JP2013121696A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inkjet image forming apparatus which can perform high-speed recording without upsizing the apparatus.SOLUTION: A recording module performs recording by switching line recording and serial recording depending on a direction in which a recording medium is conveyed.

Description

  The present invention relates to an inkjet image forming apparatus that forms an image by ejecting ink from a recording head onto a recording medium.

  2. Related Art Inkjet image forming apparatuses (inkjet recording apparatuses) that form images by discharging ink from a recording head onto a recording medium are known. In general, an inkjet image forming apparatus can form a high-definition image using a small recording head in which a plurality of nozzles from which ink is ejected are formed at high density. Further, by arranging a plurality of the small recording heads and supplying inks of different colors to the respective recording heads, a color image can be formed on the recording medium with a relatively inexpensive and small configuration. Inkjet image forming apparatuses have the advantages as described above, and are used in various image output apparatuses such as recording apparatuses, facsimile machines, and copiers regardless of whether they are for business use or home use.

  As a recording apparatus provided with such a recording head, there are, for example, a recording apparatus called a serial type and a recording apparatus called a line type. This recording apparatus called a serial type has four recording heads having a plurality of nozzles for ejecting ink (4 colors: Y, M, C, B) on a carriage, and the recording heads in a direction substantially perpendicular to the nozzle rows. Recording is performed by scanning. Such a recording apparatus can increase the resolution of the image, that is, the recording resolution, by increasing the number of scans of the recording head. However, in such a recording apparatus, it is necessary to stop the recording medium during scanning of the recording head, and the recording speed until image formation is not so high.

  On the other hand, there is a recording apparatus called a so-called line type in which the width of the recording head covers the entire width of the recording medium. In such an apparatus, since the recording unit covers the entire width of the recording medium and the recording head does not need to scan unlike the serial type, the recording speed is high, and the recording speed is several tens of sheets per minute. Is also possible. However, in such a recording apparatus, the recording resolution is not so good because of recording for one nozzle. As described above, the serial type and the line type having the recording head are incompatible with each other because the recording speed and the recording resolution are contradictory.

  In order to overcome the disadvantages of such a recording apparatus, for example, there is a recording apparatus such as the one disclosed in Patent Document 1 in which a line type recording apparatus is mounted separately from the serial type recording apparatus.

JP 7-52411 A

  However, if the line type is capable of high-speed recording and there is one recording head, only black can be recorded. When recording in full color with this type, the remaining yellow, magenta, and cyan recording heads are used. Must be installed. When the number of recording heads is increased in this way, there is a problem that the main unit becomes large.

  FIG. 7 is a diagram showing a recording method by a conventional recording apparatus. Even if the line type is reciprocated like the serial type in the longitudinal direction of the recording head (arrow D) as shown in FIG. 7 to achieve high resolution, it is necessary to record one line at a time on the recording medium, which takes too much recording time. There was no reality.

  The present invention has been made in view of the above problems, and an object thereof is to provide an inkjet image forming apparatus capable of realizing high-speed recording without increasing the size of the apparatus.

  Therefore, an image forming apparatus according to the present invention includes a recording head that performs recording on a recording medium, a first recording medium conveyance path through which the recording medium is conveyed, and a direction that intersects the first recording medium conveyance path. An image forming apparatus comprising a second recording medium conveyance path for conveying the recording medium, wherein a conveyance direction of the first recording medium conveyance path is a conveyance direction in a short direction of the recording head; The transport direction of the second recording medium transport path is the transport direction in the longitudinal direction of the recording head, and the recording head reciprocates on the recording medium transported by the first recording medium transport path. Recording is performed while the recording head performs recording on the recording medium conveyed through the second recording medium conveyance path without moving its position.

  According to the present invention, the conveyance direction of the first recording medium conveyance path in the image forming apparatus is the conveyance direction in the short direction of the recording head, and the conveyance direction of the second recording medium conveyance path is that of the recording head. It is a conveyance direction in the longitudinal direction. The recording head performs recording while reciprocating on the recording medium conveyed through the first recording medium conveyance path, and the recording head positions the recording medium conveyed through the second recording medium conveyance path. Record without moving. Accordingly, it is possible to provide an ink jet type image forming apparatus capable of realizing high speed recording without increasing the size of the apparatus.

