JP2013115476A - Reading apparatus and printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reading apparatus and a printing apparatus that are capable of achieving both reduction in a total time required for reading a pattern and improvement in accuracy.SOLUTION: A pressing plate that presses a supporting surface for supporting a sheet, and a carriage that holds a sensor unit and moves on the pressing plate are integrated into one unit. There is provided a movement mechanism that moves the unit to a first position where the pressing plate presses the supporting surface in reading and to a second position where the pressing is released in moving the sheet on the supporting surface.

Description

  The present invention relates to a reading device that measures a color pattern formed on a sheet, and a printing apparatus including the reading device.

  Patent Document 1 discloses an ink jet printer including a color measuring device. In this apparatus, a color pattern for color calibration that has been printed is measured, and a desired color is reproduced by adjusting the color of a color image to be printed next time on the basis of the color measurement data. A color patch is recorded as a color pattern for color calibration, and then the color patch measures the color patch while moving in the width direction of the sheet.

  In the apparatus disclosed in Patent Document 1, a carriage equipped with a colorimetric sensor travels on a pressing plate with wheels while the pressing plate presses the surface of the sheet, and a color patch is read by the colorimetric sensor to measure the color. When the carriage mounted with the colorimetric sensor is separated from the pressing plate, the pressing member is rotationally shifted and separated from the sheet.

JP 2008-281549 A

  In the apparatus of Patent Document 1, when performing sheet colorimetry, a sheet that is normally raised upward is rotationally shifted to press the sheet. Next, the carriage on which the colorimetric sensor is mounted moves on the push plate, and reading is performed while running on the push plate.

  In this configuration, while the carriage is on the push plate, the push plate cannot be rotated to escape. In other words, in order to release the pressing of the pressing plate in order to move the sheet, the carriage must be released to the outside of the pressing plate. Reading is performed in the forward and backward movement of the carriage, and simply returns to the home position in the return path (back feed). Until the carriage finishes the back feed and escapes from the top of the pressing plate, the movement of the next sheet cannot be started, and the loss of time required for the back feed prevents the reading throughput from being improved. This problem is particularly noticeable when a large number of inspection patterns are to be read sequentially by repeated carriage operations.

  In addition, in the apparatus of Patent Document 1, when the carriage wheel rides on the pressing plate, it passes through a step corresponding to the thickness of the pressing plate, and the impact is transmitted to the carriage. If this impact is repeated, there is a possibility that the accuracy of mounting the colorimetric sensor will be deteriorated or that the sensor may be broken. In addition, when the carriage is retracted to the outside of the pressing plate, the wheels of the carriage will run on a sheet without the pressing plate. There is a possibility of scratching. Any of these causes deterioration in reading accuracy.

  The present invention has been made based on recognition of the above-described problems. An object of the present invention is to provide a reading apparatus and a printing apparatus capable of realizing both reduction of the total time required for pattern reading and improvement of accuracy.

  A reading device according to the present invention includes a sensor unit that reads information on a sheet, a pressing plate that presses a support surface on which the sheet is supported, and a carriage that holds the sensor unit and moves on the pressing plate. And a first position where the pressing plate presses the support surface during the reading, and a second position where the pressing is released when the sheet is moved on the support surface, And a moving mechanism for moving to the position.

  According to the present invention, the total throughput when reading the inspection pattern is improved, and both the reduction of the total time required for reading and the improvement of accuracy are realized. That is, the calibration time, which is a non-productive time for the user of the apparatus, is shortened, and more time can be assigned to the original image printing, so that productivity in the printing operation is improved.

Sectional view showing the overall configuration of the printing device Sectional drawing which shows the detailed structure of a reading part The perspective view which shows the internal structure of a reading part. Sectional view showing the internal structure of the drying section System configuration diagram centering on the control unit Explanatory drawing showing the state of the device during operation Flowchart diagram showing the operation sequence of the printing apparatus The figure which shows the modification which a reading part moves up and down by parallel movement The figure which shows the example of the test | inspection pattern formed in the sheet | seat

  An ink jet printing apparatus having a reading apparatus (colorimetry apparatus) according to an embodiment of the present invention will be described. FIG. 1 is a sectional view showing the overall configuration of the apparatus. The printing apparatus 100 is large and includes a sheet supply unit 1, a conveyance unit 2, a printing unit 3, a cutter unit 4, a reading unit 200, and a control unit 300.

  In the sheet supply unit 1, the continuous sheet R wound in a roll shape is rotatably held. The sheet S pulled out from the roll is nipped by the conveyance roller pair of the conveyance unit 2 and conveyed toward the downstream. In the present specification, at an arbitrary position in the path along which the sheet is conveyed, the side toward the sheet supply unit 1 is referred to as upstream, and the opposite is referred to as downstream.

  The printing unit 3 has a plurality of print heads corresponding to a plurality of colors, and uses a serial print method in which the carriage S scans the carriage and prints one band at a time, or a line head. An image is formed by any of the line printing methods. In this embodiment, an example of a serial printing method will be described. The print head is an ink jet print head that ejects ink from nozzles by an ink jet method. The inkjet system may be any system such as a system using a heater, a system using a piezo element, a system using a MEMS element, or a system using an electrostatic element.

