JP4579607B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an inkjet recording apparatus that performs recording on a recording medium having an uneven recording surface.

Conventionally, in an ink jet recording apparatus, when printing on a medium having an uneven printing surface, the distance between the medium and the ink jet head of the ink jet recording apparatus is measured, and the drive voltage and pulse width applied to the ink jet head according to the measured distance Is known to perform printing by controlling (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-165406

  In the one described in Patent Document 1, printing is performed by changing the driving conditions of the ink jet head without changing the distance between the medium and the ink jet head. However, under conditions such as a large distance between the medium and the ink jet head. If the distance exceeds the distance that cannot be controlled under the driving conditions, printing becomes difficult.

  In addition, when the distance between the medium and the inkjet head is greatly different within the range of the recordable width of the inkjet head, it is difficult to control the recording condition corresponding to the driving condition of the inkjet head.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to perform good recording without requiring control relating to the driving conditions of the ink jet head even in a recording medium having an uneven recording surface. It is to provide an ink jet recording apparatus.

The present invention has an inkjet head provided with a plurality of nozzles that eject ink based on a predetermined driving condition, and ejects ink by selecting nozzles of the inkjet head based on image data, and also has uneven recording. In an inkjet recording apparatus that records an image on a recording medium by relatively moving a recording medium mounting table on which a recording medium having a surface is mounted and an inkjet head, for example, recording of the recording medium on a predetermined virtual plane or an inkjet head The coordinate information indicating the coordinate position of the surface is acquired, and the acquired coordinate information is converted into image data by the inkjet head based on at least characteristic information including information related to the ejection performance, outer size, and recordable width of the inkjet head. Divide it into multiple areas so that you can record. Based on the coordinate information, carved image data, and performs recording on the recording surface of the recording medium based on respective image data this cut.
Further, in order to change the direction of image recording by relatively moving the coordinate information rotating means for rotating the acquired coordinate information by a predetermined angle and the recording medium and the inkjet head, the orientation of the recording medium mounting table or the inkjet head is changed. A rotation means for rotating, and when the image data cannot be divided by the inkjet head based on the acquired coordinate information, the coordinate information acquired by the coordinate information rotation means is rotated by a predetermined angle, and the rotated coordinates The division is performed based on the information, and the rotation unit rotates the direction of the recording medium mounting table or the inkjet head in accordance with a predetermined angle obtained by rotating the coordinate information.

  According to the present invention, it is possible to provide an ink jet recording apparatus that can perform good recording on a recording medium having an uneven recording surface without requiring control relating to driving conditions of the ink jet head.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically illustrating a configuration of a recording stage 1 that performs recording on a recording medium included in an inkjet recording apparatus.

  The recording stage 1 includes a bottom plate 2, a recording medium placing table 3 disposed on the top surface of the bottom plate, and an inkjet head block 4 disposed above a predetermined distance from the top surface of the recording medium placing table 3. . In the bottom plate 2, the X-axis stage 5 is arranged so that the front-rear direction in the figure is the longitudinal direction, and the Y-axis stage 6 is orthogonal to the X-axis stage 5 (so that the left-right direction in the figure is the longitudinal direction). Is installed. The recording medium mounting table 3 moves in the front-rear direction in the figure by moving along the X-axis stage 5, and moves in the left-right direction in the figure by moving along the Y-axis stage 6. Further, a Z-axis stage 7 is installed so that the vertical direction is the longitudinal direction with respect to the recording medium mounting table 3, and the inkjet head block 4 moves in the vertical direction along the Z-axis stage 7. To do.

  In this embodiment, the inkjet head block 4 is configured to move in the vertical direction and move the recording medium mounting table 3 in the front-rear and left-right directions. However, the present invention is not limited to this, and the recording medium mounting table is not limited thereto. 3 may be configured so that the inkjet head block 4 moves in the front-rear and left-right directions together with the vertical direction. Alternatively, the inkjet head block 4 may be fixedly installed, and the recording medium mounting table 3 may be disposed not only in the front-rear left-right direction. It may be configured to move in the vertical direction.

