Inspection device and printer

Abstract

To provide an inspection device and a printer that can accurately inspect an image.SOLUTION: A ROM stores reference data indicating a reference of a white pixel value. A black and white reference part 24 is read by a CIS unit 22, and of one line image data obtained through the reading, image data obtained by reading a white reference part of the black and white reference part 24 is taken as present situation data. A decreasing ratio of a pixel value of the present situation data to a pixel value of the reference data is determined, and when the decreasing ratio is equal to or more than a threshold X%, a cleaning instruction notification signal related to an instruction to clean the CIS unit 22 is output. The instruction for cleaning according to the cleaning instruction notification signal is notified, and the CIS unit 22 is cleaned according to the instruction for cleaning. Consequently, if dirt is attached to the CIS unit 22, the dirt is removed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an inspection apparatus for inspecting an image and a printer including the same.

Background Art

[0002] Conventionally, as a type of printer, there is known a printer that uses a roll paper in which a long continuous paper is wound in a roll shape and prints an image on a printing area provided side by side in the longitudinal direction on the continuous paper (see, for example, Patent Document 1).

[0003] In this type of printer, there is a configuration for inspecting an image printed on a printing area. In the printer, a reading unit is provided downstream of the feeding direction of the continuous paper with respect to the printing unit. Then, the image printed by the printing unit is read by the reading unit, and the quality of the printing result is determined from the read image data.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In such a configuration, the reading unit may get dirty. For example, when an inkjet recording type printing unit is adopted, an un-dried printing area of the ink contacts the reading unit, and the ink may move to the reading unit or ink mist may adhere to the reading unit, whereby the reading unit may get dirty. If the reading unit is dirty, the printed image cannot be read well, and the image cannot be inspected accurately.

[0006] An object of the present invention is to provide an inspection apparatus and a printer capable of accurately inspecting an image.

Means for Solving the Problems

[0007] To achieve the above object, an inspection apparatus according to one aspect of the present invention irradiates light from a light source onto an object to be read, receives the light reflected by the object to be read with a light receiving element, and outputs a pixel signal regarding a pixel value corresponding to the amount of light received by the light receiving element. The inspection apparatus includes a reading unit, a white reference portion onto which light from the light source can be irradiated, a memory, and a controller. The memory stores reference data indicating a reference of a white pixel value. The controller irradiates light from the light source onto the white reference portion, receives the pixel signal output from the reading unit according to the amount of light received when the light receiving element receives the light reflected by the white reference portion, obtains a reduction rate of the pixel value with respect to the reference data based on the pixel signal, outputs an instruction signal regarding an instruction to clean the reading unit when the reduction rate is equal to or higher than a first threshold value, obtains the reduction rate again in response to the input of a completion signal regarding the completion of the cleaning of the reading unit after the output of the instruction signal, and updates the reference data using the reduction rate obtained again.

[0008] According to this configuration, the memory stores reference data indicating a reference of a white pixel value. When light from the light source irradiates the white reference portion and the light reflected by the white reference portion is received by the light receiving element, the reading unit outputs a pixel signal according to the amount of light received by the light receiving element. The controller obtains a reduction rate of the pixel value corresponding to the amount of light received by the light receiving element with respect to the reference data based on the pixel signal. When the reduction rate is equal to or higher than the first threshold value, the controller outputs an instruction signal regarding an instruction to clean the reading unit. When a cleaning instruction corresponding to the instruction signal is given and the reading unit is cleaned according to the cleaning instruction, if dirt adheres to the reading unit, the dirt is removed. Therefore, an image of an object to be read can be read well by the reading unit, and when an inspection of the image of the object to be read is performed using the read pixel value, the image can be inspected accurately.

[0009] The present invention can be implemented not only in the form of an inspection device but also in the form of a printer equipped with the inspection device. That is, a printer according to another aspect of the present invention includes an inspection device, a transport mechanism that feeds a medium to be read in a feed direction, and a printing unit that is located upstream of the inspection device in the feed direction and prints on the medium. The inspection device irradiates light from a light source onto the object to be read, receives the light reflected by the object to be read with a light receiving element, and outputs a pixel signal regarding a pixel value according to the amount of light received by the light receiving element. The inspection device also includes a white reference portion where the light from the light source can be irradiated, a memory, and a controller. The memory stores reference data indicating a reference for white pixel values. The controller irradiates light from the light source onto the white reference portion, receives the pixel signal output from the reading unit according to the amount of light received by the light receiving element when the light receiving element receives the light reflected by the white reference portion, obtains a reduction rate of the pixel value with respect to the reference data based on the pixel signal, outputs an instruction signal regarding an instruction to clean the reading unit when the reduction rate is equal to or higher than a first threshold value, and after outputting the instruction signal, obtains the reduction rate again in response to the input of a completion signal regarding the completion of the cleaning of the reading unit, and updates the reference data using the reduction rate obtained again.

[0010] In this printer as well, the same operational effects as those of the aforementioned inspection device can be achieved.

Effects of the Invention

[0011] According to the present invention, an image of an object to be read can be read well by the reading unit, and when an inspection of the image of the object to be read is performed using the read pixel values, the image can be inspected with high accuracy.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 4E

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0014] <Overall Configuration of Label Printer> As shown in FIG. 1, the label printer 1 is a device that prints an image on a long continuous paper P (an example of a medium). The printed continuous paper P is discharged from a discharge port 12 formed on the side surface of a housing 11 that forms the outer shell of the label printer 1.

[0015] For use in the following description, regarding the front, rear, left, and right of the label printer 1, with the side surface where the discharge port 12 is formed as the front, the front side is defined as the front side of the label printer 1, the back side is defined as the rear side of the label printer 1, and the left and right when viewing the label printer 1 from the front side are defined based on the left and right states of the label printer 1. Also, regarding the up and down, it is defined in a state where the label printer 1 is installed on a horizontal plane. The cross-sectional view shown in FIG. 1 is a view of the cross-section cut along a cutting plane line extending in the front-rear direction of the label printer 1 as seen from the right side.

