JP2018020478A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of printing information with the center position as a reference on the surface of an object to be conveyed.SOLUTION: A printer includes: a printer head 7; a printing section 12 which causes the printer head 7 to execute a printing operation; and a positional deviation detection section 17 which detects a positional deviation from a reference conveyance route of an object. The printing section 12 includes: a shift processing section 30 which generates shift line data shifting an allocation relation to an ink discharge nozzle from line data according to the positional deviation direction and positional deviation amount on the basis of positional deviation information from the position deviation detection section 17; a buffer section 32 which receives a detection signal of the object and sequentially outputs the shift line data at a prescribed discharge timing with a reception time of the detection signal as a reference; and a printing control section 33 which operates the corresponding ink discharge nozzle on the basis of the shift line data received from the buffer section 32.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a printing apparatus that performs printing on the surface of an object conveyed by a conveying apparatus, and in particular, even when the object being conveyed is displaced in a direction perpendicular to the conveying direction, The present invention relates to a printing apparatus that can perform printing appropriately.

  Conventionally, identification information such as a product name and a product number is displayed on a surface of a tablet such as a pharmaceutical product for the purpose of preventing erroneous taking and improving identification when a pharmacist prescribes a drug. As a method for displaying such identification information on a tablet, for example, a conventional printing method using a non-contact type automatic printing apparatus as disclosed in Japanese Patent Laid-Open No. 7-81050 (Patent Document 1) is known. Proposed.

  The automatic printing apparatus is provided with an aligning device for aligning objects such as tablets and capsules in a straight line, a supply conveyor for conveying the aligned objects, and an upper part of the supply conveyor. An ink jet printer having a detection device for detecting and a jet nozzle for discharging ink from a tip portion, and disposed immediately above the supply conveyor on the downstream side in the transport direction from the detection device; And a control unit that controls the operation.

  The control unit receives a detection signal when the detection device detects the object from the detection device, and at a predetermined discharge timing based on the reception time of the detection signal, that is, the object is detected. A signal for ejecting ink is transmitted to the ink jet printer at a timing when it reaches a position immediately below the ink jet printer after a predetermined time has elapsed since the detection by the apparatus.

  Thus, according to this automatic printing apparatus, first, a plurality of objects are aligned in a straight line by the aligning device, and the aligned objects are transported along a predetermined transport direction by the supply conveyor. When the object to be conveyed on the supply conveyor is detected by the detection device and the detection signal is input to the control unit, the control unit detects the discharge timing based on the reception of the detection signal, that is, the target. A signal for ejecting ink is transmitted to the ink jet printer at a timing when an object reaches a position directly below the ink jet printer. As a result, ink is ejected from the jet nozzle of the ink jet printer toward the object, and the identification information is printed on the object.

Japanese Patent Laid-Open No. 7-81050

  By the way, the printing position of the identification information printed on the surface of the object is normally set at the center position of the object. This is because if the identification information is printed at the center position of the object, the balance in appearance is good, and the viewer can feel aesthetic.

  Therefore, from this point of view, in the automatic printing apparatus, as shown in FIG. 11, the path followed by the center CP of the object T ′ conveyed by the supply conveyor 102 as viewed from above is the jet nozzle 101. When the path of the target T ′ needs to be a path (set path) passing through the center point P, the jet nozzle 101 causes the surface of each target T ′ to be Identification information can be printed on the basis of the center CP. In FIG. 11, an arrow H ′ indicates the transport direction.

  However, in the conventional automatic printing apparatus, in the design setting, the path followed by the center CP of the object T ′ conveyed by the supply conveyor 102 is a path passing through the center point P of the jet nozzle 101. In practice, the path followed by the center CP of the object T ′ is not necessarily a path (set path) passing through the center point P of the jet nozzle 101 due to the influence of various disturbances. The fact is not.

  That is, in the automatic printing apparatus, for example, when the object T ′ is transferred from the aligning apparatus to the supply conveyor, the automatic print apparatus may be affected by disturbances such as vibration generated in the alignment apparatus and vibration generated in the supply conveyor. The position of the object T ′ to be transferred to the position shifts with respect to the set position. Therefore, as shown in FIG. 12, the path followed by the center CP of the object T ′ is, for example, a jet nozzle. The position is shifted from the set route S passing through the center point P of 101 in a direction orthogonal to the transport direction H ′ by ΔX, for example.

  When the object T ′ is displaced in the direction perpendicular to the conveying direction H ′ from the setting path S in this way, as a result, as shown in FIG. 12, the object T ′ is printed on the surface of the object T ′ by the jet nozzle 101. Is displaced from the center CP of the object T ′.

  And if the identification information printed on the surface of the object is displaced from the center of the object in this way, this has been conventionally excluded as a defective product due to the above-mentioned problems in appearance, etc. When the number of defective products due to such printing problems increases, there arises a disadvantage that the yield is lowered due to the appearance problem, although there is no problem in the substantial quality of the object. Therefore, conventionally, there has been a demand for the development of a printing apparatus capable of printing the identification information with reference to the center of the object even when the position of the object to be conveyed is displaced from a predetermined set route.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a printing apparatus capable of printing information on the surface of an object to be conveyed with reference to the center position.

The present invention for solving the above problems is as follows.
A transport mechanism for transporting an object along a transport surface including a predetermined reference transport path;
An object detection mechanism for detecting the object conveyed by the conveyance mechanism;
A positional deviation detection mechanism for detecting a positional deviation of the object from the reference conveyance path in a direction orthogonal to the reference conveyance path in the conveyance plane;
A printing mechanism that prints on the surface of the object conveyed by the conveyance mechanism;
The positional deviation detection mechanism is
In the transport direction of the transport mechanism, disposed downstream of the object detection mechanism, receives a detection signal from the object detection mechanism, and at a predetermined imaging timing based on the reception time of the detection signal, An imaging camera that images the surface of the object detected by the object detection mechanism;
It comprises a displacement detection unit that processes an image captured by the imaging camera and detects the displacement of the object from the reference transport path,
The printing mechanism is
A printer head including a nozzle row in which a plurality of ink discharge nozzles are arranged at regular intervals, wherein the nozzle row is located downstream of the imaging camera in the transport direction with the reference transport path as a reference. A printer head that is arranged so as to be orthogonal to each other and forms a predetermined print area with reference to the reference transport path;
A printing unit that causes the printer head to perform a printing operation;
The printing unit
Print data for printing on the surface of the object, a print data storage unit for storing print data composed of line data for at least one line in the raster direction assigned to each ink ejection nozzle;
The misregistration information detected by the misregistration detection unit is received and processing is started. The print data is sequentially read from the print data storage unit for each line, and the read line data is read from the misregistration detection unit. A shift processing unit that generates and outputs shift line data in which the allocation relationship to the ink ejection nozzles is shifted according to the positional shift direction and the positional shift amount based on the received positional shift information;
The shift line data output from the shift processing unit is stored, the detection signal is received from the object detection mechanism, and the shift line data is sequentially output at a predetermined discharge timing with reference to the reception time of the detection signal. A buffer part to be
The present invention relates to a printing apparatus configured to receive shift line data output from the buffer unit and to operate a corresponding ink ejection nozzle based on the received shift line data.

  In the present invention, the reference transport path is a transport path set by design, and is a path that the center position of the object in plan view should follow, and is set along the transport direction in the transport surface. It is considered as a reference line.

  Further, the printer head is disposed so that a predetermined printing area is formed on the surface of the object conveyed on the reference conveyance path. The width of the print area in the direction orthogonal to the reference transport path (hereinafter referred to as the left-right direction) is set to be larger than the print width (hereinafter referred to as the actual print width) for actually printing on the object. Yes. Therefore, the width of the print area is more than the actual print width.