It is a front view which shows typically an example of the recording device of this invention. FIG. 2 is a block diagram illustrating an electrical system of the recording apparatus in FIG. 1. It is a right view which shows typically an example of the recording device of this invention. FIG. 2 is a top view of the recording apparatus in FIG. 1. It is a schematic diagram which shows concretely the reciprocating operation | movement of a recording module. (A) to (c) are flowcharts of recording control in the recording apparatus. It is the figure which showed the recording method by the conventional recording device. It is the figure which showed a part of recording method in the recording device of this embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. An example of a recording apparatus in which the recording module of the present invention is incorporated will be described with reference to FIGS. FIG. 1 is a front view schematically showing an example of a recording apparatus in which the recording module of the present invention is incorporated. FIG. 4 is a top view of the recording apparatus of FIG.

  The recording device 10 is connected to a host PC (personal computer) 12 that sends image information to the recording device 10. In the recording apparatus 10, two recording modules 22Pu and 22Pd and four recording heads 22K, 22C, 22M, and 22Y among them are arranged side by side in the conveyance direction (arrow A direction) of the recording medium P. The four recording heads 22K, 22C, 22M, and 22Y eject black, cyan, magenta, and yellow inks, respectively. A recovery unit 40 is incorporated in the recording apparatus 10 so that ink can be stably ejected from the four recording heads 22K, 22C, 22M, and 22Y. By the recovery unit 40, the ink ejection states of the recording heads 22K, 22C, 22M, and 22Y are restored to the initial ink ejection state. The recovery unit 40 is provided with a capping mechanism 50 that removes ink from the ink discharge port formation surfaces 22Ks, 22Cs, 22Ms, and 22Ys of the four recording heads 22K, 22C, 22M, and 22Y during the recovery operation. The capping mechanism 50 includes a known blade, an ink removing member, a blade holding member, a cap, and the like.

  The recording medium P is supplied from the supply unit 24 a and is conveyed in the direction of arrow A by the conveyance mechanisms 26 and 28 incorporated in the recording apparatus 10. The belt conveyance mechanisms 26 and 28 include conveyance belts 26a and 28a for loading and conveying the recording medium P, conveyance motors 26b and 28b for rotating the conveyance belt 26a, rollers 26c and 28c for applying tension to the conveyance belt 26a, and the like. Has been. When the recording medium P is conveyed in the arrow A direction (longitudinal direction of the recording medium), the conveyance mechanism 27 does not operate, and the recording medium P is conveyed by the conveyance mechanisms 26 and 28 while sliding on the surface of the conveyance mechanism 27.

  When an image is formed on the recording medium P, recording is performed based on the recording data (image information) after the recording start position of the recording medium P being conveyed reaches below the recording head 22K that ejects black ink. Black ink is selectively ejected from the head 22K. Similarly, each color ink is ejected in the order of the recording head 22C, the recording head 22M, and the recording head 22Y to form a color image on the recording medium P. In addition to the components and members described above, the recording apparatus 10 includes main tanks 28K, 28C, 28M, and 28Y that store ink supplied to the recording heads 22K, 22C, 22M, and 22Y.

  The four recording heads 22K, 22C, 22M, and 22Y extend in a direction that intersects the arrow A direction. The recording modules 22Pu and 22Pd on which these four recording heads 22K, 22C, 22M, and 22Y are mounted are fixed when the recording medium P is conveyed in the direction of arrow A (in the second recording medium conveyance path). The image is formed without moving in the touched state. The recording medium P on which the image is formed in this manner is discharged to the paper discharge tray 30a by the paper discharge roller 29a.

  Next, the other paper feeding means and image forming means will be described with reference to FIGS. FIG. 3 is a right side view schematically showing an example of a recording apparatus in which the recording module of the present invention is incorporated. The supply unit 24b supplies the recording medium P in a direction intersecting (orthogonal) with the direction supplied by the supply unit 24a, and the transport mechanism 27 transports the recording medium P in the arrow B direction. The belt transport mechanism 27 includes a transport belt 27a that stacks and transports the recording medium P, a transport motor 27b that rotates the transport belt 27a, a roller 27c that applies tension to the transport belt 27a, and the like. At this time, the transport mechanisms 26 and 28 (see FIG. 1) do not operate, and the recording medium P is transported by the transport mechanism 27 while sliding on the surfaces of the transport mechanisms 26 and 28.

