JP4322883B2 - Printing apparatus and printing method - Google Patents

Description

  The present invention supplies print data including a large number of dot information to a print head in which a plurality of dot forming elements are arranged along the sub-scanning direction, and the print head and the print medium are relatively moved in the main scanning direction and the sub-scanning direction. The present invention relates to a printing apparatus and a printing method of a system in which a head is moved in a scanning direction in an inkjet printer or a thermal printer that moves and prints an image on the surface of a printing medium.

As a printing apparatus, there is a proposal for making a printing position complicated in order to make printing unevenness in a joint portion inconspicuous (see, for example, Patent Document 1). Further, a method of controlling the amount of ink in order to reduce density unevenness such as black stripes is known (see, for example, Patent Document 2). In addition, there is known an ink jet recording apparatus in which a dot thinning process or an overlapping printing process is performed to suppress a deterioration in image quality due to a connecting stripe at a band boundary (see, for example, Patent Document 3). In addition, a recording method is known in which lines are overlapped to make the joints inconspicuous, and the recording density of overlapping lines is recorded at a lower density than other non-overlapping lines (see, for example, Patent Document 4). A printer that prints obliquely and prevents banding is known (see, for example, Patent Document 5).
JP 2003-34017 A JP 2002-200755 A JP 2000-238935 A JP 09-99550 A JP 2000-52595 A

The streak-like phenomenon in the scanning direction of the head is due to problems such as mechanical errors such as paper conveyance accuracy of the printing device, subtle deviations in the head mounting position, and slight print position of ink ejected from the head. It can be influenced by various complex factors such as misalignment and print data problems. However, considering that streaks appear in the scanning direction of the head, the biggest cause is that the print head moves in the scanning direction of the head and performs printing for a certain printing width after the paper is conveyed. it is conceivable that. Also, depending on the print head, when the ink discharge nozzle discharges ink continuously, if there are a large number of nozzles that discharge side by side among these nozzles, the nozzles located at the ends of the nozzles The print position accuracy may not be achieved. The ink ejection control of this end nozzle and the other nozzles is the same, but the accuracy of the position of the ink ejected from the end nozzle may not be achieved, so this is connected in the horizontal direction, It may be one of the causes of streaks.
The present invention prevents the phenomenon that stripes appear in the scanning direction of the head at the joints even if the print head is moved in the scanning direction, so that the scanning direction of the head does not appear. The purpose is to make the streaks inconspicuous.

In order to achieve the above object, the present invention supplies print data consisting of a large number of dot information to a print head in which a plurality of dot forming elements are arranged along the sub-scanning direction, and the print head in the main scanning direction with respect to the print medium It is relatively moved in a predetermined transport amount subscanning direction the print medium after scanning by relative movement with respect to the print head, a printing apparatus for printing an image on a surface of the print medium, supplied to each main scanning operation of the printhead A deformation data portion is formed so that dots are not arranged continuously in the main scanning direction of the print head at the end portion of the print data in the sub-scanning direction . By relative movement, printing in each area corresponding to one transport width in the sub-scanning direction of the print medium is completed, and the main print head of the first print head among the plurality of relative movements is completed. In the inspection, the first print data in which the deformation data portion is formed is printed on the print medium, and in the subsequent main scan, the print data extending over the previous print area and the next print area in the previous print area. Are sequentially printed, and in the subsequent main scan, printing of the remaining portion of the deformation data portion of the area where the first print data is printed is completed .
The present invention is also characterized in that the dot arrangement of the deformation data portion has a waveform shape.
According to the present invention, the deformation data portion is formed at the rear end in the sub-scanning direction of the print data including the front end of the print data supplied to the print head for each scan, and the intermediate portion of the image The deformation data portion is formed at the front end portion and the rear end portion in the sub-scanning direction of the print data, and the deformation data portion is formed at the front end portion of the print data including the rear end of the print data. To do.
Further, according to the present invention, when the printing of the image including the deformation data portion is completed, the deletion portion of the image of the deformation data portion is changed by the deformation data portion of the print data supplied to the print head in the next scan of the print head. It is characterized by being supplemented.
Further, the present invention is a printing method for printing on a print medium by sequentially moving the print head in the main scanning direction and transporting the print medium in the sub-scanning direction with print data of n (n is a positive number) as print units. In order not to line up a predetermined number of lines on the joint side of the print data continuously in the main scanning direction, the line at the end on the joint side repeats an uneven shape, and the print head in the main scanning direction with respect to the print medium is repeated . Printing in each area corresponding to one transport width of the print medium in the sub-scanning direction is completed by a plurality of relative movements, and the main scanning of the first print head in the plurality of relative movements is completed. In step 1, the first print data in which the unevenness is formed is printed, and in the subsequent main scan, the print is performed across the previous print area and the next print area in the previous print area. Sequentially printed over data in the subsequent main scan, characterized in that printing of the first part of the print data is left deformation data portion of the print area is to be completed.
The present invention is characterized in that the concavo-convex shape on the joint side of the print data and the concavo-convex shape on the joint side of other print data in contact with the print data are printed in a fitted state.
In the present invention, the uneven shape is a waveform.
Further, according to the present invention, the uneven shape is formed by deleting dot information on the joint side of the print data with a mask pattern, and the deleted dot information is complemented by the uneven shape of the print data printed in a subsequent scan. It is made to be made to be done.
According to the present invention, the deleted dot information complementary data is generated by inverting the mask pattern.