[0016] The continuous paper P may be a die-cut paper in which labels L (an example of a printing area) are arranged side by side in the longitudinal direction on a long base paper, or may be an endless paper (continuous paper) in which a base image for setting printing areas at regular intervals is already printed on the printing surface of a long plain paper, or may be an endless paper made of plain paper on which such a base image is not printed. In the die-cut paper, the printing surface on the side opposite to the adhesive surface of each label L is the printing area. Hereinafter, the case where the continuous paper P is a die-cut paper will be taken as an example.

[0017] The discharge port 12 is a rectangular opening extending in the left-right direction and communicates the inside and outside of the housing 11.

[0018] In the housing 11, a roll holder 13 for holding the continuous paper P in the state of a roll R is provided. The continuous paper P is wound around the roll core with the printing surface facing outward in the state of the roll R. The roll holder 13 has a substantially cylindrical shape, and the roll R is held by the roll holder 13 by externally fitting the roll core to the roll holder 13.

[0019] Also, in the housing 11, a direction-changing roller 14 is provided rearward and upward of the roll holder 13. A conveyance path 15 for conveying the continuous paper P is provided on the front side of the direction-changing roller 14. The conveyance path 15 extends from a position above the direction-changing roller 14 toward the front side, and its front end is connected to the discharge port 12. The continuous paper P is pulled out from the roll R toward the rear side of the direction-changing roller 14, and the direction is changed to the front side by running along the circumferential surface of the direction-changing roller 14, and is passed through the conveyance path 15 toward the discharge port 12.

[0020] On the conveyance path 15, a conveyance roller 16 (an example of a conveyance mechanism) for conveying the continuous paper P is provided. The conveyance roller 16 is arranged at a space in front of the direction-changing roller 14. Also, at a position behind the discharge port 12 and at a space in front of the conveyance roller 16, a conveyance roller 17 (an example of a conveyance mechanism) is arranged. Further, between the conveyance rollers 16 and 17, a conveyance belt 18 (an example of a conveyance mechanism) is provided. The conveyance belt 18 is wound around a driving roller 19 (an example of a conveyance mechanism) and a driven roller 20 (an example of a conveyance mechanism) arranged at intervals in the front-rear direction, and is arranged so that its upper surface extends along the conveyance path 15 below the conveyance path 15.

[0021] With the continuous paper P passed between the rollers of the conveyance roller 16, the power due to the forward rotation of the motor M (see FIG. 2) is transmitted to the conveyance roller 16 and the driving roller 19, causing the conveyance roller 16 and the driving roller 19 to rotate. By the rotation of the driving roller 19, the conveyance belt 18 rotates, and thus, the continuous paper P is conveyed in the feeding direction, which is one of the arrangement directions of the labels L and is toward the discharge port 12 along the conveyance path 15. Also, the transmission path of the driving force of the motor M is also connected to the roll holder 13 (an example of a conveyance unit). The power due to the reverse rotation of the motor M is transmitted to the roll holder 13, causing the roll holder 13 to rotate in the direction opposite to that during the conveyance of the continuous paper P in the feeding direction. By the roll R rotating integrally with the roll holder 13, the continuous paper P is conveyed in the pulling-back direction opposite to the feeding direction.

[0022] Also, when the continuous paper P conveyed by the conveyance roller 16 decelerates and stops, the roll holder 13 is driven to rotate forward or backward by the driving force of the motor M so as to adjust the inertial force acting on the roll R. The direction-changing roller 14 is configured to apply tension to the continuous paper P between the roll holder 13 and the conveyance roller 16, and a mechanism for detecting the magnitude of the tension of the continuous paper P is provided in association with the direction-changing roller 14.

[0023] Between the conveying rollers 16 and 17, a print head 21 (an example of a printing unit) and a CIS (Contact Image Sensor) unit 22 (an example of a reading unit) are provided side by side in this order in the feeding direction.

[0024] The print head 21 is disposed to face the upper surface of the conveyor belt 18 across the conveyance path 15. The print head 21 prints an image on the printing surface of the continuous paper P conveyed through the conveyance path 15 by, for example, an inkjet recording method. A position at a predetermined interval downstream from the upstream end in the feeding direction (rewinding direction) of the print head 21 is the printing position by the print head 21, and the print head 21 prints an image on the printing surface of the continuous paper P at the printing position.

[0025] The CIS unit 22 is disposed above the conveyance path 15 downstream of the print head 21 in the feeding direction. The CIS unit 22 reads a reading target at the reading position. Specifically, although not shown, the CIS unit 22 incorporates a light source 36 (see FIG. 2), a rod lens array, and a linear image sensor. A linear light is irradiated from the light source 36 onto the reading target located at the reading position, and the light reflected by the reading target enters the linear image sensor through the rod lens array. Thereby, at the reading position of the CIS unit 22, the reading target is read for one line in the width direction. The linear image sensor has a configuration in which a plurality of light receiving elements 37 are arranged in a row in the width direction, and the image data read by each light receiving element 37 becomes the image data (pixel value) of one pixel. The width direction is a direction that is orthogonal to the feeding direction (rewinding direction) of the continuous paper P in the conveyance path 15 and extends parallel to the conveyance path 15, that is, the left-right direction.

[0026] Further, a pressing member 23 for pressing the continuous paper P against the CIS unit 22 is provided at a position facing the CIS unit 22 with the conveyance path 15 therebetween. A black-and-white reference portion 24 is provided on the upper surface of the pressing member 23. The black-and-white reference portion 24 is formed as a rectangular tape and is adhered to the upper surface of the pressing member 23 so as to extend in the width direction at the reading position of the CIS unit 22. In the black-and-white reference portion 24, both end portions in the width direction are black reference portions which are black regions, and the remaining region (the region sandwiched by the black reference portions) is a white reference portion which is a white region.

[0027] <Main part of the electrical configuration> As shown in FIG. 2, the label printer 1 includes a CPU (Central Processing Unit) 31, a ROM (Read Only Memory) 32, and a RAM (Random Access Memory) 33.

