adjust the timing. As a result, it is possible to systematically generate the replenishment / exchange operation timing of the recording medium.

  A “recording medium” is a medium (which can be called a print medium, an image forming medium, a recording medium, an image receiving medium, or the like) that receives an image recorded by the action of an image forming unit, such as continuous paper (roll paper), cut Paper, sticker paper, resin sheets such as OHP sheets, films, cloths, printed boards on which wiring patterns and the like are formed by an inkjet recording apparatus, and other various media and shapes are included.

  For example, when roll paper is used as the recording medium, roll replacement work is performed at the end of the paper. When cut paper is used, the cassette is exchanged or the paper is replenished to the paper feed tray at the end of the paper.

As an example of the control of the end timing, by not generating an end simultaneously for recording medium supply portion of the multiple is possible to supply the recording medium from at least one of the recording medium supply unit, without completely stopping the device, Print production can be continued.

  In this case, for example, it is preferable that the “predetermined amount” is set to an amount corresponding to the continuous printing amount of time required for the replenishment / replacement operation of the recording medium. According to this aspect, the recording medium can be continuously supplied from the other recording medium supply unit until the recording medium replenishment / replacement operation is completed for the recording medium supply unit where the end has occurred, and printing is not interrupted.

The image forming apparatus of the present invention, the recording medium of the same type have a two recording medium supply unit capable of supplying, when the end on one of the recording medium supply unit, the remaining amount of the other recording medium supply portion housing There is an aspect in which the supply of the recording medium is controlled so as to be about ½ of the maximum amount .

  According to this aspect, when the two recording medium supply units are alternately ended, and one of them is the end, the other is the maximum amount that can be accommodated (such as when a new roll, a new cassette, or a paper feed tray is fully loaded). Therefore, it is possible to realize the dispersion of the recording medium replenishment / exchange operation and the uniform time interval.

And other examples of control of the end timing, there is also a mode of generating substantially simultaneously end for at least two recording medium supply portion of the recording medium supply unit of several. In this case, the replenishment / replacement operation of the recording medium can be performed at once for the plurality of recording medium supply units, and the efficiency can be improved by the concentration of the operation. In particular, the recording medium replenishment / replacement operation can be performed collectively by controlling all of the plurality of recording medium supply units so as to end almost simultaneously.

The image forming apparatus of the present invention, when one of the recording medium supply unit in the recording medium supply portion of the multiple is end, the at least one other recording medium a predetermined amount or more of the recording medium supply unit remains A first control mode for controlling the supply of the recording medium, and a second control for controlling the supply of the recording medium so that at least two of the plurality of recording medium supply units end almost simultaneously. a mode setting means for designating the switching of the control mode, the end timing control means that perform control by the first control or the second control mode by the control mode in accordance with the setting of said mode setting means manner There is.

  By providing mode setting means for the user (operator) to set the end timings of the plurality of recording medium supply units, it is possible to generate a recording medium replenishment / replacement operation in accordance with the user's printing operation mode.

In the image forming apparatus according to the aspect of the invention, the transport unit includes a multi-row transport unit capable of transporting the recording media supplied from the plurality of recording medium supply units in a plurality of rows in a direction orthogonal to the transport direction. It said image forming means, there is a mode which is characterized in being configured to include a recording head capable of forming an image at the same time to said plurality of rows aligned plurality of recording media.

  The present invention is preferably applied to an image forming apparatus capable of simultaneously forming images on a plurality of recording media by multi-line conveyance.

In the image forming apparatus of the present invention, it is possible to suppress a decrease in print speed by controlling the standby time of each paper feed row so as not to be excessive in consideration of the standby time of each row.

In the image forming apparatus of the present invention, the recording head is a line type head in which a plurality of image recording elements are arranged over a length corresponding to the entire image forming width of the plurality of recording media arranged in the plurality of rows. There is a feature aspect.

  In the case of an ink jet recording head provided with a nozzle for ejecting ink as the “image recording element”, if the waiting time is controlled to be within a predetermined time in units of a paper feed row as described in claim 7, In addition, it is possible to prevent thickening of ink and mixing of bubbles, and it is possible to reduce the number of times of preliminary ejection (purge) and suction for recovery of ejection performance.

  The line type recording head is usually arranged along a direction perpendicular to the relative feeding direction of the recording medium, but along an oblique direction having a predetermined angle with respect to the direction perpendicular to the feeding direction. There may be a mode in which the recording head is arranged. Further, the arrangement form of the image recording elements in the recording head is not limited to a single line arrangement, and may be a matrix arrangement (two-dimensional arrangement) composed of a plurality of rows. Further, by combining a plurality of short recording head units each having an image recording element array that does not satisfy the length corresponding to the entire width of the image recordable width, the image recording element array corresponding to the entire recordable width of these units as a whole. There may also be a form of configuring.

In the present invention, in order to adjust the end timing among a plurality of recording medium supply units, it is preferable to control the supply of the recording medium while grasping the remaining amount of each recording medium supply unit.

  The remaining amount grasping means may be a means for directly detecting the remaining amount of the recording medium, or a means for predicting (estimating) the remaining amount from the usage amount.

