JP5852522B2 - Skew correction device and printing device - Google Patents

Description

The present invention relates to the skew correction instrumentation 置及 beauty printing device.

  2. Description of the Related Art Conventionally, in a printing apparatus, a transport unit that transports a medium such as printing paper and a print head that prints an image such as a character on the transported medium are disposed, and the medium transported by the transport unit is a predetermined medium. It is sent to the printing position. By the way, skew, that is, skewing may occur in the medium conveyed by the conveying means. Therefore, the printing apparatus includes a skew correction device that corrects the skew of the medium (see, for example, Patent Document 1).

  The skew feeding correction device includes a medium abutting portion, and aligns the medium by bringing the leading end of the conveyed medium into contact with the medium abutting portion. The skew feeding correction device includes a plurality of optical (light transmission type) medium detection sensors on the most upstream side in the medium conveyance direction, and the conveyance roller moves the medium downstream based on the detection result of the medium detection sensor. Rotating operation to transport in the direction. Further, a plurality of optical (light transmission type) skew detection sensors are disposed downstream of the transport roller and upstream of the medium abutting portion.

  When at least two adjacent skew detection sensors arranged in the width direction of the medium detect the medium, it is determined that the medium is aligned by the medium abutting portion. On the other hand, when only one skew detection sensor detects the medium, it is determined that the medium is skewed. Thereby, it is possible to accurately determine whether or not the medium is aligned at the medium abutting portion.

JP 2005-15184 A

  However, the conventional skew correction apparatus uses a light transmission type skew detection sensor that does not mechanically contact the medium to detect the medium but detects the medium in a non-contact manner. Therefore, it may not be possible to accurately determine whether the media are aligned.

  If the medium does not transmit light, such as ordinary printing paper, the skew detection sensor can detect the leading edge of the medium, and thus can accurately determine whether the medium is aligned. . However, in the case of a medium such as a passbook with a transparent book cover, the leading end may be transparent. In the case of such a medium, since the leading end of the medium transmits light, the leading end of the medium cannot be detected. Therefore, even if the medium is aligned by the medium abutting section, it is determined that the medium is aligned. However, there is a problem that processing on the downstream side in the medium conveyance direction is stagnated.

  Of course, it is conceivable to use a skew detection sensor capable of detecting even a material having a high light transmittance or to provide a circuit system separately, but in this case, the cost becomes high. Although it is conceivable to change the position of the skew detection sensor, in this case, since the applicability is poor, the detection target is limited to a specific medium.

The present invention solves the problems in the above-described conventional skew correction device, and is capable of reliably determining skew of a medium having a highly light-transmitting portion at the tip while having a simple configuration. and to provide a printing apparatus having a skew correction apparatus and the skew correction apparatus capable of preventing the stagnation of the process on the downstream side.

Therefore, in the skew correction device of the present invention, a medium that conveys the medium along the conveyance path, and a medium alignment that is disposed downstream of the conveyance means in the conveyance path and opens and closes the conveyance path. Means, a second medium detecting means disposed between the conveying means and the medium aligning means in the conveying path, and a first medium disposed upstream of the second medium detecting means in the conveying path. A medium detection unit; and a control device that controls operations of the transport unit and the medium alignment unit based on detection results of the first and second medium detection units. The control device includes the first and second control units. Based on the detection result of the medium detecting means, the medium is a transparent part determining means for determining whether or not the medium has a transparent part at the tip part, and after the first medium detecting means detects the medium, The medium alignment hand When the second medium detecting means does not detect the medium, the medium is placed at the leading end portion. A transparent portion determining means for determining that the medium has a transparent portion; and when the transparent portion determining means determines that the medium has a transparent portion at a leading end portion, the conveyance path is opened to the medium aligning means. After that, the medium is conveyed downstream by the conveying means until the second medium detecting means detects the medium, and the skew amount of the medium is an allowable value based on the detection result of the second medium detecting means. a skew determining means for determining at either above, the oblique determination means determines that the amount of skew of the medium is not less than the allowable value, and conveys the medium to the upstream by the conveying means

