JP2017213761A - Recording device and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a decline in density of a recording image and reduction in size of a recording image even when an overlapping region of an image varies.SOLUTION: A recording device extends at least one of first scanning image data (D1) and second scanning image data (D2) in a facing direction of first scanning and second scanning so that a first recording region (S1) by first scanning and a second recording region (S2) by second scanning overlap on each other.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a serial scan type recording apparatus and recording method for recording an image on a recording medium by repeating recording scanning of a recording head.

  In such a serial scan type recording apparatus, in the case of one-pass recording, after one recording scan of the recording head, the recording medium is conveyed by the recording width of the recording scan. In this case, the conveyance amount of the recording medium needs to be exactly matched with the recording width of the recording head. When the conveyance amount of the recording medium fluctuates and fluctuates, there is a possibility that a connecting stripe is generated at the connection portion of the recording areas recorded by the adjacent different scans. Specifically, when the conveyance amount of the recording medium is shorter than the recording width of the recording head, black stripes are generated by overlapping the recording areas recorded by different adjacent scans. On the other hand, when the conveyance amount of the recording medium is longer than the recording width of the recording head, white streaks in which an image is not recorded are generated between recording areas recorded by different adjacent scans.

  In Patent Document 1, a recording area by a preceding recording scan and a recording area by a subsequent recording scan are overlapped, and regarding the overlapping recording areas, a recording image is divided into a preceding recording scan and a subsequent recording scan. The images are recorded in a complementary manner. As a method of allocating recorded images in overlapping recording areas, Patent Document 2 describes a method of gradually decreasing or increasing the number of recording dots, and Patent Document 3 describes a method of changing the distribution method according to gradation information. Is described.

Japanese Patent Publication No. 6-35191 Japanese Patent No. 2980429 Japanese Patent No. 4669608

  However, in any of the patent documents, when the conveyance amount of the recording medium is larger than the target conveyance amount, it is inevitable that the recording density of the image in the entire overlapping region is reduced considerably. On the other hand, when the conveyance amount of the recording medium is smaller than the target conveyance amount, it is inevitable that the size of the image recorded in the area including the overlapping area is reduced in the conveyance direction of the recording medium. In particular, when the recorded image is a two-dimensional code, the density of a part of the cell that is a component of the two-dimensional code becomes light or the cell shrinks, so that the recorded two-dimensional code is read accurately. There is a risk that it will not be possible. In that case, the code recorded by the two-dimensional code cannot be recognized correctly.

  An object of the present invention is to provide a recording apparatus and a recording method capable of suppressing a decrease in density of a recorded image and a reduction in the size of the recorded image even when the overlapping region of the image fluctuates.

  The recording apparatus of the present invention includes a recording element array in which a plurality of recording elements are arranged, and performs a recording operation on a recording medium based on image data in a predetermined direction intersecting the recording element array, and the recording Driving means for relatively moving the head and the recording medium in a direction intersecting the predetermined direction, a first recording area recorded by the first recording operation in the predetermined direction by the recording head, the recording head and the recording medium Are moved relative to each other in a direction crossing the predetermined direction so that the second recording area recorded by the second recording operation in the predetermined direction following the first recording operation by the recording head overlaps. , And at least one of the image data recorded in the first recording operation and the image data recorded in the second recording operation as the first recording area. And expanding means for expanding the opposing direction of the serial second recording area, characterized in that it comprises a.

  According to the present invention, it is possible to suppress a decrease in the density of the recorded image and a reduction in the size of the recorded image even when the overlapping region of the image fluctuates.

It is explanatory drawing of the inkjet recording device which can apply this invention. 2 is a block diagram of a control system of the recording apparatus. FIG. It is a flowchart for demonstrating the recording operation of a recording device. It is explanatory drawing of the image data process in a recording device. FIG. 6 is an explanatory diagram of a relationship between a conveyance amount of a recording medium and a recorded image. It is a flowchart for demonstrating the change process according to the attribute of an input image.

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

  FIG. 1A is a perspective view for explaining a basic configuration example of an ink jet recording apparatus 109 to which the present invention is applicable.