  FIG. 2 is a diagram schematically showing the inkjet head block 4. The inkjet head block 4 includes an inkjet head 4a, a distance detection sensor 4b, and a base 4c, and the inkjet head 4a and the distance detection sensor 4b are fixed to the base 4c. The distance detection sensor 4b is fixed to the base 4c so that the sense position of the distance detection sensor 4b is the same position as the ink ejection surface of the inkjet head 4a. The ink jet head 4a is provided with an ink supply unit 4d, and ink is supplied into the ink jet head 4a from an ink tank (not shown) via the ink supply unit 4d. Since the inkjet head 4a is the same as the conventional one, a detailed description thereof will be omitted. For example, nozzles that eject a plurality of inks are arranged at predetermined intervals along the longitudinal direction. Among the ink chambers communicating with the ink chamber, ink is ejected from the nozzles by applying a predetermined driving condition to the ink chamber selected based on image data transferred by processing to be described later and operating the chamber wall of the ink chamber. . In addition, the inkjet head 4a can perform image recording while maintaining recording quality when the distance from the ink ejection surface from which ink is ejected to the recording medium from which ink is ejected is in the range of 1 mm to 5 mm. It is like that.

  The distance detection sensor 4b irradiates the recording surface of the recording medium placed on the recording medium placing table 3 with, for example, an ultrasonic sensor or a laser, and detects the reflected light with a circuit described later. The distance detection sensor 4b fixes the distance from the recording surface of the recording medium at a predetermined position of the Z-axis stage 7, and then moves the recording medium mounting table 3 in the front-rear and left-right directions along the X-axis stage 5 and the Y-axis stage 6. The coordinates of the recording surface of the recording medium with respect to the inkjet head 4a are detected. The distance detection sensor 4b is configured to detect the distance between the ink ejection surface of the inkjet head 4a and the recording surface of the recording medium. However, a predetermined virtual plane is provided and the distance to the virtual plane is detected. You may make it do.

  FIG. 3 is a block diagram showing the main part of the electrical system of the inkjet recording apparatus 100. The main parts of the electric system are CPU 11, ROM 12, P / RAM 13, X drive circuit 14, Y drive circuit 15, Z drive circuit 16, X coordinate position detection circuit 17, Y coordinate position detection circuit 18, Z coordinate position and recording surface. It comprises a coordinate detection circuit 19, a PC (personal computer) interface 20, an image memory 21, an image segmentation circuit 22, an image transfer circuit 23, and the like. The CPU 11, ROM 12, P / RAM 13, X drive circuit 14, Y drive circuit 15, Z drive circuit 16, X coordinate position detection circuit 17, Y coordinate position detection circuit 18, Z coordinate position and recording surface coordinate detection circuit 19 The PC interface 20, the image memory 21, and the image segmentation circuit 22 are connected via a bus line 24.

  The CPU 11 is a control unit main body of the inkjet recording apparatus 100. The ROM 12 stores a program executed by the CPU 11, information indicating fixed data, and the like. The fixed data stored in the ROM 12 includes, for example, information on the ink ejection performance indicating the distance at which the recording quality can be maintained when the ink jet head 4a ejects ink and performs recording, and information on the ink jet head 4a. Characteristic information indicating the characteristics of the inkjet head 4a, such as information indicating the recordable width and information indicating the outer size of the inkjet head 4a (in this embodiment, the outer size of the inkjet head block 4) is stored. (Memory means). The P / RAM 13 has a work area used when the CPU 11 executes a program stored in the ROM 12.

  The X drive circuit 14 moves the recording medium mounting table 3 along the X axis stage 5 direction, and the Y driving circuit 15 moves the recording medium mounting table 3 along the Y axis stage 6 direction. The Y-axis motor 26 and the Z drive circuit 16 control a Z-axis motor 27 for moving the inkjet head block 4 in the vertical direction.