  In FIG. 4, the recording medium 22Pu on which the recording heads 22K, 22C, 22M, and 22Y are mounted on the recording medium P that has been conveyed in the arrow B direction (the short direction of the recording medium) (on the first recording medium conveyance path). , 22Pd reciprocates in the direction of arrow C perpendicular to the direction of arrow B, and an image is formed. The recording medium P on which the image is formed in this manner is discharged to the paper discharge tray 30b by the paper discharge roller 29b.

  FIG. 5 is a schematic diagram specifically showing the reciprocating operation of the recording modules 22Pu and 22Pd. In the recording module 22Pu, the timing belt 22Pub is operated by the drive motor 22Put. As the timing belt 22Pub moves in the arrow B direction, the rail R fixed to the timing belt 22Pub and the recording module 22Pu fixed to the rail R move in the arrow B direction. The recording module 22Pu records by reciprocating the rack Ra and the rack Rc in the direction of the arrow C when the drive motor 22Pum is driven. On the other hand, the recording module Pd reciprocally records the rack Ra and the rack Rb in the direction of the arrow C when the drive motor Pdm is driven.

  FIG. 8 is a diagram showing a part of the recording method in the recording apparatus of the present embodiment. The recording medium P on which an image has been formed is discharged to a paper discharge tray 30b by a paper discharge roller 29b. As shown in FIG. 8, the recording modules Pu and Pd perform recording while moving in the short direction of the recording head (longitudinal direction of the recording medium). At this time, since the recording head is a long head, the recording range is widened, and the number of scans during recording can be reduced as compared with the conventional recording method shown in FIG. Therefore, recording can be performed faster than the conventional recording speed by the recording method in the recording apparatus of the present embodiment.

  Two or more recording modules may be provided, and the same effect can be obtained by fixing one or more recording modules and reciprocating other recording modules.

  The electrical system of the recording apparatus 10 will be described with reference to FIG. FIG. 2 is a block diagram showing an electrical system of the recording apparatus of FIG. Recording data and commands transmitted from the host PC 12 are received by the CPU 150 via the interface controller 102. The CPU 150 is an arithmetic processing unit that performs overall control such as reception of recording data, recording operation, handling of the recording medium P, and the like. After analyzing the received command, the CPU 150 renders the image data of each color component of the recording data by developing a bitmap on the image memory 106. As an operation process before recording, the capping motor 122 and the head up / down motor 118 (not shown) are driven via the output port 114 and the motor driving unit 116. Then, the recording heads 22K, 22C, 22M, and 22Y are moved away from the capping mechanism 50 and moved to the recording position (image forming position).

  Subsequently, a feed motor (not shown) that feeds the recording medium P through the output port 114 and the motor driving unit 116, a transport motor 1920 that transports the recording medium P, and the like are driven to supply the recording medium P to the supply unit 24a or 24b. It is transported to the recording position. The front end position of the recording medium P is detected by the front end detection sensor S1 or S2 for determining the timing (recording timing) at which ink starts to be ejected onto the recording medium P conveyed at a constant speed. Thereafter, in synchronism with the conveyance of the recording medium P, the CPU 150 sequentially reads the corresponding color recording data from the image memory 106, and the read data is transferred to the recording heads 22K, 22C, 22M, and 22Y. Transfer via 112.

  The operation of the CPU 150 is executed based on a processing program stored in the program ROM 104. The program ROM 104 is executed based on a processing program corresponding to the control flow. The program ROM 104 stores processing programs and tables corresponding to the control flow. A work RAM 108 is used as a working memory. During the cleaning and recovery operations of the recording heads 22K, 22C, 22M, and 22Y, the CPU 150 drives a pump motor 124 (not shown) via the output port 114 and the motor control unit 116 to perform ink pressurization and suction. Take control.

  FIGS. 6A to 6C are flowcharts of recording control in the recording apparatus of the present embodiment. Hereinafter, an example of the procedure of the conveyance control will be described with reference to FIGS. FIG. 6A is a flowchart of the entire recording control. When recording control is started, recording data is received from the host PC 12 in step S11, and then the received image data is developed in the image memory 106 in step S12. In step S13, it is determined whether the received data is output by line recording or serial recording. If it is line recording, the process proceeds to step S14 to perform line recording control, and if it is serial recording, the process proceeds to step S15 to perform serial recording control. In this way, the recording control ends.