  In the printing apparatus according to the present invention, a plurality of objects are sequentially transported along the transport surface by the transport mechanism. The transport mechanism has a reference transport path set in the transport surface, and the object is transported so that its center position follows the reference transport path in setting.

  The object to be conveyed is detected by the object detection mechanism, and the detection signal is transmitted from the object detection mechanism to the imaging camera. The imaging camera has an imaging field of view for imaging the surface of the object to be conveyed, receives a detection signal from the object detection mechanism, and has a predetermined imaging timing based on the reception time of the detection signal, that is, The object is detected by the object detection mechanism, and the surface of the object is imaged at the timing when the object enters the imaging field after a predetermined time.

  When the object is imaged by the imaging camera, the image data is processed by the misalignment detection unit, and the misalignment of the object with respect to the reference transport path, that is, the reference transport with respect to the reference transport path. A displacement of the object in a direction orthogonal to the path is detected. Here, for example, the misregistration detection unit recognizes the center position of the target object by processing the captured image, and how much the recognized center position is in any of the left and right directions based on the reference transport path. Information (for example, how many pixels) the position is displaced (position displacement information) is calculated and transmitted to the shift processing unit.

  The shift processing unit receives the misregistration information from the misregistration detection unit and starts processing, sequentially reads the print data for each line from the print data storage unit, and detects the misregistration from the read line data. Based on the positional deviation information received from the unit, shift line data is generated by shifting the allocation relationship to the ink ejection nozzles in accordance with the positional deviation direction and the positional deviation amount, and stored in the buffer unit. Note that printing on the object is realized by combining a plurality of print lines along the left-right direction. The line data is data for forming one print line, and is a collection of dot data indicating ink ejection or non-ejection allocated to each ink ejection nozzle constituting the nozzle row. .

  For example, when the object is displaced by n pixels in the print data on the right side in the traveling direction, the shift processing unit is configured to detect the misalignment for the line data read from the print data storage unit. Therefore, in order to shift the assignment relationship to the ink ejection nozzles, processing for adding empty data for n pixels to the head portion of line data to be read and deleting data for n pixels from the end is performed. As a result, the allocation relationship of the print data to the ink ejection nozzles is shifted to the right by n pixels.

  On the other hand, when the object is misaligned by m pixels in the print data on the left side in the traveling direction, the shift processing unit is configured to detect the misalignment for the line data read from the print data storage unit. Therefore, in order to shift the assignment relationship to the ink ejection nozzles, data for m pixels is deleted from the beginning of the line data to be read, and empty data for m pixels is added to the end of the line data. As a result, the assignment relationship of the print data to the ink ejection nozzles is shifted to the left by m pixels.

  Subsequently, the shift line data is sequentially output to the print control unit by the buffer unit at a predetermined timing with reference to the time when the detection signal is received from the object detection mechanism. Then, based on the received shift line data, the corresponding ink ejection nozzle is operated by the print control unit.

  As described above, according to the printing apparatus of the present invention, based on the positional deviation information of the object detected by the positional deviation detection unit, ink is ejected by the shift processing unit according to the positional deviation direction and the positional deviation amount. Shift line data in which the allocation relationship to the nozzles is shifted is generated, and the ink discharge nozzle is operated by the print control unit based on the shift line data. As a result, even when the object is transported in a state in which the object is displaced in the direction orthogonal to the reference transport path with respect to the reference transport path, the allocation relationship of the print data to the ink discharge nozzles is the amount of the position shift. By operating the ink discharge nozzles based on the shifted shift line data, it is possible to correct the line data before the shift process so that the print position is appropriate. Therefore, it is possible to appropriately print the print information on the surface of the object with reference to the center position.

In the present invention, the printer head includes at least two nozzle rows arranged side by side along the reference transport path, and each nozzle row is an ink ejection nozzle constituting one nozzle row. Are arranged so that they are displaced in the direction perpendicular to the reference transport path with respect to the ink discharge nozzles constituting the other nozzle rows and located between the ink discharge nozzles constituting the other nozzle rows. Provided, and the ink ejection nozzles of each nozzle row are configured so as to be positioned at regular intervals in a direction orthogonal to the reference transport path as a whole,
The print data storage unit is configured to store print data composed of line data for at least one line in a raster direction assigned to each ink ejection nozzle constituting each nozzle row,
The shift processing unit, based on the positional deviation information received from the positional deviation detection unit, reads out the line data that has been read out according to the positional deviation direction and the positional deviation amount. It is configured to generate shift line data in which the allocation relationship for the entire nozzle is shifted,
The printing unit further receives shift line data generated by the shift processing unit, and the received shift line data corresponds to each nozzle row and is assigned to each ink ejection nozzle. A shift line data division processing unit that generates and outputs divided shift line data divided into data,
The buffer unit stores each divided shift line data corresponding to each nozzle row output from the shift line data division processing unit, receives a detection signal from the object detection mechanism, and receives the detection signal With reference to time, the shift shift line data corresponding to each nozzle row is sequentially output to the print control unit at a predetermined discharge timing corresponding to each nozzle row,
The print control unit receives the divided shift line data corresponding to each nozzle row from the buffer unit, and operates the ink discharge nozzles of the corresponding nozzle row based on the received divided shift line data. It may be configured.

  In the above aspect, the printer head includes at least two nozzle rows arranged in parallel along the reference transport path. That is, one nozzle row is disposed on the downstream side of conveyance with respect to the other nozzle rows. In each nozzle row, the ink discharge nozzles constituting the one nozzle row are displaced in the direction perpendicular to the reference transport path with respect to the ink discharge nozzles constituting the other nozzle row, and the other nozzles They are arranged so as to be positioned between the respective ink discharge nozzles constituting the row. The ink discharge nozzles of each nozzle row are located at regular intervals in the direction orthogonal to the reference transport path as a whole. Thus, the ink discharge nozzles are regularly arranged.

  According to the above aspect, the shift line data obtained by shifting the allocation relationship with respect to the entire ink discharge nozzles constituting each nozzle row is generated by the shift processing unit, and the shift line data is processed by the shift line data division processing unit. And divided shift line data divided into data assigned to the respective ink discharge nozzles. As described above, when the shift line data is generated, it is necessary to shift the allocation relationship with respect to the entire ink discharge nozzles, and thus processing speed is required. Therefore, this aspect is useful when a printing unit having a relatively high processing speed, that is, a central processing unit (CPU) is provided.