  The X coordinate position detection circuit 17 counts a pulse signal output from the X axis linear scale 28 for detecting the position in the X axis direction when the recording medium mounting table 3 is moved along the X axis stage 5. The Y-coordinate position detection circuit 18 detects the position in the Y-axis direction when moving the recording medium placement table 3 along the Y-axis stage 6. The Y coordinate of the recording medium mounting table 3 is detected by counting the pulse signals output from the linear scale 29. The Z coordinate position and recording surface coordinate detection circuit 19 detects the coordinates of the recording surface of the recording medium during pre-scanning by counting the pulse signals output from the distance detection sensor 4b, and in the Z-axis direction during recording. The position of the inkjet head 4a is detected. As described above, the distance detection sensor 4b and the Z coordinate position / recording surface coordinate detection circuit 19 detect the coordinates of the recording surface of the recording medium during pre-scanning and detect the Z coordinate of the inkjet head 4a during recording. Although the configuration is shared, it may be configured not to share these. For example, a distance detection sensor 4b, a recording surface coordinate detection circuit, a Z-axis linear scale, and a Z coordinate position detection circuit are provided. During pre-scanning, the coordinates of the recording surface are detected by the distance detection sensor 4b and the recording surface coordinate detection circuit, During recording, the position of the inkjet head 4a is detected by a Z-axis linear scale and a Z coordinate position detection circuit.

  When the PC interface 20 receives image data to be recorded on a recording medium from the PC 30 outside the inkjet recording apparatus 100, the PC interface 20 outputs the received image data to the image memory 21 under the control of the CPU 11.

  The image memory 21 temporarily stores the image data output from the PC interface 20. Then, under the control of the CPU 11, the temporarily stored image data is output to the image segmentation circuit 22.

  The image segmentation circuit 22 segments the image data output from the image memory 21 based on the coordinate segmentation information and the recording control information calculated in the later-described processing of the CPU 11 and adds recording control information to the segmented image data. (Image data separation means). The image segmentation circuit 22 outputs each image data to which the recording control information is added to the image transfer circuit 23.

  The image transfer circuit 23 transfers the segmented image data output from the image segmentation circuit 22 and the recording control information added to the image data to the inkjet head 4a.

  The inkjet head 4a moves in the vertical direction integrally with the movement of the inkjet head block 4 in the direction of the Z-axis stage 7, and is added to each separated image data output by the image transfer circuit 23 and the image data. Ink is ejected to the recording surface of the recording medium based on the recording control information. At this time, the recording medium placed on the recording medium placing table 3 is integrated with the movement of the recording medium placing table 3 in the X-axis direction along the X-axis stage 5 and the movement in the Y-axis direction along the Y-axis stage 6. And move.

  FIG. 4 is a diagram illustrating an example of a state in which the recording medium 31 is placed on the recording medium placing table 3 of the recording stage 1. Processing for recording an image transmitted from the PC 30 on the recording surface of the recording medium 31 will be described with reference to FIGS. 6 to 14 while using the flowchart of FIG.

  The CPU 11 receives image data and the like from the PC 30 via the PC interface 20 after the recording medium 31 is mounted on the recording medium mounting table 3 of the recording stage 1 of the ink jet recording apparatus 100 by the operator (ST1). Then, the CPU 11 temporarily stores the received image data in the image memory (ST2).

  The CPU 11 causes the X drive circuit 14 and the Y drive circuit 15 to perform predetermined operations without operating the Z drive circuit 16, that is, with the position of the distance detection sensor 4b in the Z-axis direction fixed. The mounting table 3 is moved along the X-axis stage 5 and the Y-axis stage 6, and the X-axis linear scale 28, the Y-axis linear scale 29, and the distance detection sensor 4b are operated. At this time, the operation of the recording medium mounting table 3 is performed so that the recording surface of the mounted recording medium 31 passes below the distance detection sensor 4b. By operating in this way, the CPU 11 can detect the coordinate position of the recording surface of the recording medium 31 from the coordinate position detected by the X coordinate position detection circuit 17, the Y coordinate position detection circuit 18, the Z coordinate position and the recording surface coordinate detection circuit 19. Is obtained (ST3, acquisition means).

  CPU11 divides | segments the coordinate information acquired by the above-mentioned process based on the characteristic information of the inkjet head 4a memorize | stored in ROM12. That is, in consideration of the uneven shape of the recording surface of the recording medium 31 and the ink ejection performance, the recordable width, and the outer size of the ink jet head 4a, the recording surface having the unevenness of the recording medium 31 is all maintained in recording quality. The coordinate information is divided so that it can be recorded (ST4, coordinate information dividing means).