[0028] The CPU 31 (an example of a controller) controls the operations of the print head 21, the CIS unit 22, and the motor M by executing programs for various processes. The CIS unit 22 is provided with an AFE (Analog Front End) that amplifies an analog signal output from the linear image sensor of the CIS unit 22 and converts it into a digital signal, and the CPU 31 receives image data, which is a digital signal after conversion by the AFE.

[0029] The ROM 32 (an example of a memory) is a rewritable non-volatile memory such as a flash memory. Programs executed by the CPU 31 and various data are stored in the ROM 32.

[0030] The RAM 33 is a volatile memory such as a DRAM (Dynamic Random Access Memory) and is used as a work area when the CPU 31 executes a program.

[0031] In addition, an encoder is provided along with the motor M, and an encoder signal, which is a pulse signal synchronized with the rotation of the motor M, is input from the encoder to the CPU 31. The RAM 33 is used as a step counter by the CPU 31. The CPU 31 can grasp the position of the continuous paper P by counting, with the step counter, the number of pulses of the encoder signal input from the encoder during the forward drive of the motor M and the number of pulses of the encoder signal input from the encoder during the reverse drive of the motor M, respectively.

[0032] The label printer 1 is provided with a USB interface 34. The USB interface 34 is an interface for data communication with a USB device such as a USB memory, and includes a USB connector to which a USB cable is connected and a USB controller that controls the USB connection with the USB device.

[0033] In addition, the label printer 1 is provided with an operation panel 35. The operation panel 35 includes an operation unit operated for various settings and a display unit for displaying information. The operation unit and the display unit may be provided separately, or may be in the form of a touch panel configured by overlapping an operation unit such as a pressure-sensitive or capacitive transparent film switch on a display unit such as a liquid crystal display.

[0034] <Preparatory Processing> Before the label printer 1 is shipped from the factory, the CPU 31 performs the preparatory processing shown in FIG. 3.

[0035] In the preparatory processing, the CPU 31 performs AFE adjustment (S11). In the AFE adjustment, the CPU 31 controls the CIS unit 22 to cause the CIS unit 22 to read the black reference portion of the black-and-white reference portion 24. Then, the CPU 31 sets an adjustment value for adjusting the offset amount of the value of the digital signal obtained by A / D converting the analog signal (voltage) output from each light receiving element 37 of the CIS unit 22 so that the minimum value of the image data (pixel value) obtained by the reading becomes a specified value (for example, 1).

[0036] Also, the CPU 31 performs light amount adjustment (S12). In this light amount adjustment, the CPU 31 controls the CIS unit 22 to cause the CIS unit 22 to read the white reference portion of the black-and-white reference portion 24. Then, the CPU 31 adjusts the current value supplied to the light source 36 of the CIS unit 22, the duty ratio of the lighting time of the light source 36, and the gain of the linear image sensor so that the maximum value of the image data (pixel value) obtained by the reading becomes a predetermined value (for example, 254).

[0037] Then, the CPU 31 causes the CIS unit 22 in the state where AFE adjustment and light amount adjustment have been performed to read the black-and-white reference portion 24 (S13: reading one line for stain detection). By this reading, image data for one line obtained by reading the black-and-white reference portion 24 is obtained. The CPU 31 extracts the image data obtained by reading the white reference portion of the black-and-white reference portion 24 from the image data for that one line, and stores it in the ROM 32 in association with each adjustment value of the AFE adjustment and the light amount adjustment using the extracted image data as reference data (S14).

[0038] <Device Adjustment Process> In the label printer 1, for example, when a USB memory storing print data is connected to the USB interface 34 (USB connector) and a print start button provided on the operation panel 35 is pressed, printing of an image related to the print data stored in the USB memory is performed. Also, in the label printer 1, inspection of the image printed on the label L is performed. In the inspection, the image printed on the label L is read by the CIS unit 22, and the quality of the print result is determined from the read image data.

[0039] At the start of printing, the continuous paper P is set by the user so that the leading label L is positioned upstream in the feeding direction with respect to the print head 21. At this time, the continuous paper P does not exist at the reading position of the CIS unit 22, and the CIS unit 22 can read the white reference portion 24.

[0040] Before starting printing, the CPU 31 performs device adjustment processing shown in FIGS. 4A, 4B, 4C, 4D, and 4E.

[0041] In the device adjustment processing, the CPU 31 determines whether the state of the dirt flag set in the ROM 32 is on (S101 in FIG. 4A). The dirt flag is a flag indicating that the threshold value used for the later-described reduction rate determination has been updated.

[0042] When the state of the dirt flag is off and the CPU 31 determines that the state of the dirt flag is not on (S101: NO), the CPU 31 sets each adjustment value of the AFE adjustment and the light amount adjustment stored in the ROM 32 to the CIS unit 22 (S102).

[0043] When the state of the dirt flag is on (S101: YES), the CPU 31 determines whether a predetermined period P (an example of the second predetermined period) or more has elapsed since the state of the dirt flag became on (S103). When the state of the dirt flag is switched from off to on, the date and time at that time are stored in the ROM 32 (timestamp recording). The period P is set to, for example, one week.

[0044] When the period P or more has not elapsed since the state of the dirt flag became on (S103: NO), the CPU 31 sets each adjustment value of the AFE adjustment and the light amount adjustment stored in the ROM 32 to the CIS unit 22 without changing the state of the dirt flag from on (S102). On the other hand, when the period P or more has elapsed since the state of the dirt flag became on (S103: YES), the CPU 31 switches the state of the dirt flag from on to off (S104) and sets each adjustment value of the AFE adjustment and the light amount adjustment stored in the ROM 32 to the CIS unit 22 (S102).

[0045] After setting each set value of AFE adjustment and light amount adjustment, the CPU 31 causes the CIS unit 22 to read the black-and-white reference section 24 (S105: Reading one line for dirt detection). By this reading, image data for one line obtained by reading the black-and-white reference section 24 is acquired. The CPU 31 extracts, as current data, the image data obtained by reading the white reference section of the black-and-white reference section 24 from among the image data for that one line. Then, the CPU 31 compares the current data with the reference data stored in the ROM 32 (S106) and performs a reduction rate determination. That is, the reduction rate of the pixel value of the current data with respect to the pixel value of the reference data is obtained, and it is determined whether the reduction rate is equal to or greater than the threshold value X% (an example of the first threshold value) (S107). The threshold value X is set to, for example, 10%.