In order to provide a method invention for achieving the above object, an image forming method according to the present invention includes a plurality of recording medium supply units, and the recording medium accommodated in each recording medium supply unit is used as the image forming unit. An image forming method for supplying and forming an image on a recording medium, the step of grasping the remaining amount of the recording medium accommodated in each of the plurality of recording medium supply units, and the remaining amount of each recording medium supply unit Based on the information, among the plurality of recording medium supply units, a control step of determining a supply source of a recording medium used for printing an input image, and print processing of the corresponding image for each recording medium supply unit according to the determination And a calculation step of calculating a waiting time until printing of an image to be reserved next is started for each buffer for each recording medium supply unit. Is The remaining amount difference among a plurality of recording medium supply unit is smaller than 1/2 of the housing maximum amount, and, from the latency of the remaining amount is small recording medium supply unit, subtracting the latency of the remaining amount is large recording medium supply unit When the obtained value is smaller than a predetermined determination reference value, the one having the smallest remaining amount among the plurality of recording medium supply units is determined as the supply source, and the difference in the remaining amount among the plurality of recording medium supply units is the maximum accommodation amount When the value obtained by subtracting the waiting time of the recording medium supply unit with a large remaining amount from the waiting time of the recording medium supply unit with a small remaining amount is less than ½ of , Determining a supply source having a low waiting time among the plurality of recording medium supply units, a difference in remaining amount of the plurality of recording medium supply units being larger than ½ of a maximum accommodation amount, and a remaining amount being The remaining amount is low due to the waiting time of many recording medium supply units. If the waiting time value obtained by subtracting the recording medium supply unit is smaller than the predetermined determination reference value, to determine what a lot of remaining of the plurality of recording medium supply section as the supply source, the plurality of recording medium The value obtained by subtracting the waiting time of the recording medium supply unit with a small remaining amount from the waiting time of the recording medium supply unit with a remaining amount difference larger than ½ of the maximum storage capacity and a large remaining amount is provided as the predetermined value. If the determination reference value is larger than the determination reference value, the recording medium supply unit having the low waiting time is determined as the supply source.
Furthermore, in order to provide another method invention for achieving the above object, an image forming method according to the present invention includes a plurality of recording medium supply units, and the recording medium accommodated in each recording medium supply unit is an image forming unit. An image forming method for forming an image on a recording medium, the step of grasping the remaining amount of the recording medium accommodated in each of the plurality of recording medium supply units, and the remaining of each recording medium supply unit Based on the quantity information, among the plurality of recording medium supply units, a control process for determining a supply source of a recording medium used for printing an input image, and print processing of the corresponding image for each recording medium supply unit according to the determination And a calculation step of calculating a waiting time until printing of the next reserved image is started for each buffer for each recording medium supply unit, and the control Craft , The remaining amount difference among a plurality of recording medium supply unit is smaller than 1/2 of the housing maximum amount, and, from the latency of the remaining amount is large recording medium supply unit, the remaining amount is small recording medium supply unit latency When the value obtained by subtracting is smaller than a predetermined determination reference value, the one having the remaining amount among the plurality of recording medium supply units is determined as the supply source, and the difference between the remaining amounts of the plurality of recording medium supply units is accommodated. When the value obtained by subtracting the waiting time of the recording medium supply unit with a small remaining amount from the waiting time of the recording medium supply unit with a small remaining amount that is smaller than ½ of the maximum amount is larger than the predetermined determination reference value Is determined as a supply source among the plurality of recording medium supply units, the difference in remaining amount of the plurality of recording medium supply units is larger than ½ of the maximum storage capacity, and the remaining The remaining amount is large due to the waiting time of the recording medium supply unit with a small amount If the waiting time value obtained by subtracting the recording medium supply unit is smaller than the predetermined determination reference value, to determine what little remaining of the plurality of recording medium supply section as the supply source, the plurality of recording medium A value obtained by subtracting the waiting time of the recording medium supply unit with a large remaining amount from the waiting time of the recording medium supply unit with a remaining amount difference larger than ½ of the maximum accommodation amount and a low remaining amount is the predetermined value. If the determination reference value is larger than the determination reference value, the recording medium supply unit having the low waiting time is determined as the supply source.

  According to the present invention, in an image forming apparatus including a plurality of recording medium supply units, the replenishment / replacement operation of the recording medium can be performed by appropriately controlling the timing when the recording mediums of the plurality of recording medium supply units end. It becomes possible to implement it systematically. Thereby, reduction of work burden and improvement of print production efficiency can be achieved.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[Overall configuration of inkjet recording apparatus]
FIG. 1 is an overall configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. As shown in the figure, the inkjet recording apparatus 10 includes a printing unit (corresponding to an image forming unit) 12 having a plurality of printing heads 12K, 12C, 12M, and 12Y provided for each ink color, and each printing. An ink storage / loading unit 14 for storing ink to be supplied to the heads 12K, 12C, 12M, and 12Y; paper supply units 18A and 18B for supplying recording paper (paper) 16A and 16B to the printing unit 12; The decurling units 20A and 20B for removing the curl of the recording papers 16A and 16B sent out from the units 18A and 18B and the nozzle surface (ink ejection surface) of the printing unit 12 are arranged to face the recording papers 16A and 16B. A suction belt conveyance unit 22 that conveys the recording papers 16A and 16B while maintaining the flatness of the print sheet, a print detection unit 24 that reads a print result by the print unit 12, and a recorded And recording paper (printed matter) with a paper output unit 26 for discharging the outside.

  In FIG. 1, two paper supply units 18A and 18B for supplying the same type of paper are shown, and magazines 19A and 19B for rolled paper (continuous paper) are shown as an example of the paper supply units 18A and 18B. Many more magazines with different paper quality may be provided. Further, instead of the roll paper magazine or in combination therewith, the paper may be supplied by a cassette in which cut papers are stacked and loaded.

  When multiple types of paper can be used, an information recording body such as a barcode or wireless tag that records paper type information is attached to the magazine, and the information on the information recording body is read by a predetermined reader. It is preferable to automatically determine the type of paper to be used and perform ink ejection control so as to realize appropriate ink ejection according to the type of paper.

  The recording paper 16A, 16B delivered from the paper supply units 18A, 18B retains curl due to having been loaded in the magazines 19A, 19B. In order to remove this curl, heat is applied to the recording paper 16A, 16B by the heating drums 30A, 30B in the direction opposite to the curl direction of the magazines 19A, 19B in the decurling units 20A, 20B. At this time, it is more preferable to control the heating temperature so that the printed surface is slightly curled outward.

  In the case of an apparatus configuration using roll paper, a cutter (first cutter) 28 is provided in each paper feed path as shown in FIG. 1, and the roll paper is cut into a desired size by the cutter 28. Is done. The cutter 28 includes a fixed blade 28A having a length equal to or greater than the conveyance path width of the recording paper 16A and 16B, and a round blade 28B that moves along the fixed blade 28A. And a round blade 28B is arranged on the printing surface side across the conveyance path. Note that the cutter 28 is not necessary when cut paper is used.

  After the decurling process, the cut recording papers 16 </ b> A and 16 </ b> B are sent to the suction belt conveyance unit 22. In FIG. 1, the paper feeding units 18A and 18B are drawn up and down for convenience, but the recording papers 16A and 16B supplied from the paper feeding units 18A and 18B are conveyed in two rows on the conveyance path.

  The suction belt conveyance unit 22 has a structure in which an endless belt 33 is wound between rollers 31 and 32, and at least portions facing the nozzle surface of the printing unit 12 and the sensor surface of the printing detection unit 24 are horizontal ( Flat surface).

  The belt 33 has a width that is wider than the total width when the recording papers 16A and 16B are arranged in two rows (twice the paper width of the recording paper 16A), and a plurality of suction holes (not shown) are formed on the belt surface. ) Is formed. An adsorption chamber 34 is provided at a position facing the nozzle surface of the print unit 12 and the sensor surface of the print detection unit 24 inside the belt 33 spanned between the rollers 31 and 32. By sucking at 35 and making negative pressure, the recording sheets 16A and 16B on the belt 33 are sucked and held.

  When the power of a motor (not shown in FIG. 1, described as reference numeral 88 in FIG. 7) is transmitted to at least one of the rollers 31 and 32 around which the belt 33 is wound, the belt 33 rotates in the clockwise direction in FIG. The recording sheets 16A and 16B held on the belt 33 are conveyed from left to right in FIG.

  Since ink adheres to the belt 33 when a borderless print or the like is printed, the belt cleaning unit 36 is provided at a predetermined position outside the belt 33 (an appropriate position other than the print area). Although details of the configuration of the belt cleaning unit 36 are not shown, for example, there are a method of niping a brush roll, a water absorbing roll, etc., an air blow method of blowing clean air, or a combination thereof. In the case where the cleaning roll is nipped, the cleaning effect is great if the belt linear velocity and the roller linear velocity are changed.