The present invention includes a transport mechanism that transports an object along a transport surface including a predetermined reference transport path;
An object detection mechanism for detecting the object conveyed by the conveyance mechanism;
A positional deviation detection mechanism for detecting a positional deviation of the object from the reference conveyance path in a direction orthogonal to the reference conveyance path in the conveyance plane;
A printing mechanism that prints on the surface of the object conveyed by the conveyance mechanism;
The positional deviation detection mechanism is
In the transport direction of the transport mechanism, disposed downstream of the object detection mechanism, receives a detection signal from the object detection mechanism, and at a predetermined imaging timing based on the reception time of the detection signal, An imaging camera that images the surface of the object detected by the object detection mechanism;
It comprises a displacement detection unit that processes an image captured by the imaging camera and detects the displacement of the object from the reference transport path,
The printing mechanism is
A printer head having at least two nozzle rows in which a plurality of ink discharge nozzles are arranged at regular intervals, with a predetermined interval therebetween, wherein the reference transport path is defined as a reference downstream of the imaging camera in the transport direction. A printer head that is arranged so that each nozzle row is orthogonal to the reference transport path, and forms a predetermined print area with reference to the reference transport path;
A printing unit that causes the printer head to perform a printing operation;
In each nozzle row of the printer head, the ink discharge nozzles constituting the one nozzle row are displaced in the direction perpendicular to the reference transport path with respect to the ink discharge nozzles constituting the other nozzle row, and Arranged so as to be positioned between the respective ink discharge nozzles constituting the other nozzle row, and configured such that the ink discharge nozzles of each nozzle row are located at regular intervals in a direction orthogonal to the reference transport path as a whole. Has been
The printing unit
Print data for printing on the surface of the object, the print data comprising line data for at least one line in the raster direction assigned to each ink ejection nozzle constituting each nozzle row A print data storage unit for storing;
Divided lines obtained by sequentially reading out the print data from the print data storage unit for each line, and dividing the read line data into line data corresponding to the nozzle rows and assigned to the ink ejection nozzles. A line data division processing unit for generating and outputting data;
A divided line data storage unit for storing divided line data output from the line data division processing unit;
The positional deviation information detected by the positional deviation detection unit is received to start processing, and the division line data corresponding to each nozzle row is sequentially read out from the division line data storage unit and received from the positional deviation detection unit. Based on the positional deviation information, divided shift line data is generated by changing at least one of the allocation relation to the nozzle row and the allocation relation to the ink ejection nozzles according to the positional deviation direction and the positional deviation amount. An output shift processing unit;
Each of the divided shift line data corresponding to each nozzle row output from the shift processing unit is stored, a detection signal is received from the object detection mechanism, and each time the detection signal is received as a reference, A buffer unit that sequentially outputs divided shift line data corresponding to each nozzle row at a predetermined discharge timing corresponding to the nozzle row;
Receiving a divided shift line data corresponding to each nozzle row from the buffer unit, and based on the received divided shift line data, a print control unit that operates the ink discharge nozzles of the corresponding nozzle row. Related to the printing apparatus.

  According to the printing apparatus of the present invention, based on the positional deviation information of the object detected by the positional deviation detection unit, the shift processing unit assigns at least the nozzle row according to the positional deviation direction and the positional deviation amount. Divided shift line data in which either the relationship or the allocation relationship to the ink ejection nozzle is changed is generated, and the ink ejection nozzle is operated by the print control unit based on the divided shift line data. As a result, even when the object is transported in a state where the object is displaced in the direction orthogonal to the reference transport path with respect to the reference transport path, the ink discharge nozzle is operated based on the divided shift line data. As a result, the line data before the shift process can be corrected so that the printing position is appropriate. Therefore, it is possible to appropriately print the print information on the surface of the object with reference to the center position.

  In the present invention, since the divided shift line data is generated after the divided line data is generated, the shift processing of the divided line data corresponding to the nozzle row is performed in parallel. It becomes possible to execute, and the processing speed can be improved.

  In the present invention, the printer head may be configured such that the same color ink is supplied to all the ink discharge nozzles constituting each nozzle row.

  According to the above aspect, by using the same color ink, the print color to be reproduced is appropriately reproduced on the object even when the allocation relationship of the line data to the ink ejection nozzle is shifted by the positional deviation as described above. can do.

  According to the printing apparatus according to the present invention, even when an object is transported in a state shifted in a direction perpendicular to the reference transport path, information is appropriately printed on the surface of the object based on the center position. It becomes possible to do.

It is a front view which shows the printing apparatus which concerns on one Embodiment of this invention. It is a block diagram which shows the structure of the printing part of the printing apparatus which concerns on 1st Embodiment. FIG. 2 is a plan view showing the arrangement of nozzle rows in the printer head of FIG. 1. FIG. 4 is an enlarged view of a portion of a region A1 in FIG. 3 and is a plan view showing an arrangement of ink discharge nozzles constituting each nozzle row. (A) is a figure which shows an example of the image of line data, (b) is a figure which shows an example of the image of shift line data. (A)-(d) is a figure which shows an example of the image of the division | segmentation shift line data corresponding to each nozzle row and allocated with respect to each ink discharge nozzle. (A) is a top view which shows the printing state on the target object when not performing a shift process, (b) is a top view which shows the printing state on the target object when a shift process is performed. It is a block diagram which shows the structure of the printing part of the printing apparatus which concerns on 2nd Embodiment. (A) is a figure which shows an example of the image of line data, (b)-(e) is a figure which shows an example of the image of the divided line data corresponding to each nozzle row. (A)-(d) is a figure which shows an example of the image of the division | segmentation shift line data corresponding to each nozzle row and allocated with respect to each ink discharge nozzle, (e) is (a)-(d). It is a figure which shows an example of the image of line data at the time of combining these division | segmentation shift line data temporarily. It is a top view which shows that the target object is conveyed as set in the conventional printing apparatus. It is a top view which shows that the target object is displaced and conveyed in the conventional printing apparatus.

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

(First embodiment)
As shown in FIG. 1, a printing apparatus 1 according to an embodiment of the present invention includes a supply mechanism 2 that supplies an object T in an aligned manner, and a predetermined reference transport path KH (see FIG. 7). (A), (b))) transport mechanism 3 that transports along a transport surface 3a (see FIGS. 7A, 7B), and rotational transport on which the object T is transferred from the transport mechanism 3 An object detection mechanism that has a mechanism 4, an object sensor 5, a rotary encoder 13 (see FIG. 2), and a timing generator 16 (see FIG. 2), and detects the position of the object T conveyed by the conveyance mechanism 3. 14 (see FIG. 2), the imaging camera 6 and the positional deviation detection unit 17 (see FIG. 2), and the reference transport path KH in the direction orthogonal to the reference transport path KH in the transport surface 3a is used as a reference. A displacement detection mechanism 19 (see FIG. 2) that detects the displacement of the object T. And a printing mechanism 15 (see FIG. 2) having a printer head 7 that performs printing on the surface of the object T conveyed by the conveyance mechanism 3 and a printing unit 12 that causes the printer head 7 to perform a printing operation. A recovery mechanism 11 for recovering the applied object T. The printing apparatus 1 includes an object sensor 8 having the same function as the object sensor 5, an imaging camera 9 having the same function as the imaging camera 6, and a print head 10 having the same function as the printer head 7. In the printing apparatus 1 of the present embodiment, printing is performed on the surface of the object T conveyed by the conveyance mechanism 3 by the printer head 7 and conveyed by the rotary conveyance mechanism 4. Printing is performed on the back surface of the object T by the printer head 10. The shape of the object T is circular in plan view. In the present invention, the method for printing on the back surface of the object T is the same as the method for printing on the surface of the object T. Therefore, only the method for printing on the surface of the object T will be described below.

  The supply mechanism 2 includes a hopper 20 into which a large number of objects T are charged, a vibration feeder 21 that imparts vibration to the object T discharged from the lower end portion of the hopper 20, and a terminal end of the vibration feeder 21. A chute 22 that slides down the target T discharged from the head, an alignment table 23 that rotates horizontally and discharges the target T supplied from the chute 22 in a line, and a disk-shaped member that rotates in a vertical plane. And a rotary transport body 24 that attracts and transports the object T discharged from the alignment table 23 to the outer peripheral surface of the disk-shaped member. The object T sucked and transported by the rotary transport body 24 is sequentially delivered to the transport mechanism 3.

  The transport mechanism 3 includes a pair of transport belts (not shown) for transporting the object T, four transport belt pulleys (not shown) around which the transport belt is wound, and one of the transport belts. A drive motor (not shown) for driving a pulley (not shown) is provided. The conveying belt is an endless circular belt arranged in parallel with a gap in the width direction. The rotary encoder 13 (see FIG. 2) is attached to the drive motor.

  The rotary transport mechanism 4 includes a rotary transport body 4a in which two transport belts (not shown) are wound on the outer peripheral surface. On the conveyor belt wound around the rotary conveyor 4a, a negative pressure suction force is applied by a negative pressure mechanism. In such a configuration, the object T is transported counterclockwise in FIG. 1 while being attracted to the transport belt by the suction force. Note that the object T is rotated and conveyed to the end point by the rotating and conveying mechanism 4 and then collected by the collecting mechanism 11.

