JP2014087933A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer which is capable of determining whether soil is on a conveyance part or on a sensor part.SOLUTION: A printer 1 comprises: a conveyance part 3 for conveying a sheet P; a sensor part 4 which emits light to the conveyance part 3 and receives reflected light from the conveyance part 3 side; an elevation driving part 54 which moves the conveyance part 3 between an upper limit position in proximity to the sensor part 4 and a lower limit position; a determination part which determines whether there is soil on the sensor part 4 on the basis of a quantity of received light at the sensor part 4 when the conveyance part 3 is positioned at the lower limit position while a sheet P is not conveyed and, if it is determined that there is no soil on the sensor part 4, determines whether there is soil on the conveyance part 3 on the basis of a quantity of light received at the sensor part 4 when the conveyance part 3 is positioned at the upper limit position.

Description

  The present invention relates to a printing apparatus that performs printing on paper.

  2. Description of the Related Art Conventionally, printing apparatuses that perform printing on a sheet while conveying the sheet by a conveyance unit having a conveyance belt are known.

  In such a printing apparatus, there is one using a CIS (Contact Image Sensor) as a sensor unit for detecting the position of the end of the conveyed paper in the main scanning direction (see, for example, Patent Document 1). In this printing apparatus, an image is printed at an appropriate position by adjusting the print position of the image according to the position of the edge of the sheet detected by the CIS.

  The CIS includes a light source that emits light toward the conveyor belt and a line sensor that receives reflected light from the conveyor belt side. Usually, the sheet has a higher light reflectivity than the transport belt, so that the amount of light received by the line sensor is larger in the area where the sheet passes than in the vicinity. For this reason, the position of the edge of the sheet in the main scanning direction is specified based on the amount of light received by the line sensor.

  Here, when there is dirt due to foreign matters adhering to the transport belt, the position of the edge of the paper may be erroneously detected due to the influence of reflected light from the dirty part. Similarly, when the CIS is dirty, the position of the end of the paper may be erroneously detected.

  In a conventional printing apparatus, when the amount of received light that is equal to or greater than the threshold is detected at a timing when no paper is present at the CIS detection target position, or the distance between the edges of the paper detected by the CIS is detected by the paper feeding unit. It was determined that the conveyor belt or the CIS is dirty when it is different from the paper width. Then, the printing apparatus displays a stain error on the operation panel, and prompts the user, service person, etc. to clean.

JP 2006-44101 A

  However, in the above-described printing apparatus, it has not been possible to determine whether the conveyance belt (conveyance unit) or the CIS (sensor unit) is dirty. For this reason, when cleaning is performed, the cleaner must visually confirm which is dirty.

  The present invention has been made in view of the above, and an object of the present invention is to provide a printing apparatus that can determine which of the conveyance unit and the sensor unit is dirty.

  In order to achieve the above object, a first feature of the printing apparatus according to the present invention is a conveyance unit that conveys a sheet, and emits light toward the conveyance unit and receives reflected light from the conveyance unit side. Transporting the paper between the sensor unit, a first position close to the sensor unit, and a second position farther from the sensor unit than the first position, and a sheet transport If the sensor unit is not soiled based on the amount of light received by the sensor unit when the transport unit is disposed at the second position in the absence of the sensor unit, And a determination unit that determines whether the conveyance unit is soiled based on the amount of light received by the sensor unit when the conveyance unit is arranged at the first position.

  A second feature of the printing apparatus according to the present invention is that, when it is determined that the sensor unit is soiled, the sensor unit indicates that the sensor unit is soiled, and when the transport unit is determined to be soiled. And a display section for displaying that the transport section is dirty.

  According to the first feature of the printing apparatus according to the present invention, the determination unit determines the presence or absence of dirt on the sensor unit based on the amount of light received by the sensor unit when the transport unit is disposed at the second position. When it is determined that the sensor unit is not soiled, the determination unit determines whether the transport unit is soiled based on the amount of light received by the sensor unit when the transport unit is disposed at the first position. Thereby, it can be determined whether a conveyance part or a sensor part is dirty.