  Although a mode using a roller / nip conveyance mechanism instead of the suction belt conveyance unit 22 is also conceivable, if the roller / nip conveyance is performed in the print area, the image easily spreads because the roller contacts the printing surface of the sheet immediately after printing. There is a problem. Therefore, as in this example, suction belt conveyance that does not bring the image surface into contact with each other in the print region is preferable.

  A heating fan 40 is provided on the upstream side of the printing unit 12 on the paper conveyance path formed by the suction belt conveyance unit 22. The heating fan 40 blows heated air onto the recording papers 16A and 16B before printing to heat the recording papers 16A and 16B. Heating the recording papers 16A and 16B immediately before printing makes it easier for the ink to dry after landing.

  The printing unit 12 is a so-called full-line head in which line-type heads having a length corresponding to the two-line conveyance width of the recording papers 16A and 16B are arranged in a direction orthogonal to the paper feed direction (see FIG. 2). ). Although a detailed structure example will be described later, each of the print heads 12K, 12C, 12M, and 12Y has a plurality of ink discharge ports (nozzles) over a length exceeding at least one side of the maximum size paper targeted by the inkjet recording apparatus 10. It is composed of arranged line type heads.

Printing corresponding to each color ink in the order of black (K), cyan (C), magenta (M), and yellow (Y) from the upstream side along the feeding direction of the recording papers 16A and 16B (hereinafter referred to as the paper conveying direction). Heads 12K, 12C, 12M, and 12Y are disposed, and color inks are ejected from the print heads 12K, 12C, 12M, and 12Y while transporting the recording papers 16A and 16B, respectively, so that the color is printed on the recording papers 16A and 16B. An image can be formed.

  As described above, according to the printing unit 12 in which the line head covering the entire width of the paper is provided for each ink color, the recording papers 16A and 16B and the printing unit 12 are relatively moved in the paper feeding direction (sub-scanning direction). An image can be recorded on the entire surface of the recording papers 16A and 16B by performing the moving operation only once (that is, by one sub-scan). Thereby, printing can be performed at a higher speed than the shuttle type head in which the print head reciprocates in the direction orthogonal to the paper conveyance direction, and productivity can be improved.

  In this example, the configuration of KCMY standard colors (four colors) is illustrated, but the combination of ink color and number of colors is not limited to this embodiment, and light ink, dark ink, and special color ink are used as necessary. May be added. For example, it is possible to add a print head that discharges light ink such as light cyan and light magenta. Also, the arrangement order of the color heads is not particularly limited.

  As shown in FIG. 1, the ink storage / loading unit 14 includes tanks (ink tanks) that store inks of colors corresponding to the print heads 12K, 12C, 12M, and 12Y, and each ink tank is not shown. The print heads 12K, 12C, 12M, and 12Y communicate with each other through the pipe line. Further, the ink storage / loading unit 14 includes notifying means (display means, warning sound generating means) for notifying when the ink remaining amount is low, and has a mechanism for preventing erroneous loading between colors. ing.

  The print detection unit 24 includes an image sensor for imaging the droplet ejection result of the print unit 12, and functions as a means for checking nozzle clogging and other ejection defects from the droplet ejection image read by the image sensor.

  The print detection unit 24 of this example is composed of a line sensor having a light receiving element array that is wider than at least the ink ejection width (image recording width) by the print heads 12K, 12C, 12M, and 12Y. The line sensor includes an R sensor row in which photoelectric conversion elements (pixels) provided with red (R) color filters are arranged in a line, a G sensor row provided with green (G) color filters, The color separation line CCD sensor is composed of a B sensor array provided with a blue (B) color filter. Instead of the line sensor, an area sensor in which the light receiving elements are two-dimensionally arranged can be used.

  The print detection unit 24 reads test patterns or practical images printed by the print heads 12K, 12C, 12M, and 12Y of the respective colors, and detects ejection of each head. The ejection determination includes the presence / absence of ejection, measurement of dot size, measurement of dot landing position, and the like.

  A post-drying unit 42 is provided following the print detection unit 24. The post-drying unit 42 is means for drying the printed image surface, and for example, a heating fan is used. Since it is preferable to avoid contact with the printing surface until the ink after printing is dried, a method of blowing hot air is preferred.

  When printing on porous paper with dye-based ink, the weather resistance of the image is improved by preventing contact with ozone or other things that cause dye molecules to break by pressurizing the paper holes with pressure. There is an effect to.

  A heating / pressurizing unit 44 is provided following the post-drying unit 42. The heating / pressurizing unit 44 is a means for controlling the glossiness of the image surface, and pressurizes with a pressure roller 45 having a predetermined surface uneven shape while heating the image surface to transfer the uneven shape to the image surface. To do.

  The printed matter generated in this manner is outputted from the paper output unit 26. It is preferable that the original image to be printed (printed target image) and the test print are discharged separately. The ink jet recording apparatus 10 is provided with a sorting means (not shown) that switches the paper discharge path so as to select the print product of the main image and the print product of the test print and send them to the discharge units 26A and 26B. Yes. Note that when the main image and the test print are simultaneously formed in parallel on a large sheet, the test print portion is separated by a cutter (second cutter) 48. The cutter 48 is provided immediately before the paper discharge unit 26, and cuts the main image and the test print unit when the test print is performed on the image margin. The structure of the cutter 48 is the same as that of the first cutter 28 described above, and includes a fixed blade 48A and a round blade 48B.

  Although not shown in FIG. 1, the paper output unit 26A for the target prints is provided with a sorter for collecting prints according to print orders.

[Print head structure]
Next, the structure of the print head will be described. Since the structures of the print heads 12K, 12C, 12M, and 12Y provided for the respective ink colors are common, the print heads are represented by reference numeral 50 in the following.

  FIG. 3A is a plan perspective view showing an example of the structure of the print head 50, and FIG. 3B is an enlarged view of a part thereof. 3C is a plan perspective view showing another example of the structure of the print head 50, and FIG. 4 is a cross-sectional view showing a three-dimensional configuration of one droplet discharge element (an ink chamber unit corresponding to one nozzle 51). FIG. 4 is a cross-sectional view taken along line 4-4 in FIG.

  In order to increase the dot pitch printed on the recording papers 16A and 16B, it is necessary to increase the nozzle pitch in the print head 50. As shown in the figure, the print head 50 of this example includes a plurality of ink chamber units (droplet discharge elements) 53 including nozzles 51 serving as ink droplet discharge ports and pressure chambers 52 corresponding to the nozzles 51. In this way, a substantial nozzle interval (projection nozzle) projected so as to be arranged along the longitudinal direction of the head (direction perpendicular to the paper conveyance direction) is arranged in a matrix (two-dimensionally). High density of pitch) has been achieved.