  In the printing unit 3, an inspection pattern for inspection can be printed on the sheet S in addition to a normal desired image. The inspection pattern is a color pattern such as a color patch for color calibration (color calibration), a pattern for nozzle discharge failure inspection, or the like.

  A reading unit 200 is provided downstream of the printing unit 3. The reading unit 200 is a unit for acquiring color information and the like by reading an inspection pattern formed on the sheet S with a scanner. The reading unit 200 can be detached from the printing apparatus 100 as a unit.

  A cutter unit 4 for cutting a continuous sheet is provided between the printing unit 3 and the reading unit 200. The cutter unit 4 is for cutting and cutting an area where an inspection pattern of the sheet S is formed, or for cutting a plurality of images printed on the sheet S in image units.

  A basket-shaped sheet receiving unit is provided at the lower part of the apparatus ahead of the reading unit 200, and sheets discharged after being printed or inspected are dropped by gravity and accumulated therein.

  The printing apparatus 100 is further provided with a temperature / humidity sensor 24 for measuring the gas temperature and humidity inside the apparatus, and an operation unit 25 having input keys and a display for the user to make settings relating to printing. .

  Under the control of the control unit 300, the printing apparatus according to the present embodiment can execute an inspection mode in which an inspection pattern is printed and inspected for calibration or the like, in addition to a normal mode in which normal image printing is performed. In the normal mode, the sheet S on which one or more images are printed by the printing unit 3 is cut and discharged in image units by the cutter unit 4. On the other hand, in the inspection mode, the sheet S on which one or a plurality of inspection patterns are printed by the printing unit 3 is read by the reading unit 200 and then the rear end of the inspection pattern is cut by the cutter unit 4 and then discharged. To do.

  Next, the configuration and operation of the reading unit 200, which is a feature of the present embodiment, will be described in detail. 2 is a cross-sectional view showing an internal configuration of the reading unit 200, and FIG. 3 is a partial perspective view thereof. In FIG. 3, some members illustrated in FIG. 2 are omitted.

  The reading unit 200 is a unit that integrally includes a scanner unit U and a drying unit. The reading unit 200 is fixedly provided below the unit and can move up and down with respect to the fixed guide 16. The fixed guide 16 supports the sheet S on the support surface 16a on the upper surface thereof, and the support surface is inclined downward so as to become lower in the gravity direction toward the downstream side (discharge side) in the first direction. Surface. The sheet S supported by the support surface is dried by the drying unit and further read by the scanner unit U.

  The scanner unit U includes a sensor unit 5 that reads color information of an inspection pattern, a carriage 6 that holds the sensor unit 5 and moves along the surface of the sheet, and a pressing plate that presses a support surface of a fixed guide 16 on which the sheet is supported. 7 These are integrated units. The lower surface of the pressing plate 7 is a flat pressing surface 7a, and the sheet being read is fixed by pressing the sheet S to be read between the pressing surface 7a and the supporting surface.

  The sensor unit 5 is a unit including a light source and a light receiving element. The inspection pattern formed on the sheet S by the printing unit 3 is irradiated with light from another direction by a light source, and the light that is reflected and returned is received by the light receiving element. Information on the density and color of the pattern can be obtained from the signal intensity of the light receiving element.

  The carriage 6 reciprocates along a second direction intersecting (orthogonal) with the first direction in which the sheet is conveyed. The reciprocating movement has a moving range that can cover, for example, a sheet width of 60 inches. The carriage 6 moves while a plurality of contact members 8 provided on the bottom surface of the carriage 6 are in contact with the top surface of the push plate 7. The abutting member 8 is a driven rotating body such as a wheel, or a sliding body having a small frictional resistance at a contact portion. The driving belt 9, the motor 10, the driving pulley 11, and the idler pulley 12 serve as driving means for moving the carriage 6 back and forth. The drive belt 9 is bridged between the drive pulley 11 and the idler pulley 12 along the second direction, and a part of the drive belt 9 is fixed to the carriage 6. By this driving means, the rotation of the motor 10 is converted into a linear movement of the carriage 6. Further, the guide shaft 30 and the push plate 7 serve as guide means for guiding the movement of the carriage in the second direction. When the carriage 6 reciprocates, the contact member 8 and the upper surface of the pressing plate 7 as well as the guide hole inner surface of the carriage 6 and the cylindrical surface of the guide shaft 30 are in contact with each other, and the posture of the sensor unit 5 is maintained. The push plate 7 is attached to the unit housing via a coupling member 19 with a predetermined adjustment stroke (play). The posture of the surface of the pressing plate 7 with respect to the unit can be displaced within the range of the adjustment stroke of the coupling member 19.

  A slit 7b that is an elongated opening is formed in the middle of the pressing plate 7 along the second direction. The slit 7b is an opening for allowing light to pass for reading the inspection pattern. The carriage 6 moves along the longitudinal direction of the slit 7b, and the sensor unit 5 detects reflected light by irradiating light onto the surface of the sheet S from the opening of the slit while moving. That is, the inspection pattern reading position (reading area) is directly below the slit 7b.