  According to the present invention, in a printing apparatus that moves the print head in the scanning direction, it is possible to easily realize a printing result in which a phenomenon that looks like a streak in the scanning direction of the head is not noticeable simply by changing data. .

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a schematic overall configuration of a printing apparatus according to the present invention. The ink jet printer 2 is controlled by a controller 4 including a computer circuit, and the controller 4 is connected to an external computer 8 via a connector 6. The controller 4 incorporates a program for performing conversion processing of the end portions before and after the printing data conveyance direction. The computer 8 transmits print data to the controller 4 mounted on the printer 2. As will be described later, the controller 4 analyzes the received data and controls the drive unit of the printer 2. The printer 2 includes a sub-scan feed mechanism that transports the print medium 10 such as roll paper in the arrow direction B by a paper feed motor, and a main scan feed mechanism that reciprocates the carriage 12 in the axial direction of the drive roller 14 by a carriage motor. have.

Here, the feed direction B of the print medium 10 by the sub-scan feed mechanism is called a sub-scan direction, and the movement direction A of the carriage 12 by the main scan feed mechanism is called a main scan direction. The term “print” does not mean simply writing characters, but is used in a broad concept including images, symbols, and the like. A print unit 16 having a plurality of print heads is mounted on the carriage 12. The carriage 12 is reciprocally driven in the main scanning direction A along a Y-axis rail (not shown) by a head driving belt 22 stretched around belt driving rollers 18 and 20. The print medium 10 is driven in the sub-scanning direction by the drive roller 14 and the pinch roller 24 and slides on the platen 26. As the print medium 10, roll paper is usually used. The position of the carriage 12 is detected by a timing fence signal from a linear encoder including a sensor provided in the printing unit 16 and a linear scale 28 provided to face the sensor.

  In the above configuration, when the printing operation starts, the carriage 12 is reciprocated in the main scanning direction along the Y-axis rail under the control of the controller 4, and ink droplets are ejected from the nozzles of the print head mounted on the print unit 16. Discharge. When the printing unit 16 reaches the end in the main scanning direction, the controller 4 moves the printing medium 10 by a predetermined pitch in the sub-scanning direction and executes a printing operation in the next main scanning direction. The printer 2, the controller 4, and the computer 8 constitute a printing apparatus as a whole.

Next, the printing operation of the printing apparatus according to the present invention will be described with reference to FIG.
The computer 8 generates print data such as signature characters, figures and patterns to be printed out. The print data generated by the computer 8 is transferred to the controller 4 via the connector 6 (steps 1 and 2). The controller 4 receives print data from the computer 8 based on the program stored in the memory, and analyzes this print data (step 3). The CMYK conversion unit of the controller 4 converts the color of each pixel into an ink color that can be output by the printer 2. Next, the print data is converted into print data corresponding to the ink jet print head (step 4). The print head 30 is shown in FIG.