  According to the present invention, the skew correction device can reliably determine skew of a medium having a highly light-transmitting portion at the tip, and can prevent stagnation of processing on the downstream side in the transport direction. .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side perspective view showing a main part of a skew feeding correction apparatus and a printing apparatus having the skew feeding correction apparatus in a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective perspective view of a skew correction device and a printing apparatus having the skew correction device according to a first embodiment of the present invention. It is a perspective view which shows the medium detection sensor and skew feeding sensor in the 1st Embodiment of this invention. 1 is a block diagram illustrating a functional configuration of a skew feeding correction device and a printing apparatus including the skew feeding correction device according to a first embodiment of the present invention. It is a figure which shows the booklet-shaped medium in the 1st Embodiment of this invention. It is a 1st figure which shows operation | movement of the skew correction apparatus in the 1st Embodiment of this invention. It is a 2nd figure which shows operation | movement of the skew correction apparatus in the 1st Embodiment of this invention. It is a figure which shows operation | movement of the conveyance roller press means in the 1st Embodiment of this invention. It is a 1st flowchart which shows operation | movement of the skew correction apparatus in the 1st Embodiment of this invention, and the printing apparatus which has this skew correction apparatus. It is a 2nd flowchart which shows operation | movement of the skew correction apparatus in the 1st Embodiment of this invention, and the printing apparatus which has this skew correction apparatus. It is a side perspective view which shows the principal part of the skew correction apparatus and printing apparatus which has this skew correction apparatus in the 2nd Embodiment of this invention. It is a block diagram which shows the function structure of the skew correction apparatus in the 2nd Embodiment of this invention, and the printing apparatus which has this skew correction apparatus. It is a figure which shows the booklet-shaped medium in the 2nd Embodiment of this invention. It is a 1st figure which shows operation | movement of the skew feeding correction apparatus in the 2nd Embodiment of this invention. It is a 2nd figure which shows operation | movement of the skew feeding correction apparatus in the 2nd Embodiment of this invention. It is a flowchart which shows operation | movement of the skew correction apparatus in the 2nd Embodiment of this invention, and the printing apparatus which has this skew correction apparatus.

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

  FIG. 1 is a side perspective view illustrating a main part of a skew feeding correction apparatus and a printing apparatus having the skew feeding correction apparatus according to the first embodiment of the present invention, and FIG. 2 is a skew perspective view according to the first embodiment of the present invention. FIG. 3 is a perspective view showing the medium detection sensor and the skew detection sensor in the first embodiment of the present invention. FIG. 3 is a perspective view of the line correction device and the printing apparatus having the skew correction device.

  1 and 2, reference numeral 10 denotes a printer, that is, a printing apparatus according to the present embodiment, which is an apparatus for printing on a medium, and a skew correction apparatus for correcting skew of the medium, that is, skew. Have The printing apparatus 10 may be an apparatus that performs printing by any method, for example, a printing apparatus such as an ink jet method, a thermal method, or a thermal transfer method, but here, an apparatus that performs printing by a wire dot method. It is assumed that The medium may be of any type as long as it is a printable medium. For example, the medium is a printing sheet such as a cut sheet. Here, as will be described later, a passbook issued by a financial institution is used. A booklet-like medium 51 in which a plurality of sheets are stacked and bundled in a booklet shape as described above, and a transparent book cover is applied to the cover, and the front end portion is a transparent portion that transmits light. Is also included.

  In the present embodiment, the printing apparatus 10 is a so-called serial impact horizontal printer, and as shown in FIG. 2, a print head 11 that moves left and right by a space motor about a carriage shaft and a conveying means. It has an upper roller 13a as one roller, a lower roller 13b as a second roller, and a plate-like platen 12 extending in the left-right direction. As shown in FIG. 1, the lower roller 13b is pressed against the upper roller 13a by conveying roller pressing means including a slide rack 25 and a spring 26. The pressing force for pressing the lower roller 13b against the upper roller 13a is adjusted by a conveying roller pressing force adjusting motor 27 which is a motor for driving the conveying roller pressing means. Specifically, since the rack gear formed on the slide rack 25 meshes with a pinion gear attached to the shaft of the transport roller pressing force adjusting motor 27, the transport roller pressing force adjusting motor 27 is driven. As a result, the slide rack 25 moves in the left-right direction, and the position of the lower end of the spring 26 is raised and lowered to increase or decrease the pressing force for pressing the lower roller 13b against the upper roller 13a. When the upper roller 13a and the lower roller 13b are described in an integrated manner, they will be described as the transport roller 13.