  As described above, the push plate 7 has the first elongated portion and the first portion extending over a predetermined range in a direction parallel to the moving direction of the carriage 6 on both sides of the reading position of the sensor unit 5. Has two sites. The first part and the second part may be different parts of a single pressing plate, or may be respective parts of a plate divided into two. A lower part of the sensor unit 5 is provided with a first contact member that contacts the surface of the first part and a second contact member that contacts the surface of the second part when the carriage 6 moves. ing.

  A color calibration plate 15 is provided outside one end of the slit 7b. The color proofing plate 15 functions as a reading reference for performing calibration with respect to changes in reading characteristics of the sensor unit 5 over time due to temperature changes and aging changes. When calibration is performed, the carriage 6 moves to a position where the sensor unit 5 faces the color calibration plate 15, and detection is performed by the sensor unit 5, whereby the color or brightness of the color calibration plate 15 is detected from the output of the detector. Get information about the length.

  The unit of the reading unit 200 can be rotated around the rotation shaft 18 provided upstream of the sensor unit 5 by the moving mechanism 17. The moving mechanism 17 has a driving means including a motor and a worm gear. By the rotation of the unit, an opening that opens and closes on the downstream side is formed between the pressing surface 7a of the pressing plate 7 and the support surface of the fixed guide 16 like a crocodile mouth. If the interval (or angle) H at the most downstream side of the opening is defined, H can vary from zero to a predetermined maximum value.

  The reading unit 200 is in a pressing position (H is zero, referred to as a first position) where the pressing plate 7 presses the support surface during reading. On the other hand, the reading unit 200 is moved by the moving mechanism 17 to a retreat position (H is larger than zero) so that the pressing of the pressing plate 7 is released during the sheet feeding operation and the drying operation. The retreat position is not limited to one, but a second position suitable for step feeding of sheets (minimum value H1 where H is greater than zero), and a third position suitable for drying sheets (H is an intermediate value H3 between maximum and minimum values). A plurality of fourth positions (H is a maximum value H4) suitable for the introduction of the sheet front end can be taken. That is, the push plate 7 is controlled to take four types of positions (postures). When the inspection pattern is read, the pressing plate 7 is pressed against the support surface, so that the slit 7b is completely covered with the fixed guide 16, and external light and ink mist are prevented from entering the scanner unit U from the slit 7b. Is done. For this reason, it is possible to perform highly accurate reading.

  In order to maintain high reading accuracy in the sensor unit 5, it is desirable to keep the relative distance and relative angle between the sensor unit 5 and the surface of the sheet S facing the sensor unit 5 within a predetermined range. In reality, the sheet S may absorb ink and moisture in the air and cause undulation (cockling), or may have curl wrinkles when the sheet S is roll paper. That is, the surface of the sheet S is not necessarily flat. Therefore, at the time of reading, the pressing plate 7 presses the sheet against the support surface of the fixed guide 16 and adjusts it flatly. Since the slit formed in the pressing plate 7 is an opening, the sheet cannot be pressed in that portion, but the width of the slit (the width in the first direction) is very narrow, so the sheet is pressed on both sides of the slit. Thus, the floating of the sheet in the reading area is sufficiently corrected.

  The push plate 7 is easily deformed by a material made of resin such as ABS or PC having a thickness of about 1 to 3 mm so that the surface of the sheet S (particularly, the portion where the inspection pattern P is formed) is hardly damaged. Made of flexible material. On the other hand, the fixed guide 16 is made of a rigid body, and the support surface thereof has higher rigidity than the push plate 7. When the sheet S is pressed by the pressing plate 7, both the sheet S and the pressing plate 7 follow the surface shape (plane) of the fixed guide 16.

  When the sheet S is strongly curled or wavy (cock ring), the flexible push plate 7 may be partially lifted to the floating position of the sheet, and the sheet may be incompletely adhered. There is sex. Even in this case, in the vicinity of the portion where the contact member 8 is on the upper surface of the push plate 7, the contact member 8 intensively presses the push plate 7 with the force of the total weight of the sensor unit 5 and the carriage 6. Therefore, the sheet floating from the support surface is eliminated in the vicinity of the reading position. Therefore, high reading accuracy is maintained.

  In the present embodiment, the interval between the pressing plate 7 and the support surface is changed by rotating the reading unit 200 around the rotation axis and changing the posture, but the present invention is not limited to this. . A form in which the reading unit 200 is moved up and down while maintaining the posture of the reading unit 200, that is, the pressing plate 7 is moved in the vertical direction or the oblique direction while always maintaining a parallel state with the support surface of the fixed guide 16. It may be a form that performs evacuation. FIG. 8 shows an example of a modified example. The entire reading unit 200 moves up and down in an oblique direction indicated by an arrow between a first position where pressing is performed (solid line) and a second position where pressing is released (broken line).

  The drying unit is a unit for promoting the drying of the ink applied to the sheet before reading by the reading unit 200. The drying unit includes a blower 14 including a heater and a drying fan, and a duct 13 that sends warm air generated by the blower 14 toward the surface of the sheet S. Note that the drying unit is not limited to a form including both the heater and the drying fan, and either one may be omitted as long as the necessary drying capacity is exhibited. The duct 13, together with the guide shaft 30, also serves as a reinforcing body that increases the overall rigidity of the unit as a basic structure that constitutes the unit of the reading unit 200. The end of the duct 13 is an air outlet 13a. The blower outlet 13a blows warm air from the mouth having a width equal to or larger than the sheet width of the sheet S to be dried, and can simultaneously dry the entire width of the sheet S immediately below.

