Printing device, method for controlling printing device, and non-temporary storage medium storing printing device control program

Abstract

To provide a printing device, a method for controlling a printing device, and a non-temporary storage medium storing a printing device control program that contribute to increasing probability that a printing surface of a medium converges within a focal range where a contact image sensor is in focus even when deviation or the like occurs in a thickness of the medium and a perpendicular direction of the medium relative to the platen when a user places the medium on the platen.SOLUTION: A printing device 1 includes: a platen 5; print heads 3, 4 configured to perform printing on a printing surface N of a medium M placed on the platen 5; and a plurality of contact image sensors configured to read the printing surface N of the medium M and having mutually different focal ranges where an image comes into focus in a direction perpendicular to the platen 5.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a printing device, a printing device control method, and a non-transitory storage medium storing a printing device control program. [Background technology]

[0002] The printing device in Patent Document 1 includes nozzles that eject ink, a platen, an optical sensor that can detect color, and a control unit. The control unit prints a determination pattern on a medium placed on the platen and determines whether or not there is an ink ejection defect in the nozzle based on the detection result of the determination pattern obtained by the optical sensor. Examples of optical sensors that can be used include a contact image sensor and a CCD. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 8,636,331 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, the focal depth of a contact image sensor is relatively shallow, i.e., the focal range over which the contact image sensor is in focus is relatively narrow. Therefore, when a contact image sensor is used as an optical sensor, the printed surface of the medium may not fall within the focal range over which the contact image sensor is in focus due to factors such as the thickness of the medium and vertical displacement of the medium relative to the platen when the user places the medium on the platen, and the optical sensor may not be able to accurately read the printed surface of the medium.

[0005] The object of the present invention is to provide a printing device, a printing device control method, and a non-transitory storage medium storing a printing device control program that contributes to increasing the likelihood that the printing surface of a medium will fall within the focal range of a contact image sensor, even when there is a difference in the thickness of the medium or when the medium is misaligned in a direction perpendicular to the platen when the user places the medium on the platen. [Means for solving the problem]

[0006] A printing device according to a first aspect of the present invention includes a platen, a print head configured to print on a printing surface of a medium placed on the platen, and a plurality of contact image sensors configured to read the printing surface of the medium, the contact image sensors having different focal ranges in focus in a direction perpendicular to the platen. Compared to conventional printing devices, the printing device includes a plurality of contact image sensors having different focal ranges in focus in a direction perpendicular to the platen, which contributes to increasing the likelihood that the printing surface of the medium will fall within the focal range in focus of the contact image sensors even when there is a difference in the thickness of the medium or when the medium is misaligned in a direction perpendicular to the platen when the user places the medium on the platen.

[0007] A second aspect of the present invention provides a printing device control method executed by a processor of a printing device. The printing device control method includes a reading step of reading the print surface of a medium placed on a platen using multiple contact image sensors provided in the printing device, each of which has a different focal range in which the image is focused in a direction perpendicular to the platen, to obtain multiple read data corresponding to the multiple contact image sensors; and a defect detection step of detecting defects based on target read data among the multiple read data that is focused on the medium. Compared to conventional printing device control methods, the reading step of the printing device control method contributes to increasing the likelihood of obtaining read data in which the print surface of the medium falls within the focal range, even when there is a difference in the thickness of the medium or when the medium is misaligned in a direction perpendicular to the platen when the user places the medium on the platen. The defect detection step of the printing device control method contributes to appropriately detecting defects based on target read data that is focused on the medium among the multiple read data corresponding to the multiple contact image sensors.

[0008] A non-transitory storage medium according to a third aspect of the present invention is a non-transitory storage medium that stores a printing device control program executed by a processor of a printing device, the printing device control program including instructions for executing a reading process that reads the printing surface of a medium placed on a platen with each of a plurality of contact image sensors provided in the printing device, the contact image sensors having different focal ranges in focus in a direction perpendicular to the platen, and obtains a plurality of read data corresponding to the plurality of contact image sensors, and a defect detection process that detects defects based on target read data of the plurality of read data that is focused on the medium. Compared to conventional printing device control methods, the reading process of the printing device control program stored on the non-transitory storage medium contributes to increasing the likelihood of obtaining read data in which the printing surface of the medium falls within the focal range, even when there is a difference in medium thickness or when the medium is misaligned in a direction perpendicular to the platen when the user places the medium on the platen. The defect detection process of the printing device control program stored in the non-temporary storage medium contributes to appropriately detecting defects based on target read data that is focused on the medium among multiple read data corresponding to multiple contact image sensors. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a printing device 1. [Figure 2] (A) is a schematic left side view of the printing device 1 when the platen 5 is in the attachment / detachment position P and the CIS unit 8 is in the pre-printing reading position V, (B) is a schematic left side view of the printing device 1 when the platen 5 is in the reading position Q and the CIS unit 8 is in the pre-printing reading position V, (C) is a schematic left side view of the printing device 1 when the platen 5 is in the folding position R and the CIS unit 8 is in the post-printing reading position W, and (D) is a schematic left side view of the printing device 1 when the platen 5 is in the printing position U and the CIS unit 8 is in the post-printing reading position W. [Figure 3](A) is a schematic left side view of the CIS unit 8, platen 5, and medium M when the CIS unit 8 is in the pre-print reading position V, and (B) is a schematic left side view of the CIS unit 8, platen 5, and medium M when the CIS unit 8 is in the post-print reading position W. [Figure 4] 2 is a block diagram showing the electrical configuration of the printing device 1. FIG. [Figure 5] FIG. 2 is an explanatory diagram of a table T stored in the memory 44. [Figure 6] 10 is a flowchart of a main process. DETAILED DESCRIPTION OF THE INVENTION

[0010] A printing device 1 according to one embodiment of the present invention will be described with reference to the drawings. The top, bottom, bottom left, top right, bottom right, and top left in Fig. 1 respectively correspond to the top, bottom, front, back, right, and left of the printing device 1. The left-right and front-back directions of the printing device 1 are also referred to as the main scanning direction and sub-scanning direction, respectively.

[0011] 1 to 3, the schematic configuration of the printing apparatus 1 will be described. As shown in FIG.