  Further, instead of the configuration of FIG. 3 (a), as shown in FIG. 3 (c), short head units 50 ′ in which a plurality of nozzles 51 are two-dimensionally arranged are arranged in a staggered manner and connected. Thus, a line head having a nozzle row having a length corresponding to the entire width of the two-row conveying width of the recording papers 16A and 16B may be configured.

  The pressure chamber 52 provided corresponding to each nozzle 51 has a substantially square planar shape (see FIGS. 3 (a) and 3 (b)), and is connected to the nozzle 51 at both corners on a diagonal line. An outlet and an inlet (supply port) 54 for supply ink are provided. The shape of the pressure chamber 52 is not limited to this example, and the planar shape may have various forms such as a quadrangle (rhombus, rectangle, etc.), a pentagon, a hexagon, other polygons, a circle, and an ellipse.

  As shown in FIG. 4, each pressure chamber 52 communicates with a common flow channel 55 through a supply port 54. The common flow channel 55 communicates with an ink tank (not shown in FIG. 4, described as reference numeral 60 in FIG. 6) serving as an ink supply source, and ink supplied from the ink tank passes through each pressure chamber via the common flow channel 55. 52 is distributed and supplied.

  An actuator 58 having an individual electrode 57 is joined to a pressure plate (vibration plate) 56 constituting a part of the pressure chamber 52 (the top surface in FIG. 4). By applying a driving voltage to the individual electrode 57, the actuator 58 is deformed to change the volume of the pressure chamber 52, and ink is ejected from the nozzle 51 due to the pressure change accompanying this. For the actuator 58, a piezoelectric body such as a piezoelectric element is preferably used. After ink discharge, new ink is supplied from the common channel 55 to the pressure chamber 52 through the supply port 54.

  As shown in FIG. 5, a large number of ink chamber units 53 having such a structure are arranged in a row direction along the main scanning direction and an oblique column direction having a constant angle θ that is not orthogonal to the main scanning direction. The structure is arranged in a lattice pattern. With a structure in which a plurality of ink chamber units 53 are arranged at a constant pitch d along a certain angle θ with respect to the main scanning direction, the pitch P of the nozzles projected so as to be aligned in the main scanning direction is d × cos θ. .

  That is, in the main scanning direction, each nozzle 51 can be handled equivalently as a linear arrangement with a constant pitch P. With such a configuration, it is possible to realize a high-density nozzle configuration in which 2400 nozzle rows are projected per inch (2400 nozzles / inch) so as to be aligned in the main scanning direction.

  When the nozzles are driven by a full line head having a nozzle row having a length corresponding to the entire printable width, (1) all the nozzles are driven simultaneously, (2) the nozzles are sequentially moved from one side to the other. (3) The nozzles are divided into blocks, and the nozzles are sequentially driven from one side to the other for each block, etc., and one line (1 in the width direction of the paper (direction perpendicular to the paper conveyance direction)) Driving a nozzle that prints a line of dots in a row or a line consisting of dots in a plurality of rows is defined as main scanning.

  In particular, when driving the nozzles 51 arranged in a matrix as shown in FIG. 5, the main scanning as described in (3) above is preferable. That is, nozzles 51-11, 51-12, 51-13, 51-14, 51-15, 51-16 are made into one block (other nozzles 51-21,..., 51-26 are made into one block, Nozzles 51-31,..., 51-36 as one block,...), And the nozzles 51-11, 51-12,. One line is printed in the width direction of 16A and 16B.

  On the other hand, by performing relative movement between the above-described full line head and the paper, sub-scanning is performed by repeatedly performing one line (a line formed by a single row of dots or a line composed of a plurality of rows of dots) formed by the above-described main scan. It is defined as

  The direction indicated by one line (or the longitudinal direction of the belt-like region) recorded by the main scanning is referred to as a main scanning direction, and the direction in which the sub scanning is performed is referred to as a sub scanning direction. That is, in the present embodiment, the conveyance direction of the recording papers 16A and 16B is the sub-scanning direction, and the direction orthogonal to the recording paper 16A and 16B is the main scanning direction.

  In implementing the present invention, the nozzle arrangement structure is not limited to the illustrated example. In the present embodiment, a method of ejecting ink droplets by deformation of an actuator 58 typified by a piezo element (piezoelectric element) is adopted. However, in the practice of the present invention, the method of ejecting ink is not particularly limited. Instead of the piezo jet method, various methods such as a thermal jet method in which ink is heated by a heating element such as a heater to generate bubbles and ink droplets are ejected by the pressure can be applied.

  FIG. 6 is a schematic diagram showing the configuration of the ink supply system in the inkjet recording apparatus 10.

  The ink tank 60 is a base tank that supplies ink to the print head 50 and is installed in the ink storage / loading unit 14 described with reference to FIG. In the form of the ink tank 60, there are a system that replenishes ink from a replenishing port (not shown) and a cartridge system that replaces the entire tank when the remaining amount of ink is low. A cartridge system is suitable for changing the ink type according to the intended use. In this case, it is preferable that the ink type information is identified by a barcode or the like, and ejection control is performed according to the ink type. The ink tank 60 in FIG. 6 is equivalent to the ink storage / loading unit 14 in FIG. 1 described above.

  As shown in FIG. 6, a filter 62 is provided between the ink tank 60 and the print head 50 in order to remove foreign substances and bubbles. The filter mesh size is preferably equal to or smaller than the nozzle diameter (generally about 20 μm).

  Although not shown in FIG. 6, a configuration in which a sub tank is provided in the vicinity of the print head 50 or integrally with the print head 50 is also preferable. The sub-tank has a function of improving a damper effect and refill that prevents fluctuations in the internal pressure of the head.

  Further, the inkjet recording apparatus 10 is provided with a cap 64 as a means for preventing the nozzle 51 from drying or preventing an increase in ink viscosity near the nozzle, and a cleaning blade 66 as a means for cleaning the nozzle surface 50A. .

  The maintenance unit including the cap 64 and the cleaning blade 66 can be moved relative to the print head 50 by a moving mechanism (not shown), and is moved from a predetermined retracted position to a maintenance position below the print head 50 as necessary. The

  The cap 64 is displaced up and down relatively with respect to the print head 50 by an elevator mechanism (not shown). The cap surface 64A is covered with the cap 64 by raising the cap 64 to a predetermined raised position when the power is turned off or during printing standby, and bringing the cap 64 into close contact with the print head 50.

  The cleaning blade 66 is made of an elastic member such as rubber, and can slide on the ink discharge surface (surface of the nozzle plate) of the print head 50 by a blade moving mechanism (not shown). When ink droplets or foreign substances adhere to the nozzle plate, the nozzle plate surface is wiped by sliding the cleaning blade 66 on the nozzle plate to clean the nozzle plate surface.

  During printing or standby, when a specific nozzle is used less frequently and the ink viscosity in the vicinity of the nozzle increases, preliminary discharge is performed toward the cap 64 to discharge the deteriorated ink.