  According to the second feature of the printing apparatus of the present invention, when it is determined that the sensor unit is dirty, the fact that the sensor unit is dirty is displayed on the display unit, and it is determined that the transport unit is dirty. In the case that the transfer unit is dirty, a message indicating that the conveyance unit is dirty is displayed on the display unit. Thereby, the printing apparatus can notify a user or the like of which of the conveyance unit and the sensor unit is dirty. As a result, it is not necessary for a cleaning person such as a user to visually check whether the conveyance unit or the sensor unit is dirty during cleaning, and the cleaning efficiency is improved.

1 is a schematic configuration diagram of a printing apparatus according to an embodiment. FIG. 3 is a block diagram illustrating a configuration of a control system of the printing apparatus according to the embodiment. It is a top view of a conveyance part and a sensor part. It is sectional drawing which shows the structure of a sensor part. It is a flowchart of a dirt determination process. It is a figure which shows the lower limit position of a conveyance part. It is a figure which shows an example of the light reception amount in a light-receiving part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

  Further, the embodiment described below exemplifies an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention is to arrange the components and the like as follows. It is not something specific. The technical idea of the present invention can be variously modified within the scope of the claims.

  1 is a schematic configuration diagram of a printing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram illustrating a configuration of a control system of the printing apparatus illustrated in FIG. 1, and FIG. 3 is a plan view of a conveyance unit and a sensor unit. 4 and 4 are cross-sectional views showing the configuration of the sensor unit. In the following description, the paper surface direction of FIG. Moreover, as shown in FIG. 1, when viewed from the user, the top, bottom, left, and right are defined as the top, bottom, left and right directions. Further, a path indicated by a broken line in FIG. 1 is a transport path R along which the paper P that is a print medium is transported, and a direction from left to right is a transport direction. In the following description, upstream and downstream mean upstream and downstream in the transport direction.

  As shown in FIGS. 1 and 2, the printing apparatus 1 includes a paper feeding unit 2, a transport unit 3, a sensor unit 4, a printing unit 5, an operation panel unit 6, and a control unit 7.

  The paper feeding unit 2 feeds the paper P. The sheet feeding unit 2 includes a sheet feeding table 11, a sheet feeding roller 12, and a registration roller 13.

  The paper feed table 11 is used for loading paper P used for printing.

  The paper feed roller 12 picks up the paper P stacked on the paper feed tray 11 one by one and conveys it toward the registration roller 13. The paper feed roller 12 is disposed on the upper side of the paper feed tray 11. The paper feed roller 12 is rotationally driven by a motor (not shown).

  The registration roller 13 temporarily stops the paper P conveyed by the paper supply roller 12 and then conveys the paper P toward the conveyance unit 3. The registration roller 13 is disposed on the downstream side of the paper feed roller 12. The registration roller 13 is rotationally driven by a motor (not shown).

  The transport unit 3 transports the paper P transported from the registration rollers 13. The conveyance unit 3 is disposed on the downstream side of the registration roller 13. The transport unit 3 includes a transport belt 21, a driving roller 22, driven rollers 23 to 25, and a belt motor 26.

  The conveyor belt 21 is an annular belt that is stretched around the driving roller 22 and the driven rollers 23 to 25. The conveyor belt 21 is made of a material having a light reflectance smaller than that of the paper P. For example, the conveyance belt 21 is made of black rubber. A number of belt holes (not shown) for attracting and holding the paper P are formed in the transport belt 21. The transport belt 21 sucks and holds the paper P on the transport surface 21a by the suction force generated in the belt hole by driving a fan (not shown). The conveyance surface 21 a is an upper surface of the conveyance belt 21 that is substantially horizontal between the driving roller 22 and the driven roller 23. The conveyor belt 21 rotates in the clockwise direction in FIG. Thereby, the conveyance belt 21 moves endlessly, and conveys the paper P sucked and held on the conveyance surface 21a in the right direction.

