JP2009248501A - Ink jet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ink jet recording device having an attachable/detachable recording head, shortening the recording time and suppressing image degradation. <P>SOLUTION: A plurality of ink jet head cartridges KIJC-YIJC are loaded on a carriage 10 so that a plurality of respective discharge ports are aligned in the conveyance direction of a recording medium and the plurality of ink jet head cartridges KIJC-YIJC are aligned in the scanning direction of the carriage 10. In at least one ink jet head cartridge out of the ink jet head cartridges disposed at both ends of the carriage 10, discharge port rows 101K-101Y are disposed toward the inside of the carriage 10 from the center of the ink jet head cartridge. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet recording apparatus, and more particularly to an inkjet recording apparatus that performs recording with a plurality of ink colors.

  In recent years, with the widespread use of personal computers, word processors, facsimiles, and the like in offices and homes, printers of various recording methods have been developed as information output devices for these devices. Among them, an ink jet printer is advantageous in that it can easily cope with color recording, has low noise during operation, can perform high-quality recording on a wide variety of recording media, and is small in size. . This makes it ideal for personal use in the office or home. Among them, a serial scan type ink jet recording apparatus that performs recording while a recording head reciprocally scans on a recording medium is widely used in the market because it can record a high-quality image at a low cost.

  A general serial scan type ink jet recording apparatus capable of color recording uses a recording head having discharge ports for discharging four types of inks of cyan, magenta, yellow, and black. In such a recording apparatus, recording is performed by reciprocally scanning the recording head while ejecting ink droplets of respective colors from ejection ports.

  In such a recording apparatus, from the viewpoint of ease of maintenance by the user, each color ink tank and each color discharge port have a recording head, and each color recording head can be attached and detached independently ( A replaceable ink jet recording apparatus is known. In addition, a recording apparatus in which a plurality of color ink tanks and discharge ports are integrated is also known because of the difference in use frequency of black ink and color ink. In this recording apparatus, the black ink and the black ejection opening are integrated, and the black recording head and the color recording head can be attached and detached independently. The ink tank can be removed for each color ink tank.

  An ink jet recording apparatus in which a plurality of recording heads can be individually attached / detached must be provided with a mechanism for attaching / detaching / holding to / from the recording apparatus main body for each of the plurality of recording heads. For this reason, generally, all the heads of black, cyan, magenta, and yellow are configured as a single unit, and compared with a configuration in which only a single head is removable, the entire recording head mounted on the recording apparatus main body. The width becomes wider. Therefore, when the recording head is reciprocally scanned for recording, the recording width of the recording apparatus in which the recording head can be individually attached / detached becomes large. As a result, the scan time becomes relatively long, leading to a decrease in recording speed.

  In order to suppress a decrease in the recording speed due to such an increase in the width of the entire recording head, an ejection port array in which a plurality of ejection ports for ejecting ink are arranged is arranged inside the center of the recording head. Therefore, it is conceivable to reduce the scan width. For example, Patent Document 1 discloses a configuration in which the ejection port array is offset from the center of the ink tank. By using two such ink tanks in a symmetrical configuration, the scan width can be made smaller than when using a recording head in which the ejection port array is arranged at the center of the ink tank. it can. Thereby, the recording speed can be improved.

US Pat. No. 6,533,396

  However, in the recording head using three or more ink tanks disclosed in Patent Document 1, the distance between the outer discharge port arrays is simply shortened, and the central discharge port array is close to one of them. It will be.

  In this case, when the droplets are arranged on the same pixel for recording, if the adjacent ejection port arrays are close to each other, the landing time difference between the droplets that have landed first and the droplets that landed later becomes short. For this reason, when the absorbency of the recording medium is poor, an image defect due to ink absorption failure may occur.

  Further, when the recording duty is increased, an air flow may be generated due to the flow of the ejected ink droplets. When the influence of the airflow is great, the ink droplets in flight may be flown into the airflow, causing landing disturbance and causing image degradation. This air flow is promoted as the distance between the discharge port arrays becomes shorter.

  The present invention has been made in view of the above points, and an object of the present invention is to provide an ink jet recording apparatus capable of reducing recording time and suppressing image deterioration in an ink jet recording apparatus to which a recording head can be attached and detached. To do.