  Further, when air bubbles are mixed into the ink (pressure chamber) in the print head 50, the cap 64 is applied to the print head 50, and the ink in the pressure chamber (ink mixed with air bubbles) is removed by suction with the suction pump 67, and suction is performed. The removed ink is sent to the collection tank 68. In this suction operation, the deteriorated ink with increased viscosity (solidified) is sucked out when the ink is initially loaded into the head or when the ink is used after being stopped for a long time.

  If the print head 50 is not ejected for a certain period of time, the ink solvent near the nozzle evaporates and the viscosity of the ink near the nozzle increases. Ink will not be ejected. Therefore, before this state is reached (within the viscosity range in which ink can be discharged by the operation of the actuator 58), the actuator is operated toward the ink receiver to discharge ink in the vicinity of the nozzle whose viscosity has increased. "Preliminary discharge" is performed. In order to prevent foreign matter from being mixed into the nozzle 51 by the wiper rubbing operation after the dirt on the nozzle plate surface is cleaned by a wiper such as a cleaning blade 66 provided as a nozzle surface cleaning means. Preliminary discharge is performed. Note that the preliminary discharge may be referred to as “empty discharge”, “purge”, “spitting”, or the like.

  In addition, if bubbles are mixed into the nozzle 51 or the pressure chamber 52 or if the viscosity increase of the ink in the nozzle 51 exceeds a certain level, ink cannot be ejected by the preliminary ejection, and the suction operation described below is performed.

That is, when bubbles are mixed in the ink in the nozzle 51 or the pressure chamber 52, or when the ink viscosity in the nozzle 51 rises to a certain level or more, the ink can be ejected from the nozzle 51 even if the actuator 58 is operated. Disappear. In such a case, a suction means for sucking the ink in the pressure chamber 52 with a pump or the like is brought into contact with the nozzle surface of the print head 50, and an operation of sucking ink mixed with bubbles or thickened ink is performed.

  However, since the above suction operation is performed on the entire ink in the pressure chamber 52, the ink consumption is large. Therefore, when the increase in viscosity is small, it is preferable to perform preliminary discharge as much as possible.

[Explanation of control system]
Next, the control system of the inkjet recording apparatus 10 will be described. FIG. 7 is a principal block diagram showing the system configuration of the inkjet recording apparatus 10. The inkjet recording apparatus 10 includes a communication interface 70, a system controller 72, an image memory 74, a motor driver 76, a heater driver 78, a print control unit 80, an image buffer memory 82, a head driver 84, a paper feed control unit 85, and the like. Is done.

The communication interface 70 is an interface unit that receives image data sent from the host computer 86. A serial interface such as USB (Universal Serial Bus) , IEEE 1394, Ethernet (registered trademark) , a wireless network, or a parallel interface such as Centronics can be applied to the communication interface 70. In this part, a buffer memory (not shown) for speeding up communication may be mounted. Image data sent from the host computer 86 is taken into the inkjet recording apparatus 10 via the communication interface 70 and temporarily stored in the image memory 74. The image memory 74 is a storage unit that temporarily stores an image input via the communication interface 70, and data is read and written through the system controller 72. The image memory 74 is not limited to a memory made of a semiconductor element, and a magnetic medium such as a hard disk may be used.

  The system controller 72 is a control unit that controls the communication interface 70, the image memory 74, the motor driver 76, the heater driver 78, the paper feed control unit 85, and the like. The system controller 72 includes a central processing unit (CPU) and its peripheral circuits, and performs communication control with the host computer 86, read / write control of the image memory 74, and the like, as well as a transport system motor 88 and heater 89. A control signal for controlling is generated.

  The motor driver 76 is a driver (drive circuit) that drives the motor 88 in accordance with an instruction from the system controller 72. The heater driver 78 is a driver that drives the heaters 89 of the post-drying unit 42 and other units in accordance with instructions from the system controller 72.

  The print control unit 80 has a signal processing function for performing various processing and correction processing for generating a print control signal from the image data in the image memory 74 according to the control of the system controller 72, and the generated print A control unit that supplies a control signal (print data) to the head driver 84. Necessary signal processing is performed in the print controller 80, and the ejection amount and ejection timing of the ink droplets of the print head 50 are controlled via the head driver 84 based on the image data. Thereby, a desired dot size and dot arrangement are realized.

  The print control unit 80 includes an image buffer memory 82, and image data, parameters, and other data are temporarily stored in the image buffer memory 82 when image data is processed in the print control unit 80. In FIG. 7, the image buffer memory 82 is shown in a mode associated with the print control unit 80, but it can also be used as the image memory 74. Also possible is an aspect in which the print controller 80 and the system controller 72 are integrated and configured with one processor.

  The head driver 84 drives the ejection drive actuator 58 of the print head 50 for each color based on the print data given from the print controller 80. The head driver 84 may include a feedback control system for keeping the head driving conditions constant.

  Image data to be printed is input from the outside via the communication interface 70 and stored in the image memory 74. At this stage, for example, RGB image data is stored in the image memory 74. The image data stored in the image memory 74 is sent to the print control unit 80 via the system controller 72, and the print control unit 80 converts it into dot data for each ink color by a known method such as dithering or error diffusion. Converted.

  Thus, the print head 50 is driven and controlled based on the dot data generated by the print control unit 80, and ink is ejected from the print head 50. An image is formed on the recording papers 16A and 16B by controlling ink ejection from the print head 50 in synchronization with the conveyance speed of the recording papers 16A and 16B.

  As described with reference to FIG. 1, the print detection unit 24 is a block including a line sensor. The print detection unit 24 reads images printed on the recording papers 16A and 16B, performs necessary signal processing, etc. For example, variations in droplet ejection), and the detection result is provided to the print controller 80. The reading start timing of the line sensor is determined from the distance between the sensor and the nozzle and the conveyance speed of the recording paper 16.

  The print control unit 80 performs various corrections on the print head 50 based on information obtained from the print detection unit 24 as necessary.

  The paper feed control unit 85 functions as a “timing control unit” together with the system controller 72. The paper feed control unit 85 controls the paper supply from the magazines 19A and 19B in accordance with a command from the system controller 72, and controls the paper end timing (that is, the roll replacement timing) of the two magazines 19A and 19B. .

  The paper feed controller 85 includes means for detecting the remaining amount of paper, and the remaining paper amount information is sent to the system controller 72. The paver remaining amount detecting means includes means for predicting (estimating) the remaining amount from the usage amount. For example, a mode using means for calculating the amount of paper used by counting the number of used sheets (means for predicting the remaining amount by subtracting the amount used from a new roll or cassette), means for measuring the outer diameter of the roll paper A mode in which the remaining amount of paper is grasped from the measurement result, a mode in which a sensor (end sensor) for detecting the paper end is used, or an appropriate combination thereof is used.