[0046] The reduction rate is the ratio (percentage) of the amount of reduction of the pixel value of the current data from the pixel value of the reference data with respect to the pixel value of the reference data. That is, as shown in FIG. 5, when the pixel value of the reference data is α and the pixel value of the current data is α', the reduction rate is calculated by subtracting the pixel value α' from the pixel value α, dividing the obtained value by the pixel value α, and multiplying the division value by 100. The reduction rate may be obtained for each pixel for all the pixels included in the current data and the reference data, may be obtained for specific pixels from among the pixels included in the current data and the reference data, or may be obtained as the reduction rate of the average value of all the pixel values included in the current data with respect to the average value of all the pixel values included in the reference data.

[0047] When the CPU 31 determines that the reduction rate is not equal to or greater than the threshold value X% (S107: NO), the CPU 31 performs AFE adjustment (S108 in FIG. 4B). Also, the CPU 31 performs light amount adjustment (S109). The content of the AFE adjustment and the light amount adjustment is as described in the AFE adjustment and the light amount adjustment in the preliminary preparation process.

[0048] After the light quantity adjustment, the CPU 31 determines the replacement timing of the CIS unit 22 (S110). Specifically, it determines whether each adjustment value (current value, duty ratio, gain) of the light quantity adjustment is set to its respective maximum value, in other words, whether the adjustment range by each adjustment value of the light quantity adjustment value is the maximum for each. Then, when each adjustment value is set to its respective maximum value, the CPU 31 determines that it is the replacement timing of the CIS unit 22, and when any one of the adjustment values is not set to the maximum value, it determines that it is not the replacement timing of the CIS unit 22.

[0049] When the CPU 31 determines that it is not the replacement timing of the CIS unit 22 (S111: NO), it causes the CIS unit 22 in the state of AFE adjustment and light quantity adjustment to read the black-and-white reference part 24. Then, it reads the black level data, which is the image data of the black reference part of the black-and-white reference part 24, from the image data obtained by the reading, and creates a black correction value from the black level data (S112). Also, the CPU 31 reads the white level data, which is the image data of the white reference part of the black-and-white reference part 24, and creates a shading correction value from the white level data (S113). After that, the CPU 31 performs the main reading that causes the CIS unit 22 to read the image printed on the label L (S114), and ends the device adjustment process.

[0050] When the CPU 31 determines that it is the replacement timing of the CIS unit 22 (S111: YES), it outputs a replacement instruction notification signal regarding the notification instructing the replacement of the CIS unit 22 (S115). By the output of the replacement instruction notification signal, for example, a display instructing the replacement of the CIS unit 22 is output to the display part of the operation panel 35. In this case, the main reading is not performed, and the device adjustment process is ended.

[0051] On the other hand, when the CPU 31 determines that the reduction rate is equal to or higher than the threshold value X% (S107: YES), it resets the count value N of the trial count counter set in the RAM 33 to 0 (S116). Further, the CPU 31 determines whether or not a predetermined period Q (an example of the first predetermined period) has elapsed since the update of the reference data (S117 in FIG. 4C). The period Q is set to a period longer than the period P, for example, one year. When the reference data has never been updated, it is determined whether or not a period Q or more has elapsed since the reference data was stored in the ROM 32 in the preliminary preparation process.

[0052] Then, when the elapsed period from the update of the reference data is less than the period Q and the CPU 31 determines that a period Q or more has not elapsed since the update of the reference data (S117: NO), it determines whether or not the state of the dirt flag is on (S118).

[0053] When the state of the dirt flag is off and the CPU 31 determines that the state of the dirt flag is not on (S118: NO), it increments (+1) the count value N of the trial count counter set in the RAM 33 (S119). The count value N of the trial count counter is reset to 0 at the start of the device adjustment process.

[0054] The CPU 31 determines whether or not the count value N of the trial count counter after the increment is larger than a second predetermined number (for example, 5) (S120). When the count value N is equal to or less than the second predetermined number and the CPU 31 determines that the count value N is not larger than the second predetermined number (S120: NO), it outputs a first cleaning instruction notification signal (an example of a notification signal) regarding notification instructing cleaning (wiping off dirt) of the contact glass of the CIS unit 22 (S121). By outputting the first cleaning instruction notification signal, for example, a message such as "The reading mechanism is dirty. Please wipe it" is displayed on the display unit of the operation panel 35, thereby performing the notification of pattern A. Further, a cleaning completion button to be pressed for inputting that the cleaning has been completed is displayed on the display unit of the operation panel 35.

[0055] After outputting the first cleaning instruction notification signal, the CPU 31 determines whether the cleaning of the CIS unit 22 has been completed (S122). When the cleaning of the CIS unit 22 is performed and the cleaning completion button is pressed, a completion signal regarding the completion of the cleaning of the CIS unit 22 is input from the operation panel 35 to the CPU 31. When the completion signal is input, the CPU 31 determines that the cleaning of the CIS unit 22 has been completed. The process does not proceed until it is determined by the CPU 31 that the cleaning of the CIS unit 22 has been completed.

[0056] When the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S122: YES), it causes the CIS unit 22 to read the black-and-white reference portion 24 (S123: One-line reading for dirt detection). Then, the CPU 31 extracts, as improvement confirmation data, the image data of the white reference portion of the black-and-white reference portion 24 from the image data of one line read from the black-and-white reference portion 24. Then, the CPU 31 compares the improvement confirmation data with the reference data stored in the ROM 32 (S124), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines whether the reduction rate is equal to or greater than the threshold X% (an example of the third threshold) (S125).

[0057] When the CPU 31 determines that the reduction rate is equal to or greater than the threshold X% (S125: YES), after incrementing the count value N of the trial count counter (S119), it determines again whether the count value N is greater than the second predetermined number of times (S120). When the count value N is less than or equal to the second predetermined number of times and the CPU 31 determines that the count value N is not greater than the second predetermined number of times (S120: NO), it outputs the first cleaning instruction notification signal again (S121). Then, when the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S122: YES), it causes the CIS unit 22 to read the black-and-white reference portion 24 (S123), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines again whether the reduction rate is equal to or greater than the threshold X% (S125).