  In order to achieve the above object, the present invention can attach and detach a plurality of ink jet head cartridges having a recording head having an ejection port array composed of a plurality of ejection ports for ejecting ink and an ink tank containing the ink. An inkjet recording apparatus that performs recording on a recording medium by causing the carriage mounted on the apparatus to scan and eject ink from three or more of the ejection port arrays, wherein each of the plurality of inkjet head cartridges includes the plurality of ejection ports. Of the inkjet head cartridges mounted on the carriage and arranged at both ends of the carriage so that the inkjet head cartridges are aligned in the conveyance direction of the recording medium and the inkjet head cartridges are aligned in the scanning direction of the carriage. At least one inkjet head cover Cartridge, the ejection opening array is being disposed inwardly of the carriage than the center of the ink jet head cartridge.

  According to the above configuration, the distance between the discharge port arrays at both ends among the three or more discharge port arrays can be shortened. As a result, the recording time can be shortened and image degradation can be suppressed.

Embodiments of the present invention will be described below in detail with reference to the drawings.
(First embodiment)
FIG. 1 is a schematic perspective view showing the ink jet recording apparatus of the present embodiment. The recording apparatus according to the present embodiment mainly includes a recording medium conveyance unit, a recording unit, and a recording head maintenance unit (recovery unit). Recording data is sent from a host device (not shown) such as a personal computer, stored in the recording device control unit (not shown) on the control board, and a recording operation start command is issued from the control unit to perform the recording operation. Starts.

  In the recording unit, the carriage 10 is slidably engaged along the guide shaft 11 and is connected to a part of the drive belt 12 that is moved by the main scanning motor. Accordingly, each inkjet head cartridge IJC mounted on the carriage 10 moves for scanning along the guide shaft 11. Two transport rollers 13, 14, 15, and 16 extending in parallel with the guide shaft 11 are combined in each of the back side and the near side in the drawing of the recording area scanned by each inkjet head cartridge IJC. Is provided. Each of the transport rollers 13 to 16 is driven by a sub-scanning motor to transport the recording medium P in the transport direction. The transported recording medium P faces the surface on which the ejection port surface of each inkjet head cartridge IJC is disposed.

  The ink jet recording apparatus 1 is an apparatus that performs recording with four color inks of black (K), cyan (C), magenta (M), and yellow (Y). The recording apparatus 1 is provided with four ink tank integrated ink jet head cartridges IJC containing replaceable inks of black (KIJC), cyan (CIJC), magenta (MIJC), and yellow (YIJC). The recording head of the recording apparatus 1 has 128 ejection openings with a resolution of 400 dpi and a driving frequency of 4 kHz. The four inkjet head cartridges KIJC, CIJC, MIJC, and MIJC correspond to the four colors K, C, M, and Y, respectively, and contain the recording head and ink that supplies ink to the recording head. The ink tank is integrally formed. Each inkjet head cartridge IJC is detachably mounted on the carriage 10 with a configuration not shown. The head cartridges IJC for each color are mounted on the carriage 10 in the order of black, cyan, magenta, and yellow from the left in FIG.

  A plurality of ink flow paths are formed inside the recording head 100, and the ink flow paths communicate with ejection ports arranged on a surface (ejection port surface) facing the platen that presses the recording medium P. Ink discharge actuators (energy generating means) are arranged inside each of the plurality of discharge ports forming the discharge port array. As this actuator, for example, an actuator using a film boiling pressure of a liquid by an electrothermal transducer (heating element), an electromechanical transducer (electric-pressure transducer) such as a piezo element, or the like is used.

  In an ink jet recording apparatus using the recording head 100, it is possible to eject ink droplets according to recording data by transmitting a head driver (not shown) signal to the recording head 100 via a flexible flat cable. . Further, by reading the code strip stretched on the chassis by the CR encoder mounted on the carriage 10, ink droplets can be ejected toward the recording sheet at an appropriate timing. In this way, when the recording for one line is completed, the recording medium is conveyed (paper fed) by a necessary amount by the paper conveying unit. By repeating this operation, the recording operation over the entire surface of the recording sheet becomes possible.

  A recovery system unit is provided to face a movable area (the area on the right side in the drawing) of each inkjet head cartridge IJC adjacent to the recording area by each inkjet head cartridge IJC. This recovery system unit is used when performing preliminary discharge (forced ink discharge for recovery of discharge). The recovery system unit has cap units 17 provided corresponding to the four inkjet head cartridges IJC each having a recording head. Each cap unit 17 can slide in the horizontal direction in the figure as the carriage 10 moves, and can move up and down in the vertical direction in the figure. When the carriage 10 is at the home position, each cap unit 17 is joined to the recording head portion of each recording cartridge IJC to cap each recording head portion. The recovery system unit includes a blade (not shown) as a wiping member, and a pump unit for sucking ink and the like from the discharge port of the inkjet head cartridge IJC and the vicinity of the discharge port via the cap units 17. 18.