  Then, as shown in FIG. 2, the medium is placed on a table indicated as A, and is inserted until the tip of the medium hits the transport roller 13. When the medium detection sensor 15 detects that the medium has been set against the conveying roller 13, the conveying roller 13 is driven, and the medium is sandwiched from above and below by the upper roller 13a and the lower roller 13b, and is indicated by an arrow B. It is conveyed in the conveyance direction (sub-scanning direction) that is the direction in which the image is transferred. The print head 11 includes a plurality of wires, that is, dot pins, moves in the left-right direction (main scanning direction) to selectively drive the dot pins, and strikes the ink ribbon at the tip of the dot pins. (Tap) to print on the medium. The platen 12 is a member that absorbs the impact of the dot pins of the print head 11, and is arranged in parallel with the print head 11 across the medium conveyance path.

  As shown in FIG. 1, on the upstream side in the medium conveyance direction of the conveyance roller 13, a medium detection sensor 15 as a first medium detection means for detecting a medium, that is, a light emission side which is an optical transmission type sensor. A medium detection sensor 15a and a light reception side medium detection sensor 15b are disposed above the medium conveyance path, and a prism 19 that forms part of an optical path from the light emission side medium detection sensor 15a to the light reception side medium detection sensor 15b. It is disposed below the medium conveyance path. On the other hand, on the downstream side of the conveyance roller 13 in the medium conveyance direction, a skew detection sensor 16 as a second medium detection unit that detects the skew of the medium, that is, a light reception side skew detection sensor that is an optical transmission type sensor. 16a and the light-emission-side skew detection sensor 16b are arranged above and below the medium conveyance path. When the light emitting side medium detection sensor 15a and the light receiving side medium detection sensor 15b are described in an integrated manner, they are described as the medium detection sensor 15, and the light receiving side skew detection sensor 16a and the light emitting side skew detection sensor 16b are integrated. In the following description, the skew detection sensor 16 will be described. A plurality of the medium detection sensors 15 and the skew feeding detection sensors 16 are basically arranged at equal intervals in the width direction of the medium (direction perpendicular to the medium conveyance direction). The arrangement positions of the medium detection sensor 15 and the skew detection sensor 16 are such that, regardless of the position in the main scanning direction, the medium is set and the skew correction can be performed by detecting that the medium has been set. In addition, even if the medium is the minimum width medium used in the printing apparatus 10, the medium detection sensor 15 is set so that at least it can detect the medium.

  Further, on the downstream side in the medium conveyance direction of the skew detection sensor 16 and on the upstream side in the medium conveyance direction of the platen 12, a medium alignment plate 17 as medium alignment means for aligning the medium is arranged to be movable in the vertical direction. Has been. With respect to the medium conveyance direction, the skew detection sensor 16 and the medium alignment plate 17 are close to each other. Specifically, the distance between the skew detection sensor 16 and the medium alignment plate 17 is about 1 [mm]. Since the rack gear formed on the medium alignment plate 17 meshes with a pinion gear attached to the shaft of the medium alignment plate drive motor 22, the medium alignment plate 17 is moved up and down by driving the medium alignment plate drive motor 22. Move in the direction to open and close the transport path of the medium. Further, a medium width sensor 24 for detecting the size of the medium in the main scanning direction, that is, the medium width, is attached to the print head 11 located above the platen 12 with the medium conveyance path interposed therebetween.