[0058] In this way, until the count value N of the trial count counter exceeds the second predetermined number of times, the output of the first cleaning instruction notification signal and the determination of the reduction rate are repeated. Then, when the count value N of the trial count counter exceeds the second predetermined number of times and the CPU 31 determines that the count value N is greater than the second predetermined number of times (S120: YES), it outputs an exchange instruction notification signal regarding the notification instructing the replacement of the CIS unit 22 (S115 in FIG. 4B) and ends the device adjustment process.

[0059] Before the count value N of the trial count counter exceeds the second predetermined number of times, if the CPU 31 determines, based on the reduction rate determination, that the reduction rate is not equal to or higher than the threshold value X% (S125: NO in FIG. 4C), it switches the state of the dirt flag from off to on (S126). Further, the CPU 31 stores the date and time at the point when the state of the dirt flag is switched to on in the ROM 32 (timestamp recording).

[0060] Furthermore, the CPU 31 stores in the ROM 32 the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data obtained last as the threshold value Y% (S127).

[0061] Then, after performing AFE adjustment (S108 in FIG. 4B) and light amount adjustment (S109), the CPU 31 performs the processes (S110 to S114) after the above-described replacement timing determination. As the process proceeds and this reading is performed (S114), the device adjustment process ends. After that, when new printing is performed, the device adjustment process is newly started, and the CPU 31 determines whether or not the state of the dirt flag is on (S101 in FIG. 4A). In this case, since the state of the dirt flag is on, the CPU 31 determines whether or not a period P or more has elapsed since the state of the dirt flag became on (S103). If a period P or more has not elapsed (S103: NO), without changing the state of the dirt flag from on, after setting each set value of the AFE adjustment and the light amount adjustment, the CPU 31 causes the CIS unit 22 to read the black-and-white reference portion 24 (S105). Then, the CPU 31 performs a reduction rate determination (S106, S107). When it is determined that the reduction rate is equal to or higher than the threshold value X% (S107: YES), it is determined whether or not a period Q or more has elapsed since the update of the reference data (S117 in FIG. 4C).

[0062] When the elapsed period from the update of the reference data is less than the period Q (S117: NO), the CPU 31 determines whether or not the state of the dirt flag is on (S118). At this time, since the state of the dirt flag is on, the CPU 31 determines that the state of the dirt flag is on (S118: YES), and increments (+1) the count value N of the trial count counter set in the RAM 33 (S128 in FIG. 4D). Then, the CPU 31 determines whether or not the count value N of the trial count counter after the increment is larger than the third predetermined number (for example, 5) (S129).

[0063] When the count value N is less than or equal to the third predetermined number of times, and the CPU 31 determines that the count value N is not greater than the third predetermined number of times (S129: NO), the CPU 31 outputs a second cleaning instruction notification signal (an example of an instruction signal) regarding the notification for instructing the cleaning (wiping off dirt) of the contact glass of the CIS unit 22 (S130). By outputting the second cleaning instruction notification signal, for example, a message such as "There is a possibility that correct determination cannot be made due to dirt on the reading mechanism. Please wipe it carefully." is displayed on the display unit of the operation panel 35, thereby performing the notification of the B pattern. Also, a cleaning completion button is displayed on the display unit of the operation panel 35.

[0064] After outputting the second cleaning instruction notification signal, the CPU 31 determines whether the cleaning of the CIS unit 22 has been completed (S131). The CPU 31 does not proceed with the processing until it determines that the cleaning of the CIS unit 22 has been completed.

[0065] When the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S131: YES), the CPU 31 causes the CIS unit 22 to read the black-and-white reference portion 24 (one-line reading for dirt detection) (S132). Then, the CPU 31 extracts, as improvement confirmation data, the image data of the white reference portion of the black-and-white reference portion 24 from the image data of one line read from the black-and-white reference portion 24. Then, the CPU 31 compares the improvement confirmation data with the reference data stored in the ROM 32 (S133), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines whether the reduction rate is equal to or greater than the threshold Y% (an example of the fourth threshold) (S134). The threshold Y is the value (reduction rate) stored in the ROM 32 in step S127, is smaller than the threshold X, and is set to, for example, 7%.

[0066] When the CPU 31 determines that the reduction rate is equal to or higher than the threshold value Y% (S134: YES), after incrementing the count value N of the trial count counter (S128), it determines again whether the count value N is greater than the third predetermined number of times (S129). When the count value N is equal to or less than the third predetermined number of times and the CPU 31 determines that the count value N is not greater than the third predetermined number of times (S129: NO), it outputs the second cleaning instruction notification signal again (S130). Then, when the CPU 31 determines that the cleaning of the CIS unit 22 is completed (S131: YES), it causes the CIS unit 22 to read the black-and-white reference section 24 (S132), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines again whether the reduction rate is equal to or higher than the threshold value Y% (S133, S134).

[0067] In this way, until the count value N of the trial count counter exceeds the third predetermined number of times, the output of the second cleaning instruction notification signal and the reduction rate determination are repeated. Then, when the count value N of the trial count counter exceeds the third predetermined number of times and the CPU 31 determines that the count value N is greater than the third predetermined number of times (S129: YES), it outputs an exchange instruction notification signal regarding the notification instructing the replacement of the CIS unit 22 (S115 in FIG. 4B) and ends the device adjustment process.

[0068] Before the count value N of the trial count counter exceeds the third predetermined number of times, when the CPU 31 determines by the reduction rate determination that the reduction rate is not equal to or higher than the threshold value Y% (S134: NO in FIG. 4D), while keeping the state of the dirt flag on (S126 in FIG. 4C), it stores the current date and time in the ROM 32 (timestamp recording). Further, the CPU 31 stores the reduction rate Y% of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data obtained last in the ROM 32 (S127). Then, after performing the AFE adjustment (S108 in FIG. 4B) and the light amount adjustment (S109), it performs the processes after the replacement timing determination described above (S110 to S114).