  In the present embodiment, the paper end timing can be set by an operator (user). For example, two paper rolls are set to end at the most distant time interval (the other is ½ remaining when one ends) (referred to as “first mode”). Any of the settings (referred to as “second mode”) can be designated. An input device (for example, an instruction input unit represented by a keyboard and a mouse) 90 and a display unit 92 of the host computer 86 are used as a setting unit for the above setting by the user. Of course, a mode in which a user interface for performing the above setting is provided on the main body side of the inkjet recording apparatus 10 is also possible.

  In the first mode (corresponding to the first control mode), the printing operation can be continued even when one paper roll reaches the end, so that the production of the print proceeds with the other roll even while one roll is replaced. There is.

  In the case of the second mode (corresponding to the second control mode), both rolls are eliminated at once, so that there is an advantage that the replacement work can be completed simultaneously.

  The system controller 72 adjusts the roll replacement timing of each magazine 19A, 19B by controlling which of the two magazines 19A, 19B is used for printing according to the designated setting.

  Specifically, when there are two or more images ready for printing, printing is performed using both columns. When the number of ready images is one, according to the end timing setting by the user, in the first mode, printing is performed by selecting a row in which the difference in the remaining amount of paper approaches 1/2 of the new roll, In the second mode, printing is performed by selecting a column in which the remaining amount of paper is close to each other.

  However, if one of the columns is being printed, the empty column is preferentially used from the standpoint of speed. Whether to use the empty column or wait for the used column is determined by whether or not the time difference between the two exceeds a certain reference time (judgment time). If the time difference between the two exceeds a certain time difference, the empty column is used. You may control to do.

  Next, a print control sequence in the inkjet recording apparatus 10 configured as described above will be described. Here, for convenience of explanation, the paper feed row of the recording paper 16A supplied from the magazine 19A is called “A row”, and the paper feed row of the recording paper 16B supplied from the magazine 19B is called “B row”.

  FIG. 8A is a flowchart illustrating an example of paper end mode switching control. As shown in the drawing, first, an end mode selection input is received from an operator (user) (step S10). The user performs an input operation for designating a desired end mode (first mode or second mode) using a predetermined user interface (for example, the input device 90 described with reference to the drawing). The designated mode information is stored in a storage means (not shown) (for example, EEPROM) in the system controller 72.

  The system controller 72 determines the end mode set by the user (step S12). If it is determined that “end mode = 1” (ie, “first mode”) is set, the control according to the first mode is selected. Then, control in the first mode (paper end non-simultaneous mode) in which the two rows of paper end timings are different is executed (step S14).

  On the other hand, if it is determined in step S12 that “end mode = 2” (that is, “second mode”) is set, the control in the second mode is selected, and the second paper end timing is substantially matched. Control in two modes (paper end simultaneous mode) is executed (step S16).

  FIG. 8B is a flowchart of the sequence in the first mode, that is, the sequence in which the two columns end at the farthest time (when one reaches the end, the other becomes ½ remaining state).

  When the print preparation completion image is generated (step S110), first, the remaining amount of paper in the A row and the remaining amount of paper in the B row are compared (step S112). If the relationship “A column remaining amount> B column remaining amount” is not satisfied (NO in step S112), the process proceeds to step S114, and the difference between the B column remaining amount and the A column remaining amount is ½ roll. It is determined whether or not it is smaller.

  If YES in step S114, the process proceeds to column A priority print processing (step S116). On the other hand, if the determination in step S114 is NO, the process proceeds to B column priority print processing (step S118).

  If the relationship of “A column remaining amount> B column remaining amount” is satisfied in the determination in step S112, the process proceeds to step S120, and the difference between the A column remaining amount and the B column remaining amount is less than 1/2 roll. It is determined whether or not it is small. If NO in step S120, the process proceeds to column A priority print processing (step S122). On the other hand, if the determination in step S120 is YES, the process proceeds to B column priority print processing (step S124).

  FIG. 9 is a flowchart showing the sequence of A column priority printing.

  When the processing flow of the A column priority print starts (step S210), it is determined whether or not the difference between the print waiting time for the A column and the print waiting time for the B column is smaller than a predetermined determination reference value T (step S212). ). If the relationship of “A-row waiting time−B-row waiting time <T” is satisfied (YES in step S212), the image is reserved in the A-column print buffer (step S214), and the A-row waiting time is updated. (Step S216). Images reserved in the buffer are printed in the order of reservation by first-in first-out (FIFO).

  In addition, when NO determination is made in step S212, that is, when the relationship of “A-row waiting time−B-row waiting time <T” is not satisfied, if the reservation is made for the A-row, the waiting time is further increased. Therefore, the image is reserved in the B column print buffer (step S218), and the B column waiting time is updated (step S220).

  FIG. 10 is a flowchart showing the sequence of B column priority printing.

  When the processing flow for B-column priority printing starts (step S310), it is determined whether or not the difference between the print waiting time for column B and the print waiting time for column A is smaller than a predetermined determination reference value T (step S312). ). If the relationship “B column waiting time−A column waiting time <T” is satisfied (YES in step S312), the corresponding image is reserved in the B column print buffer (step S314). Update (step S316). Images reserved in the buffer are printed in the order of reservation by first-in first-out (FIFO).

  In addition, when NO determination is made in step S312, that is, when the relationship of “B column waiting time−A column waiting time <T” is not satisfied, if the reservation is made in the B column, the waiting time becomes further longer. Therefore, the image is reserved in the A column print buffer (step S318), and the A column waiting time is updated (step S320).

  9 and 10 described above, the determination reference value T is set to a time of 0 or more. If a time greater than 0 is set, the print output time is increased by T. It is set to an appropriate value depending on how much priority is given to the print output time. Note that the waiting time may be handled as infinite when the remaining amount of paper = 0 (no remaining amount).

  As described above, the column used for printing is determined in consideration of the number of images ready for printing and the state (waiting time) of the paper feed column in use. It can be used effectively and the printing speed can be improved.

  When sorting the output prints (when collecting print orders, and stacking them in a predetermined order within the print order), the print stacking order is set to the print preparation completion order (for example, this is the order of shooting). If equal, the last two columns of print output are merged.

  At this time, if the order output from the A column and the B column is different from the print preparation completion order, it is necessary to change the order in which the prints are overlapped, so that the sorting process becomes complicated. If a value greater than 0 is set as the determination reference value T and the print preparation completion interval is short, such a state may occur.

  In order to avoid such a situation, a flow as shown in FIGS. 11 and 12 may be employed. In these drawings, the same steps as those in FIGS. 9 and 10 are denoted by the same step numbers, and the description thereof is omitted.

  In FIG. 11, compared to FIG. 9, step S <b> 213 is added after the YES determination in step S <b> 212, and step S <b> 217 is added after the NO determination in step S <b> 212, and the process proceeds to step S <b> 214 after step S <b> 213. After that, the process proceeds to step S218.

Similarly, in FIG. 12, compared to FIG. 10, step S313 is added after the YES determination in step S312, and step S317 is added after the NO determination in step S312, and the process proceeds to step S314 after step S313, After step S317, the process proceeds to step S318.