  Here, a plurality of pairs of light emitting side medium detecting sensors 15a and light receiving side medium detecting sensors 15b and a plurality of light receiving side skew detecting sensors 16a are mounted on the upper sensor circuit board 18a as shown in detail in FIG. A plurality of light emission side skew detection sensors 16b are mounted on the lower sensor circuit board 18b. In FIG. 3, the dotted arrows connecting the light emitting side medium detecting sensor 15a and the light receiving side medium detecting sensor 15b indicate the optical path of the sensor light from the light emitting side medium detecting sensor 15a to the light receiving side medium detecting sensor 15b. The dotted arrows connecting the light receiving side skew detecting sensor 16a and the light emitting side skew detecting sensor 16b indicate the optical path of the sensor light from the light emitting side skew detecting sensor 16b to the light receiving side skew detecting sensor 16a. Yes. Further, in FIG. 3, the prism 19 that is disposed below the medium conveyance path and forms part of the optical path of the sensor light from the light emitting side medium detecting sensor 15 a to the light receiving side medium detecting sensor 15 b is omitted. ing.

  Further, as shown in FIG. 1, the upper roller 13a and the lower roller 13b, the light emission side medium detection sensor 15a and the light reception side medium detection sensor 15b, and the light reception side skew detection sensor 16a and the light emission side skew detection sensor. A cover 23 covering 16b is arranged above and below the medium transport path. Further, a conveyance roller drive motor 21 for driving the conveyance roller 13 is disposed in the vicinity of the lower roller 13b.

  The skew correction device in the present embodiment includes the transport roller 13, the medium detection sensor 15, the skew detection sensor 16, the medium alignment plate 17, and various members for driving them.

  Next, the functional configuration of the skew correction device and the printing apparatus 10 having the skew correction device will be described.

  FIG. 4 is a block diagram showing a functional configuration of the skew feeding correction apparatus and the printing apparatus having the skew feeding correction apparatus according to the first embodiment of the present invention.

  In the figure, reference numeral 30 denotes a control device that controls the operation of the printing apparatus 10, and includes a print head 11, a medium detection sensor circuit 37 including a plurality of medium detection sensors 15, and a skew detection sensor including a plurality of skew detection sensors 16. The AC / DC power supply unit 41 serving as a power supply unit of the printing apparatus 10 and printing are connected to the circuit 36, the conveyance roller drive motor 21, the medium alignment plate drive motor 22, and the conveyance roller pressing force adjustment motor 27. It is connected to an external computer 47 as a host device of the device 10. The AC / DC power supply unit 41 functions as a power source that converts an AC current into a DC current and supplies the DC current to each unit of the printing apparatus 10, and the external computer 47 outputs print data to be printed by the printing apparatus 10. Create and send.

  The control device 30 drives a controller 31 that is a SoC (System-on-a-Chip) that integrates a microprocessor and memories such as a ROM and a RAM into a single chip. A crystal oscillator 32 that is a crystal oscillator (OSC), a memory such as a flash-ROM, a program storage means 33 for storing a program of the controller 31, and each medium detection sensor 15 included in the medium detection sensor circuit 37. The state of each skew detection sensor 16 included in the first analog selector 34 and the skew detection sensor circuit 36 that switches the state and inputs to the A / D port of the controller 31 is switched and input to the A / D port of the controller 31. The second analog selector 35, the external computer 47 An I / F driver / receiver 42 for controlling the communication, a print head driver 43 for driving the print head 11, a medium alignment plate opening / closing driver 44 for driving the medium alignment plate driving motor 22, and the transport roller driving motor 21. A conveying roller driving driver 45 for driving the conveying roller, and a conveying roller pressing force adjusting driver 46 for driving the conveying roller pressing force adjusting motor 27.