[0012] The housing 2 has a front wall 21, a right wall 22, a rear wall 23, a left wall 24, a top wall 25, and a bottom wall 26, and is a rectangular parallelepiped that is long in the left-right direction. An opening 27 that penetrates the housing 2 in the front-to-rear direction is formed in the front wall 21 of the housing 2. The opening 27 extends from the front wall 21 to the rear wall 23 of the housing 2, penetrating the housing 2 in the front-to-rear direction. A display 28 and an input unit 29 are provided on the front wall 21 of the housing 2 to the right of the opening 27. The display 28 is a liquid crystal display that displays images. The input unit 29 is a plurality of buttons provided below the display 28 on the front wall 21 of the housing 2. A user of the printing device 1 inputs various information to the printing device 1 by operating the input unit 29.

[0013] The platen moving unit 6 has a rectangular parallelepiped shape that is long in the front-rear direction when viewed from the side, and is inserted through the opening 27. The front end of the platen moving unit 6 is located forward of the front wall 21 of the housing 2, and the rear end of the platen moving unit 6 is located rearward of the rear wall 23 of the housing 2. As shown in FIGS. 2(A) to 2(D), the platen moving unit 6 includes a rail 61, a platen support member 62, a sub-scanning motor 63, and a transmission mechanism 64. The rail 61 extends in the front-rear direction. The platen support member 62 is located above the platen moving unit 6 and is supported by the rail 61. The sub-scanning motor 63 is, for example, a pulse motor that can rotate forward and backward. The transmission mechanism 64 is, for example, a drive belt connected to the sub-scanning motor 63 and the platen support member 62, and uses the power of the sub-scanning motor 63 to move the platen support member 62 along the rail 61 in the sub-scanning direction, i.e., the front-to-back direction, between the attachment / detachment position P shown in Figure 2(A) and the folding position R shown in Figure 2(C).

[0014] As shown in FIG. 2A, the attachment / detachment position P is the position of the platen 5 when the medium M is removed from or attached to the platen 5. The attachment / detachment position P is a standby position of the platen 5 before printing by the printing device 1 starts or after printing is completed. The attachment / detachment position P shown in FIG. 2A is the front end of the movement range of the platen 5, and is also the start and end points of the transport path of the platen 5. The turn-back position R shown in FIG. 2C is the rear end of the movement range of the platen 5, and is also a midpoint in the transport path of the platen 5.

[0015] 1, the platen 5 has a rectangular plate shape in a plan view that extends horizontally. The platen 5 is attached to a platen support member 62 from above, and is supported by the platen support member 62 with its vertical position relative to the platen support member 62 adjusted. A medium M is placed on the upper surface of the platen 5. The medium M is, for example, a fabric such as a T-shirt. When the platen support member 62 moves in the front-to-rear direction, the platen 5 and the medium M placed on the platen 5 also move in the front-to-rear direction.

[0016] As shown in Figures 2(A) to 2(D), the printing device 1 includes, inside a housing 2, a main scanning drive unit 7, print heads 3 and 4, a contact image sensor unit (hereinafter referred to as the "CIS unit") 8, and a sensor movement unit 9.

[0017] The main scanning drive unit 7 includes a rail 71, a guide shaft 72, a carriage 73, a main scanning motor 74, and a transmission mechanism 75. The rail 71 extends in the left-right direction of the printing device 1. The guide shaft 72 is provided in front of the rail 71 and extends in the left-right direction. The carriage 73 is located between the rail 71 and the guide shaft 72 in the front-rear direction and is supported by the rail 71 and the guide shaft 72. The main scanning motor 74 is provided on the right side of the right end of the guide shaft 72. The transmission mechanism 75 is, for example, a drive belt connected to the main scanning motor 74 and the carriage 73, and moves the carriage 73 in the main scanning direction, i.e., the left-right direction, along the rail 71 and the guide shaft 72 by being driven by the main scanning motor 74.

[0018] Print heads 3 and 4 are inkjet heads mounted on carriage 73. Print head 3 is located at the rear of carriage 73 and ejects white ink downward. Print head 4 is aligned in front of head 31 and ejects color inks downward. White ink is used in printing to represent the white part of an image or as a base for color inks. Color inks are ejected directly onto the printing surface N of medium M or on a base of white ink and are used to print color images. Color inks include, for example, four colors of ink: black, cyan, yellow, and magenta. Print heads 3 and 4 move left and right together with carriage 73. In this embodiment, printing surface N is the top surface of medium M.

[0019] The CIS unit 8 includes multiple contact image sensors (hereinafter referred to as CIS). As shown in FIGS. 3A and 3B, the multiple CISs include CISs 81 to 84. Each of the CISs 81 to 84 is configured to read the printing surface N of the medium M, and has a different focal range in the direction perpendicular to the platen 5, i.e., the up-down direction. The CISs 81 to 84 are arranged in this order from front to back and include modules 77 to 80 and contact glasses 87 to 90. Each of the modules 77 to 80 has the same configuration and includes a light source and a light receiving element. The light source irradiates light onto the medium M. The light source is, for example, multiple LEDs arranged in a line along the sub-scanning direction. The light receiving element receives reflected light from the medium M. The light receiving element is, for example, multiple CMOS sensors arranged in a line. The medium M is transported while in contact with or slightly spaced from, i.e., close to, the glass surfaces 91 to 94, which are the undersides of the contact glasses 87 to 90. The light source irradiates light onto the medium M through the contact glasses 87 to 90, and the light receiving element receives the light reflected from the medium M and converts the image information into read data.