The print unit 16 is equipped with a plurality of print heads that eject inks of black (K), cyan (C), magenta (M), and yellow (Y). For convenience of explanation, one print head 30 among the plurality of print heads will be described. The configuration and operation of other print heads are the same as those of the print head 30 described below. In the present embodiment, the print head 30 has 256 nozzles 32 arranged in the sub-scanning direction. In the drawing, not all nozzles are shown for the convenience of drawing. Of course, various resolutions of the print head 30 can be employed, and the number of nozzles is not particularly limited to 256. Among the 256 nozzles, for example, in the case where printing is completed by four scans, if the sheet transport distance for one time is 60 nozzles, 240 nozzles corresponding to four times 60 nozzles and end portions 14 nozzles for data printing are assigned as nozzles used for printing, and printing is performed while using the 254 nozzles. Therefore, the remaining two nozzles are unused. The number of nozzles to be used, the transport distance, the number of scans, etc. can be changed as necessary.

4 to 7 disclose print data A, B, C, and D corresponding to the first four scans of the print head 30. As shown in FIG. 7, the printing of the image corresponding to the scanning region 34 for 60 nozzles is completed by the scanning of the print head 30 four times. The print data A corresponds to the size of the 74 nozzles of the print head in the sub-scanning direction of the data. When the print medium A is based on the conveyance direction of the print medium 10, the print data A is 14 at the rear end 34 (joint) of the main data portion. A waveform deformation data portion 36 for the nozzle is formed. The deformation data portion 36 is formed at all the rear end portions 34 (joints) of the print data A, B, C, and D.

FIG. 13 shows a method for generating the deformation data portion 36. The controller 6 stores a basic mask pattern 38 for creating a deformation data portion in a memory in advance. The basic mask pattern 38 is a waveform in the present embodiment, but as shown in FIG. 14, in addition to the waveform pattern (w), a triangular waveform pattern (t), a convex pattern (p), and a sawtooth pattern ( In addition, any irregular shape may be used as long as dots are not continuously arranged in the main scanning direction. The height, length, etc. of the waveform pattern may be arbitrarily set as necessary, and is not particularly limited to the drawing. In order to generate the deformation data portion 36 in the print data A, the data corresponding to the width of 14 nozzles adjacent to the rear end portion of the main data portion of the print data A is used as the changed portion data 40. 13 is expanded as shown in FIG. 13 so as to be connected to the waveform, and the portion 42 deviated from the basic mask pattern 38 of the changed portion data 40 is deleted, and as shown in FIG. 36 is generated.

In the print data A, the portion 42 deleted from the changed portion data 40 is normally discarded, but is stored in the memory as complement data A ′ of the print data A, and as described later, the fifth print operation is performed. 8 may be created as a supplement to the front end 44 of the print data E shown in FIG. The supplementary data A 'can be created by turning the basic mask pattern 38 upside down and in the same procedure. In the print data, the print data A, B, C, D including the front end portion 46 of the original image, that is, the print start end, is formed with a deformation data portion 36 at the rear end 34 in the transport direction, and the rear end of the original image. In the print data F, G, H, and I including the portion 48, that is, the print end end, the deformation data portion 36 is formed at the front end portion 44 in the transport direction, and the intermediate portion print data E not including the front and rear end portions of the original image. The deformation data portion 36 is formed at the front and rear end portions 44 and 34 in the transport direction. The joint side of each print data A, B, C, D, E, F, G, H, and I in which the deformation data portion 36 is formed has a waveform shape.

As described above, when the change processing of the front and rear ends of the print data is performed (step 5), the controller 4 next transfers the print data to the print head 30 (step 6), and the head unit. 16 (step 7), the printing medium 10 is conveyed (step 8), and the original image is printed on the printing medium 10. The operation of steps 7 and 8 will be described below with reference to FIGS.

  FIG. 4 shows the first scan by the print head 30. When the first scan by the 74 nozzle group of the print head 30 is completed, the print data A having a waveform at the joint side is printed on the print medium 10. Next, the print medium 10 is conveyed in the conveyance direction by 60 nozzles. Next, as shown in FIG. 5, the print head 30 moves in the main scanning direction, the second printing is performed, and the print data B having a length corresponding to 134 nozzles and having a waveform on the joint side is printed. . When the second printing by the print head 30 is completed, the print medium 10 is transported in the transport direction by 60 nozzles. In this way, as shown in FIGS. 6 and 7, the third printing and the fourth printing are performed.