  The driving roller 22 and the driven rollers 23 to 25 are for the conveyance belt 21 to be stretched over. The driving roller 22 is driven to rotate by a belt motor 26 and rotates the conveyor belt 21. The driven rollers 23 to 25 are driven by the driving roller 22 via the conveyance belt 21. The driven roller 23 is substantially the same height as the drive roller 22 and is spaced from the drive roller 22 by a predetermined distance in the left-right direction. The driven rollers 24 and 25 are disposed at substantially the same height below the driving roller 22 and the driven roller 23 and spaced apart from each other by a predetermined distance in the left-right direction.

  The belt motor 26 drives the drive roller 22 to rotate.

  The sensor unit 4 is for detecting the position of the end of the paper P conveyed by the conveyance belt 21 in the main scanning direction. The sensor unit 4 is disposed above the transport belt 21 on the upstream side of the most upstream ink jet head 51 described later. As shown in FIG. 3, the sensor unit 4 is formed in a long and narrow shape in the main scanning direction (front-rear direction). The sensor unit 4 is configured by CIS. As shown in FIG. 4, the sensor unit 4 includes light source units 31 </ b> A and 31 </ b> B, a light receiving unit 32, a SELFOC (registered trademark) lens array (SLA) 33, a cover glass 34, and a frame body 35.

  The light source units 31 </ b> A and 31 </ b> B emit light toward the transport unit 3. The light source sections 31A and 31B have dimensions in the main scanning direction that are equal to or larger than the maximum sheet width of the sheet P. The light source units 31A and 31B are arranged on the upstream side (left side) and the downstream side (right side) with respect to the light receiving unit 32, respectively. Each of the light source units 31 </ b> A and 31 </ b> B includes a plurality of light emitting diodes (LEDs) 41 and a substrate 42.

  The LED 41 emits white light. The plurality of LEDs 41 are arranged linearly in the main scanning direction.

  The board | substrate 42 mounts several LED41. The substrate 42 is formed in a plate shape elongated in the main scanning direction. The substrate 42 of the light source unit 31 </ b> A is disposed so as to be inclined so that the light of the LED 41 of the light source unit 31 </ b> A is irradiated from the obliquely upward direction on the upstream side (left side) with respect to the object directly below the SLA 33. The substrate 42 of the light source unit 31 </ b> B is disposed so as to be inclined such that the light of the LED 41 of the light source unit 31 </ b> A is irradiated from the obliquely upward direction on the downstream side (right side) with respect to the object directly below the SLA 33.

  The light receiving unit 32 is a line sensor that receives reflected light from the transport unit 3 side of the light emitted from the LED 41. The light receiving unit 32 has the same size as the light source units 31A and 31B in the main scanning direction. The light receiving unit 32 includes a plurality of photoelectric conversion elements 46 and a substrate 47.

  The photoelectric conversion element 46 receives a part of the reflected light from the paper P or the conveyor belt 21 and outputs an electrical signal corresponding to the amount of received light. The plurality of photoelectric conversion elements 46 are arranged linearly in the main scanning direction.

  The substrate 47 is for mounting a plurality of photoelectric conversion elements 46. The substrate 47 is formed in a plate shape elongated in the main scanning direction. The substrate 47 is disposed above the SLA 33 with the mounting surface of the photoelectric conversion element 46 facing downward.

  The SLA 33 collects a part of the reflected light from the paper P or the conveyance belt 21 on the photoelectric conversion element 46 of the light receiving unit 32. The SLA 33 is disposed below the photoelectric conversion element 46 with the vertical direction as the optical axis direction.

  The cover glass 34 protects the light source units 31A, 31B and the like. The cover glass 34 is disposed below the light source units 31A and 31B and the SLA 33. The cover glass 34 is light transmissive.

  The frame 35 stores and holds each part such as the light source parts 31A and 31B. The frame 35 is formed in a long and narrow shape in the main scanning direction.

  The printing unit 5 performs printing on the paper P conveyed by the conveyance unit 3. The printing unit 5 is provided above the transport unit 3. The printing unit 5 is fixed in a housing (not shown) of the printing apparatus 1. The printing unit 5 includes an inkjet head 51, a head holder 52, a head gap adjusting member 53, and a lift drive unit (corresponding to a drive unit in claims) 54.