  FIG. 2 is a block diagram showing a configuration of a control system in the ink jet recording apparatus shown in FIG. The controller 20 forms a main control unit and includes a CPU 21, a ROM 22, a RAM 23, and a timer 24. The CPU 21 is in the form of a microcomputer that executes various processes. The ROM 22 stores a program corresponding to the procedure, a table for pulse width modulation, a voltage value of the heat pulse, a pulse width, and other fixed data. Yes. The RAM 23 is provided with an area for developing image data, an area for work, and the like. The timer 24 is a timer for measuring a non-recording time or the like. The host device 25 is a source of image data (in this embodiment, an image reading reader unit), and image data and other commands and status signals are transmitted to and received from the controller 20 via an interface (I / F) 26. Is done.

  The switch group 27 includes a power switch 271, a copy switch 272 for instructing start of recording, a large recovery switch 273 for instructing activation of large recovery which is one mode of the ejection recovery processing, and the like. It accepts input. The sensor group 28 includes a carriage position sensor 281 and a pump position sensor 282, and detects the apparatus state. The carriage position sensor 281 detects the position of the carriage 10 such as a home position or a start position. The pump position sensor 282 includes a leaf switch and is used for detecting the pump position.

  The head driver 29 is for driving the electrothermal transducer of the recording head according to the recording data. A part of the head driver 29 is also used to drive the temperature control heaters 30A and 30B. Further, the temperature detection values from the temperature sensors 40 </ b> A and 40 </ b> B are input to the controller 20. The main scanning motor 31 is for moving the carriage 10 in the main scanning direction, and is driven by a motor driver 32. The sub-scanning motor 33 is used for conveying (sub-scanning) the recording medium, and is driven by a motor driver 34.

  FIG. 3 is a perspective view showing an ink jet head cartridge that can be mounted on the carriage 10 of the ink jet recording apparatus 1 shown in FIG. 3A shows a black ink cartridge KIJC, FIG. 3B shows a cyan ink cartridge CIJC, FIG. 3C shows a magenta ink cartridge MIJC, and FIG. 3D shows a yellow ink cartridge YIJC. Each cartridge has the same configuration except for the position of the ejection port array 101.

  The ink jet head cartridge integrally includes an ink tank unit IT and a head unit IJU. Further, the ink tank unit IT and the head unit IJU are detachable from each other. A wiring connector 102 is provided at a position aligned with the head unit IJU and the ink tank unit IT. The wiring connector 102 receives a signal for driving each ejection port of the ink ejection port array 101 of the head unit IJU and outputs an ink remaining amount detection signal. In the posture when the ink jet head cartridge is loaded on a carriage, which will be described later, the height can be lowered and the thickness of the ink jet head cartridge can be reduced.

  The ink jet head cartridge is mounted on the carriage 10 by placing the ink jet head cartridge on the carriage by holding the knob 105 provided in the ink tank unit IT with the ink discharge port array 101 facing downward. Can do. The knob 105 engages with a lever provided on the carriage for performing the mounting operation of the inkjet head cartridge. At the time of mounting, the pin provided on the carriage side is engaged with the pin engaging portion 103 of the head unit IJU, and the head unit IJU is positioned. In the ink jet head cartridge, the absorber 104 is juxtaposed with the ink discharge port array 101. The absorber 104 is for cleaning a member that wipes and cleans the surface of the discharge port array 101. Further, an air communication port 203 for introducing air as the ink is consumed is provided in the approximate center of the ink tank unit IT.

  Referring to FIGS. 3A to 3D, the positions of the ejection port arrays 101 in the cartridge width direction are different for each cartridge. In FIG. 3A, in the black ink cartridge KIJC, the discharge port array 101K of the nozzle portion is arranged on the upper side in the drawing. Further, in FIG. 3D, in the yellow ink cartridge YIJC, the ejection port array 101Y is arranged on the lower side in the drawing. 3B and 3C, in the cyan ink cartridge CIJC and the magenta ink cartridge MIJC, the ejection port arrays 101C and 101M are disposed near the center in the width direction of the cartridge.