  FIG. 4 is a cross-sectional view showing the internal configuration of the drying unit. The left-right direction in the figure is the second direction, which is the sheet width direction. The air outlet 13a has a long hole that blows air over a range that covers the width of the sheet to be used, and the long hole has a plurality of air holes in order to make the air volume in the second direction uniform and to stabilize the direction of the air. The fins 20 are provided at regular intervals. The warm air generated by the blower 14 is rectified by the fins 20 so that the blowing direction is substantially in one direction and each has a uniform air volume (a number of arrows in the figure), and the sheet S is supported on the fixed guide 16. It is sprayed uniformly on the surface of the sheet as long as it covers the sheet width.

  The wind from the blower outlet 13a flows from the downstream to the upstream in the closed space between the push plate 7 and the support surface of the fixed guide 16 in the vertical direction. By blowing the warm air into the closed space in the vertical direction between the fixed guide 16 and the push plate 7, it is possible to efficiently blow air while suppressing the decrease in the wind speed. In particular, the wedge-shaped space becomes narrower toward the upstream side, which has the effect of suppressing a reduction in wind speed.

  In addition, the flow of warm air from the downstream to the upstream is effectively dried because the support surface of the fixed guide 16 before the sheet S hangs down from the fixed guide 16 becomes a drying region. In the present specification, a region where warm air flows from the downstream to the upstream along the sheet surface and a desired drying effect is obtained is referred to as an “effective drying region”. In the sheet conveying direction, the length of the effective drying area is an integral multiple (N times) of a step feed amount to be described later.

  Further, the flow of warm air from the downstream to the upstream of the scanner unit U suppresses the ink mist generated in the upstream printing unit 3 from flowing into the scanner unit U, and the light source and light receiving element of the sensor unit 5 It is possible to prevent the ink mist from becoming dirty.

  FIG. 5 is a system configuration diagram of the printing apparatus according to the present embodiment centering on the control unit 300. A central part of the control unit is a computer system including a CPU 301, an input / output interface 303, a RAM 304, and a ROM 305. These may be configured as ASICs. The CPU 301 controls the entire printing operation, drying operation, reading operation, and calibration operation in accordance with the control program stored in the ROM 305. The RAM 304 is used as a work area at that time. The CPU 301 receives print data, various setting information, and the like from the host computer 302 via the input / output interface 303. The CPU 301 also performs input / output with the operation unit 25. In addition, the CPU 301 drives the transport unit 2 (drive motor), the heater and fan of the blower 14, the moving mechanism 17 (drive motor), the print carriage motor 306, the sensor carriage motor 307, and the print head 308, respectively. Control individually. Further, the CPU 301 receives a signal acquired by the sensor unit 5 and a signal acquired by the temperature / humidity sensor 24, and performs a calibration process or the like based on the input signal.

  Next, an operation of performing calibration (color calibration) by reading an inspection pattern in the printing apparatus having the above configuration will be described. FIG. 6 is an explanatory view showing the state of the apparatus in operation, and FIG. 7 is a flowchart showing an operation sequence controlled by the control unit 300.

  The sheet that can be used in the printing apparatus of the present embodiment is roll paper or cut paper. In step 1, the reading unit 200 is released to the fourth position (maximum interval H4), which is the retracted position, so that the sheet can be conveyed. Then, the sheet S unwound from the roll R of the sheet supply unit 1 is conveyed to the bottom of the printing unit 3 by the conveyance unit 2.

  In step S2, the image P, which is an inspection pattern, is printed on the sheet. When the head of the image forming area of the sheet S is conveyed below the printing unit 3, ink is ejected from the print head while scanning the carriage of the printing unit, and one band is printed on the sheet S. An image P (inspection pattern for calibration) consisting of a plurality of rows of patterns is formed on the sheet S by a serial printing method in which step feeding of one band of the sheet S and printing of one band are alternately repeated. Specifically, while the sheet S is moved in the forward direction, the printing unit 3 sequentially prints the patch rows included in the inspection pattern for each row.

  Thus, the sheet S on which the inspection pattern is formed and introduced into the reading unit 200 moves downstream while being guided on the support surface of the fixed guide 16. When the leading edge of the sheet S passes through the fixed guide 16, it is bent downward by gravity and proceeds in the direction of dropping (state shown in FIG. 6A).

  There is a case where the leading edge of the sheet S being conveyed has a strong curl (broken line in FIG. 6A). Further, there may be a case where the sheet S having high sheet rigidity does not follow the fixed guide 16 and travels in a substantially horizontal direction away from the support surface (one-dot chain line in FIG. 6A). In particular, when the ink is not dried immediately after being applied, the curl tends to increase depending on the applied amount of ink. In the example shown by the broken line in FIG. 6A, the curl is downward, but conversely, the curl may be upward. When the curl is downward or the sheet S advances horizontally, the curled portion of the sheet S is strongly rubbed against the pressing surface 7a of the pressing plate 7, and the ink of the test pattern that is not sufficiently dried adheres to the pressing surface 7a. And the inspection pattern itself may be damaged. In addition, when the curl is upward or the sheet S advances horizontally, the introduced sheet leading edge may enter the slit 7b and cause a conveyance jam.