  The inkjet head 51 ejects ink onto the paper P that is transported by the transport belt 21. The inkjet head 51 is a line-type inkjet head in which a plurality of nozzles are arranged in the main scanning direction. In the printing apparatus 1, four inkjet heads 51 are provided, and these eject inks of different colors (cyan, black, magenta, yellow).

  The head holder 52 holds the inkjet head 51 above the transport unit 3. The head holder 52 is formed in a hollow, substantially rectangular parallelepiped shape.

  The head gap adjusting member 53 is a member for adjusting the head gap. The head gap is a distance between the ejection surface (lower surface) of the inkjet head 51 and the transport surface 21a. The head gap adjusting member 53 is erected on the corner of the lower surface of the head holder 52. The head gap adjusting member 53 is configured such that the length in the vertical direction can be adjusted. When the transport unit 3 is abutted against the head gap adjusting member 53, the head gap becomes a distance corresponding to the length of the head gap adjusting member 53.

  The raising / lowering drive part 54 raises / lowers the conveyance part 3. The lifting drive unit 54 includes a lifting mechanism 61 and a lifting motor 62.

  The lifting mechanism 61 is a mechanism that lifts and lowers the transport unit 3 with respect to the printing unit 5. Two lifting mechanisms 61 are provided apart in the front-rear direction. The lifting mechanism 61 includes a pair of pulleys 71 and 72, a shaft 73, and wires 74 and 75.

  Pulleys 71 and 72 wind and unwind wires 74 and 75, respectively. The pulleys 71 and 72 are supported in the head holder 52 so as to be spaced apart from each other in the left-right direction.

  The shaft 73 connects a pair of pulleys 71 and 72 to each other. The shaft 73 is made of a long member extending in the left-right direction. One end of the shaft 73 is fixed to the pulley 71, and the other end is fixed to the pulley 72. Thereby, a pair of pulleys 71 and 72 rotate synchronously.

  The wires 74 and 75 suspend and support the transport unit 3. One end of the wires 74 and 75 is connected to the transport unit 3, and the other end is wound around the pulleys 71 and 72. As the wires 74 and 75 are wound and fed by the rotation of the pulleys 71 and 72, the transport unit 3 moves up and down.

  The lifting motor 62 drives the pulleys 71 and 72 to rotate.

  The operation panel unit 6 accepts user input operations and displays various types of information. The operation panel unit 6 includes an input unit 81 and a display unit 82.

  The input unit 81 accepts an input operation by the user and outputs an operation signal corresponding to the operation. The input unit 81 includes various operation keys, a touch panel, and the like.

  The display unit 82 displays various information. The display unit 82 includes a liquid crystal display panel and the like.

  The control unit 7 controls the operation of the entire printing apparatus 1. The control unit 7 includes a CPU, a RAM, a ROM, and the like.

  When the control unit 7 receives the print job, the control unit 7 executes a stain determination process. The stain determination process is a process for determining whether the conveyance belt 21 of the conveyance unit 3 and the sensor unit 4 are dirty. In the stain determination process, the control unit 7 does not carry the paper P, and first, the amount of light received by the sensor unit 4 when the carrying unit 3 is placed at the lower limit position (corresponding to the second position in the claims). Based on the above, the presence or absence of contamination of the sensor unit 4 is determined. When the control unit 7 determines that the sensor unit 4 is not soiled, based on the amount of light received by the sensor unit 4 when the transport unit 3 is disposed at the upper limit position (corresponding to the first position in the claims), The presence or absence of dirt on the conveyor belt 21 of the conveyor 3 is determined. The control part 7 comprises the determination part of a claim.

  Next, the operation of the printing apparatus 1 will be described.

  As described above, when the printing apparatus 1 receives a print job, the printing apparatus 1 executes a stain determination process. The stain determination process will be described with reference to the flowchart of FIG.