  In the recording apparatus 109, the ink jet recording head 101 is moved in the main scanning direction indicated by the arrow Y by the moving mechanism, and the recording medium 102 is subordinate to the arrow X that intersects (in the present example, orthogonal) to the main scanning direction by the transport mechanism. It is conveyed in the scanning direction. The moving mechanism of this example is configured to reciprocate a carriage (not shown) on which the recording head 101 is mounted in the main scanning direction by a carriage motor 105 via a belt 107. Further, the transport mechanism of this example is configured to transport the recording medium 102 in the sub-scanning direction by rotating the transport roller 103 by the transport motor 104. The moving position of the recording head 101 is detected by the linear encoder 108. In the recording head 101, as shown in FIG. 1B, a plurality of ejection ports 201 are formed along a direction intersecting (in the present example, orthogonal) with the sub-scanning direction. Can be selectively ejected from the plurality of ejection ports 201. The recording head 101 includes an ejection energy generating element such as an electrothermal conversion element (heater) or a piezoelectric element in order to eject ink from the ejection port 201. As described above, in the inkjet recording head 101, the recording element includes an ejection energy generating element that functions to eject ink from the ejection port 201 based on image data, and an ejection port array in which a plurality of ejection ports 201 are arranged. This corresponds to the recording element array. In this example, in order to record a monochromatic image, one row of discharge ports 201 (discharge port row) is formed. However, when recording a full-color image, an ejection port array may be provided for each of a plurality of ink colors, and a plurality of ejection port arrays may be provided for each ink color in order to increase the recording speed.

  While moving the recording head 101 in the main scanning direction, an operation of selectively ejecting ink from a plurality of ejection openings based on recording data and a transporting operation of transporting the recording medium 102 in the sub-scanning direction are alternately repeated. Thus, images can be sequentially recorded on the recording medium 102. In the basic one-pass recording method, an operation for recording an image for one band by one pass (recording scanning) of the recording head 101, and the recording medium 102 by a length corresponding to the width for the one band. The operation of conveying is repeated alternately.

  FIG. 1C is an explanatory diagram of an operation of recording one image by the first and second two scans of the recording head 101. In FIG. 1C, for convenience of explanation, it is assumed that the recording head 102 is moved in the direction opposite to the arrow X direction without the recording medium 102 being conveyed in the arrow X direction.

  In the first scan, an image is recorded in the recording area S1 (preceding recording area) by ejecting ink from the ejection port 201 while moving the recording head 101 in the forward direction of the arrow Y1. Thereafter, the recording medium 102 is conveyed in the arrow X direction by a length smaller than the width of the recording area S1. In the subsequent second scan, an image is recorded in the second recording area S2 (subsequent recording area) by ejecting ink from the ejection port 201 while moving the recording head 101 in the backward direction of the arrow Y2. The recording areas S1 and S2 overlap in the shaded area in FIG.

  FIG. 2 is a block diagram of a control system of the recording apparatus 109.

  The recording device 109 includes an interface 402, a CPU 403, a RAM 404, a ROM 405, an EEPROM 409, a motor driver 406, a recording control circuit 407, and an encoder 108. The interface 402 receives recording data from a host PC (host device) 401. The interface 402 may be directly connected to an interface provided in a general PC such as a USB (Universal Serial Bus), or may be connected via a line such as a LAN (Local Area Network). The CPU 403 controls the overall operation of the recording device 109 according to the program stored in the ROM 405. The CPU 403 is provided with a calculation device that performs various calculations for performing control. A RAM 404 that is a work memory for temporarily storing data may be used for these calculations. The CPU 403 is also provided with a DMA controller for transferring the recording data received from the interface 402 to the RAM 404, and the recording data for one page received from the host PC 401 can be expanded in the RAM 404. Further, before starting the recording operation, the CPU 403 can perform image data processing in which the recording data is read from the RAM 404 into the arithmetic device and subjected to arithmetic processing, and then the image data is returned to the RAM 404. A motor driver 406 is a circuit for driving a carriage motor 105 for reciprocating the recording head 101 and a conveyance motor 104 for conveying the recording medium 102. The encoder 108 detects the moving position of the recording head 101, and the timing at which the recording head 101 ejects ink is determined based on the detection result. Based on the detection signal from the encoder 108, the CPU 403 reads out the recording data from the RAM 404 and DMA-transfers the read data to the recording control circuit 407. The recording control circuit 407 outputs a signal in a format suitable for the interface of the recording head 101 according to the input recording data and each setting parameter. Specifically, ink droplets are ejected from the ejection ports of the recording head 101 by outputting a driving pulse for driving the ejection energy generating element of the recording head 101. The EEPROM 409 is a storage area for storing various setting values for recording. In the present embodiment, as will be described later, information on the amount of change in recording position predicted when recording scanning is performed using the recording head 101, that is, subsequent recording (second scan) with respect to preceding recording (first scan). The maximum shift amount (Lmax) is stored.