  With respect to this problem, in the present embodiment, the reading unit 200 is set to the fourth position, so that the interval between the support surface of the fixed guide 16 and the pressing surface 7a of the pressing plate 7 is expanded to the maximum interval H4. Accordingly, even the sheet S as shown by the broken line or the alternate long and short dash line in FIG. 6A is less likely to cause the above-described problem of rubbing or conveyance jam. Of course, with the normal sheet S as shown by the solid line, the above problem does not occur.

  In step S3, the sheet area on which the image P has been printed is conveyed to the effective drying area of the drying unit. When the printing process of the image P is finished, the process proceeds to the drying process before the image reading process in order to promote the drying of the ink applied to the sheet. The reason for forced drying is to shorten the time until the color of the image P formed on the sheet S is stabilized.

  As described above, in the reading unit 200, the scanner unit U and the drying unit are disposed on the downstream side thereof. The sheet S is conveyed until the rear end region (last patch row) of the image P formed on the sheet S skips the scanner unit U and reaches the effective drying region of the drying unit (state of FIG. 6B). . As described above, the effective drying region is a region in which warm air hits during drying and a desired drying effect is obtained. In the sheet conveying direction, the length of the effective drying area is an integral multiple (N times) of a step feed amount to be described later. By setting it as an integral multiple, multiple rows of patches can be dried together in a single drying operation.

  In step S4, the reading unit 200 is switched from the fourth position (maximum interval H4) to the third position (intermediate interval H3). The interval H3 of the third position is suitable for the next drying operation. The blower outlet 13a is in the direction which blows out warm air toward the upstream of a conveyance path | route. That is, the area including the area directly below the scanner unit U on the upstream side of the drying unit is the drying region. By doing so, the escape of warm air is reduced compared to the case where the drying region is taken on the downstream side, and a wide region can be efficiently dried at once (the state of FIG. 6A).

  In step S5, the region where the inspection pattern is formed is forcibly dried. The drying fan and heater of the blower 14 are turned on. Hot air is generated by the blower 14, and the hot air is blown toward the sheet S from the outlet 13 a through the duct 13. The image P of one block area (for example, three rows of patches) located in the effective drying area is forcibly dried. When the time required for drying has passed, the drying fan is turned off to reduce the fan output. The heater remains ON. Here, “OFF” is not limited to a form in which the rotation of the fan is completely stopped, but also includes a form in which the number of rotations of the fan is reduced to a level where vibration is sufficiently reduced.

  In step S6, in order to read the image P, the sheet S is back-fed and fed back in the opposite direction. The sheet S is conveyed in the reverse direction and fed back until the rear end of the area of the image P (the last formed patch row) reaches the reading position immediately below the slit 7b of the scanner unit U. When the reading position is included in the effective drying area and the rear end area is in the reading position, this back feed is not necessary.

  From step S1 to step S6 described above, the reading unit 200 is in the retracted state, and the push plate 7 is separated from the support surface of the fixed guide 16 because of the difference in interval, so that the sheet can freely move through the gap. Can do.

  In step S7, sensor calibration of the reading characteristics of the sensor unit 5 is performed before reading for colorimetry. The sensor unit 5 may change the colorimetric value due to changes in the read value due to the environment and changes over time. For this reason, the sensor unit 5 is calibrated prior to actual reading in step S9.

  Specifically, the carriage 6 is moved to the end portion on the side where the color calibration plate 15 is provided, and the optical characteristic (color) of the color calibration plate 15 is detected by the sensor unit 5. Then, sensor calibration is performed based on the measurement result. In the sensor calibration, the detection result is data-corrected so that the measurement result when the color calibration plate 15 is measured becomes the original reference value. Or you may make it adjust the light emission intensity of the light source contained in the sensor unit 5, and the gain of a light receiving element so that an original output value may be obtained.

  When performing sensor calibration in step S7, the output of the drying fan is reduced in the drying section. Therefore, when reading the color calibration plate, there is no vibration of the fan, and the color calibration plate can be read with high accuracy. If the sensor calibration in step S7 is simultaneously performed during the back feed in step S6, the total throughput is further improved. Note that the movement of the reading unit 200 to the first position may be performed before step S7.

  In step S8, the reading unit 200 is switched from the third position (intermediate interval H3) to the first position (interval zero). The sheet S for pattern reading is pressed between the pressing plate 7 and the support surface of the fixed guide 16 and fixed at the reading position so as not to move (state of FIG. 6D).

  In step S <b> 8, the reading unit 200 rotates about the upstream rotation shaft 18 and descends. The pressing surface 7a of the pressing plate 7 comes into contact with the sheet S on the upstream side first, and the contact surface gradually expands toward the downstream side. Therefore, the sheet S is fixed between the pressing surface 7 a and the support surface of the fixed guide 16 without causing the sheet S to sag or wrinkle. In addition, since the posture of the pressing surface 7a slightly changes following the support surface within the range of the adjustment stroke of the coupling member 19, the surfaces of the pressing surface 7a are completely in contact with each other with the sheet S interposed therebetween.

  In step S9, a part (one line) of the inspection pattern of the sheet S is read by the scanner unit U. As the carriage 6 moves in the second direction, the sensor unit 5 also moves, and the sensor unit 5 reads one row of the inspection pattern on the sheet surface to acquire color information.