[0020] In this embodiment, the contact glasses 87 to 90 have different thicknesses. The contact glass 87 of CIS 81 has a thickness D1 mm, and its focal range is a range R1 below a glass surface 91 of the contact glass 87. The contact glass 88 of CIS 82 has a thickness D2 mm, and its focal range is a range R2 below a glass surface 92 of the contact glass 88. The contact glass 89 of CIS 83 has a thickness D3 mm, and its focal range is a range R3 below a glass surface 93 of the contact glass 89. The contact glass 90 of CIS 84 has a thickness D4 mm, and its focal range is a range R4 below a glass surface 94 of the contact glass 90. The contact glasses 87 to 90 can be made of glass or a transparent resin such as acrylic. The glass surfaces 91 to 94 are located at the same vertical position and are parallel to the upper surface of the platen 5. Therefore, the distances from the modules 77 to 80 to the glass surfaces 91 to 94 of the corresponding contact glasses 87 to 90 differ from one another depending on the thickness of the contact glasses 87 to 90, and the focal ranges in the vertical direction differ from one another. Each of the ranges R1 to R4 is set taking into consideration the range of thicknesses of the medium M that can be placed on the platen 5. The ranges R1 and R2 may partially overlap. Similarly, the ranges R2 and R3 may partially overlap. The ranges R3 and R4 may partially overlap.

[0021] The sensor moving unit 9 is configured to move the CIS unit 8, which includes CISs 81 to 84, in a proximity direction E3, which moves the CIS unit 8 closer to the platen 5, and in a separation direction E4, which is opposite to the proximity direction E3. In this embodiment, the proximity direction E3 is downward, which is the same as the ink ejection direction of the print heads 3 and 4, and the separation direction E4 is upward. The sensor moving unit 9 includes a drive motor 96 and a transmission mechanism 97. The transmission mechanism 97 is, for example, a pinion and rack connected to the drive motor 96. Driven by the drive motor 96, the transmission mechanism 97 moves the CIS unit 8 in the proximity direction E3 and the separation direction E4 between a pre-printing reading position V shown in FIG. 3A and a post-printing reading position W shown in FIG. 3B. The pre-printing reading position V is located further in the proximity direction E3 than the post-printing reading position W.

[0022] The electrical configuration of the printing device 1 will be described with reference to FIG. 4. The printing device 1 includes a CPU 41, a ROM 42, a RAM 43, and a memory 44. The CPU 41 controls the printing device 1 and is electrically connected to the ROM 42, RAM 43, and memory 44 via a signal line 39. The ROM 42 stores information required by the CPU 41 when it executes a printing device control program (described below) and various other programs for controlling the operation of the printing device 1. The ROM 42 stores the position of the platen 5 in the sub-scanning direction, corresponding to the rotation angle of the sub-scanning motor 63. The RAM 43 temporarily stores various data used in the programs. The memory 44 is nonvolatile and stores print data for printing. The print data may be generated by the printing device 1 and stored in the memory 44, or may be obtained from an external device and stored in the memory 44. The external device is a device other than the printing device 1, such as a personal computer (PC) or a smartphone.

[0023] The CPU 41 is electrically connected to the main scanning motor 74, sub-scanning motor 63, drive motor 96, print heads 3 and 4, display 28, input unit 29, and CISs 81 to 84 via signal lines 39. The main scanning motor 74, sub-scanning motor 63, drive motor 96, and print heads 3 and 4 are each driven under the control of the CPU 41.

[0024] The input unit 29 outputs various information to the CPU 41. By operating the input unit 29, the user of the printing device 1 can input information such as the platen size and print instructions for starting printing by the printing device 1 to the printing device 1. The CISs 81 to 84 read images in response to instructions from the CPU 41 or instructions from the user, and output the read data to the CPU 41.

[0025] According to the above configuration, the printing device 1 moves the platen 5 in the sub-scanning direction, thereby transporting the medium M on the platen 5 in the front-to-back direction relative to the print heads 3 and 4. The printing device 1 moves the carriage 73 in the main scanning direction, thereby moving the print heads 3 and 4 left-to-right relative to the medium M on the platen 5. The printing device 1 ejects ink from the print heads 3 and 4 onto the medium M on the platen 5. In this way, the printing device 1 prints an image on the medium M on the platen 5.

[0026] Table T stored in memory 44 will be described with reference to FIG. 5. As shown in FIG. 5, Table T stores identification information, contact glass thickness, focal range, and printable position in association with each other. "Identification information" is information for identifying CISs 81 to 84. For simplicity, the identification information in this embodiment is represented by the reference symbol assigned to each CIS. "Contact glass thickness" and "focal range" store the contact glass thickness and focal range of the CIS represented by the identification information, respectively. The focal range is represented, for example, by the distance from the glass surface of the contact glass. "Printable position" stores whether the platen 5 is determined to be in the printable position when the read data obtained by the corresponding CIS reading the print surface N of the medium M before printing is read data that is focused on the print surface N. The printable position is a position where the platen 5 is supported in an appropriate vertical position by the platen support member 62 and where the vertical distance between the print heads 3 and 4 and the print surface N of the medium M is within a predetermined range where printing can be performed appropriately. In the main processing described below, the CPU 41 of this embodiment identifies a CIS from CISes 81 to 84 that is in focus on the printing surface N of the medium M. In the printable position column, if it is determined that the CIS associated with the identification information is in focus, a cross indicates that the platen 5 is not installed in a printable position and the platen 5 is in a faulty installation position, and a circle indicates that the platen 5 is installed in a printable position and the platen 5 is not in a faulty installation position. As shown in FIG. 5, the value in the printable position column for each of CISes 81 to 83 is a circle, and the value in the printable position column for CIS 84 is a cross. As shown in Fig. 3(A), when the CIS unit 8 is in the pre-printing reading position V, the range R4 of the CIS 84 is located below the upper surface of the platen 5. Therefore, if the printing device 1 of this embodiment determines that the CIS 84 is an in-focus CIS, it determines that the installation position of the platen 5 is incorrect based on the value of the printable position of the table T. On the other hand, as shown in Fig. 3(B), when the CIS unit 8 is in the post-printing reading position W, the range R4 of the CIS 84 is located above the upper surface of the platen 5, and it may be determined that the CIS is an in-focus CIS.

[0027] The main processing will be described with reference to FIG. 6. When the printing device 1 is powered on and a print instruction is input by the user, the CPU 41 executes the main processing by reading and running the printing device control program from the ROM 42. The printing device control program includes instructions for the CPU 41 to execute the following processes. The main processing includes detecting improper installation position of the platen 5, detecting defects on the printing surface N of the medium M placed on the platen 5, transporting the platen 5, controlling printing, and detecting print defects. Various parameters required to execute the main processing are stored in the memory 44. Various data obtained during the main processing is appropriately stored in the RAM 43. Hereinafter, steps are abbreviated as S. At the start of the main processing, the platen 5 is in the attachment / detachment position P shown in FIG. 2A, and the medium M has been placed. At the start of the main processing, the CIS unit 8, which includes CISs 81 to 84, is positioned at the pre-printing reading position V. As a specific example, a case in which the medium M is placed on the platen 5 as shown in FIGS. 1 to 3B will be described.