  FIG. 3 is a flowchart for explaining the recording operation of the recording apparatus 109.

  In the recording operation, the CPU 403 first receives image data from the host PC 401 (step S1), and immediately transfers the received image data to the RAM 404 (step S2). The following operations are also executed under the control of the CPU 403. The transferred image data can be recorded by image data processing (step S3) described later, and an image recording operation on the recording medium 102 is performed in step S4 and subsequent steps based on the image data processed. In this example, an image is completed by one first scan and one subsequent second scan.

  First, in step S4, the first scan of the recording head 101 is started. That is, the recording head 101 starts to move in the forward direction of the arrow Y1 that intersects (or orthogonally intersects in this example) with the ejection port array. The recording start position for the recording medium 102 is separately defined, and the system waits until the recording head 101 moves to the recording start position (step S5). During this standby, the recording head 101 does not eject ink. When the recording head 101 reaches the recording start position, slice data is transferred at a timing based on a signal (encoder signal) from the encoder 108 (steps S6 and S7), and slice recording (step S8) is performed. A slice means the timing at which ink is ejected once from a plurality of ejection ports forming an ejection port array. By repeating steps S6, S7, and S8 and repeating slice recording by the number of recording pixels of the image in the scanning direction of the recording head 101, recording of an image for one band is completed (step S9). The band is a range where an image is recorded by one scan of the recording head 101. The recording area by the first scan of the recording head 101 corresponds to the recording area S1 in FIG.

  After the recording of the image for one band is completed by the first scan of the recording head 101, the scanning of the recording head 101 is stopped (step S10). After confirming that the second scan has not ended (step S11), the recording medium 102 is conveyed in the direction of the arrow X (step S12), and then the second scan of the recording head 101 is started (step S12). S13).

  After starting the second scan, the operations of steps S5 to S9 are repeated as in the case of the first scan, and an image for one band is recorded by the second scan. After confirming that the second scan has been completed (step S11), the recording operation of FIG. 3 is terminated.

  FIG. 4A is a flowchart for explaining image data processing, and FIGS. 4B, 4C, and 4D are explanatory diagrams of image data to be processed. The CPU 403 performs image data processing on the recording data expanded in the RAM 404, and then transfers the processed data to the recording control circuit 407 to drive various motors, thereby driving the image on the recording medium 102. Perform a recording operation.

  In the image data processing, first, in step S21, the input image data D0 is divided into first image data D1 to be recorded by the first scan and second image data D2 to be recorded by the second scan. . The divided image data D1 and D2 are stored in separate areas of the RAM 404. Next, in step S22, an expansion process is performed to expand the end data (end data) of the image data D1. The edge data is data recorded in the recording area S10 in FIG. 4C, located on the image data D2 side (lower side in FIG. 4C) in the image data D1. That is, the edge data is image data recorded by a predetermined number of recording elements located on the recording area S2 side (subsequent recording area side) in the first scan. Due to the expansion processing, the recording area of the image recorded based on the edge data reaches the size of the recording area S11 (S11> Lmax) larger than the predetermined amount Lmax (the direction opposite to the recording area S2). ). Lmax is an assumed amount when a deviation occurs in the recording area S2 of the image data D2 due to a change in the conveyance amount of the recording medium, and a deviation of Lmax / 2 in the + x direction and a deviation of Lmax / 2 in the -x direction. ,including. That is, Lmax is a variation amount of the position of the recording region S2 with respect to the recording region S1, and the recording region S11 is expanded to be larger than the variation amount Lmax. The expansion amount of the image data D1 only needs to be larger than the assumed variation amount.

  The method of extending the edge data is arbitrary, and for example, the edge data may be expanded uniformly, or the expansion rate may be increased toward the lower side in FIG. Further, the size of the end data can be arbitrarily set. For example, the entire image data D1 may be expanded. If the recording position of the image data D2 is shifted in the + x direction, the final recorded image is smaller in the + x direction than the recording area corresponding to the input image data. Therefore, in step S23, as shown in FIG. 4D, the recording start position of the image data D2 is corrected in advance in the -x direction by half of Lmax (Lmax / 2) (start position correction).