  Next, the configuration of the printer head 7 will be described. As shown in FIG. 1, the printer head 7 is disposed downstream of the imaging camera 6 in the transport direction D1. As shown in FIG. 3, the printer head 7 includes nozzle rows La, Lb, Lc, and Ld in which a plurality of ink discharge nozzles are arranged at regular intervals. The printer head 7 is disposed so that the nozzle rows La, Lb, Lc, and Ld are orthogonal to the reference transport path KH with reference to the reference transport path KH (see FIGS. 7A and 7B). That is, the nozzle rows La, Lb, Lc, and Ld are arranged along a direction D2 (hereinafter referred to as the left-right direction) orthogonal to the transport direction D1. The nozzle rows La, Lc, Lb, and Ld are arranged in this order from the upstream side to the downstream side in the transport direction D1. Although details of the arrangement of the ink discharge nozzles will be described later, the width between the ink discharge nozzle Na1 located at the left end in the left-right direction D2 of the nozzle row La and the ink discharge nozzle Ndm located at the right end of the nozzle row Ld is The printable width RC (see FIGS. 7A and 7B). The printable width RC is set to be larger than the actual print width, which is the width that is actually printed on the object T.

  4, the nozzle row La includes a plurality of ink discharge nozzles Na, the nozzle row Lb includes a plurality of ink discharge nozzles Nb, the nozzle row Lc includes a plurality of ink discharge nozzles Nc, and the nozzle row Ld includes A plurality of ink discharge nozzles Nd are provided. As for the ink discharge nozzles Na, Na1, Na2, Na3, Na4,... Are arranged in order from the left side to the right side in the left-right direction D2, and Nam is arranged at the right end (FIG. 5A). , (B)). The same numbering is applied to the ink discharge nozzles Nb, Nc, and Nd. In the present embodiment, the same color ink (for example, black ink) is supplied from an ink tank (not shown) to all of the ink discharge nozzles Na, Nb, Nc, and Nd that form the nozzle rows La, Lb, Lc, and Ld. The

  In each nozzle row, the ink discharge nozzles constituting one nozzle row are displaced in the left-right direction D2 with respect to each ink discharge nozzle constituting the other nozzle row, and each ink constituting the other nozzle row It arrange | positions so that it may be located between discharge nozzles. In the example of FIG. 4, the ink discharge nozzles Na constituting the nozzle row La are arranged so as to be displaced in the left-right direction D2 with respect to the respective ink discharge nozzles Nc constituting the nozzle row Lc, and each ink discharge. It arrange | positions so that it may be located between the nozzles Nc. The same applies to the positional relationship between the ink ejection nozzle Na and the ink ejection nozzle Nb constituting the nozzle row Lb, and the positional relationship between the ink ejection nozzle Na and the ink ejection nozzle Nd constituting the nozzle row Ld. In addition, the ink ejection nozzles of each nozzle row are arranged so as to be positioned at regular intervals in the left-right direction D2 as a whole. In the example of FIG. 4, the ink ejection nozzles Na of the nozzle row La are disposed at regular intervals in the left-right direction D2 as a whole. The same applies to the ink discharge nozzles Nb, Nc, Nd.

  In such a configuration, in the left-right direction D2, each ink discharge nozzle Nb is arranged on the right side of each ink discharge nozzle Na, and each ink discharge nozzle Nc is arranged on the right side of each ink discharge nozzle Nb. Each ink discharge nozzle Nd is arranged on the right side of each ink discharge nozzle Nc by one. As described above, the ink discharge nozzles Na, Nb, Nc, and Nd are arranged in a lattice shape. In FIG. 4, in order to facilitate understanding of the positional relationship among the ink discharge nozzles Na, Nb, Nc, and Nd, any one of the ink discharge nozzles Na1, Nb1, Nc1, and Nd1 extends along the transport direction D1. Four two-dot chain lines passing through one are supplementarily given.

  As illustrated in FIG. 2, the printing unit 12 according to the first embodiment includes a print data storage unit 18, a shift processing unit 30, a shift line data division processing unit 31, a buffer unit 32, and a print control unit 33. These components are functionally realized when a central processing unit (CPU) provided in the printing apparatus 1 executes a predetermined program stored in a memory.

  The timing generation unit 16 calculates the position of the target T from the pulse signal output from the rotary encoder 13 and the detection signal of the target T output from the target sensor 5, and captures the imaging timing with respect to the imaging camera 6. Is transmitted to the buffer unit 32, and the buffer unit 32 transmits a print signal for causing the printer head 7 to perform printing. The function of the buffer unit 32 will be described later.

  Next, a description will be given of a method for correcting the printing position when the object T is transported in a state shifted in the left-right direction D2 with reference to the reference transport path KH while explaining the configuration of the control system of the printing apparatus 1. explain.

  As shown in FIG. 1, the imaging camera 6 is disposed on the downstream side of the object sensor 5 in the transport direction D1. As shown in FIG. 2, the imaging camera 6 receives the imaging signal from the timing generation unit 16, and at a predetermined imaging timing with reference to the time when the imaging signal is received, that is, the target T is the target sensor 5. The surface of the object T is imaged at the timing when the image enters the imaging field after a predetermined time.

  The misalignment detection unit 17 receives the image data from the imaging camera 6, processes the image, and uses the reference transport path KH (see FIGS. 7A and 7B) as a reference for the object T in the left-right direction D2. Detect misalignment. For example, the position shift detection unit 17 detects the center position of the target T, and information (hereinafter, how many pixels) the position shift of the detected center position in which direction of the left-right direction D2 (for example, how many pixels) is performed , Referred to as misregistration information) and transmitted to the shift processing unit 30.

  The print data storage unit 18 is data for printing print information on the object T, and is configured by collecting a plurality of lines of raster direction line data assigned to the respective ink ejection nozzles constituting each nozzle row. Print data to be stored. As described above, the line data is data for forming one print line (one line), and is a collection of dot data assigned to each ink discharge nozzle constituting the nozzle row. The line data is composed of, for example, 320 dot data.

  The line data will be described using an example. As shown in FIG. 5A, the line data is data for forming one line of print information (for example, print information such as alphabet as shown in FIGS. 7A and 7B). In FIG. 5A, black circles are dot data representing instructions to eject ink, and white circles are dot data representing instructions not to eject ink.

  As shown in FIG. 5A, the line data is composed of a plurality of dot data assigned to each ink ejection nozzle of each nozzle row. For example, the data D1 is assigned to the ink ejection nozzle Na1 located at the left end of the nozzle row La before the shift process described later. The data D2 is assigned to the ink discharge nozzle Nb1 located at the left end of the nozzle row Lb before the shift process described later. The data D3 is assigned to the ink discharge nozzle Nc1 located at the left end of the nozzle row Lc before the shift process described later. The data D4 is assigned to the ink discharge nozzle Nd1 located at the left end of the nozzle row Ld before the shift process described later. In FIGS. 5 and 6, the symbols of the ink ejection nozzles to which the data are assigned are shown below the black circle and the white circle representing each data. In the line data, a data group that has been subjected to the same numbering for each nozzle row is arranged in order from the left to the right in FIG. Data D1, D2, D3, D4 shall belong to data group G1, data D5, D6, D7, D8 shall belong to data group G2, and so on. Data D1, D2, D3, D4 belonging to the data group G1 in FIG. 5A and data Dn-3, Dn-2, Dn-1, Dn belonging to the data group Gi are from the printable width RC in FIG. This corresponds to a margin width obtained by subtracting the actual print width. In the present embodiment, in order to facilitate understanding, the data corresponding to the margin width is set to four on the left side and the right side, but in reality, it is set to five or more (for example, about 40 to 50). Note that the data corresponding to the margin width is data representing an instruction not to eject ink.