When the fourth printing is completed, the printing of the first area 50 corresponding to the length of 60 nozzles of the printing medium 10 is completed. In this area 50, as indicated by A + B + C + D in FIG. 7, the scan is performed four times by the print data A, B, C, D, but the deletion portion 52 of the deformation data portion is based on the print data B, C, D. Only three printings are performed. Therefore, it is necessary to complement the deleted portion 52. Next, as shown in FIG. 8, the print medium 10 is conveyed by 60 nozzles in the conveyance direction, the print head 30 is moved in the main scanning direction, the fifth printing is performed, and an intermediate portion of the original image is printed. Print data E having a length of 254 nozzles is printed. At this time, the data deletion portion 52 of the waveform deforming portion of the first region 50 is complemented by the supplement data A ′ of the print data A described above. That is, the front end portion 44 (joint side) of the print data E is generated as the deformation data portion 36 as the complement data A ′ of the print data A.

As described above, the print data E having a length corresponding to 254 nozzles in the middle portion of one original image has complementary data that complements the deformation data portion of the adjacent region 50 at the front end portion 44. It is created as a deformation data part 36. The deformation data portion 36 of the print data E, that is, the waveform uneven shape on the joint side, fits closely with the waveform uneven shape on the joint side of the print data A. As a result, a line continuously extending in the main scanning direction is not formed at the joint (boundary) between the first area 50 and the second area 54 of the print medium 10 and appears as a streak in the head scanning direction. The phenomenon will not occur. The same applies to the joints of the other areas of the print medium 10. As shown in FIG. 9, the sixth printing is executed by the print data F having a length of 254 nozzles including the rear end portion 48 of the original image. The print data F is formed with a deformation data portion 36 that complements the deformation data portion 36 of the print data B at the front end thereof.

The waveform uneven shape on the joint side of the print data F fits exactly with the waveform uneven shape on the joint side of the print data B. As shown in FIG. 10, the seventh printing is executed by print data G having a length corresponding to 194 nozzles including the rear end portion 48 of the original image. The print data G is formed with a deformation data portion 36 that complements the deformation data portion 36 of the print data C at the front end thereof. The waveform uneven shape on the joint side of the print data G fits closely with the waveform uneven shape on the joint side of the print data C.

As shown in FIG. 11, the eighth printing is executed by the print data H having a length of 134 nozzles including the rear end portion 48 of the original image. In the print data H, a deformation data portion 36 that complements the deformation data portion 36 of the print data D is formed at the front end thereof. The corrugated uneven shape on the joint side of the print data H fits closely with the corrugated uneven shape on the joint side of the print data D. The ninth printing is executed by the print data H having a length of 74 nozzles including the rear end portion 48 (print end end) of the original image. In the print data I, a deformation data portion 36 that complements the deformation data portion 36 of the print data E is formed at the front end portion 44 thereof. The waveform uneven shape of the deformation data portion 36 on the joint side of the print data I fits closely with the waveform uneven shape on the joint side of the print data E, and the printing of the original image is completed. Note that this embodiment only explains the concept as an explanation. When data continues, a data portion corresponding to E is created (step 9), and finally data after F is created. Needless to say.
In the above embodiment, by providing the deformation data portion at the joint of the print data, the regularity (linearity) of the print is eliminated at the joint of the print data, thereby generating randomness, and preventing the occurrence of streaks in the uneven shape of the deformation data portion. The synergistic effect of the effect and the printing divided into multiple times prevents the streaking at the joint. In addition, it is also effective that printing from nozzles with poor printing accuracy located at the end when the nozzles from which ink is ejected are arranged do not continue in the horizontal direction.

  In this embodiment, the conveyance of the print medium is set to be performed at equal intervals by 60 nozzles as described above, but may be changed for each conveyance. This is for printing dots that are finer than the pitch of the nozzles. The regular interval is for 60 nozzles. For example, 59 nozzles are fed or 61 nozzles are fed. It may be changed for each conveyance. Also, regarding the relationship between printing medium (paper) transport and print head scanning, printing and paper feeding may occur when the print head moves forward, and printing and paper feeding may occur when the head moves backward. In some cases, the same line is printed by movement, and in the practice of the present invention, the scanning of the head and the conveyance of the paper are not particularly limited to the illustrated system.