  As a result of such image data processing, the image data D1 expanded as shown in FIG. 4C and the image data D2 whose recording start position is corrected as shown in FIG. Stored on top.

  FIG. 5 is an explanatory diagram of an image recorded based on the image data D1 and D2 of FIGS. 4 (c) and 4 (d).

  FIG. 5A is an explanatory diagram of an image recorded when the conveyance amount of the recording medium 102 matches the target conveyance amount. In the first scan, an image is recorded in the area S1 based on the expanded image data D1, and in the second scan, an image is recorded in the area S2 based on the image data D2. As described above, in the present embodiment, the image data D1 is recorded in the region S1 that is larger than Lmax in the −x direction from the image division position P, and the image data D2 is recorded from the image division position P to −x. It is recorded in a region S2 that is shifted by Lmax / 2 in the direction. That is, the recording start position of the image data D2 is shifted by ½ of Lmax in the direction away from the area S1. The shift amount may be an amount smaller than Lmax. The region S3 is a region where the regions S1 and S2 overlap.

  The position of the recording area S <b> 2 by the second scan is shifted in the + x direction or the −x direction in the range of the assumed maximum shift amount Lmax due to variations in the transport amount of the recording medium 102. When the amount of deviation is Lmax / 2 in the −x direction, as a result, as shown in FIG. 5B, the amount of deviation of the recording area S2 from the division position P is Lmax in the −x direction. . However, since the recording area S1 is expanded in the −x direction to be larger than Lmax, and an area S3 where the recording areas S1 and S2 overlap is generated, the final recorded image is more than the recording area corresponding to the input image data. It will not get smaller. On the other hand, when the shift amount of the recording area S2 is Lmax / 2 in the + x direction, as a result, the shift amount of the recording area S2 from the division position P is “0” as shown in FIG. It becomes. Also in this case, an area S3 where the recording areas S1 and S2 overlap is generated, so that the final recorded image is not smaller than the recording area corresponding to the input image data.

  In this way, by overlapping the recording areas of the first and second scans adjacent in the conveyance direction of the recording medium 102, no gap is generated between the images recorded in each scan, and the size of the recorded image is reduced. There is no reduction. However, as described above, since the target transport amount of the recording medium 102 is set large and the end of the image data D1 is expanded, the recorded images in FIGS. 5A and 5B are the input image data D0. The image is extended in the direction of the arrow -x than the image recorded based on the image. However, for example, when the image is a single color image such as a character or a figure, the shape of the image is not a problem. Even if the image is a part of the two-dimensional code, the readability of the recorded two-dimensional code is not affected.

  In the image data processing described above, as shown in FIG. 5A, the overlapping area S3 exists even if the transport amount of the recording medium 102 is the same as the target transport amount. For this reason, when a halftone image is recorded, a black streak may occur in the overlapping region S3. From such a viewpoint, the CPU 403 may determine whether or not to execute the above-described image data processing based on the attribute of the image to be recorded. FIG. 6 is a flowchart for explaining such a determination process. The CPU 403 receives image attribute data together with the recording data from the host PC 401, and determines whether or not the image attribute is a binary image made up of graphics and characters (step S31). When the image to be recorded is a binary image, the above-described image data processing including image division (step S32) and data expansion processing (step S33)) and start position correction processing (step S34) is executed. On the other hand, when the image to be recorded is a multi-valued image such as a photograph, the image is recorded as usual based on the input image data without executing the above-described image data processing.

  As described above, in this embodiment, even when the movement amount of the recording medium varies, an image without white stripes can be recorded on the recorded image. For example, a readable two-dimensional code can be recorded regardless of variations in the amount of movement of the recording medium. In addition to the two-dimensional code, the recording apparatus of this embodiment can reliably record various images that need to avoid a decrease in the density of the recorded image and a reduction in the size of the recorded image.

(Other embodiments)
According to the present invention, it is possible to suppress a decrease in the density of a recorded image and a reduction in the size of the recorded image even when the conveyance amount of the recording medium varies. As a result, an image such as a two-dimensional code with high readability can be reliably recorded.