  11 and FIG. 12, “B-row waiting time = B-row waiting time + T + α” in steps S213 and S317 means that the paper supply is also delayed so as to actually delay the print start time of the B-row by T + α. means. That is, a rewriting process is performed in which a value obtained by adding T + α to the current B-column waiting time is newly set as the B-column waiting time. The delay constant α is set to an appropriate value of 0 or more.

  Similarly, “row A waiting time = column A waiting time + T + α” in steps S217 and S313 means that the paper supply is also delayed so that the printing start time of column A is actually delayed by T + α. In other words, a rewriting process is performed in which a value obtained by adding T + α to the current A column waiting time is newly set as the A column waiting time.

  Thus, the print output order from the two rows of conveyance paths can be made equal to the print preparation completion order, which is convenient when stacking prints by order in the print preparation completion order.

  FIG. 13 is a flowchart of the second mode, that is, a sequence in which two columns end almost simultaneously.

  When a print preparation completion image is generated (step S410), first, the remaining amount of paper in the A row and the remaining amount of paper in the B row are compared (step S412). If the relationship “A column remaining amount> B column remaining amount” is not satisfied (NO in step S412), the process proceeds to step S414, and the difference between the B column remaining amount and the A column remaining amount is ½ roll. It is determined whether or not it is smaller.

  If YES in step S414, the process proceeds to B column priority print processing (step S416). The processing contents of the B column priority printing are as described with reference to FIG. 10 or FIG.

  If NO in step S414, the process proceeds to column A priority print processing (step S418). This path means that the paper in row B has been replaced relatively recently, in which case the paper in row A with low remaining capacity is used up rather than generating paper ends almost simultaneously in two rows. Therefore, such control is performed from the viewpoint that it is more efficient to promote the roll replacement in the A row. The processing contents of the A column priority print are as described in FIG. 9 or FIG.

  If the relationship of “A column remaining amount> B column remaining amount” is satisfied in the determination in step S412, the process proceeds to step S420, and the difference between the A column remaining amount and the B column remaining amount is less than 1/2 roll. It is determined whether or not it is small. If NO in step S420, the process proceeds to B column priority print processing (step S422). This pass means that the paper in row A has been replaced relatively recently. In this case, the paper in row B, which has a small remaining amount, is used up first, rather than generating paper ends almost simultaneously in two rows. , B roll exchange is urged.

  On the other hand, if the determination in step S420 is YES, the process proceeds to column A priority print processing (step S424). With the sequence shown in FIG. 13, two rows can be ended almost simultaneously, and paper replacement work can be performed at a time.

In the above embodiment, the recording paper 16A sent from the supply unit 18A and the recording paper 16B sent from the supply unit 18B are arranged in the A row and the B row, respectively, and conveyed in two rows. It is also possible to provide a means for switching the conveyance paths of the recording papers 16A and 16B in the upstream conveyance path (means for guiding the recording paper 16A to the B row and the recording paper 16B to the A row).
Recording sheets (for example, 16A) supplied from the same supply unit (for example, 18A) can be arranged in two rows and printed by the printing unit 12.

  In the above embodiment, the line head type ink jet recording apparatus has been described as an example of the image forming apparatus, but the scope of application of the present invention is not limited to this. Even if it is not a line head system, the present invention can be applied as long as it has an image forming unit capable of recording simultaneously on a plurality of rows of media, and can also be applied to a shuttle-type ink jet recording apparatus that scans across a plurality of rows of media. . Furthermore, the present invention can be applied to a thermal transfer recording apparatus having a thermal head, an LED rain head, a laser scanning type electrophotographic printer, and a silver salt photographic type printer in addition to the ink jet type.

1 is an overall configuration diagram of an ink jet recording apparatus according to an embodiment of the present invention. 1 is a perspective view of a main part around a printing unit of the ink jet recording apparatus shown in FIG. Plane perspective view showing the configuration of the print head Enlarged view of the main part of Fig. 3 (a) Plane perspective view showing another configuration example of the print head Sectional view along line 4-4 in Figs. 3 (a) and 3 (b) Enlarged view showing the nozzle arrangement of the print head shown in FIG. Schematic diagram showing the configuration of the ink supply system in the inkjet recording apparatus of this example Main block diagram showing the system configuration of the inkjet recording apparatus of this example Flowchart illustrating an example of paper end mode switching control in the inkjet recording apparatus according to the present embodiment. A flowchart showing an operation sequence in the ink jet recording apparatus according to the present embodiment. A flowchart showing an operation sequence in the ink jet recording apparatus according to the present embodiment. A flowchart showing an operation sequence in the ink jet recording apparatus according to the present embodiment. A flowchart showing an operation sequence in the ink jet recording apparatus according to the present embodiment. A flowchart showing an operation sequence in the ink jet recording apparatus according to the present embodiment. A flowchart showing an operation sequence in the ink jet recording apparatus according to the present embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Inkjet recording device, 12 ... Printing part, 12K, 12C, 12M, 12Y ... Print head, 14 ... Ink storage / loading part, 16A, 16B ... Recording paper (equivalent to a recording medium), 18A, 18B ... Supply part ( 19A, 19B ... magazine, 22 ... suction belt conveyance unit, 50 ... print head, 51 ... nozzle, 72 ... system controller, 80 ... print control unit, 84 ... head driver, 85 ... paper feed Control unit, 86 ... host computer, 90 ... input device, 92 ... display unit

Claims (6)