[0028] As shown in FIG. 6, the CPU 41 drives the sub-scanning motor 63 to start a process of transporting the platen 5 in the feed-in direction E1 (S1). The process of S1 moves the platen 5 backward from the loading / unloading position P shown in FIG. 2(A). The CPU 41 starts a feed-in reading process (S2) in which each of the CISs 81 to 84 reads the printed surface N of the medium M placed on the platen 5 as it moves in the feed-in direction E1, and acquires multiple read data corresponding to the CISs 81 to 84. As shown in FIGS. 2(B) and 3(A), each of the CISs 81 to 84 sequentially reads the printed surface N of the medium M passing below the CIS unit 8. After completing the process of reading the printed surface N of the medium M, the CPU 41 acquires multiple read data corresponding to each of the CISs 81 to 84 (S3).

[0029] The CPU 41 determines whether there is a CIS that is in focus based on the multiple pieces of scanned data acquired in S3 (S4). The CPU 41 may, for example, calculate an evaluation value indicating the degree of focus for each of the multiple pieces of scanned data, and determine that the image is in focus if the calculated evaluation value meets a predetermined standard. The CPU 41 may also calculate the evaluation value using the contrast value of the scanned data. Since each of the ranges R1 to R4 is set taking into account the range of thicknesses of the medium M that can be placed on the platen 5, when the medium M is properly placed on the platen 5, the printing surface N of the medium M will fall within the focus range of one of the CISs 81 to 83.

[0030] If there is no CIS that is in focus (S4: NO), the CPU 41 notifies the user that the platen 5 is improperly positioned (S6). In this embodiment, the CPU 41 displays a message on the display 28 in S6 notifying the user that the platen 5 is improperly positioned. The CPU 41 then stops printing (S18), drives the sub-scanning motor 63, and positions the platen 5 at the attachment / detachment position P, after which the main processing ends.

[0031] 3A, the print surface N falls within the range R2 of the CIS 82, and it is determined that the read data of the CIS 82 is in focus (S4: YES). In this case, the CPU 41 performs a storage control process to store in the memory 44 the identification information of the CIS 82 corresponding to the target read data, which is the read data that is in focus on the medium M, among the CISs 81 to 84 (S5).

[0032] The CPU 41 refers to table T shown in FIG. 5 and determines whether the value of the printable position of the CIS 82 corresponding to the identification information stored in S5 is a circle (S7). In this embodiment, the CPU 41 detects the platen 5 as being improperly positioned in S4 and S7 when it determines that the platen 5 is not supported in the appropriate vertical position by the platen support member 62—that is, when it determines that the vertical distance between the print heads 3 and 4 and the printing surface N of the medium M is outside the predetermined range for proper printing due to improper installation of the platen 5. If the value of the printable position is a cross (S7: NO), the CPU 41 notifies the user that the platen 5 is improperly positioned (S9). In this embodiment, the CPU 41 displays a message on the display 28 in S9 informing the user that the platen 5 is improperly positioned. The CPU 41 then stops printing (S18), drives the sub-scanning motor 63, and positions the platen 5 at the mounting / dismounting position P, and then ends the main process.

[0033] Since the printable position value of the CIS 82 is a circle (S7: YES), the CPU 41 performs a defect detection process (S8, S10) to detect defects based on the image analysis results of the target scan data, which is focused on the medium M, among the multiple scan data acquired in S3. The types and number of defects detected in S8 and S10 may be set as appropriate. In this embodiment, the CPU 41 performs image analysis of the target scan data to detect defects on the print surface N of the medium M placed on the platen 5 from four perspectives: whether there are wrinkles, whether there is off-centering, whether there is an incorrect placement orientation, and whether there is lint or other debris. The CPU 41 determines whether there is off-centering, for example, by detecting the neck area of ​​the medium M and determining whether the lateral position of the detected neck area is misaligned compared to a reference. The CPU 41 determines whether there is an incorrect placement orientation, for example, based on the direction of the fabric grain of the medium M. The CPU 41 determines whether there are wrinkles or lint or other debris based on whether unexpected patterns such as lines are detected.

[0034] If an abnormality is detected on the printing surface N of the medium M based on the image analysis result of S8 (S10: NO), the CPU 41 notifies the user that the printing surface is defective (S17). In this embodiment, the CPU 41 displays a message on the display 28 in S17 notifying the user of the printing surface being defective. In S17, the CPU 41 may also notify the user of the specific details of the detected defect. The CPU 41 stops printing (S18), drives the sub-scanning motor 63, and positions the platen 5 at the attachment / detachment position P, after which the main processing ends.

[0035] If it is determined based on the image analysis result of S8 that the printed surface N of the medium M is normal (S10: YES), the CPU 41 performs a sensor movement process after the loading reading process of S2 and S3 by driving the drive motor 96 to move the CIS unit 8, which includes the CISs 81 to 84, a predetermined distance in the separation direction E4 perpendicular to the platen 5 and away from the platen 5 (S11). The predetermined distance is set taking into consideration the focal ranges of the CISs 81 to 84 and the distance between the medium M and the glass surface of the contact glass. By the process of S11, the CIS unit 8 is moved from the pre-printing reading position V shown in FIGS. 2(A), 2(B), and 3(A) to the post-printing reading position W shown in FIGS. 2(C), 2(D), and 3(B). The post-printing reading position W is a position moved a predetermined distance in the separation direction E4 from the pre-printing reading position V.