  In step S10, the reading unit 200 is switched from the first position (zero interval) to the second position (minimum interval H2). The reading unit 200 shifts from the pressed state to the retracted state, and the pressing of the sheet S by the pressing plate 7 is released (the state shown in FIG. 6E). The interval H2 between the second positions is the minimum interval at which the sheet can be conveyed.

  At the second position set in step S10 (example in FIG. 6E), since the time required to rotate the reading unit 200 to move from the first position to the second position is short, repeated reading is performed. A larger number of columns contributes to an improvement in throughput. If it is known that the sheet S to be used has a characteristic that tends to have a strong curl, in step S10, as shown in FIG. The third position may be set as follows. As parameters reflecting the likelihood of curling, the type of sheet to be used (input by the user from the operation unit 25) and temperature / humidity information inside the print measured by the temperature / humidity sensor 24 can be used. In addition, a recording duty, a print mode (in the high-quality mode in which more ink is applied, the curl is larger than in the normal mode), patch arrangement, and the like can be used as parameters. The control unit 300 sets the interval in the retracted state according to these parameters.

  In step S11, it is determined whether or not reading of a plurality of patch arrays included in the inspection pattern of one block dried in step S5 has been completed (Yes) or not (No). If there is a patch row that has not yet been read in the inspection pattern of one block, the determination is no. If the determination is Yes, the process proceeds to step S12. If the determination is No, the process proceeds to step S13.

  In step S13, the sheet S is fed back by one row in the reverse direction so that the next patch of the one row of patches read immediately before is at the reading position. And it returns to step S8 and repeats the same sequence. As described above, when reading the pattern, the inspection pattern formed over a plurality of rows is repeatedly read by the sensor unit for each row and the step feed (back feed) of the sheet. . Then, in the reading for each row, the pressing plate 7 and the support surface of the fixed guide 16 are pressed, and in the step feed, the pressing is released.

  As described above, the reading unit 200 including the push plate 7 can be transported by retracting the entire unit from the sheet, so that it is possible to move to the sheet transport operation wherever the carriage 6 is. After reading in the forward path of the carriage 6 that reciprocates in step 9, the carriage home position returning operation is performed during the subsequent movement of the reading unit 200 (step S10) to step S13 (step feed). In this case, the total throughput is greatly improved. As an alternative method, reading is performed on the forward path and the backward path when the carriage is reciprocally moved, and a step feed is performed after reading a row of patterns on the forward path, and then a pattern of the next row is read on the backward path. May be performed.

  In step S12, it is determined whether or not all the patterns of the plurality of blocks constituting the entire inspection pattern have been read (Yes) or not (No). If the determination is yes, the process proceeds to step S15, and if the determination is no, the process proceeds to step S14.

  In step S14, the sheet S is fed until the pattern of the next block comes to the effective dry area. Then, returning to step S4, the same sequence is repeated from the drying of the pattern of the next block. In the second and subsequent drying steps, natural drying is added for the time spent in the previous step, and therefore it is preferable to reduce the drying time or drying capacity in anticipation thereof.

  In step S15, the sheet S for which all the pattern reading has been completed is cut by the cutter unit 4, sent in the forward direction, and discharged from the printing apparatus.

  In step S16, color-related calibration processing is performed. Information on the color of the pattern is acquired based on the data obtained by the pattern reading in step S8. Then, the control unit performs color calibration for adjusting the amount of ink applied by the print head of each color so that a desired color is reproduced in the final print result.

  By the way, drying of the next sheet area sent to the reading position by the step feed in step S13 is promoted by the drying unit before reading the sheet area. Although the drying section reduces the output of the drying fan in order to reduce vibration, the heater is operating and thus has a certain level of drying capacity. That is, during the reading of a certain row included in the inspection pattern and during the step feed, the sheet area including another row to be read later is forcibly dried.

  The vibration of the drying fan can affect the reading. Therefore, reducing the output of the drying fan is limited to the time when the scanner unit U is scanning, and if the output of the drying fan is increased during step feeding, the total throughput can be further improved. it can. If the throughput is further improved, drying may be performed with the maximum capacity while the scanner unit U is scanning. In this case, the drying unit preferably uses a low-vibration drying fan or directly irradiates the sheet surface with an infrared heater that does not generate vibration.

  During the step feeding and reading, the time interval from one step feeding to the next step feeding is a predetermined time T suitable for sheet drying so that the subsequent patch row is in an appropriate dry state. It is preferable to manage with a timer. A method for determining the predetermined time and a processing sequence of the reading operation will be described.

  The distance M for one step feed, the length L in the transport direction of the effective drying area, and K the total time for forcibly drying one patch. As described above, L is an integral multiple of M, that is, L / M = N (N is an integer equal to or greater than 1). Using these parameters, the predetermined time T is determined as T = K / N. Using the predetermined time T determined in this way, repeated reading processing is performed.