  Returning to FIG. 2, the shift processing unit 30 receives the positional deviation information from the positional deviation detection unit 17 and sequentially reads out the print data for each line from the print data storage unit 18, and reads the positional deviation information from the read line data. Shift line data is generated by shifting the allocation relationship with respect to all the ink ejection nozzles constituting each nozzle row in accordance with the position shift direction and the position shift amount, and is transmitted to the shift line data division processing unit 31. This will be described in detail below.

  Here, the position shift information by the position shift detector 17 indicates that the center position CP of the object T in FIG. 7A is shifted to the right in the left-right direction D2 by the position shift amount GA with reference to the reference transport path KH. The shift line data generated in the case where it is indicated that this is the case will be described. For example, the positional deviation amount GA is assumed to be two pixels.

  Although details will be described later, when the shift processing by the shift processing unit 30 is executed, even when the target T is transported out of position as shown in FIG. Printing information (for example, character information “TIPS”) can be printed at a desired upper position (that is, a position based on the center position CP of the object T). On the other hand, when the shift processing by the shift processing unit 30 is not executed, as shown in FIG. 7A, when the object T is transported while being shifted to the right side, The print information is printed with the position shifted to the left from the desired position. Actually, the positional deviation amount GA in FIG. 7A corresponds to about 20 pixels, but for the sake of easy explanation, it is set to 2 pixels.

  In such a case, the shift processing unit 30 reads out the line data to be read out as shown in FIG. 5B in order to shift the assignment relationship to the ink ejection nozzles by the amount of positional deviation GA. Shift line data is generated by adding empty data De1 and De2 for two pixels to the head of. As a result, the allocation relationship for each ink ejection nozzle is shifted by two pixels to the right in the raster direction.

  In the example of FIG. 5B, the data discharge D1 assigned to the ink discharge nozzle Na1 before the shift process is positioned at the right of the ink discharge nozzle Na1 by two after the shift process. Assigned to nozzle Nc1. Further, the data D2 assigned to the ink discharge nozzle Nb1 before the shift process is assigned to the ink discharge nozzle Nd1 that is two positions to the right of the ink discharge nozzle Nb1 after the shift process. Similarly, other data is shifted in allocation, and the data Dn-5 allocated to the ink ejection nozzle Ncm-1 that is two times left of the ink ejection nozzle Nam before the shift processing is converted into data after the shift processing. Are assigned to the ink discharge nozzles Nam. Further, the data Dn-4 assigned to the ink discharge nozzle Ndm-1 that is two left of the ink discharge nozzles Nbm before the shift process is assigned to the ink discharge nozzles Nbm after the shift process. Further, the data Dn-3 assigned to the ink discharge nozzles Nam that are two positions to the left of the ink discharge nozzles Ncm before the shift process are assigned to the ink discharge nozzles Ncm after the shift process. Further, the data Dn-2 assigned to the ink discharge nozzles Nbm that are two left of the ink discharge nozzles Ndm before the shift process is assigned to the ink discharge nozzles Ndm after the shift process. In addition, the shift processing unit 30 generates data corresponding to two pixels from the end of the line data before the shift process, that is, the data Dn− assigned to the ink ejection nozzles Ncm and Ndm before the shift process. 1 and Dn are deleted.

  On the other hand, empty data De1 and De2 are assigned to the ink discharge nozzles Na1 and Nb1. Therefore, ink is not ejected by these ink ejection nozzles Na1 and Nb1. In the above description, the example in which the assignment relationship is shifted to the right side when the center position CP of the target object T is displaced to the right side in the left-right direction D2 with respect to the reference transport path KH has been described. The same applies to the method of shifting the assignment relationship to the left side when the center position CP of T is shifted to the left side with respect to the reference transport path KH.

  Next, the shift line data division processing unit 31 in FIG. 2 corresponds to the received shift line data (that is, the shift line data in FIG. 5B) for each nozzle row and for each ink ejection nozzle. Divided shift line data divided for allocation is generated. Then, the shift line data division processing unit 31 transmits the generated divided shift line data to the buffer unit 32.

  FIG. 6A shows an image of divided shift line data assigned to each ink discharge nozzle Na in the nozzle row La, and FIG. 6B shows the divided shift line data assigned to each ink discharge nozzle Nb in the nozzle row Lb. FIG. 4C shows an image of divided shift line data assigned to each ink discharge nozzle Nc in the nozzle row Lc, and FIG. 4D shows a division assigned to each ink discharge nozzle Nd in the nozzle row Ld. An image of shift line data is shown. As shown in FIG. 6A, the divided shift line data assigned to each ink discharge nozzle Na is an aggregate of data De1 to Dn-5 assigned to the ink discharge nozzles Na1 to Nam in FIG. 5B. is there. Similarly, as shown in FIG. 6B, the divided shift line data assigned to each ink discharge nozzle Nb is the data De2 to Dn-4 assigned to the ink discharge nozzles Nb1 to Nbm in FIG. It is an aggregate. As shown in FIG. 6C, the divided shift line data assigned to each ink discharge nozzle Nc is an aggregate of data D1 to Dn-3 assigned to the ink discharge nozzles Nc1 to Ncm in FIG. is there. As shown in FIG. 6D, the divided shift line data assigned to each ink discharge nozzle Nd is an aggregate of data D2 to Dn-2 assigned to the ink discharge nozzles Nd1 to Ndm in FIG. is there.

  Subsequently, the buffer unit 32 in FIG. 2 stores each divided shift line data output from the shift line data division processing unit 31. The buffer unit 32 receives the above-described print signal from the timing generation unit 16, and the division corresponding to each nozzle row at a predetermined discharge timing corresponding to each nozzle row with reference to the time when the print signal is received. The shift line data is sequentially output to the print control unit 33. In this case, the buffer unit 32 outputs the divided shift line data corresponding to the nozzle row La for one line with reference to the time when the print signal is received from the timing generation unit 16, and then at a predetermined timing after the output. Divided shift line data corresponding to the nozzle row Lc is output. Similarly, the buffer unit 32 outputs the divided shift line data corresponding to the nozzle row Lb at a predetermined timing after outputting the divided shift line data corresponding to the nozzle row Lc, and then the nozzle row at a predetermined timing after the output. Divided shift line data corresponding to Ld is output. The buffer unit 32 executes such processing for each line.

  Next, the print control unit 33 receives the divided shift line data corresponding to each nozzle row from the buffer unit 32, and operates each ink ejection nozzle of each corresponding nozzle row based on the received divided shift line data. As a result, as shown in FIG. 7B, when the object T is transported in a state shifted in the left-right direction D2 with respect to the reference transport path KH, the printing position on the object T is on the right side. Shifted. As a result, the positional deviation of the print information as shown in FIG. 7A does not occur. Note that if the data corresponding to an ink discharge nozzle in a certain nozzle row is black circle data (that is, data indicating an ink discharge instruction; see FIG. 6), the print control unit 33 performs ink from the ink discharge nozzle. In contrast, if the data is white circle data (that is, data indicating an ink non-ejection instruction, see FIG. 6), the ink ejection nozzle is controlled so that the ink ejection nozzle is opened. Control is performed to close the ink discharge nozzle so that ink is not discharged from the nozzle.

  As described above, in the printing apparatus 1 according to the present embodiment, based on the positional deviation information of the target T detected by the positional deviation detection unit 17, the shift processing unit according to the positional deviation direction and the positional deviation amount. 30 generates shift line data in which the assignment relationship to the ink discharge nozzles is shifted, and the print control unit 33 operates the ink discharge nozzles based on the shift line data. As a result, even when the object T is transported in a position shifted in the left-right direction D2 with respect to the reference transport path KH, the allocation relationship of the print data to the ink discharge nozzles is shifted by the position shift. By operating the ink discharge nozzles based on the shift line data, the line data before the shift process can be corrected so that the printing position is appropriate. Thereby, it becomes possible to appropriately print the print information on the surface of the object T with reference to the center position CP.