[0036] After moving the platen 5 to the turning-back position R shown in Figure 2(C), the CPU 41 reverses the rotation direction of the sub-scanning motor 63 and starts movement in the unloading direction E2 (S12). When the platen 5 is at the turning-back position R, the print target area of ​​the printing surface N of the medium M is in the carry-in direction E1, that is, behind the print heads 3 and 4. When the CPU 41 moves the platen 5 from the turning-back position R in the unloading direction E2 and reaches a position where the print target area of ​​the printing surface N is below the print heads 3 and 4, the CPU 41 starts a printing process in which ink is ejected from the print heads 3 and 4 in accordance with the print data included in the print command to print an image on the printing surface N of the medium M placed on the platen 5 (S13).

[0037] The CPU 41 determines a CIS to be used in the post-printing reading process, which will be described later, from among the CISs 81 to 84, based on the identification information stored in memory 44 in S5, the predetermined amount in S11, and the focal ranges of each of the CISs 81 to 84 stored in table T (S14). In a specific example, as shown in FIG. 3B, the CPU 41 determines the CIS 84 in which the printed surface N of the medium M falls within range R4 when the CIS unit 8 is at the post-printing reading position W. If the CIS 84 is determined to be the CIS to be used in the pre-printing reading process, the installation position of the platen 5 is determined to be incorrect in the process of S7. However, because the post-printing reading position W and the pre-printing reading position V are different positions, the process of S14 determines that the CIS 84 can be a candidate for the CIS to be used in the post-printing reading process.

[0038] The CPU 41 then starts an unloading reading process (S15) in which the CIS 84 determined in S14 based on the identification information, the predetermined amount, and the focal ranges of each of the CISs 81 to 84 reads the printed surface N of the medium M placed on the platen 5, which is moved in the unloading direction E2 opposite to the loading direction E1 after the sensor movement process of S11, and acquires the read data. The process of S15 may be performed in parallel with the printing process or after the printing process is completed. When performing the unloading reading process of S15 shown in FIG. 3B, the distance F2 between the glass surfaces 91 to 94 and the printed surface N of the medium M is greater than the distance F1 between the glass surfaces 91 to 94 and the printed surface N of the medium M when performing the loading reading process of S2 shown in FIG. 3A. Because the glass surfaces 91 to 94 are spaced apart from the printed surface N in the separation direction E4, ink adhering to the printed surface N does not adhere to the glass surfaces 91 to 94.

[0039] When the process of reading the print surface N of the medium M, which began in S15, is completed, the CPU 41 acquires the read data output by the CIS 84 and performs image analysis to detect printing defects (S16). The types and number of types of printing defects detected in S16 may be set as appropriate. The CPU 41 of this embodiment detects whether printing defects have occurred as a result of the printing process begun in S13 from three perspectives: whether banding has occurred, whether color unevenness has occurred, and whether bleeding has occurred. The CPU 41 may, for example, compare the image data represented by the print data with the read data to determine whether printing defects have occurred.

[0040] The CPU 41 determines whether printing was successful based on the analysis result of S16 (S19). If a printing defect is detected (S19: NO), the CPU 41 reports the printing defect (S20). If printing was successful (S19: YES), or after S20, the CPU 41 moves the CIS unit 8 in the approach direction E3 to the pre-printing reading position V (S21). After the CPU 41 moves the platen 5 to the attachment / detachment position P in FIG. 2(A), the main processing ends.

[0041] In the above embodiment, the printing device 1, platen 5, platen moving unit 6, sensor moving unit 9, CPU 41, and memory 44 are examples of the printing device, platen, platen moving unit, sensor moving unit, processor, and memory of the present invention, respectively. The print heads 3 and 4 are examples of the print head of the present invention. The contact glasses 87 to 90 are examples of the contact glasses of the present invention. The CISs 81 to 84 are examples of the contact image sensors of the present invention. The carry-in direction E1, the carry-out direction E2, the approaching direction E3, and the separating direction E4 are examples of the carry-in direction, the carry-out direction, the approaching direction, and the separating direction of the present invention, respectively. The processes of S2 and S3 are examples of the carry-in reading process, the reading process, and the reading step of the present invention. The process of S10 is examples of the defect detection process, the defect detection step, and the printed surface defect detection process of the present invention. The process of S11 is examples of the sensor movement process and the sensor movement step of the present invention. The process of S13 is examples of the printing process and the printing step of the present invention. The processing of S5 is an example of a storage control processing and a storage control step of the present invention. The processing of S15 and S16 is an example of a reading processing, a reading processing, and a reading step at the time of carrying out of the present invention. The processing of S19 is an example of a printing defect detection processing and a printing defect detection step. ROM 42 is an example of a non-transitory storage medium of the present invention.

[0042] The printing device 1 includes a platen 5, print heads 3 and 4 configured to print on a printing surface N of a medium M placed on the platen 5, and CISs 81 to 84 configured to read the printing surface N of the medium M and having different focal ranges in which the image is focused in a direction perpendicular to the platen 5. Compared to conventional printing devices 1, the printing device 1 contributes to increasing the likelihood that the printing surface N of the medium M will fall within the focal range in which the CIS is focused, even when there is a difference in the thickness of the medium M or when the medium M is misaligned in a direction perpendicular to the platen 5 when the user places the medium M on the platen 5.

[0043] The CISs 81 to 84 each have contact glasses 87 to 90 of different thicknesses, and the different thicknesses of the contact glasses 87 to 90 result in different focal ranges. The contact glasses 87 to 90 of the printing device 1 contribute to different focal ranges in the direction perpendicular to the platen 5 for the CISs 81 to 84 with a relatively simple configuration.

[0044] The platen 5 is supported so as to be movable in the feed-in direction E1. The CISs 81 to 84 are each disposed upstream in the feed-in direction E1 from the print heads 3 and 4. The CISs 81 to 84 of the printing device 1 contribute to easier reading of the printing surface N of the medium M before printing, compared to when they are disposed downstream in the feed-in direction E1 from the print heads 3 and 4.

[0045] The printing device 1 includes a CPU 41. The platen 5 is supported so as to be movable in the carry-in direction E1. The CPU 41 executes a carry-in reading process in which, for each of the CISs 81 to 84, the printing surface N of the medium M placed on the platen 5 as it is moved in the carry-in direction E1 is read and multiple pieces of read data corresponding to the CISs 81 to 84 are acquired (S2, S3). The carry-in reading process executed by the CPU 41 of the printing device 1 contributes to easily reading the printing surface N of the medium M before printing.