  FIG. 6 is a diagram showing an example of the obtained coordinate information of the recording surface of the recording medium 31 on the XY plane, and FIG. 7 shows the ZX plane (Y = 0) in FIG. FIG. The acquired coordinate information is divided into areas A1 to A11 in consideration of the uneven shape of the recording surface of the recording medium 31 and the characteristic information of the inkjet head 4a.

  Subsequently, the CPU 11 determines whether or not the process of dividing the coordinate information has been performed (ST5). That is, it is determined whether or not the inkjet recording apparatus 100 can perform recording on the recording surface of the recording medium 31 that has acquired the coordinate information. If the CPU 11 determines that the process of dividing the coordinate information could not be performed, for example, the CPU 11 performs an error process such as sending a message indicating that the recording cannot be performed to the PC 30 (ST6), and ends the process.

  When the CPU 11 determines that the process of dividing the coordinate information has been performed, the CPU 11 calculates recording control information indicating the timing of recording an image on each area of the divided recording surface based on the divided coordinate information calculated in the above-described process. To do. On the recording medium 31 mounted on the recording medium mounting table 3, images are recorded one by one in each of the divided areas A1 to A11. At this time, the recordable width of the inkjet head 4a is recorded. Therefore, if the width of the area is narrower than the recordable width, the image is overlapped and recorded as a result. In order to avoid this, recording control information for controlling image recording is calculated in accordance with the width of each area so as not to record an image other than the area to be recorded (ST7).

  FIG. 8 is a diagram used for explaining the recording control information. As shown in the figure, when image recording is performed in the area A4, the areas A1 to A3 indicated by hatching in the drawing are already recorded. When recording the area A4, the recording medium 31 moves in the Y direction so that the inkjet head 4a is positioned with respect to the recording surface to the recording start position P1, the center position P2, and the recording end position P3. In order to simplify the description, the drawing shows the position of the inkjet head 4a relative to the recording surface when recording is performed on the area A4. The recordable width of the inkjet head 4a at this time includes not only the area A4 but also a part of areas A3 and A5. A recording range control signal shown in FIG. 9 is created as recording control information in order not to perform recording in areas A3 and A5 when recording in area A4.

  FIGS. 9A to 9C are diagrams showing recording range control signals when the inkjet head 4a is positioned at the recording start position P1, the center position P2, and the recording end position P3. c) is a diagram showing a recording range of the inkjet head 4a when the inkjet head 4a is positioned at the recording start position P1, the central position P2, and the recording end position P3. When the inkjet head 4a is positioned at the recording start position P1, the central position P2, and the recording end position P3, image data corresponding to the recordable width is sent, but only the image portion corresponding to the area A4 has a recording range control signal. It is not ON. That is, as shown in FIGS. 10A to 10C, image recording is performed in a recording range corresponding to the width of the area A4. The case where the inkjet head 4a is located at the recording start position P1, the center position P2, and the recording end position P3 has been described. Similarly, when the ink jet head 4a is located at other positions, only the portion corresponding to the area A4 is used. Since the recording range control signal is not turned on, it is possible to prevent duplicate image recording.

  In this embodiment, the recording control information is the recording range control signal shown in FIG. 9, but is not limited to this. For example, as shown in FIG. 11, the recording control information is based on the coordinate information divided by the image dividing circuit 22. The image data may be segmented into each area, and the CPU 11 may calculate an offset signal indicating the timing for writing the segmented image data as recording control information and output the offset signal to the image segmentation circuit 22. Also, as shown in FIG. 12, the image segmentation circuit 22 segments the image data for the recordable width, and the CPU 11 controls the white range so that the portion outside each area where image recording is not performed is a white signal as the recording control information. The signal may be calculated and output to the image segmenting circuit 22 so that the image transfer circuit 23 does not perform image recording into a white image (a portion not shaded in the drawing).

  Subsequently, the CPU 11 calculates movement position information of the inkjet head block 4 and the recording medium mounting table 3 in order to perform image recording in each divided area. That is, when performing image recording on each area of the recording medium, Z-axis movement position information for moving the inkjet head block 4 in the Z-axis direction and X-axis movement position information for moving the recording medium mounting table 3 in the X-axis direction. Then, Y-axis movement position information to be moved in the Y-axis direction is calculated (ST8).