[0069] The device adjustment process is newly started, and the CPU 31 determines the reduction rate by comparing the current data with the reference data. When it is determined in the reduction rate determination that the reduction rate is equal to or higher than the threshold X% (S107: YES in Fig. 4A), and when it is determined that a period Q or more has elapsed since the update of the reference data (S117: YES in Fig. 4C), the CPU 31 increments (+1) the count value N of the trial count counter set in the RAM 33 (S135 in Fig. 4E). Then, the CPU 31 determines whether the count value N of the trial count counter after the increment is greater than the first predetermined number of times (for example, 5) (S136).

[0070] If the count value N is less than or equal to the first predetermined number of times, and the CPU 31 determines that the count value N is not greater than the first predetermined number of times (S136: NO), the CPU 31 outputs a third cleaning instruction notification signal (an example of an instruction signal) regarding the notification for instructing the cleaning (removing dirt) of the contact glass of the CIS unit 22 (S137). By outputting the third cleaning instruction notification signal, for example, a message such as "There may be a need to replace the reading mechanism, but please try wiping the reading mechanism." is displayed on the display unit of the operation panel 35, thereby performing the notification of the C pattern. Also, a cleaning completion button is displayed on the display unit of the operation panel 35.

[0071] After outputting the third cleaning instruction notification signal, the CPU 31 determines whether the cleaning of the CIS unit 22 has been completed (S138). The CPU 31 does not proceed with the process until it determines that the cleaning of the CIS unit 22 has been completed.

[0072] When the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S138: YES), it causes the CIS unit 22 to read the black-and-white reference section 24 (S139: One-line reading for dirt detection). Then, the CPU 31 extracts, as improvement confirmation data, the image data of the white reference section of the black-and-white reference section 24 from the image data of one line in which the black-and-white reference section 24 has been read. Then, the CPU 31 compares the improvement confirmation data with the reference data stored in the ROM 32 (S140), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines whether the reduction rate is equal to or higher than the threshold value Z% (an example of the second threshold value) (S141). The threshold value Z is set to a value smaller than the threshold value X and the threshold value Y, for example, 5%.

[0073] When the CPU 31 determines that the reduction rate is equal to or higher than the threshold value Z% (S141: YES), after incrementing the count value N of the trial count counter (S135), it determines again whether the count value N is larger than the first predetermined number of times (S136). When the count value N is equal to or less than the first predetermined number of times and the CPU 31 determines that the count value N is not larger than the first predetermined number of times (S136: NO), it outputs the third cleaning instruction notification signal again (S137). Then, when the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S138: YES), it causes the CIS unit 22 to read the black-and-white reference section 24 (S139), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines again whether the reduction rate is equal to or higher than the threshold value Z% (S140, S141).

[0074] In this way, until the count value N of the trial count counter exceeds the first predetermined number of times, the output of the third cleaning instruction notification signal and the reduction rate determination are repeated. When the count value N of the trial count counter exceeds the first predetermined number of times and the CPU 31 determines that the count value N is larger than the first predetermined number of times (S136: YES), it updates the reference data to new reference data by storing the finally obtained improvement confirmation data in the ROM 32 as new reference data (S142).

[0075] Also, before the count value N of the trial count counter exceeds the first predetermined number of times, even when it is determined by the reduction rate determination that the reduction rate is not equal to or higher than the threshold value Z% (S141: NO), the CPU 31 updates the reference data to new reference data by storing the last acquired improvement confirmation data in the ROM 32 as new reference data (S142).

[0076] Thereafter, after the CPU 31 performs the AFE adjustment (S108 in FIG. 4B) and the light amount adjustment (S109), the CPU 31 performs the processes (S110 to S114) after the replacement timing determination described above.

[0077] <Operation and Effect> According to this configuration, reference data indicating the reference of the white pixel value is stored in the ROM 32. After setting each adjustment value of the AFE adjustment and the light amount adjustment, the black and white reference unit 24 is read by the CIS unit 22, and the image data of one line obtained by this reading and including the white reference unit of the black and white reference unit 24 is used as the current data. Then, the reduction rate of the pixel value of the current data with respect to the pixel value of the reference data is obtained. When the reduction rate is equal to or higher than the threshold value X%, the first to third cleaning instruction notification signals regarding the cleaning instruction of the CIS unit 22 are output. The cleaning instruction corresponding to the first to third cleaning instruction notification signals is notified, and according to the cleaning instruction, when the CIS unit 22 is cleaned, if dirt is attached to the CIS unit 22, the dirt is removed. Therefore, the CIS unit 22 can read the image to be read well, and when the image is inspected using the read pixel value, the image can be accurately inspected (the quality of the printing result can be well determined).

[0078] When the degradation rate is equal to or higher than the threshold value of X% and the elapsed time since the update of the reference data is less than the period Q, and when the state of the dirt flag is off, the CPU 31 outputs a first cleaning instruction notification signal. After the output of the first cleaning instruction notification signal, when a completion signal regarding the completion of the cleaning of the CIS unit 22 is input to the CPU 31, the degradation rate is obtained again. If the degradation rate obtained again is equal to or higher than the threshold value of X%, the first cleaning instruction notification signal is output again. If the degradation rate obtained again becomes less than the threshold value of X% before the number of times the first cleaning instruction notification signal is output exceeds the second predetermined number of times, the last obtained degradation rate is stored in the ROM 32 as the threshold value of Y%, and the state of the dirt flag is switched from off to on.

[0079] When the degradation rate is equal to or higher than the threshold value of X% and the elapsed time since the update of the reference data is less than the period Q, and when the state of the dirt flag is on, the CPU 31 outputs a second cleaning instruction notification signal. After the output of the second cleaning instruction notification signal, when a completion signal regarding the completion of the cleaning of the CIS unit 22 is input to the CPU 31, the degradation rate is obtained again. If the degradation rate obtained again is equal to or higher than the threshold value of Y%, the second cleaning instruction notification signal is output again. If the degradation rate obtained again becomes less than the threshold value of Y% before the number of times the second cleaning instruction notification signal is output exceeds the third predetermined number of times, the state of the dirt flag remains on, and the last obtained degradation rate is stored in the ROM 32 as the threshold value of Y%.