  In step S13 in FIG. 7, before step feed (back feed), wait is performed until the time measured by the timer reaches a predetermined time T (wait process). Specifically, the timer of the control unit 300 is used to start the timer counting simultaneously with the start of the process of step S8. And if it branches to step S13 through the process of step S9-step S11, it waits until the measured value of a timer reaches | attains predetermined time T. FIG. When it reaches, start step feeding. As a result of such processing, individual patches included in the inspection pattern have a total drying time K, and are read in an appropriate dry state. If the drying capacity of the drying unit during reading and step feeding is appropriately set, the necessary drying can be performed in one cycle of reading and step feeding. In this case, the above-described wait processing is not necessary.

  In this way, if the timer management is introduced and the subsequent patch train is in a form in which an appropriate dry state can be obtained during step feeding and reading, the prior drying process in step S5 in FIG. The determination and the sending process in step S14 can be omitted.

  FIG. 9 is a diagram illustrating an example of an inspection pattern formed on a sheet. A large number of color patches 42 and sample images 41 for comparison before and after color calibration are mixed. The layout of the color patch 42 and the sample image 41 can be freely set by the user.

  In this example, the color patch 42 has six rows from the a row to the f row in the conveyance direction A (back feed direction) of the sheet S. The f row is the patch row on the most downstream side (sheet front end side), and the inspection unit is formed by the print unit 3 in the order of the f row to the a row. The a row and the b row are formed in a range from B to D, which is almost the entire sheet width. The subsequent columns c, d, e, and f are printed in the range from B to C, which is about half the sheet width. A sample image 41 is formed in the remaining half of the range from C to D.

  The color patch 42 formed in such a layout is read one column at a time from the a column to the f column while repeating the step feed of the back feed. The B side is the home position of the carriage 6.

  The sheet S on which these inspection patterns are formed by the printing unit 3 is back-fed until the first row a reaches the reading position immediately below the slit 7b. At this time, the reading unit 200 is in the second position (press release). Next, the reading unit 200 is moved to the first position (pressing), and the sheet S is pressed between the pressing plate 7 and the support surface 16a. While the carriage 6 is scanned and moved from B to D, the sensor unit 5 reads the patch rows in the a row one by one in the order from B to D. Next, the reading unit 200 is moved to the second position, and the sheet S is stepped by a distance corresponding to one patch in the backfeed direction. Then, the reading unit 200 is moved again to the first position, and while the carriage 6 is scanned and moved from D to B, the sensor unit 5 reads the patch rows in the b row one by one in the order from D to B. . When the reading of row b is completed, the reading unit 200 is moved to the second position, and the sheet S is stepped in the back feed direction.

  As described above, the scanning direction of reading is alternately switched for each column. As described above, the scanning direction for reading each patch row may always be the same direction (B to D). In this case, the operation of returning the carriage 6 to the home position (B side) is performed while the sheet S is being stepped.

  Subsequently, when reading the patch rows c and d, the scanning range is set to a distance corresponding to the length of the patch row in the sheet width direction. While the reading unit 200 is moved to the first position and the carriage 6 is scanned and moved from B to C, the sensor unit 5 reads the patch rows in the c row one by one in the order from B to C. Next, the reading unit 200 is moved to the second position, and the sheet S is stepped in the back feed direction. Then, the reading unit 200 is moved to the first position, and while the carriage 6 is scanned and moved from C to B, the sensor unit 5 reads the patch rows in the d row one by one in the order of C to B. When reading of the d-row is completed, the reading unit 200 is moved to the second position, and the sheet S is stepped in the back feed direction.

  In this way, since it is possible to shift to the next column without scanning the area of the sample image 41 that does not require color measurement, the reading throughput can be improved. Further, since the carriage 6 does not travel on the sample image 41, the contact member 8 does not strongly press the sample image 41 via the flexible pressing plate 7, and the damage to the sample image 41 is small.

  Subsequently, when reading the e- and f-line patch rows, the scanning range is set to a distance corresponding to the length of the patch row in the sheet width direction. However, in this example, after the e-row reading, a sensor calibration process for maintaining a constant reading characteristic of the sensor that may change depending on the temperature is interrupted. In the sensor calibration, the sensor unit 5 reads the color information on the surface of the color calibration plate 15 and adjusts the sensor or corrects the sensor output so that a correct reading result is obtained.

  While the reading unit 200 is moved to the first position and the carriage 6 is scanned and moved from B to C, the sensor unit 5 reads the patch row of the e row one by one in the order of B to C. Here, a sensor calibration process is performed before reading the f-th column. Since the color calibration plate 15 is provided on the B side, it is necessary to move the sensor unit 5 to that position. While the reading unit 200 is moved to the second position and the sheet S is step-feeded in the back feed direction, the carriage 6 is moved from C to B, and further moved to the outside above the color proofing plate 15. Then, the scanner unit 50 is moved to the first position, and the sensor unit 5 reads the surface of the color calibration plate 15 to acquire color information. The control unit 300 performs sensor calibration processing based on the acquired color information. When the sensor calibration processing is completed, the last f-row patch rows are read in the order of B to C in the same manner as described above, and when the carriage is returned to the home position, a series of processing is terminated.

  When all the patch rows have been read in this way, the control unit 300 performs color calibration for adjusting the amount of ink applied by the print head of each color so that a desired color is reproduced in the final print result. .