  The process of the flowchart of FIG. 5 starts when the control unit 7 receives a print job. Here, in the standby state where the printing apparatus 1 is waiting for a print job, the transport unit 3 is disposed at the lower limit position shown in FIG. The lower limit position is below the upper limit position and is farther from the sensor unit 4 than the upper limit position. As shown in FIG. 1, the upper limit position is a position where the conveyance unit 3 abuts against the head gap adjustment member 53 and is close to the sensor unit 4. The lower limit position is far from the sensor unit 4 to such an extent that the reflected light from the conveyor belt 21 hardly reaches the sensor unit 4.

  When the print job is received, in step S1 of FIG. 5, the control unit 7 executes a sensor unit stain detection process. Specifically, the control unit 7 causes the LEDs 41 of the light source units 31 </ b> A and 31 </ b> B to emit light while the transport unit 3 is in the lower limit position, and determines whether or not the amount of received light in the light receiving unit 32 is abnormal. Here, as shown in FIG. 7, the control unit 7 determines that there is an abnormality when a region where a predetermined number or more of photoelectric conversion elements 46 having a received light amount equal to or greater than the threshold Th are detected in the main scanning direction is detected. And the control part 7 judges that the stain | pollution | contamination of the sensor part 4 was detected, when there exists abnormality in the light reception amount in the light-receiving part 32. FIG.

  The dirt of the sensor unit 4 is, for example, a foreign object attached to the cover glass 34. When the transport unit 3 is at the lower limit position, even if there is dirt on the transport belt 21 having a higher reflectance than that of the transport belt 21, the reflected light from there hardly reaches the sensor unit 4. That is, when the transport unit 3 is at the lower limit position, the presence or absence of dirt on the transport belt 21 does not affect the amount of light received by the light receiving unit 32. For this reason, when the amount of received light equal to or greater than the threshold Th is detected when the transport unit 3 is at the lower limit position, it is considered that this is due to contamination of the sensor unit 4. Therefore, the control unit 7 determines that the sensor unit 4 is contaminated when there is an abnormality in the amount of light received by the light receiving unit 32 in step S1.

  Next, in step S2, the control unit 7 determines whether or not the sensor unit 4 has been detected as a result of the sensor unit contamination detection process in step S1.

  If it is determined that the sensor unit 4 is dirty (step S2: YES), in step S3, the control unit 7 causes the display unit 82 to display an error message indicating that the sensor unit 4 is dirty.

  On the other hand, if it is determined that the sensor unit 4 is not soiled (step S2: NO), in step S4, the control unit 7 drives the lifting motor 62 to move the transport unit 3 to the upper limit position.

  Next, in step S <b> 5, the control unit 7 executes conveyance unit dirt detection processing. Specifically, the control unit 7 drives the belt motor 26 in a state where the LEDs 41 of the light source units 31A and 31B emit light. Paper P is not fed from the paper feed unit 2. Then, the control unit 7 determines whether there is an abnormality in the amount of light received by the light receiving unit 32.

  Here, the control unit 7 has the photoelectric conversion element 46 whose light reception amount is equal to or larger than the threshold Th as shown in FIG. 7 at the same position in the circumferential direction and the main scanning direction on the transport belt 21 continuously for a predetermined number of times or more. When a predetermined number or more of continuous regions are detected in the scanning direction, it is determined that there is an abnormality. The predetermined number of laps is, for example, 3 laps. And the control part 7 judges that the stain | pollution | contamination of the conveyance part 3 was detected, when there is abnormality in the light reception amount in the light-receiving part 32. FIG.

  Here, an HP detection signal is input to the control unit 7 from a belt home position (HP) sensor (not shown) that detects a reference mark (not shown) provided on the conveyor belt 21. ing. In addition, a pulse signal is input to the control unit 7 from an encoder (not shown) installed on the driven roller 23. The control unit 7 can recognize the position of the conveyor belt 21 in the circumferential direction that passes immediately below the sensor unit 4 from the number of output pulses of the encoder from the time when the HP detection signal is input.

  Next, in step S6, the control unit 7 determines whether or not the conveyance unit 3 has been detected as a result of the conveyance unit contamination detection process in step S5.