  In the embodiment described above, the image data D1 is expanded in the conveyance direction of the recording medium so that the recording areas S1 and S2 of the first and second scans overlap. However, the image data D2 may be expanded, or both the image data D1 and D2 may be expanded. For example, when the end data (end data) of the image data D2 is expanded, the end data is data recorded on the image area S1 side (previous recording area side) in the image data D2. In short, it is only necessary that the recording areas S1 and S2 can overlap each other. Further, the input image data may be divided into three or more image data so as to correspond to a plurality of scans of three times or more. In short, the recording area of the preceding scan, the recording area of the subsequent scan, Need only overlap each other.

  The recording head is not limited to an inkjet recording head provided with an ejection energy generating element for ejecting ink from an ejection port as a recording element, and may be a thermal transfer recording head, for example. Therefore, the recording apparatus of the present invention can be widely applied to recording apparatuses of various recording systems in addition to the inkjet recording apparatus.

  In this embodiment, the first scan of the recording head is performed, then the recording medium is transported to the position of the second scan, and then the second scan of the recording head is performed. However, the present invention can also be implemented by a configuration in which the recording head is moved to the second scan position without transporting the recording medium. In this case, the assumed maximum shift amount Lmax corresponds to a variation in the moving amount of the recording head. The present invention also records an image using a recording head that performs a recording operation in a predetermined direction that intersects the recording element array, and a drive mechanism that relatively moves the recording head and the recording medium in a direction that intersects the predetermined direction. The present invention can be widely applied to recording apparatuses.

101 Recording Head 102 Recording Medium 109 Recording Device 403 CPU

Claims (9)

A recording head including a recording element array in which a plurality of recording elements are arranged, and performing a recording operation on a recording medium based on image data in a predetermined direction intersecting the recording element array;
Drive means for relatively moving the recording head and the recording medium in a direction intersecting the predetermined direction;
The first recording area recorded by the first recording operation in the predetermined direction by the recording head, the recording head and the recording medium are moved relative to each other in a direction intersecting the predetermined direction, and the first by the recording head. Image data recorded in the first recording operation and the second recording area so as to overlap a second recording area recorded by the second recording operation in the predetermined direction following the recording operation of Expansion means for expanding at least one of the image data recorded in the operation in the opposing direction of the first recording area and the second recording area;
A recording apparatus comprising:   The expansion means includes an end portion of image data recorded by a predetermined number of the recording elements positioned on the second recording area side in the first recording operation, and the first recording operation in the first recording operation. At least one of the end portions of the image data recorded by the predetermined number of the recording elements located on the recording area side is expanded in the facing direction of the first recording area and the second recording area. The recording apparatus according to claim 1.   The recording apparatus according to claim 1, wherein the expansion amount of the image data is larger than a variation amount of a position of the second recording area with respect to the first recording area.   The recording apparatus according to claim 3, further comprising storage means for storing information relating to the fluctuation amount. The expansion means expands the image data recorded in the first recording operation by a predetermined amount in the direction of the second recording area,
The recording apparatus includes correction means for shifting a recording start position of image data recorded in the second recording operation in a direction away from the first recording area by an amount smaller than the predetermined amount. The recording apparatus according to any one of claims 1 to 4.   The recording apparatus according to claim 5, wherein a shift amount of the recording start position by the correction unit is ½ of the predetermined amount. Determining means for determining whether an image to be recorded based on the image data is a binary image or a multi-valued image;
The expansion means functions when the determination means determines that the image to be recorded is a binary image, and does not function when the determination means determines that the image to be recorded is a multi-valued image. The recording apparatus according to claim 1, wherein:   The recording apparatus according to claim 1, wherein the image data is image data for recording a two-dimensional code. A recording element array in which a plurality of recording elements are arranged, and a recording head that performs a recording operation based on image data in a predetermined direction intersecting the recording element array with respect to the recording medium and a direction intersecting the predetermined direction with the recording medium Recording method for relative movement,
The first recording area recorded by the first recording operation in the predetermined direction by the recording head, the recording head and the recording medium are moved relative to each other in a direction intersecting the predetermined direction, and the first by the recording head. Image data recorded in the first recording operation and the second recording area so as to overlap a second recording area recorded by the second recording operation in the predetermined direction following the recording operation of A recording method comprising: an expanding step of expanding at least one of image data recorded in operation in a direction opposite to the first recording area and the second recording area.