The controller 4 determines whether or not the print data has been completed in step 9, and ends the printing if it determines affirmative. In the above embodiment, an inkjet printer having a head for ejecting ink using a piezo element is used. However, the present invention is not particularly limited to an inkjet printer using a piezo element. Can be used for printers in which the head unit moves in the horizontal direction, such as printers that discharge ink and other thermal printers.

1 is an overall schematic configuration diagram of a printing apparatus according to the present invention. It is a flowchart which shows operation | movement of this invention. It is explanatory drawing of a print head. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention. It is explanatory drawing of this invention.

Explanation of symbols

2 Printer 4 Controller 6 Connector 8 Computer 10 Print medium 12 Carriage 14 Drive roller 16 Print unit 18 Belt drive roller 20 Belt drive roller 22 Belt 24 Pinch roller 26 Platen 28 Linear scale 30 Print head 32 Nozzle 34 Rear end 36 Deformation data section 38 basic mask pattern 40 data 42 part 44 front end part 46 front end part 48 rear end part 50 area 52 deletion part 54 area

Claims (9)

Print data consisting of a large number of dot information is supplied to a print head in which a plurality of dot forming elements are arranged along the sub- scan direction, and the print medium is printed after scanning by relative movement of the print head with respect to the print medium in the main scan direction. A printing apparatus that prints an image on the surface of a print medium by moving relative to the head in a predetermined transport amount in the sub-scanning direction, and an end portion of print data supplied for each main scanning operation of the print head in the sub-scanning direction Forming a deformation data portion so that dots are not arranged continuously in the main scanning direction of the print head, and the sub-scanning direction of the print medium by a plurality of relative movements of the print head with respect to the print medium in the main scanning direction. Printing in each area corresponding to one transport width is completed, and the deformation of the print medium in the main scan of the first print head among the plurality of relative movements is performed. The first print data in which the data portion is formed is printed, and in the subsequent main scan, the print data extending over the previous print area and the next print area are sequentially printed in the previous print area. A printing apparatus characterized in that, in main scanning, printing of the remaining portion of the deformation data portion of the area where the first print data is printed is completed . The printing apparatus according to claim 1, wherein the dot array of the deformation data portion has a waveform shape. Of the print data supplied to the print head for each scan, the deformation data portion is formed at the rear end portion in the sub-scan direction of the print data including the leading end of the image, and the sub-scan of the print data in the intermediate portion of the image 2. The deformation data portion is formed at each of a front end portion and a rear end portion in a direction, and the deformation data portion is formed at a front end portion in a sub-scanning direction of print data including a rear end of an image. The printing device described. When printing of the image including the deformation data portion is completed, the deleted portion of the image of the deformation data portion is complemented by the deformation data portion of the print data supplied to the print head in the next scan of the print head. The printing apparatus according to claim 1, wherein A printing method for printing on a print medium by sequentially moving the print head in the main scanning direction and transporting the print medium in the sub-scanning direction with print data of n lines (n is a positive number) as a print unit, and connecting the print data A plurality of relative movements in the main scanning direction with respect to the print medium of the print head so that the line at the end of the joint side repeats an uneven shape so that a predetermined number of lines on the side are not continuously arranged in the main scanning direction. To complete printing in each area corresponding to one transport width of the print medium in the sub-scanning direction, and the first print head main scan of the plurality of relative movements is performed on the print medium. The first print data on which the unevenness is formed is printed, and in the subsequent main scan, the print data extending over the previous print area and the next print area are sequentially printed in the previous print area. And, in the subsequent main scanning, printing method characterized in that printing of the first part of the print data is left deformation data portion of the print area is to be completed. Wherein the joint side of the irregular shape of the print data, according to claim 5, characterized in that as the other of the print data joint side of the concavo-convex shape in contact with the indicia character data is printed in a fitted state with each other Printing method. The printing method according to claim 5 , wherein the uneven shape is a waveform. The concavo-convex shape is formed by deleting dot information on the joint side of the print data with a mask pattern, and the deleted dot information is complemented by the concavo-convex shape of the print data printed in the subsequent scan. The printing method according to claim 6 or 7 , wherein: The printing method according to claim 8, wherein the complementary data of the deleted dot information is created by inverting the mask pattern.

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