A plurality of recording medium supply units that contain the recording medium and supply the recording medium to the image forming unit;
Conveying means for conveying a recording medium supplied from the plurality of recording medium supply units;
Image forming means for forming an image on a recording medium provided in the image forming section and conveyed by the conveying means;
A remaining amount grasping means for grasping the remaining amount of the recording medium accommodated in each recording medium supply unit;
Control means for determining a supply source of a recording medium to be used for printing an input image among the plurality of recording medium supply sections based on the remaining amount information of each recording medium supply section obtained by the remaining amount grasping means When,
Means for reserving print processing of the corresponding image in the buffer for each recording medium supply unit according to the determination;
A calculation means for calculating a waiting time until the printing of the next reserved image is started for each buffer for each recording medium supply unit;
With
The control means includes a recording medium supply unit having a large remaining amount due to a waiting time of the recording medium supply unit having a remaining amount difference between the plurality of recording medium supply units being smaller than ½ of the maximum storage capacity and a small remaining amount. When the value obtained by subtracting the waiting time is smaller than a predetermined determination reference value, the one having a small remaining amount among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a large remaining amount is subtracted from the waiting time of the recording medium supply unit with a difference in remaining amount of the plurality of recording medium supply units being less than ½ of the maximum accommodation amount and a small remaining amount. If the obtained value is larger than the predetermined determination reference value, the one having the low waiting time among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a small remaining amount is subtracted from the waiting time of the recording medium supply unit with a large remaining amount in which the difference in remaining amount of the plurality of recording medium supply units is larger than ½ of the maximum accommodation amount. When the obtained value is smaller than the predetermined determination reference value, the recording medium supply unit among the plurality of recording medium supply units is determined as the supply source,
The waiting time of the recording medium supply unit with a small remaining amount is subtracted from the waiting time of the recording medium supply unit with a large remaining amount in which the difference in remaining amount of the plurality of recording medium supply units is larger than ½ of the maximum accommodation amount. When the measured value is larger than the predetermined determination reference value, the image forming apparatus is characterized in that, among the plurality of recording medium supply units, the one with the low waiting time is determined as the supply source. A plurality of recording medium supply units that contain the recording medium and supply the recording medium to the image forming unit;
Conveying means for conveying a recording medium supplied from the plurality of recording medium supply units;
Image forming means for forming an image on a recording medium provided in the image forming section and conveyed by the conveying means;
A remaining amount grasping means for grasping the remaining amount of the recording medium accommodated in each recording medium supply unit;
Control means for determining a supply source of a recording medium to be used for printing an input image among the plurality of recording medium supply sections based on the remaining amount information of each recording medium supply section obtained by the remaining amount grasping means When,
Means for reserving print processing of the corresponding image in the buffer for each recording medium supply unit according to the determination;
A calculation means for calculating a waiting time until the printing of the next reserved image is started for each buffer for each recording medium supply unit;
With
The control means includes a recording medium supply unit having a small remaining amount due to a waiting time of the recording medium supply unit having a residual amount difference between the plurality of recording medium supply units being less than ½ of the maximum accommodation amount and having a large remaining amount. When the value obtained by subtracting the waiting time is smaller than a predetermined determination reference value, the one having a large remaining amount among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a small remaining amount is subtracted from the waiting time of the recording medium supply unit having a remaining amount difference smaller than ½ of the maximum accommodation amount and having a large remaining amount. If the obtained value is larger than the predetermined determination reference value, the one having the low waiting time among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a large remaining amount is subtracted from the waiting time of the recording medium supply unit with a difference in remaining amount of the plurality of recording medium supply units being larger than ½ of the maximum accommodation amount and a small remaining amount. When the obtained value is smaller than the predetermined determination reference value, the one having a small remaining amount among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a large remaining amount is subtracted from the waiting time of the recording medium supply unit with a difference in remaining amount of the plurality of recording medium supply units being larger than ½ of the maximum accommodation amount and a small remaining amount. When the measured value is larger than the predetermined determination reference value, the image forming apparatus is characterized in that, among the plurality of recording medium supply units, the one with the low waiting time is determined as the supply source. The transport unit is configured by a multi-row transport unit capable of transporting a plurality of rows of recording media supplied from the plurality of recording medium supply units in a direction orthogonal to the transport direction,
The image forming apparatus according to claim 1, wherein the image forming unit includes a recording head capable of simultaneously forming images on the plurality of recording media arranged in the plurality of rows.   4. The line head according to claim 3, wherein the recording head is a line type head in which a plurality of image recording elements are arranged over a length corresponding to a total image forming width of the plurality of recording media arranged in the plurality of rows. Image forming apparatus. An image forming method including a plurality of recording medium supply units, supplying a recording medium accommodated in each recording medium supply unit to an image forming unit to form an image on the recording medium,
Grasping the remaining amount of the recording medium accommodated in each of the plurality of recording medium supply units;
A control step of determining a supply source of a recording medium to be used for printing an input image among the plurality of recording medium supply units based on the remaining amount information of each recording medium supply unit;
Reserving print processing of the corresponding image in a buffer for each recording medium supply unit according to the determination;
A calculation step for calculating a waiting time until printing of the next reserved image is started for each buffer for each recording medium supply unit,
With
The control step includes a recording medium supply unit having a large remaining amount from a waiting time of a recording medium supply unit in which a difference in remaining amount among the plurality of recording medium supply units is smaller than ½ of the maximum storage capacity and the remaining amount is small. When the value obtained by subtracting the waiting time is smaller than a predetermined determination reference value, the one having a small remaining amount among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a large remaining amount is subtracted from the waiting time of the recording medium supply unit with a difference in remaining amount of the plurality of recording medium supply units being less than ½ of the maximum accommodation amount and a small remaining amount. If the obtained value is larger than the predetermined determination reference value, the one having the low waiting time among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a small remaining amount is subtracted from the waiting time of the recording medium supply unit with a large remaining amount in which the difference in remaining amount of the plurality of recording medium supply units is larger than ½ of the maximum accommodation amount. When the obtained value is smaller than the predetermined determination reference value, the recording medium supply unit among the plurality of recording medium supply units is determined as the supply source,
The waiting time of the recording medium supply unit with a small remaining amount is subtracted from the waiting time of the recording medium supply unit with a large remaining amount in which the difference in remaining amount of the plurality of recording medium supply units is larger than ½ of the maximum accommodation amount. When the measured value is larger than the predetermined determination reference value, the image forming method is characterized in that, among the plurality of recording medium supply units, the one having the low waiting time is determined as the supply source. An image forming method including a plurality of recording medium supply units, supplying a recording medium accommodated in each recording medium supply unit to an image forming unit to form an image on the recording medium,
Grasping the remaining amount of the recording medium accommodated in each of the plurality of recording medium supply units;
A control step of determining a supply source of a recording medium to be used for printing an input image among the plurality of recording medium supply units based on the remaining amount information of each recording medium supply unit;
Reserving print processing of the corresponding image in a buffer for each recording medium supply unit according to the determination;
A calculation step for calculating a waiting time until printing of the next reserved image is started for each buffer for each recording medium supply unit,
With
The control process includes a recording medium supply unit with a small remaining amount due to a waiting time of a recording medium supply unit having a residual amount difference between the plurality of recording medium supply units being less than ½ of the maximum storage capacity and a large remaining amount. When the value obtained by subtracting the waiting time is smaller than a predetermined determination reference value, the one having a large remaining amount among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a small remaining amount is subtracted from the waiting time of the recording medium supply unit having a remaining amount difference smaller than ½ of the maximum accommodation amount and having a large remaining amount. If the obtained value is larger than the predetermined determination reference value, the one having the low waiting time among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a large remaining amount is subtracted from the waiting time of the recording medium supply unit with a difference in remaining amount of the plurality of recording medium supply units being larger than ½ of the maximum accommodation amount and a small remaining amount. When the obtained value is smaller than the predetermined determination reference value, the one having a small remaining amount among the plurality of recording medium supply units is determined as a supply source,
The waiting time of the recording medium supply unit with a large remaining amount is subtracted from the waiting time of the recording medium supply unit with a difference in remaining amount of the plurality of recording medium supply units being larger than ½ of the maximum accommodation amount and a small remaining amount. When the measured value is larger than the predetermined determination reference value, the image forming method is characterized in that, among the plurality of recording medium supply units, the one having the low waiting time is determined as the supply source.

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