[0046] The CPU 41 executes a defect detection process to detect defects based on the target read data that is focused on the medium M among the multiple read data (S10). The defect detection process executed by the CPU 41 of the printing device 1 contributes to detecting defects based on the target read data that is focused on the medium M.

[0047] The printing device 1 includes a memory 44. The CPU 41 executes a storage control process to store, in the memory 44, the identification information of the CIS corresponding to the target read data among the CISs 81 to 84 (S5). The storage control process executed by the CPU 41 of the printing device 1 contributes to automatically storing the identification information of the CIS used to detect the defect.

[0048] If the CPU 41 determines in the defect detection process that the medium M is not in focus for all of the multiple pieces of read data, it determines that the installation position of the platen 5 is incorrect (S4: NO). The defect detection process executed by the CPU 41 of the printing device 1 contributes to appropriately detecting a defect in the installation position of the platen 5 based on the multiple pieces of read data.

[0049] The printing device 1 includes a platen movement unit 6 configured to move the platen 5 in a carry-in direction E1, a sensor movement unit 9 configured to move the CISs 81 to 84 in an approaching direction E3 that moves them closer to the platen 5 and in a separating direction E4 that is opposite to the approaching direction E3, and a CPU 41. The print heads 3 and 4 are inkjet heads that eject ink. The CPU 41 executes a carry-in reading process (S2, S3) in which each of the CISs 81 to 84 reads the printing surface N of the medium M placed on the platen 5 that is being moved in the carry-in direction E1 and acquires multiple read data corresponding to the CISs 81 to 84. After the carry-in reading process, the CPU 41 executes a sensor movement process (S11) in which the CISs 81 to 84 are moved a predetermined distance in the separating direction E4 that is perpendicular to the platen 5 and away from the platen 5. The sensor movement process executed by the CPU 41 of the printing device 1 contributes to automatically moving the CISs 81 to 84 in the separation direction E4 after the loading reading process. The sensor movement process contributes to preventing ink from adhering to the CISs 81 to 84 due to printing.

[0050] After acquiring the plurality of read data, the CPU 41 executes a printing process to print on the medium M (S13). After the sensor movement process of S11, the CPU 41 executes a read-at-exit process to read the print surface N of the medium M placed on the platen 5, which is moved in the unloading direction E2 opposite to the feed-in direction E1, with each of the CISs 81 to 84, and acquires the plurality of read data corresponding to the CISs 81 to 84 (S15). The read-at-exit process executed by the CPU 41 of the printing device 1 is executed after the sensor movement process, and therefore contributes to preventing ink adhering to the print surface N of the medium M from adhering to the CISs 81 to 84.

[0051] The CPU 41 performs a print surface defect detection process to detect defects on the print surface N based on target read data focused on the medium M among the multiple read data acquired in the load-in read process (S10). After the load-in read process, the CPU 41 performs a print process to print on the medium M (S13). The CPU 41 performs a storage control process to store identification information of the CIS among the CISs 81 to 84 that corresponds to the target read data (S5). After the sensor movement process, the CPU 41 performs a load-out read process to read the print surface N of the medium M placed on the platen 5, which is moved in the load-out direction E2 opposite to the load-in direction E1, using a CIS determined based on the identification information, a predetermined amount, and the focal range of each of the CISs 81 to 84, and acquires the read data (S15, S16). The print surface defect detection process executed by the CPU 41 of the printing device 1 contributes to detecting print surface defects based on the target read data acquired before the printing process. The storage control process and the reading process at the time of removal executed by the CPU 41 of the printing device 1 contribute to obtaining read data that is in focus on the printing surface N of the medium M with simpler processing than when determining the read data that is in focus from multiple read data obtained from each of the CISs 81 to 84.

[0052] The CPU 41 performs a print defect detection process to detect print defects based on the read data acquired in the unloading reading process (S19). The print defect detection process performed by the CPU 41 of the printer 1 contributes to detecting print defects based on the read data. The print defect detection process performed by the CPU 41 of the printer 1 contributes to simplifying the configuration of the printer 1 compared to when print defects are detected by a CIS separate from CISs 81 to 84 used to detect print surface defects.

[0053] The printing device control method executed by the CPU 41 of the printing device 1 includes a reading step (S2, S3, S15, S16) of reading the printing surface N of the medium M placed on the platen 5 with each of the CISs 81 to 84 provided in the printing device 1, each having a different focal range in which the image is focused in a direction perpendicular to the platen 5, and acquiring multiple pieces of read data corresponding to the CISs 81 to 84. The printing device control method also includes a defect detection step (S10, S19) of detecting defects based on target read data that is focused on the medium M among the multiple pieces of read data. Compared to conventional printing device control methods, the reading step of the printing device control method contributes to increasing the likelihood of acquiring read data in which the printing surface N of the medium M falls within the focal range of the CIS, even when there is a difference in the thickness of the medium M or when the medium M is misaligned in a direction perpendicular to the platen 5 when the user places the medium M on the platen 5. The defect detection process of the printing apparatus control method contributes to appropriately detecting defects based on target read data that is in focus on the medium M, among the multiple read data corresponding to the CISs 81 to 84.

[0054] The present invention may be modified in various ways from the above-described embodiment. The present invention can be implemented in various forms, and may be realized, for example, in the form of a printing device control program. The various modifications described below and the above-described embodiment may be combined as appropriate to the extent that no contradictions arise.

[0055] The configuration of the printing device 1 may be modified as appropriate. For example, in the above embodiment, the printing device 1 may be a type other than an inkjet printer, such as a laser printer. The number of print heads 3 and 4 may be one or three or more. The platen moving unit 6 and the sensor moving unit 9 may each be modified as appropriate or omitted. For example, the sensor moving unit 9 may include a solenoid, and the CIS unit 8 may be moved in the separation direction E4 by the power of the solenoid. The input unit 29 may be modified as appropriate to another configuration, such as a touch screen, or may be omitted. If the printing device 1 does not include the input unit 29, various instructions may be acquired from an external device. The display 28 may be any display capable of displaying images, such as an organic electroluminescence (EL) display, a plasma display, a plasma tube array display, or an electronic paper display using electrophoresis. The display 28 may be omitted. If the printing device 1 does not have a display 28, the process of notifying the defect detection results may be performed by an audio output device such as a speaker, by an illuminant such as an LED lamp, or by outputting notification information to an external device and having the external device execute the process.