  FIG. 4 is a diagram illustrating the positions of the ejection port arrays 101K, 101C, 101M, and 101Y of the black, cyan, magenta, and yellow ink cartridges. This figure is a schematic diagram when the state where the cartridges KIJC, CIJC, MIJC, and YIJC are mounted on the carriage 10 is viewed from the front of the recording apparatus.

  In the black ink cartridge KIJC, the ejection port array 101K is arranged in the inner direction with all the ink cartridges mounted, that is, closer to the other cartridge than the center of the black cartridge. In the yellow ink cartridge YIJC, the ejection port array 101Y is arranged in the inner direction with all the ink cartridges mounted, that is, closer to the other cartridge than the center of the yellow cartridge. In the cyan ink cartridge CIJC and the magenta ink cartridge MIJC, the ejection port arrays 101C and 101M are arranged at positions where the nozzle widths are equal intervals (W) with the cartridge width.

  By arranging the discharge port arrays in this way, the distance between the discharge port arrays at both ends of the plurality of discharge port arrays can be shortened. Further, by setting the intervals W to the discharge port rows in the center to be equal intervals, the distance between the nozzle rows becomes the maximum among the distances determined by the nozzle rows at both ends. As a result, when performing printing, the scanning width for reciprocating the carriage can be shortened, the recording time can be shortened, and image degradation can be suppressed within a predetermined range of width. .

  In the present embodiment, a description has been given of a configuration in which one ejection port array is provided for each cartridge. However, a plurality of ejection port arrays may be provided. For example, the cartridge may be such that the discharge ports are divided into two rows of even-numbered discharge ports and odd-numbered discharge ports.

  In this embodiment, the recording apparatus that performs recording with four colors of ink has been described. However, the recording apparatus of the present invention is not limited to the recording apparatus that performs recording with four colors of ink. That is, a recording apparatus that performs recording with three colors of ink or a recording apparatus that performs recording with five or more colors of ink may be used. In this case, the discharge port arrays arranged at both ends may be arranged in the entire inner direction, and the other discharge port arrays may be arranged so that the widths of the respective discharge port arrays become equal distances.

  Furthermore, in the present embodiment, both of the ejection port arrays arranged at both ends are arranged in the inner direction, but one of the ejection port arrays arranged in both ends is arranged in the inner direction. It may be.

(Second Embodiment)
The first embodiment is an ink jet recording apparatus that performs recording with four colors of ink, and includes four replaceable ink tank integrated ink jet head cartridges IJC corresponding to the number of inks. However, the present invention is not limited to such a recording apparatus.

  FIG. 5 is a schematic perspective view showing the ink jet recording apparatus of the present embodiment. The recording apparatus of this embodiment has substantially the same configuration as the recording apparatus of the above-described embodiment, but differs in that it includes two inkjet head cartridges IJC.

  That is, in this embodiment, an ink jet head cartridge KIJC in which a black ink ink tank and a black recording head 200K are integrated, and an ink tank of three colors of cyan, magenta, and yellow, and the recording head 200C are separately configured. And a detachable inkjet head cartridge CIJC. The color ink cartridge CIJC can replace only the ink tank with the recording head 200C detachably attached to the recording apparatus mounted on the recording apparatus main body. The color cartridge CIJC is provided with nozzle rows 201C, 201M, and 201Y, respectively.

  FIG. 6 is a perspective view showing an inkjet head cartridge that can be mounted on the carriage 10 of the inkjet recording apparatus of the present embodiment. FIG. 6A shows a black ink cartridge KIJC, and FIG. 6B shows a color ink cartridge CIJC. The nozzle row 201BK of the black cartridge KIJC is disposed closer to the color cartridge CIJC than the center of the cartridge. The nozzle rows 201C, 201M, and 201Y of the color cartridge CIJC are arranged closer to the black cartridge CIJC than the center of the cartridge. And the distance between each nozzle row is the same. For this reason, compared with the case where the black nozzle row is arranged at the center of the black cartridge and the center of the color nozzle row is arranged at the center of the color cartridge, the nozzle row distances at both ends (K and Y in this embodiment) are compared. Nozzle row distance) is shortened. The distance between the nozzle rows is maximum, that is, the distance between adjacent nozzle rows is equal. For this reason, when performing recording, it is possible to shorten the scanning width for reciprocating scanning of the carriage, and to shorten the recording time.