  According to the embodiment described above, the total throughput and the reading accuracy when sequentially reading a plurality of rows of inspection patterns are improved. That is, it is possible to achieve both reduction of the total time required for calibration of the apparatus and improvement of accuracy. As a result, the calibration time, which is a non-productive time for the user of the apparatus, is reduced, and more time can be allocated to the original image printing, thereby improving the productivity in the printing operation.

  In particular, in the present embodiment, in the repetition of reading and backfeed step feeding, a sheet area including another row to be read later is dried in the drying unit while reading a certain row and performing step feeding. Is one of the features. In a sequence in which the inspection pattern is read by repeating three steps of drying, reading, and step feeding, the reading and step feeding processing and the drying processing overlap in time to perform parallel processing, so the total throughput is greatly improved. .

  Furthermore, in this embodiment, there is no conveyance roller downstream from the printing unit 3, and one of the features is that reading is performed by repeating step feed of back feed. The inspection pattern printed by the printing unit 3 is not nipped by the conveyance roller until at least reading by the scanner unit U is completed. Therefore, no matter how long the inspection pattern to be formed becomes long in the transport direction, scratches are not given to the pattern before reading and ink stains do not adhere to the transport roller, and high accuracy over a long period of time. Can be read.

  Furthermore, in this embodiment, the reading unit 200 is a unit in which the pressing plate 7 that presses the support surface on which the sheet is supported and the carriage 6 that holds the sensor unit 5 and reciprocates on the pressing plate 7 are integrated. This is one of the structural features. As a result, the reading unit 200 including the push plate 7 can retreat the entire unit from the sheet and can carry the sheet, so that the sheet carrying operation is started regardless of the carriage 6 on the push plate 7. Can do. This greatly contributes to the improvement of the total throughput in the sequence of reading the inspection pattern by repeating reading and step feeding. In addition, since the carriage 6 is always on the pressing plate 7 without a step, no impact is generated during traveling. Therefore, the sensor failure due to the deterioration of the mounting accuracy of the sensor unit 5 hardly occurs, and high reading accuracy is maintained over a long period of time.

DESCRIPTION OF SYMBOLS 3 Print part 5 Sensor unit 6 Carriage 7 Press plate 16 Fixed guide 200 Reading part U Scanner part

Claims (16)

A reading unit including a sensor unit that reads information on the sheet, a pressing plate that presses a support surface on which the sheet is supported, and a carriage that holds the sensor unit and moves on the pressing plate;
The reading unit is moved to a first position where the pressing plate presses the support surface during the reading and a second position where the pressing is released when the sheet is moved on the support surface. A moving mechanism
A reading apparatus comprising:   The reading apparatus according to claim 1, wherein the moving mechanism rotates the reading unit to move the reading unit to the first position and the second position.   The reading apparatus according to claim 1, wherein the moving mechanism moves the reading unit up and down relative to the support surface to move the reading unit to the first position and the second position.   4. The reading apparatus according to claim 2, wherein the support surface has an inclined surface whose downstream side falls in the direction of gravity, and the pressing plate is inclined so as to follow the inclined surface at the first position. 5. The push plate has a first part and a second part extending over a predetermined range in a direction parallel to the moving direction of the carriage on both sides of the reading position of the sensor unit,
A lower part of the sensor unit includes a first contact member that contacts the surface of the first part when the carriage moves, and a second contact that contacts the surface of the second part when the carriage moves. The reading apparatus according to claim 1, wherein a contact member is provided.   The reading apparatus according to claim 5, wherein both of the first contact member and the second contact member are rotating bodies that are in contact with the surface of the pressing plate and are driven to rotate.   The reading device according to claim 1, wherein the pressing plate is made of a flexible member having rigidity smaller than that of the support surface.   A printing apparatus comprising: a printing unit that records information on a sheet; and the reading device according to claim 1.   The printing apparatus according to claim 8, wherein a conveyance roller for conveying the sheet is provided upstream of the printing unit, and no conveyance roller is provided downstream of the printing unit.   The sheet on which the pattern is formed by the printing unit is conveyed so that the area on which the pattern is formed passes through a position where the sensor unit reads, and then the sheet is conveyed in the reverse direction by the sensor unit. The printing apparatus according to claim 8, wherein the pattern is read. With respect to the pattern formed over a plurality of rows, reading the pattern in one row and moving the step of the sheet with the sensor unit while moving the carriage is performed,
11. The printing apparatus according to claim 10, wherein the reading unit is in the first position during reading for each row, and the reading unit is in the second position during step feeding. 11. .   The second position has a plurality of different distances between the pressing plate and the support surface, and compared with a case where a sheet tip of a sheet on which a pattern is formed in the print unit is introduced on the support surface. The printing apparatus according to claim 11, wherein the interval is reduced when the step feeding is performed.   12. The reading apparatus according to claim 11, wherein the carriage returns to the home position during the step feed.   It is possible to perform the reading in each of the forward path and the backward path when the carriage reciprocates, and the step feed is performed after the reading of the pattern in one line in the forward path, and then the pattern in the next line in the backward path. The printing apparatus according to claim 11, wherein:   The said reading part further includes the drying part which blows a wind on a sheet | seat, The said drying part is provided in the downstream rather than the said sensor unit, The any one of Claims 9-14 characterized by the above-mentioned. Printing device. The printing apparatus according to claim 9, wherein the reading apparatus can be detached from the printing apparatus as a unit.

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