Then, the CPU 11 sends the divided coordinate information and recording control information calculated by the above processing to the image segmentation circuit 22, the X movement position information to the X drive circuit 14, the Y movement position information to the Y drive circuit 15, and the Z movement. Each position information is output to the Z drive circuit, etc., and each part of the ink jet recording apparatus 100 is comprehensively controlled to record an image on the recording medium 31 (recording means is configured by ST9, ST7 to ST9).
FIG. 13 is a diagram showing the relative positional relationship between the inkjet head 4a and the recording surface of the recording medium 31 on the XY plane when recording from the area A1 to A11. For ease of explanation, the position of the inkjet head 4a with respect to the recording surface of the recording medium 31 is shown. FIG. 14 is a diagram illustrating a ZX plane (Y = 0) in FIG. This shows that the position of the inkjet head 4a in the Z-axis direction has changed when recording is performed from area A1 to area A11.

  The image recording operation of the ink jet recording apparatus 100 adjusts the position of the recording medium 31 by moving the recording medium mounting table 3 in the Y-axis direction in order to perform recording in the area A1 based on the movement position information. The position of the inkjet head 4a is adjusted by moving the inkjet head block 4 in the Z-axis direction, and the recording medium 31 is moved in the X-axis direction by moving the recording medium mounting table 3 along the X-axis stage 5. As the recording medium 31 moves in the X-axis direction, ink is ejected from the inkjet head 4a based on the image data corresponding to the area A1 and the recording control information to record an image on the recording surface of the recording medium 31. By sequentially performing this operation from area A1 to area A11, image recording on the recording surface of the recording medium 31 is performed.

  Further, as shown in the figure, when performing image recording from the area A1 to the area A6, the recording surface of the recording medium 31 is rising to the right, and therefore image recording is performed using only the right end portion of the inkjet head 4a. ing. On the other hand, when the recording surface of the recording medium 31 is lowered to the right as in the seventh and eighth times, image recording is performed using only the left end portion of the inkjet head 4a. Thereby, the inkjet head 4a can be brought close to the recording surface of the recording medium 31 within a range in which the recording quality can be maintained while preventing contact between the inkjet head 4a and the recording surface of the recording medium 31.

  Therefore, according to the ink jet recording apparatus 100 of this embodiment, the recording surface of the recording medium 31 and the ink jet head 4a of the recording medium 31 having a recording surface that is uneven in a range larger than the outer size of the ink jet head block 4 can be obtained. Based on the characteristic information such as ink ejection performance, recordable width and outer size, the range for recording the image is divided, and the positions of the recording medium 31 and the inkjet head 4a are relatively adjusted based on the divided image data. By performing recording in this manner, it is possible to perform good recording without requiring control relating to the driving conditions of the inkjet head 4a.

  In the above-described embodiment, when the coordinate information acquired from the recording surface of the recording medium 31 cannot be divided, the error process of step ST6 is performed. However, there is further provided a recording medium rotating means (rotating means) capable of rotating the recording medium placing table 3 on which the recording medium 31 is placed at a preset angle, for example, 90 degrees (or 180 degrees, 270 degrees). As a result, the following processing can be performed. In addition, you may comprise so that the direction of the inkjet head 4a may rotate a predetermined angle.

  If the CPU 11 determines in step ST5 that the coordinate information cannot be divided, the CPU 11 rotates the acquired coordinate information by 90 degrees (coordinate information rotation means). And the process which divides | segments the coordinate information demonstrated by step ST4 is performed, and it is judged whether the process which divides | segments the coordinate information of step ST5 was again performed. Note that the process of rotating the coordinate information and determining whether or not the rotated coordinate information can be divided is not limited to the case of 90 degrees, but for all angles rotated by the recording medium rotating means. May be performed.

  If the coordinate information cannot be divided even if this processing is performed, error processing is performed. If the coordinate information can be divided, the CPU 11 displays angle information indicating the rotated angle in addition to the divided coordinate information. Output to the dividing circuit 22. Further, the CPU 11 performs a process of rotating the recording medium rotating means according to the rotation angle before performing the image recording in step ST9.