  Further, in the present embodiment, shift line data obtained by shifting the allocation relationship with respect to the entire ink discharge nozzles constituting each nozzle row is generated by the shift processing unit 30, and the shift line data is processed by the shift line data division processing unit 31. Divided shift line data divided into data corresponding to each nozzle row and assigned to each ink ejection nozzle is generated. As described above, when the shift line data is generated, it is necessary to shift the allocation relationship with respect to the entire ink discharge nozzles, and thus processing speed is required. Therefore, this aspect is useful when the printing unit 12 having a relatively high processing speed, that is, a central processing unit (CPU) is provided.

  In the present embodiment, the same color ink (for example, black ink) is supplied to all of the ink ejection nozzles Na, Nb, Nc, and Nd that form the nozzle rows La, Lb, Lc, and Ld. By using the same color ink as described above, the print color to be reproduced can be reproduced on the object T even if the assignment relationship with respect to the ink ejection nozzles in the line data is shifted as described above.

(Second Embodiment)
Hereinafter, a printing apparatus according to the second embodiment will be described. As shown in FIG. 8, the configuration of the printing unit 12a of the second embodiment is different from the configuration of the printing unit 12 of the first embodiment (see FIG. 2) in place of the shift line data division processing unit 31 of FIG. 2 is provided with a line data division processing unit 34, a shift processing unit 30a is provided instead of the shift processing unit 30 in FIG. 2, and a divided line data storage unit 35 is further provided. The printing unit 12a is functionally realized by a central processing unit (CPU) executing a predetermined program stored in a memory. Since the other configuration in FIG. 8 is the same as the configuration in FIG. 2, only the line data division processing unit 34, the divided line data storage unit 35, and the shift processing unit 30a will be described below.

  The line data division processing unit 34 sequentially reads the print data from the print data storage unit 18 for each line, and divides the read line data into data corresponding to each nozzle row and assigned to each ink ejection nozzle. Generate split line data. In this case, the line data division processing unit 34 converts the line data in FIG. 9A (the same as the line data in FIG. 5A) into divided line data corresponding to the nozzle row La (FIG. 9B). Reference), division line data corresponding to the nozzle row Lb (see FIG. 9C), division line data corresponding to the nozzle row Lc (see FIG. 9D), and division lines corresponding to the nozzle row Ld. The data is divided into data (see FIG. 9E).

  As shown in FIG. 9B, the divided line data corresponding to each ink discharge nozzle Na is an aggregate of data D1 to Dn-3 assigned to the ink discharge nozzles Na1 to Nam in FIG. 9A. . Similarly, as shown in FIG. 9C, the divided line data corresponding to each ink discharge nozzle Nb is a set of data D2 to Dn-2 assigned to the ink discharge nozzles Nb1 to Nbm in FIG. 9A. Is the body. As shown in FIG. 9D, the division line data corresponding to each ink ejection nozzle Nc is an aggregate of data D3 to Dn-1 assigned to the ink ejection nozzles Nc1 to Ncm in FIG. 9A. . As shown in FIG. 9E, the divided line data corresponding to each ink discharge nozzle Nd is an aggregate of data D4 to Dn assigned to the ink discharge nozzles Nd1 to Ndm in FIG. 9A. Such divided line data is composed of, for example, 80 dot data. The line data division processing unit 34 transmits the divided line data to the divided line data storage unit 35. The divided line data storage unit 35 stores the received divided line data.

  The shift processing unit 30a receives the above-described misalignment information from the misalignment detection unit 17, and sequentially reads out the divided line data for each line from the divided line data storage unit 35, and the misalignment direction and the misregistration amount of the misalignment information. In response to this, divided shift line data in which at least one of the allocation relationship to the nozzle row and the allocation relationship to the ink ejection nozzle is changed is generated from the division line data, and is transmitted to the buffer unit 32. This will be described in detail below. In the following description, unless otherwise specified, as in FIG. 7A, the positional deviation information by the positional deviation detection unit 17 indicates that the center position CP of the object T is left and right with reference to the reference conveyance path KH. The premise is that the position is shifted to the right of the direction D2 by the amount of displacement GA (two pixels), and the same reference numerals as in the first embodiment have the same meaning.

  Here, as described above with reference to FIG. 4, in the printing apparatus 1, each ink discharge nozzle Nb is disposed on the right side of each ink discharge nozzle Na in the left-right direction D <b> 2, and is equivalent to one of each ink discharge nozzle Nb. Each ink discharge nozzle Nc is disposed on the right side, and each ink discharge nozzle Nd is disposed on the right side of each ink discharge nozzle Nc. In the present embodiment, by using such a positional relationship between the ink ejection nozzles Na, Nb, Nc, and Nd, it is possible to print by shifting the print information by, for example, two pixels to the right. This will be described in detail below.

  The shift processing unit 30a, for the read divided line data, according to the misalignment amount GA (for two pixels), the divided line data corresponding to each ink ejection nozzle Na in the nozzle row La (see FIG. As shown in FIG. 10C, the ink discharge nozzles 9 (b) divided line data) are located on the right side of the ink discharge nozzle Na by two (two right sides in the left-right direction D2, the same applies hereinafter). Assigned to the nozzle row Lc composed of Nc. Therefore, in this case, only the assignment relationship to the nozzle row is changed. In this way, by changing the assignment relationship to the nozzle row, the print information that is scheduled to be formed by the ink discharge nozzles Na is changed to the ink positioned on the right side of the two ink discharge nozzles Na after the shift process. It can be formed by the discharge nozzle Nc. This makes it possible to shift the printing on the object T to the right for the ink discharge nozzle Nc.

  Further, the shift processing unit 30a corresponds to the amount of misalignment GA (2 pixels), and the divided line data (in FIG. 9C) corresponding to each ink ejection nozzle Nb of the nozzle row Lb before the shift processing. As shown in FIG. 10D, the divided line data) is assigned to the nozzle row Ld composed of the ink discharge nozzles Nd that are two right from the ink discharge nozzle Nb. Therefore, also in this case, only the assignment relationship to the nozzle row is changed. In this way, by changing the assignment relationship to the nozzle row, the print information that is scheduled to be formed by the ink discharge nozzles Nb is changed to the ink positioned on the right side by two of the ink discharge nozzles Nb after the shift process. It can be formed by the discharge nozzle Nd. This makes it possible to shift the printing on the object T to the right for the ink discharge nozzle Nd.

  Further, the shift processing unit 30a, according to the positional deviation amount GA (2 pixels), corresponds to the divided line data (in FIG. 9D) corresponding to each ink ejection nozzle Nc of the nozzle row Lc before the shift processing. As shown in FIG. 10A, the divided line data) is assigned to the nozzle row La composed of the ink discharge nozzles Na that are two right sides of the ink discharge nozzles Nc. However, in this case, it is necessary to assign the divided line data to the ink discharge nozzles Na that are two positions to the right of the ink discharge nozzles Nc. That is, in the example of FIG. Since it is necessary to assign the data D3 of Nc1 to the ink discharge nozzle Na2, the shift processing unit 30a assigns the empty data De1 to the ink discharge nozzle Na1 in FIG. 10A and deletes the data Dn-1. In this process, both the assignment relationship to the nozzle row and the assignment relationship to the ink ejection nozzle are changed.