[0056] The number, arrangement, and configuration of the CISs 81 to 84 may be changed as appropriate. Some or all of the CISs 81 to 84 may be located downstream of the print heads 3 and 4 in the carry-in direction E1. The thickness of the contact glass of some or all of the CISs 81 to 84 may be the same. The glass surfaces 91 to 94 of the contact glasses 87 to 90 may be on the same plane or on different planes. The CISs 81 to 84 may be arranged from rear to front in order of increasing contact glass thickness, or may be arranged in any order in the sub-scanning direction regardless of thickness. Some or all of the CISs 81 to 84 may be immovable in the separation direction E4 away from the platen 5, or their positions in the separation direction E4 or approach direction E3 may be manually adjustable. The carry-in direction E1, the carry-out direction E2, the approach direction E3, and the approach direction E4 may each be changed as appropriate depending on the configuration of the printing device 1.

[0057] The program including the instructions for executing the main processing of Fig. 6 may be stored in the storage device of each device before the CPU 41 executes the program. Therefore, the program acquisition method, acquisition path, and device storing the program may each be changed as appropriate. The program executed by the CPU 41 may be received from another device via a cable or wireless communication and stored in a storage device such as a memory unit. The other device may include, for example, a PC and a server connected via a network.

[0058] The steps of the main processing are not limited to being executed by the CPU 41, and some or all of them may be executed by other electronic devices (e.g., ASIC). The steps of the main processing may be distributed among multiple electronic devices (e.g., multiple CPUs). The order of the steps of the main processing may be changed, and steps may be omitted or added as necessary. The following modifications may be made to the main processing as appropriate.

[0059] The loading reading process, reading process, and reading step of S2 and S3 may be modified as appropriate or may be omitted. The reading step only needs to acquire multiple read data corresponding to multiple contact image sensors, and may be performed while the platen 5 is moving in the loading direction E1, while the platen 5 is moving in the unloading direction E2, or while the platen 5 is stopped.

[0060] The defect detection process, defect detection step, and print surface defect detection process of S10 may be modified or omitted as appropriate. For example, the CPU 41 may output the target read data to an external device, and the print surface defect detection process may be executed by the external device. In this case, the CPU 41 may acquire the detection results from the external device and notify the detection results on the display 28. The CPU 41 may display an image represented by the data read at the time of loading on the display 28, allowing the user to visually determine whether there is a print surface defect. In another example, S4 may be omitted. The CPU 41 may omit the processes of S7 and S9. In this case, the CPU 41 may not drive the CIS 84 in the read process at the time of loading, the read process, and the read step of S2 and S3, and may instead acquire read data obtained by reading the print surface N of the medium M with the CISs 81 to 83. The CPU 41 may execute the defect detection process and defect detection step to detect print defects based on the target read data that is focused on the medium M among the multiple read data. The determination process of S4 may be modified as appropriate. For example, the CPU 41 may determine whether the image is in focus based on the result of comparison with reference data that is the standard for determining whether the image is in focus. In another example, the CPU 41 may determine whether the image is in focus based on whether there is a clear difference in pixel values ​​in the read data.

[0061] The storage control process and the storage control step of S5 may be modified or omitted as appropriate. The CPU 41 may omit S5 and S14 and obtain the scanned data of the CIS that is in focus from the scanned data obtained by scanning the print surface N of the medium M with each of the CISs 81 to 84 in the scanning process at the time of unloading in S15 and S16.

[0062] The sensor movement processing and sensor movement step of S11 may be modified as appropriate or may be omitted. The sensor movement processing of S11 may be performed before the processing of S15, and may be performed while the platen 5 is being moved in the unloading direction E2. The printing processing and printing step of S13 may be modified as appropriate or may be omitted. The CPU 41 may perform the printing processing while transporting the platen 5 from the attachment / detachment position P to the turning back position R in the loading direction E1. In this case, the printing processing may be performed in parallel with the loading reading processing, or may be performed after the loading reading processing is completed.

[0063] The unloading reading process and the unloading reading process of S15 and S16 may be modified or omitted as appropriate. The position of the CIS unit 8 in the direction perpendicular to the platen 5 in the loading reading process of S2 and S3 and the unloading reading process of S15 and S16 may be the same or different.

[0064] The print defect detection process and the print defect detection step in S19 may be modified as appropriate or omitted. For example, the CPU 41 may output the scanned data acquired in S16 to an external device, and the print defect detection process may be executed by the external device. In this case, the CPU 41 may acquire the detection results from the external device and notify the detection results on the display 28. The CPU 41 may display an image represented by the scanned data on the display 28, allowing the user to visually determine whether there is a print defect. In this case, the CPU 41 may acquire the detection results from the external device and notify the detection results on the display 28. The CPU 41 may omit at least one of the processes in S6, S9, S17, and S20. The CPU 41 may output the detection results of the platen 5 installation position defect, the printing surface defect, or the print defect to the external device, and the detection results may be notified by the external device. [Explanation of symbols]

[0065] 1: Printing device, 3, 4: Print head, 5: Platen, 6: Platen moving part, 9: Sensor moving part, 41: CPU, 44: Memory, 87 to 90: Contact glass, E1: Loading direction, E2: Loading direction, E3: Approaching direction, E4: Separating direction, M: Medium, N: Printing surface

Claims

1. A platen and a print head configured to print on a print surface of a medium placed on the platen; a plurality of contact image sensors configured to read the printing surface of the medium, the contact image sensors having different focal ranges in focus in a direction perpendicular to the platen; A printing device comprising:

2. 2. The printing device according to claim 1, wherein the plurality of contact image sensors each have a contact glass having a different thickness, and the different thicknesses of the contact glass result in different focal ranges.

3. The platen is supported so as to be movable in a carry-in direction, 2. The printing apparatus according to claim 1, wherein each of the plurality of contact image sensors is disposed upstream of the print head in the feed direction.