  For example, in a recording medium having unevenness on the recording surface such as a roof tile, coordinate information can be divided by changing the relative movement direction of the roof tile with respect to the recordable width of the inkjet head 4a depending on the degree of the unevenness. There are times when it cannot be divided. That is, when the uneven shape of the recording surface of the roof tile and the characteristic information of the inkjet head 4a are taken into consideration, there are cases where recording is possible in a certain direction but recording is impossible in a certain direction. However, by providing the recording medium rotating means, the ink jet recording apparatus 100 can change the direction of the recording medium placed on the recording medium placing table 3 and change the orientation to enable image recording. Image recording can be performed by automatically rotating the direction of the recording medium.

  Note that the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying constituent elements without departing from the scope of the invention in the implementation stage.

FIG. 2 is a diagram schematically showing a configuration of a recording stage of the ink jet recording apparatus in the embodiment of the present invention. The figure which shows the inkjet head block in the same embodiment roughly. FIG. 3 is a block diagram showing a main part of an electric system of the ink jet recording apparatus according to the embodiment. The figure which shows an example of the state which mounted the recording medium in the recording medium mounting base of the recording stage in the embodiment. 6 is a flowchart showing image recording processing in the embodiment. An example when the coordinate information of the acquired recording medium is divided on the XY plane in the same embodiment is shown. The figure which shows the ZX plane (Y = 0) in FIG. The figure used in order to demonstrate the recording control information in the same embodiment. The figure which shows the recording range control signal when the inkjet head in the embodiment is located in each position. The figure which shows the recording range of the inkjet head of each position in FIG. The figure which shows an offset signal when the inkjet head in the embodiment is located in each position. The figure which shows the image data which added the white signal when the inkjet head in the embodiment is located in each position. FIG. 3 is a diagram illustrating a relative positional relationship between an inkjet head and a recording surface of a recording medium during image recording in the same embodiment. The figure which shows the ZX plane (Y = 0) in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Recording stage, 2 ... Bottom plate, 3 ... Recording medium mounting base, 4 ... Inkjet head block, inkjet head 4a, distance detection sensor 4b, 5 ... X-axis stage, 6 ... Y-axis stage, 7 ... Z-axis stage, 11 ... CPU, 12 ... ROM, 22 ... Image separation circuit, 100 ... Inkjet recording apparatus

Claims (2)

It has an inkjet head provided with a plurality of nozzles that eject ink based on a predetermined driving condition, selects an inkjet head nozzle based on image data, ejects ink, and has an uneven recording surface In an inkjet recording apparatus that records an image on the recording medium by relatively moving a recording medium mounting table on which the recording medium is mounted and the inkjet head,
Storage means for storing at least characteristic information including information relating to ejection performance, external size, and recordable width relating to ink ejection of the inkjet head;
Obtaining means for obtaining coordinate information indicating the coordinate position of the recording surface of the recording medium;
Coordinate information dividing means for dividing the coordinate information acquired by the acquiring means into a plurality of areas so that the image data can be recorded by the inkjet head based on the characteristic information stored in the storage means;
Based on the coordinate information divided by the coordinate information dividing means, image data dividing means for dividing the image data;
Recording means for recording on the recording surface of the recording medium based on the respective image data cut by the image data cutting means ;
Coordinate information rotating means for rotating the acquired coordinate information by a predetermined angle;
A rotation means for rotating the recording medium mounting table or the direction of the inkjet head in order to change the direction of image recording by relatively moving the recording medium and the inkjet head;
The coordinate information dividing means rotates the acquired coordinate information by a predetermined angle by the coordinate information rotating means when the image data cannot be divided by the inkjet head based on the acquired coordinate information, Performing the division based on the rotated coordinate information,
The ink jet recording apparatus , wherein the rotating means rotates the direction of the recording medium mounting table or the ink jet head in accordance with a predetermined angle obtained by rotating the coordinate information . The inkjet recording apparatus according to claim 1, wherein the acquisition unit acquires a predetermined virtual plane or a coordinate position with respect to the inkjet head.

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