  When line recording control is started in step S14, the recording modules 22Pu and 22Pd are prepared in step S21 in the flowchart of FIG. 6B. Here, the recording modules 22Pu and 22Pd are moved to predetermined positions when performing the line recording operation, and the recording heads 22K, 22C, 22M and 22Y in the recording modules 22Pu and 22Pd are brought into a dischargeable state. In step S22, the recording material stored in the supply unit 24a is fed and transported using the transport mechanisms 26 and 28. Thereafter, in step S23, when the transported recording medium P reaches below the recording heads, the recording heads perform ink in synchronization with the movement timing of the recording medium P based on the image data stored in the image memory 106. The recording operation is performed on the recording medium P. Then, after the recording for one page is completed, the recording medium P is discharged to the paper discharge tray 30a. Thereafter, in step S24, it is determined whether there is image data of the next page in the image memory 106. If there is image data, the process returns to step S22 to start the paper feeding / conveying operation again and repeat the recording operation.

  If it is determined in step S24 that there is no image data for the next page, the process proceeds to step S25, where post-processing after recording is performed, and recording control ends. In the post-processing in step S25, the transport mechanisms 26 and 28 are stopped, and each recording head uses the capping mechanism 50 to perform a capping operation and enter a standby state.

  When the serial recording control is started in step S15, the recording modules 22Pu and 22Pd are prepared in step S31 in the flowchart of FIG. 6C. Here, the recording modules 22Pu and 22Pd are moved to predetermined positions when performing the serial recording operation, and the recording heads 22K, 22C, 22M and 22V in the recording modules 22Pu and 22Pd are brought into a dischargeable state. In step S32, the recording material stored in the supply unit 24b is fed and transported using the transport mechanism 27. Then, after the recording material that has been conveyed reaches under each recording head, the conveyance mechanism 27 temporarily stops. In step S33, the recording modules 22Pd and 22Pu are reciprocated in the vertical direction of the transport direction, and each recording head discharges ink in synchronization with the movement of the recording module based on the image data stored in the image memory 106. To form an image on the recording medium P. Then, after the recording for one page is completed, the recording medium P is discharged to the paper discharge tray 30b. Thereafter, in step S34, it is determined whether or not there is image data of the next page in the image memory 106. If there is image data, the process returns to step S32 to start the paper feeding / conveying operation again and repeat the recording operation. .

  If it is determined in step S34 that there is no image data for the next page, the process proceeds to step S35 to perform post-processing after recording, and the recording control is terminated. In the post-processing in step S35, the transport mechanisms 26 and 28 are stopped, and each recording head uses the capping mechanism 50 to perform a capping operation and enter a standby state.

  As described above, according to the image forming apparatus of the present invention, the recording module performs recording by switching between line recording and serial recording according to the direction of the recording medium being conveyed. As a result, it was possible to prevent an increase in the size of the apparatus and to realize an image forming apparatus capable of full-color, high-speed recording and high-definition recording.

DESCRIPTION OF SYMBOLS 10 Recording device 22K Recording head 22Y Recording head 22M Recording head 22C Recording head 26 Conveyance mechanism 27 Conveyance mechanism 28 Conveyance mechanism 114 Output port 150 CPU
P Recording medium

Claims (2)

A recording head for recording on the recording medium, a first recording medium conveying path for conveying the recording medium, and a second for conveying the recording medium in a direction intersecting the first recording medium conveying path. In an image forming apparatus comprising a recording medium conveyance path,
The conveyance direction of the first recording medium conveyance path is a conveyance direction in the short direction of the recording head,
The transport direction of the second recording medium transport path is the transport direction in the longitudinal direction of the recording head,
On the recording medium conveyed by the first recording medium conveyance path, the recording head performs recording while reciprocating,
An image forming apparatus, wherein the recording head performs recording on the recording medium conveyed through the second recording medium conveyance path without moving a position.   The image forming apparatus according to claim 1, comprising a plurality of the recording heads, wherein at least one of the recording heads performs recording.

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