  As described above, the data assigned to any of the ink ejection nozzles corresponding to one data group (for example, the data group G1 in FIG. 9A) before the shift process is skipped by the shift process. When assigning to any of the ink discharge nozzles corresponding to another data group (for example, data group G2 in FIG. 9A), at least one (in this example, One (one) empty data is added, and at least one (in this example, one) data is deleted based on the end. For example, when the data assigned to any ink ejection nozzle corresponding to the data group G1 is assigned to any ink ejection nozzle corresponding to the data group G3 by the shift process, the divided shift line data In FIG. 2, two empty data are added and two data are deleted based on the end.

  Further, the shift processing unit 30a, according to the positional deviation amount GA (2 pixels), corresponds to the divided line data (FIG. 9E) corresponding to each ink ejection nozzle Nd of the nozzle row Ld before the shift processing. As shown in FIG. 10B, the divided line data) is assigned to the nozzle row Lb composed of the ink discharge nozzles Nb that are two right from the ink discharge nozzle Nd. However, in this case, it is necessary to assign the divided line data to the ink discharge nozzles Nb that are two positions to the right of the ink discharge nozzles Nd. In other words, in the example of FIG. Since it is necessary to assign the data D4 of Nd1 to the ink discharge nozzle Nb2, the shift processing unit 30a assigns the empty data De2 to the ink discharge nozzle Nb1 of FIG. 10B and deletes the data Dn as described above. Therefore, also in this process, both the assignment relationship to the nozzle row and the assignment relationship to the ink ejection nozzle are changed. FIG. 10 (e) shows an image of line data when the divided shift line data of FIGS. 10 (a) to 10 (d) are temporarily combined, and the line data is the shift line data of FIG. 5 (b). It turns out that it is the same. In the above description, the example in which the assignment relationship is changed when the center position CP of the object T is displaced to the right in the left-right direction D2 with respect to the reference transport path KH has been described. The same applies to the method of changing the assignment relationship when the position CP is displaced to the left with respect to the reference transport path KH.

  Other examples will also be described. In the same manner as described above, when the misregistration amount GA is, for example, one pixel, the division line data (division of FIG. 9B) corresponding to each ink ejection nozzle Na of the nozzle row La before the shift processing is performed. Line data) is assigned to a nozzle row Lb composed of ink ejection nozzles Nb located one right side of the ink ejection nozzle Na (one right side in the left-right direction D2, hereinafter the same). The divided line data (the divided line data in FIG. 9C) corresponding to each ink discharge nozzle Nb of the nozzle row Lb before the shift processing is the ink discharge nozzle located on the right side by one of the ink discharge nozzles Nb. Assigned to the nozzle row Lc composed of Nc. The division line data (division line data in FIG. 9D) corresponding to each ink ejection nozzle Nc of the nozzle row Lc before the shift processing is the ink ejection nozzle located one right of the ink ejection nozzle Nc. Assigned to the nozzle row Ld composed of Nd. The divided line data (divided line data in FIG. 9E) corresponding to each ink discharge nozzle Nd of the nozzle row Ld before the shift processing is the ink discharge nozzle located on the right side by one of the ink discharge nozzles Nd. In addition to being assigned to the nozzle row La composed of Na, one empty data is added to the divided shift line data, and the last data is deleted.

  Further, when the positional deviation amount GA is, for example, 3 pixels, the divided line data (the divided line data in FIG. 9B) corresponding to each ink ejection nozzle Na in the nozzle row La before the shift process is Are assigned to the nozzle row Ld composed of the ink discharge nozzles Nd located on the right side of the three ink discharge nozzles Na (three right sides in the left-right direction D2; hereinafter the same). The divided line data (divided line data in FIG. 9C) corresponding to each ink discharge nozzle Nb of the nozzle row Lb before the shift processing is the ink discharge nozzles located on the right side by three of the ink discharge nozzles Nb. In addition to being assigned to the nozzle row La composed of Na, one empty data is added to the divided shift line data, and the last data is deleted. The divided line data (divided line data in FIG. 9D) corresponding to each ink discharge nozzle Nc of the nozzle row Lc before the shift processing is the ink discharge nozzle located on the right side by three of the ink discharge nozzles Nc. In addition to being assigned to the nozzle row Lb composed of Nb, one empty data is added to the divided shift line data, and the last data is deleted. The divided line data (divided line data in FIG. 9E) corresponding to each ink discharge nozzle Nd of the nozzle row Ld before the shift processing is the ink discharge nozzles located on the right side by three of the ink discharge nozzles Nd. In addition to being assigned to the nozzle row Lc composed of Nc, one empty data is added to the divided shift line data, and the last data is deleted.

  Further, when the positional deviation amount GA is, for example, 4 pixels, it is not necessary to change the allocation relationship to the nozzle row, and empty data is respectively included in each divided shift line data of FIGS. 10 (a) to 10 (d). By assigning and deleting the last data, only the assignment relationship to the ink discharge nozzles needs to be changed. That is, if the divided line data corresponding to the nozzle row La shown in FIG. 9B is described as an example, the data D9 assigned to, for example, the ink ejection nozzle Na3 before the shift process is converted into the ink ejection by the shift process. The four nozzles Na3 are allocated to the ink discharge nozzle Na4 located on the right side. As a result, the print information that was scheduled to be formed by the ink discharge nozzle Na3 can be formed by the ink discharge nozzle Na4 that is four times the ink discharge nozzle Na3 after the shift process. This makes it possible to shift the printing on the object T to the right for the ink discharge nozzle Na. The other data in the divided line data corresponding to the nozzle row La and the respective data in the divided line data corresponding to the nozzle rows Lb, Lc, and Ld are similarly assigned by the shift process.

  As described above, the positional deviation amount GA (for example, for four pixels) is n times (n is a natural number, that is, 1, 2, 3,...) Times the total number of nozzle rows (four in this embodiment). In such a case, in each divided shift line data, the n empty data is added and the n data is deleted with reference to the end, so that only the assignment relationship to the ink ejection nozzle is changed. On the other hand, when the positional deviation amount GA is not n times the total number of nozzle rows (1 pixel, 2 pixels, 3 pixels, 5 pixels, 6 pixels, etc.), the allocation relationship to the nozzle rows And the assignment relationship to the ink discharge nozzles are both changed.

  As described above, according to the present embodiment, based on the positional deviation information of the target T detected by the positional deviation detection unit 17, at least the nozzle row is generated by the shift processing unit 30a according to the positional deviation direction and the positional deviation amount. Divided shift line data is generated by changing either the assignment relationship to the ink and the assignment relationship to the ink ejection nozzles, and the ink ejection nozzles are operated by the print control unit 33 based on the division shift line data. As a result, even when the object T is transported in a position shifted in the left-right direction D2 with reference to the reference transport path KH, the ink ejection nozzle is operated based on the divided shift line data, The line data before the shift process can be corrected so that the printing position is appropriate. Thereby, it becomes possible to appropriately print the print information on the surface of the object T with reference to the center position CP.

  Further, in the present invention, since divided line data is generated and divided shift line data is generated by shifting the divided line data, each shift process of the divided line data corresponding to the nozzle row is performed in parallel. It becomes possible to execute, and the processing speed can be improved.

  Although the printing apparatus 1 according to the present embodiment has been described above, the aspect of the printing apparatus 1 is not limited to this, and the following modifications can be applied.

  In the said embodiment, although it was set as the structure which performs printing with respect to both the surface of the target object T, and a back surface, it is not limited to this, It prints with respect to either the front surface of the target object T, or a back surface. It is good also as a structure which performs.

  In the above embodiment, the printer head 7 is provided with four nozzle rows La, Lb, Lc, and Ld. However, the present invention is not limited to this, and at least one nozzle row may be provided. .

  Moreover, in the said embodiment, although the target object T whose shape in planar view was circular was used, it is not limited to this, You may use the target T which has shapes other than the said circle. In this case, the position shift detection unit 17 may be configured to process the captured image to recognize the position of the center of gravity of the object T and calculate position shift information regarding the recognized position of the center of gravity.