  In this embodiment, the positions of the nozzle rows of both the black and color cartridges are moved inward from the center of the cartridge, but the present invention is not limited to such a configuration. That is, the configuration may be such that the position of one nozzle row of the black or color cartridge is moved inward from the center of the cartridge. Even in this case, the scanning width can be reduced and the recording speed can be improved.

(Third embodiment)
In the above-described embodiment, in order to increase the distance between the nozzle rows, the distance between adjacent nozzle rows is made equal. However, the present invention is not limited to such a configuration.

  In an ink jet recording apparatus, an air flow may be generated along the ejection of ink droplets. Then, due to the influence of the air flow, the landing positions of the ink droplets may be shifted, and image deterioration may be caused. In particular, when high-resolution recording is performed, the number of ink droplets ejected per unit time increases, so that a large airflow is generated, and the degree of image degradation due to the airflow tends to increase. The displacement of the ink droplet landing position due to the influence of the airflow is more susceptible to the influence of the airflow than the large ink drop because the weight of the ink drop is small in the case of a small ink drop.

  In the present embodiment, the interval between the ejection port arrays is varied based on the size of the ink droplets, thereby improving the recording speed and suppressing image deterioration due to the influence of the airflow.

  FIG. 7 is a diagram illustrating an example of the ink cartridge of the present embodiment. In the recording apparatus of the present embodiment, the black ink and yellow ink droplets ejected from the black and yellow ejection ports are 5 pl. Also, cyan and magenta ink droplets ejected from the cyan and magenta ejection ports are 1 pl. In general, since black ink is often used for characters, high gradation characteristics may not be required. Further, since yellow ink has low visibility, high gradation characteristics may not be required in some cases. In consideration of such characteristics, cyan and magenta ink droplets are relatively small, and black and yellow ink droplets are relatively large.

  The ejection port array 301K of the black ink cartridge KIJC is disposed closer to the color ink cartridge CIJC. Further, the discharge port arrays of the color ink cartridge CIJC are arranged in the order of the yellow discharge port array 301Y, the cyan discharge port array 301C, and the magenta discharge port 301M from the side close to the black ink cartridge KIJC. The ejection port arrays 301Y, 301C, and 301M are disposed near the black ink cartridge KIJC. Further, if the intervals between the black, yellow, and magenta ejection port arrays are W1, W2, and W3, W1 is arranged to be narrower than W2 and W3.

  Thus, by arranging the nozzle rows, the recording apparatus of the present embodiment can improve the recording speed and suppress image deterioration due to the influence of airflow.

1 is a schematic perspective view showing an ink jet recording apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram illustrating a configuration example of a control system in the ink jet recording apparatus illustrated in FIG. 1. 1 is a perspective view illustrating an inkjet head cartridge according to a first embodiment of the present invention. FIG. 3 is a diagram illustrating positions of ejection port arrays of the ink cartridge according to the first embodiment of the present invention. It is a schematic perspective view which shows the inkjet recording device of 2nd Embodiment of this invention. It is a perspective view which shows the inkjet head cartridge of this embodiment of 2nd Embodiment of this invention. It is a perspective view which shows the inkjet head cartridge of this embodiment of 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 10 Carriage IJC Ink cartridge 100 Recording head 101 Discharge port row

Claims (3)

3 or more by scanning a carriage on which a plurality of ink jet head cartridges having a recording head having a plurality of ejection openings for ejecting ink and an ink tank containing the ink are detachably mounted. An inkjet recording apparatus that records on a recording medium by ejecting ink from the ejection port array,
Each of the plurality of inkjet head cartridges is mounted on the carriage so that the plurality of ejection openings are aligned in the conveyance direction of the recording medium, and the plurality of inkjet head cartridges are aligned in the scanning direction of the carriage,
At least one ink jet head cartridge among the ink jet head cartridges arranged at both ends of the carriage has the ejection port array arranged in an inner direction of the carriage than the center of the ink jet head cartridge. Recording device.   The inkjet recording apparatus according to claim 1, wherein the plurality of ejection port arrays have the same distance from the adjacent ejection port arrays. The plurality of ejection port arrays include an ejection port array composed of ejection ports that eject one amount of ink droplets, and a plurality of adjacent ejection port arrays composed of ejection ports that eject an amount of ink droplets larger than one amount. And
The distance between each of a plurality of adjacent ejection port arrays composed of ejection ports that are larger than the one amount is smaller than the distance from the ejection port array composed of ejection ports that eject the one amount of ink droplets. The inkjet recording apparatus according to claim 1, wherein the inkjet recording apparatus is short.

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