  If it is determined that the conveyance unit 3 is dirty (step S6: YES), in step S7, the control unit 7 displays an error message on the display unit 82 indicating that the conveyance belt 21 of the conveyance unit 3 is dirty. Let

  On the other hand, if it is determined that the conveyance unit 3 is not dirty (step S6: NO), in step S8, the control unit 7 determines that the conveyance unit 3 and the sensor unit 4 are not dirty and executes the print job. To do.

  Specifically, the control unit 7 feeds the paper P from the paper feeding unit 2 to the transport unit 3. Then, the control unit 7 causes ink droplets to be ejected from the inkjet head 51 to the paper P conveyed by the conveyance unit 3 based on the image data to be printed. As a result, an image is printed on the paper P.

  At this time, the control unit 7 specifies the position of the end of the sheet P conveyed by the conveyance belt 21 in the main scanning direction based on the amount of light received by the light receiving unit 32 of the sensor unit 4. Since the reflectivity of the transport belt 21 is smaller than the reflectivity of the paper P, the amount of reflected light from the paper P is larger than the amount of reflected light from the transport belt 21. For this reason, the control unit 7 can specify the position of the end of the paper P in the main scanning direction from the amount of light received by each photoelectric conversion element 46 of the light receiving unit 32. Then, the control unit 7 adjusts the printing position of the image in the main scanning direction by the inkjet head 51 according to the position of the end of the paper P in the main scanning direction.

  As described above, in the printing apparatus 1, the control unit 7 determines whether the sensor unit 4 is dirty based on the amount of light received by the sensor unit 4 when the transport unit 3 is disposed at the lower limit position. When it is determined that the sensor unit 4 is not soiled, the control unit 7 determines whether the transport belt 21 of the transport unit 3 is soiled based on the amount of light received by the sensor unit 4 when the transport unit 3 is disposed at the upper limit position. Determine. Thereby, the printing apparatus 1 can determine which of the conveyance unit 3 and the sensor unit 4 is dirty.

  Further, in the printing apparatus 1, when it is determined that the sensor unit 4 is dirty, the display unit 82 displays that the sensor unit 4 is dirty, and when it is determined that the transport unit 3 is dirty, the transport unit 3. Is displayed on the display unit 82. Thereby, the printing apparatus 1 can notify a user or the like of which of the transport unit 3 and the sensor unit 4 is dirty. As a result, at the time of cleaning, there is no need for a cleaner such as a user to visually check which of the transport unit 3 and the sensor unit 4 is dirty, and the cleaning efficiency is improved.

  In this embodiment, the stain determination process is executed when the printing apparatus 1 receives a print job. However, the stain determination process may be executed at another timing.

  The present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments. For example, some components may be deleted from all the components shown in the embodiment.

DESCRIPTION OF SYMBOLS 1 Printing apparatus 2 Paper feeding part 3 Conveying part 4 Sensor part 5 Printing part 6 Operation panel part 7 Control part 21 Conveying belt 31A, 31B Light source part 32 Light receiving part 33 Selfoc (registered trademark) lens array 34 Cover glass 35 Frame body 54 Lifting Drive unit 61 Elevating mechanism 62 Elevating motor 82 Display unit

Claims (2)

A transport unit for transporting paper;
A sensor unit that emits light toward the transport unit and receives reflected light from the transport unit side;
A drive unit that moves the transport unit between a first position close to the sensor unit and a second position farther from the sensor unit than the first position;
Based on the amount of light received by the sensor unit when the transport unit is disposed at the second position in a state where the sheet is not transported, the sensor unit determines whether the sensor unit is soiled, and the sensor unit is not soiled. A determination unit that determines whether the conveyance unit is soiled based on the amount of light received by the sensor unit when the conveyance unit is disposed at the first position. .   When it is determined that the sensor unit is dirty, a display is displayed to indicate that the sensor unit is dirty. When it is determined that the transfer unit is dirty, a display is displayed to indicate that the transfer unit is dirty. The printing apparatus according to claim 1, further comprising a unit.