[0080] As a result, when dirt adheres to the CIS unit 22, by having the user wipe off the dirt, the CIS unit 22 can read the image to be read well. Also, when the dirt adhering to the CIS unit 22 is wiped off and the degradation rate is improved to the value of Y% less than the threshold value of X%, by setting the degradation rate as the threshold value of Y%, the frequency of the output of the second cleaning support notification signal increases, and the user can be made to clean the CIS unit 22 frequently. As a result, the CIS unit 22 can read the image to be read even better, and the image can be inspected with higher accuracy.

[0081] Also, when the number of output times of the first cleaning instruction notification signal exceeds a second predetermined number, or when the number of output times of the second cleaning instruction notification signal exceeds a third predetermined number, an exchange instruction notification signal is output from the CPU 31, and for example, a display instructing the replacement of the CIS unit 22 is output to the display unit of the operation panel 35. Thereby, the user can be instructed to replace the CIS unit 22. Further, it is possible to prevent the output of the first cleaning instruction notification signal or the second cleaning instruction notification signal from being repeatedly output infinitely, and it is possible to prevent the notification of the cleaning instruction from being repeatedly output infinitely.

[0082] When the reduction rate is equal to or higher than the threshold value X% and a period Q or more has elapsed since the update of the reference data, a third cleaning instruction notification signal is output from the CPU 31. After the output of the third cleaning instruction notification signal, when a completion signal regarding the completion of the cleaning of the CIS unit 22 is input to the CPU 31, the reduction rate is obtained again. If the reduction rate obtained again is equal to or higher than the threshold value Z%, the third cleaning instruction notification signal is output again. If the reduction rate obtained again becomes less than the threshold value Z% before the number of output times of the third cleaning instruction notification signal reaches the first predetermined number, the reference data is updated to the improvement confirmation data last acquired. Also, even when the reduction rate obtained again is equal to or higher than the threshold value Z% after the number of output times of the third cleaning instruction notification signal reaches the first predetermined number, the reference data is updated to the improvement confirmation data last acquired.

[0083] By updating the reference data, when the cause of the decrease in the pixel value of the current data with respect to the pixel value of the reference data is due to aging deterioration, it is possible to suppress the notification of the cleaning instruction for the CIS unit 22 even though the CIS unit 22 is not dirty.

[0084] Also, even when the number of output times of the third cleaning instruction notification signal reaches the first predetermined number, by updating the reference data with the improvement confirmation data, it is possible to prevent the output of the third cleaning instruction notification signal from being repeatedly output infinitely, and it is possible to prevent the notification of the cleaning instruction corresponding to the third cleaning instruction notification signal from being repeatedly output infinitely.

[0085] <Modification Example> As described above, although one embodiment of the present invention has been described, the present invention can also be implemented in other forms.

[0086] For example, in the device adjustment process, instead of steps S117 to S142 shown in FIGS. 4C, 4D, and 4E, steps S151 to S158 shown in FIG. 6 may be performed.

[0087] That is, the CPU 31 performs a reduction rate determination by comparing the current data with the reference data. When it is determined in the reduction rate determination that the reduction rate is equal to or greater than the threshold value X% (an example of the first threshold value) (S107: YES in FIG. 4A), the CPU 31 increments (+1) the count value N of the trial count counter set in the RAM 33 (S151 in FIG. 6). Then, the CPU 31 determines whether the count value N of the trial count counter after the increment is greater than the first predetermined number of times (for example, 5) (S152).

[0088] When the count value N is less than or equal to the first predetermined number of times and the CPU 31 determines that the count value N is not greater than the first predetermined number of times (S152: NO), the CPU 31 outputs a cleaning instruction notification signal (an example of an instruction signal) regarding the notification for instructing the cleaning of the contact glass of the CIS unit 22 (wiping off dirt) (S153). By outputting the cleaning instruction notification signal, for example, a message such as "Please wipe the reading mechanism." is displayed on the display unit of the operation panel 35. Also, a cleaning completion button is displayed on the display unit of the operation panel 35.

[0089] After outputting the cleaning instruction notification signal, the CPU 31 determines whether the cleaning of the CIS unit 22 has been completed (S547). The CPU 31 does not proceed with the process until it determines that the cleaning of the CIS unit 22 has been completed.

[0090] When the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S154: YES), it causes the CIS unit 22 to read the black-and-white reference section 24 (S155: 1-line reading for dirt detection). Then, the CPU 31 extracts, as improvement confirmation data, the image data of the white reference section of the black-and-white reference section 24 from the image data of one line read from the black-and-white reference section 24. Then, the CPU 31 compares the improvement confirmation data with the reference data stored in the ROM 32 (S156), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines whether the reduction rate is equal to or higher than the threshold X% (an example of the first threshold) (S157).

[0091] When the CPU 31 determines that the reduction rate is equal to or higher than the threshold X% (S157: YES), after incrementing the count value N of the trial count counter (S151), it determines again whether the count value N is larger than the first predetermined number of times (S152). When the count value N is equal to or less than the first predetermined number of times and the CPU 31 determines that the count value N is not larger than the first predetermined number of times (S152: NO), it outputs the cleaning instruction notification signal again (S153). Then, when the CPU 31 determines that the cleaning of the CIS unit 22 has been completed (S154: YES), it causes the CIS unit 22 to read the black-and-white reference section 24 (S155), obtains the reduction rate of the pixel value of the improvement confirmation data with respect to the pixel value of the reference data, and determines again whether the reduction rate is equal to or higher than the threshold X% (S156, S157).

[0092] In this way, the output of the cleaning instruction notification signal and the reduction rate determination are repeated until the count value N of the trial count counter exceeds the first predetermined number of times. When the count value N of the trial count counter exceeds the first predetermined number of times and the CPU 31 determines that the count value N is larger than the first predetermined number of times (S152: YES), it updates the reference data to new reference data by storing the finally acquired improvement confirmation data as new reference data in the ROM 32 (S158).