4. further comprising a processor; The platen is supported so as to be movable in a carry-in direction, The processor: a loading-time reading process in which the print surface of the medium placed on the platen, which is moved in the loading direction, is read by each of the plurality of contact image sensors, and a plurality of read data corresponding to the plurality of contact image sensors is obtained; 2. The printing device according to claim 1, wherein the printing device executes the following steps.

5. The processor: A defect detection process for detecting defects based on target read data that is focused on the medium among the plurality of read data.

5. The printing device according to claim 4, further comprising:

6. further comprising a memory; The processor: a storage control process for storing, in the memory, identification information of a contact image sensor corresponding to the target read data among the plurality of contact image sensors; 6. The printing device according to claim 5, further comprising:

7. The processor:

7. The printing apparatus according to claim 6, wherein, in the defect detection process, if the medium is not in focus for all of the plurality of read data, it is determined that the platen is in a defective position.

8. a platen moving unit configured to move the platen in a carry-in direction; a sensor moving unit configured to move the plurality of contact image sensors in a proximity direction that brings them closer to the platen and in a separation direction opposite to the proximity direction; Processor and Further provided with the print head is an inkjet head that ejects ink, The processor: an input reading process in which the print surface of the medium placed on the platen, which is moved in the input direction, is read by each of the plurality of contact image sensors, and a plurality of read data corresponding to the plurality of contact image sensors is obtained; a sensor moving process for moving the plurality of contact image sensors by a predetermined amount in a direction perpendicular to the platen and away from the platen after the loading reading process; 2. The printing device according to claim 1, further comprising:

9. The processor: a printing process for printing the plurality of read data on the medium after acquiring the plurality of read data; an unloading reading process in which, after the sensor moving process, each of the plurality of contact image sensors reads the printed surface of the medium placed on the platen, which is moved in an unloading direction opposite to the carry-in direction, and a plurality of read data corresponding to the plurality of contact image sensors is obtained; 9. The printing device according to claim 8, further comprising:

10. The processor: a print surface defect detection process for detecting defects on the print surface based on target read data that is focused on the medium among the plurality of read data acquired in the carry-in reading process; a printing process for printing on the medium after the carrying-in reading process; a storage control process for storing identification information of a contact image sensor corresponding to the target read data among the plurality of contact image sensors; a carry-out reading process for reading the print surface of the medium placed on the platen, which is moved in a carry-out direction opposite to the carry-in direction after the sensor movement process, using a contact image sensor determined based on the identification information, the predetermined amount, and the focal range of each of the plurality of contact image sensors, and acquiring read data; 9. The printing device according to claim 8, further comprising:

11. The processor: A print defect detection process for detecting print defects based on the read data acquired in the carry-out reading process.

11. The printing device according to claim 10, further comprising:

12. 1. A printing device control method executed by a processor of a printing device, comprising: a reading step of reading a print surface of a medium placed on the platen with each of a plurality of contact image sensors provided in the printing device, the contact image sensors having different focal ranges in focus in a direction perpendicular to the platen, and acquiring a plurality of read data corresponding to the plurality of contact image sensors; a defect detection step of detecting defects based on target read data that is focused on the medium among the plurality of read data; A printing device control method comprising:

13. a storage control step of storing identification information of a contact image sensor corresponding to the target read data among the plurality of contact image sensors; 13. The method of claim 12, further comprising:

14. 14. The printing device control method according to claim 13, wherein the processor determines that the platen is in a faulty position when the focus is not on the medium for all of the plurality of read data in the defect detection step.

15. In the reading step, the print surface of the medium placed on the platen that is moved in a carry-in direction is read by each of the plurality of contact image sensors, and the plurality of read data are obtained; a sensor moving step of moving each of the plurality of contact image sensors by a predetermined amount in a direction perpendicular to the platen and away from the platen after the reading step; a printing step of ejecting ink from a print head of the printing device to print on the printing surface of the medium after the reading step; a storage control step of storing identification information of a contact image sensor corresponding to the target read data among the plurality of contact image sensors; a carry-out reading step of reading the print surface of the medium placed on the platen, which is moved in an unloading direction opposite to the carry-in direction, with a contact image sensor determined based on the identification information, the predetermined amount, and the focal range of each of the plurality of contact image sensors after the sensor moving step, and acquiring read data; a print defect detection step of detecting print defects based on the read data acquired in the carry-out reading step; 13. The method of claim 12, further comprising:

16. A non-transitory storage medium storing a printing device control program for execution by a processor of a printing device, a reading process in which a printing surface of a medium placed on the platen is read by each of a plurality of contact image sensors provided in the printing device, the contact image sensors having different focal ranges in focus in a direction perpendicular to the platen, and a plurality of read data corresponding to the plurality of contact image sensors is obtained; a defect detection process for detecting defects based on target read data that is focused on the medium among the plurality of read data; A non-transitory storage medium storing the printing device control program containing instructions for executing the above.

17. a storage control process for storing identification information of a contact image sensor corresponding to the target read data among the plurality of contact image sensors; 17. The non-transitory storage medium of claim 16, further comprising instructions for executing the printing device control program.

18. The non-transitory storage medium according to claim 17, characterized in that the processor stores the printing device control program that determines that the platen installation position is incorrect if the focus is not on the medium for all of the multiple read data during the defect detection process.

19. In the reading process, the print surface of the medium placed on the platen that is moved in a carry-in direction is read by each of the plurality of contact image sensors, and the plurality of read data are acquired; a sensor moving process for moving each of the plurality of contact image sensors by a predetermined amount in a direction perpendicular to the platen and away from the platen after the reading process; a printing process in which ink is ejected from a print head of the printing device to print on the printing surface of the medium after the reading process; a storage control process for storing identification information of a contact image sensor corresponding to the target read data among the plurality of contact image sensors; an unloading reading process for reading the print surface of the medium placed on the platen, which is moved in an unloading direction opposite to the loading direction, with a contact image sensor determined based on the identification information, the predetermined amount, and the focal range of each of the plurality of contact image sensors after the sensor movement process, and acquiring read data; a print defect detection process for detecting print defects based on the read data acquired in the carry-out reading process; 17. The non-transitory storage medium of claim 16, further comprising instructions for executing the printing device control program.

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