  Furthermore, in the above-described embodiment, the ink discharge nozzles constituting one nozzle row are arranged so as to be positioned between the respective ink discharge nozzles constituting the other nozzle row. However, the present invention is not limited to this. Instead, the ink discharge nozzles constituting one nozzle row and the ink discharge nozzles constituting another nozzle row may be arranged so as to be positioned on one imaginary line along the transport direction D1.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 3 Conveyance mechanism 3a Conveyance surface 5 Object sensor 6 Imaging camera 7 Printer head 12 Printing part 12a Printing part 14 Object detection mechanism 15 Printing mechanism 17 Misalignment detection part 18 Print data memory | storage part 19 Misregistration detection mechanism 30 Shift Processing unit 30a Shift processing unit 31 Shift line data division processing unit 32 Buffer unit 33 Print control unit 34 Line data division processing unit 35 Divided line data storage unit D1 Conveyance direction D2 Left and right direction KH Reference conveyance path RC Printable width (predetermined printing) region)
T object

Claims (4)

A transport mechanism for transporting an object along a transport surface including a predetermined reference transport path;
An object detection mechanism for detecting the object conveyed by the conveyance mechanism;
A positional deviation detection mechanism for detecting a positional deviation of the object from the reference conveyance path in a direction orthogonal to the reference conveyance path in the conveyance plane;
A printing mechanism that prints on the surface of the object conveyed by the conveyance mechanism;
The positional deviation detection mechanism is
In the transport direction of the transport mechanism, disposed downstream of the object detection mechanism, receives a detection signal from the object detection mechanism, and at a predetermined imaging timing based on the reception time of the detection signal, An imaging camera that images the surface of the object detected by the object detection mechanism;
It comprises a displacement detection unit that processes an image captured by the imaging camera and detects the displacement of the object from the reference transport path,
The printing mechanism is
A printer head including a nozzle row in which a plurality of ink discharge nozzles are arranged at regular intervals, wherein the nozzle row is located downstream of the imaging camera in the transport direction with the reference transport path as a reference. A printer head that is arranged so as to be orthogonal to each other and forms a predetermined print area with reference to the reference transport path;
A printing unit that causes the printer head to perform a printing operation;
The printing unit
Print data for printing on the surface of the object, a print data storage unit for storing print data composed of line data for at least one line in the raster direction assigned to each ink ejection nozzle;
The misregistration information detected by the misregistration detection unit is received and processing is started. The print data is sequentially read from the print data storage unit for each line, and the read line data is read from the misregistration detection unit. A shift processing unit that generates and outputs shift line data in which the allocation relationship to the ink ejection nozzles is shifted according to the positional shift direction and the positional shift amount based on the received positional shift information;
The shift line data output from the shift processing unit is stored, the detection signal is received from the object detection mechanism, and the shift line data is sequentially output at a predetermined discharge timing with reference to the reception time of the detection signal. A buffer part to be
A printing apparatus comprising: a print control unit that receives shift line data output from the buffer unit and operates a corresponding ink discharge nozzle based on the received shift line data. The printer head includes at least two nozzle rows arranged side by side along the reference transport path, and each nozzle row includes an ink ejection nozzle that constitutes one nozzle row and the other nozzle row. Each ink discharge nozzle is disposed so as to be displaced in a direction orthogonal to the reference transport path and located between each ink discharge nozzle constituting the other nozzle row, The ink discharge nozzles are configured to be positioned at regular intervals in a direction orthogonal to the reference transport path as a whole,
The print data storage unit is configured to store print data composed of line data for at least one line in a raster direction assigned to each ink ejection nozzle constituting each nozzle row,
The shift processing unit, based on the positional deviation information received from the positional deviation detection unit, reads out the line data that has been read out according to the positional deviation direction and the positional deviation amount. It is configured to generate shift line data in which the allocation relationship for the entire nozzle is shifted,
The printing unit further receives shift line data generated by the shift processing unit, and the received shift line data corresponds to each nozzle row and is assigned to each ink ejection nozzle. A shift line data division processing unit that generates and outputs divided shift line data divided into data,
The buffer unit stores each divided shift line data corresponding to each nozzle row output from the shift line data division processing unit, receives a detection signal from the object detection mechanism, and receives the detection signal With reference to time, the shift shift line data corresponding to each nozzle row is sequentially output to the print control unit at a predetermined discharge timing corresponding to each nozzle row,
The print control unit receives the divided shift line data corresponding to each nozzle row from the buffer unit, and operates the ink discharge nozzles of the corresponding nozzle row based on the received divided shift line data. The printing apparatus according to claim 1, wherein the printing apparatus is configured. A transport mechanism for transporting an object along a transport surface including a predetermined reference transport path;
An object detection mechanism for detecting the object conveyed by the conveyance mechanism;
A positional deviation detection mechanism for detecting a positional deviation of the object from the reference conveyance path in a direction orthogonal to the reference conveyance path in the conveyance plane;
A printing mechanism that prints on the surface of the object conveyed by the conveyance mechanism;
The positional deviation detection mechanism is
In the transport direction of the transport mechanism, disposed downstream of the object detection mechanism, receives a detection signal from the object detection mechanism, and at a predetermined imaging timing based on the reception time of the detection signal, An imaging camera that images the surface of the object detected by the object detection mechanism;
It comprises a displacement detection unit that processes an image captured by the imaging camera and detects the displacement of the object from the reference transport path,
The printing mechanism is
A printer head having at least two nozzle rows in which a plurality of ink discharge nozzles are arranged at regular intervals, with a predetermined interval therebetween, wherein the reference transport path is defined as a reference downstream of the imaging camera in the transport direction. A printer head that is arranged so that each nozzle row is orthogonal to the reference transport path, and forms a predetermined print area with reference to the reference transport path;
A printing unit that causes the printer head to perform a printing operation;
In each nozzle row of the printer head, the ink discharge nozzles constituting the one nozzle row are displaced in the direction perpendicular to the reference transport path with respect to the ink discharge nozzles constituting the other nozzle row, and Arranged so as to be positioned between the respective ink discharge nozzles constituting the other nozzle row, and configured such that the ink discharge nozzles of each nozzle row are located at regular intervals in a direction orthogonal to the reference transport path as a whole. Has been
The printing unit
Print data for printing on the surface of the object, the print data comprising line data for at least one line in the raster direction assigned to each ink ejection nozzle constituting each nozzle row A print data storage unit for storing;
Divided lines obtained by sequentially reading out the print data from the print data storage unit for each line, and dividing the read line data into line data corresponding to the nozzle rows and assigned to the ink ejection nozzles. A line data division processing unit for generating and outputting data;
A divided line data storage unit for storing divided line data output from the line data division processing unit;
The positional deviation information detected by the positional deviation detection unit is received to start processing, and the division line data corresponding to each nozzle row is sequentially read out from the division line data storage unit and received from the positional deviation detection unit. Based on the positional deviation information, divided shift line data is generated by changing at least one of the allocation relation to the nozzle row and the allocation relation to the ink ejection nozzles according to the positional deviation direction and the positional deviation amount. An output shift processing unit;
Each of the divided shift line data corresponding to each nozzle row output from the shift processing unit is stored, a detection signal is received from the object detection mechanism, and each time the detection signal is received as a reference, A buffer unit that sequentially outputs divided shift line data corresponding to each nozzle row at a predetermined discharge timing corresponding to the nozzle row;
Receiving a divided shift line data corresponding to each nozzle row from the buffer unit, and based on the received divided shift line data, a print control unit that operates the ink discharge nozzles of the corresponding nozzle row. A printing apparatus. 4. The printing apparatus according to claim 2, wherein the printer head supplies ink of the same color to all the ink discharge nozzles constituting each nozzle row.

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