[0093] Also, before the count value N of the trial count counter exceeds the first predetermined number of times, even when it is determined that the reduction rate is not equal to or higher than the threshold value X% by the reduction rate determination (S157: NO), the CPU 31 updates the reference data to new reference data by storing the last acquired improvement confirmation data in the ROM 32 as new reference data (S158).

[0094] Instead of the steps S117 to S142 shown in FIGS. 4C, 4D, and 4E, the steps S151 to S158 shown in FIG. 6 are performed, whereby the device adjustment process can be simplified.

[0095] The printing head 21 is not limited to a configuration that prints an image by an inkjet recording method, and may be a configuration that prints an image on the printing surface of the continuous paper P by a thermal transfer method, or may be a configuration that prints an image by an electrophotographic method.

[0096] Further, an inspection device having a control unit (including a CPU) having the same functions as those of the CIS unit 22 and the CPU 31 may be externally attached to the label printer 1.

[0097] Also, the black-and-white reference portion 24 is not limited to a configuration provided on the upper surface of the pressing member 23, and may be a configuration attached to a movable member.

[0098] In the foregoing embodiment, it is assumed that the CPU 31 executes each process. However, a plurality of CPUs may be provided in the label printer 1, and the plurality of CPUs may cooperate to execute each process.

[0099] In addition, various design changes can be made to the foregoing configuration within the scope of the matters described in the claims.

Description of Reference Numerals

[0100] 1: Label printer 16, 17: Conveyor roller 18: Conveyor belt 19: Driving roller 20: Driven roller 21: Printing head 22: CIS unit 24: Black-and-white reference part 31: CPU 32: ROM 36: Light source 37: Light-receiving element P: Continuous paper

Claims

1. A reading unit that irradiates light from a light source onto an object to be read, receives the light reflected by the object to be read with a light receiving element, and outputs a pixel signal regarding a pixel value corresponding to the amount of light received by the light receiving element; A white reference portion onto which the light from the light source can be irradiated; A memory; A controller, and comprising: The memory stores reference data indicating a reference of a white pixel value; The controller: Irradiates light from the light source onto the white reference portion, receives the pixel signal output from the reading unit according to the amount of light received by the light receiving element when the light receiving element receives the light reflected by the white reference portion, obtains a reduction rate of the pixel value with respect to the reference data based on the pixel signal, When the reduction rate is equal to or greater than a first threshold value, outputs an instruction signal regarding an instruction to clean the reading unit, After the output of the instruction signal, obtains the reduction rate again in response to the input of a completion signal regarding the completion of the cleaning of the reading unit, When the reduction rate obtained again is equal to or greater than a second threshold value that is smaller than the first threshold value, outputs the instruction signal again, When the reduction rate obtained again is less than the second threshold value, updates the reference data. An inspection apparatus.

2. The inspection apparatus according to Claim 1, wherein The controller updates the reference data when the reduction rate obtained again is equal to or greater than the second threshold value after outputting the instruction signal a first predetermined number of times. An inspection apparatus.

3. The inspection apparatus according to Claim 2, wherein The controller: When the reduction rate is equal to or greater than the first threshold value and the elapsed period from the last update of the reference data is equal to or greater than a first predetermined period, after outputting the instruction signal, obtains the reduction rate again in response to the input of the completion signal, and if the reduction rate obtained again is equal to or greater than the second threshold value, repeats the process of outputting the instruction signal again, Before the output count of the instruction signal reaches the first predetermined count, if the recalculated reduction rate becomes less than the second threshold value, update the reference data, After the output count of the instruction signal reaches the first predetermined count, even if the recalculated reduction rate is greater than or equal to the second threshold value, update the reference data, An inspection apparatus that does not update the reference data when the reduction rate is greater than or equal to the first threshold value and the elapsed period since the last update of the reference data is less than the first predetermined period.

4. The inspection apparatus according to claim 3, wherein the memory stores the state of the dirt flag, and the controller, when the reduction rate is greater than or equal to the first threshold value and the elapsed period since the last update of the reference data is less than the first predetermined period, if the state of the dirt flag is off, after outputting the instruction signal, in response to the input of the completion signal, recalculate the reduction rate, and if the recalculated reduction rate is greater than or equal to the third threshold value, repeat the process of outputting the instruction signal again, before the output count of the instruction signal reaches the second predetermined count, if the recalculated reduction rate drops below the third threshold value, store the recalculated reduction rate as the fourth threshold value in the memory, turn on the dirt flag, if the state of the dirt flag is on, after outputting the instruction signal, in response to the input of the completion signal, recalculate the reduction rate, and if the recalculated reduction rate is greater than or equal to the fourth threshold value, repeat the process of outputting the instruction signal again, before the output count of the instruction signal reaches the third predetermined count, if the recalculated reduction rate drops below the fourth threshold value, store the recalculated reduction rate as the fourth threshold value in the memory. An inspection apparatus.

5. The inspection apparatus according to claim 4, wherein the controller, When the state of the dirt flag is off and the reduction rate obtained again does not drop below the third threshold value before the number of output times of the instruction signal reaches the second predetermined number of times, an alarm signal regarding replacement of the reading unit is output. An inspection apparatus that outputs the alarm signal when the state of the dirt flag is on and the reduction rate obtained again does not drop below the fourth threshold value before the number of output times of the instruction signal reaches the third predetermined number of times.

6. The inspection apparatus according to claim 4 or 5, wherein when the elapsed period since the dirt flag was turned on becomes equal to or more than a second predetermined period, the controller turns off the dirt flag.

7. The inspection apparatus according to any one of claims 1 to 6, wherein the controller after updating the reference data, adjusts the light quantity of the reading unit according to the updated reference data, determines whether replacement of the reading unit is necessary based on the adjustment range, and when it is determined that replacement of the reading unit is necessary, outputs an alarm signal regarding replacement of the reading unit.

8. The inspection apparatus according to any one of claims 1 to 7, and a transport mechanism that transports the medium to be read in a feeding direction, and a printing unit that is located upstream of the inspection apparatus in the feeding direction and prints on the medium.

Images