The control device 30 always detects the state of the medium detection sensor 15, specifically, the output voltage level of the light receiving side medium detection sensor 15b. A plurality of the medium detection sensors 15 are basically arranged at regular intervals in the width direction of the medium (main scanning direction). The arrangement position of the medium detection sensor 15 is such that, regardless of the position in the main scanning direction, the medium can be detected and the skew correction can be performed by detecting that the medium has been set, and the medium is a printing device. 10 is set so that at least two medium detection sensors 15 can detect even the smallest width medium used in the above-mentioned medium. Therefore, as shown in FIG. 3, when any one of the medium detection sensors 15 arranged side by side in the left-right direction (main scanning direction) detects the medium, the medium detection sensor circuit 37 passes through the medium detection sensor circuit 37. You can grasp the existence. Since the medium detection sensor 15 is a light transmission type, it is ON when the medium is not detected (the output voltage level of the light reception side medium detection sensor 15b is high), and the light reception side medium detection sensor 15a detects the light reception side medium. When the optical path to the sensor 15b is interrupted by the medium, the medium is detected by turning OFF (the output voltage level of the light receiving side medium detection sensor 15b is low). The state of each medium detection sensor 15 included in the medium detection sensor circuit 37 is switched by the first analog selector 34 and input to the A / D port of the controller 31, so which medium detection sensor 15 detects the medium. Can be clearly identified. The A / D port constantly monitors the cycle operation and can monitor the voltage level at a period of 9.3 [μs]. Specifically, the period is determined by the following equation.
1/48 [MHz] * Divide by 4 * 14 [CLK] * 4 ports * 8 Select = 9.3 [μs]
Further, the control device 30 always detects the state of the skew detection sensor 16, specifically, the output voltage level of the light receiving side skew detection sensor 16a. A plurality of the skew detection sensors 16 are basically arranged at equal intervals in the width direction of the medium (main scanning direction). The arrangement position of the skew detection sensor 16 is such that, regardless of the position in the scanning direction, the medium can be detected and the skew correction can be performed by detecting that the medium has been set. The minimum width medium used in 10 is set so that it can be detected by at least two skew detection sensors 16. Similarly to the medium detection sensor 15, the skew detection sensor 16 is a light transmission type, and is ON when the medium is not detected (the output voltage level of the light reception side skew detection sensor 16a is high). When the optical path from the skew detection sensor 16b to the light receiving side skew detection sensor 16a is interrupted by the medium, the medium is detected by turning OFF (the output voltage level of the light receiving side skew detection sensor 16a is low). Since the state of each skew detection sensor 16 included in the skew detection sensor circuit 36 is switched by the second analog selector 35 and input to the A / D port of the controller 31, which skew detection sensor 16 uses the medium. It is possible to clearly identify whether it has been detected. The A / D port constantly monitors the cycle operation and can monitor at the same level as that of the medium detection sensor 15, but the voltage of the eight skew detection sensors 16 is applied to the second analog selector 35. Therefore, a delay of 8 selections occurs. However, the reading cycle of the medium detection sensor 15 can be shortened by adding a new analog selector. Further, the skew detection sensor 16 that monitors the state can be limited based on the state of the medium detection sensor 15.

  The print head driver 43 is a circuit that drives each dot pin of the print head 11 that forms characters. The I / F driver / receiver 42 is an interface element for connection with an external computer 47. Further, the medium alignment plate opening / closing driver 44 is a circuit that outputs a drive signal for driving and rotating the medium alignment plate drive motor 22, and the transport roller drive driver 45 rotates by driving the transport roller drive motor 21. The conveying roller pressing force adjustment driver 46 is a circuit that outputs a driving signal for driving and rotating the conveying roller pressing force adjusting motor 27.

  Next, operations of the skew correction device having the above-described configuration and the printing apparatus 10 having the skew correction device will be described. Here, only the operation from conveying the medium to starting printing will be described.

  FIG. 5 is a diagram showing a booklet-shaped medium according to the first embodiment of the present invention, FIG. 6 is a first diagram showing the operation of the skew feeding correction apparatus according to the first embodiment of the present invention, and FIG. FIG. 8 is a diagram showing the operation of the conveying roller pressing means in the first embodiment of the present invention, and FIG. 9 is a diagram showing the operation of the skew correction device in the first embodiment of the invention. FIG. 10 is a first flowchart showing the operation of the skew correction device and the printing apparatus having the skew correction device according to the first embodiment, and FIG. 10 shows the skew correction device according to the first embodiment of the present invention. It is a 2nd flowchart which shows operation | movement of the printing apparatus which has a skew feeding correction apparatus. 5A is a first diagram showing the state of the medium, FIG. 5B is a second diagram showing the state of the medium, and FIG. 5C is an enlarged view of the main part of the medium. 7, (a) to (g) are diagrams showing the steps of the operation of the skew feeding correction device. In FIG. 8, (a) and (b) are diagrams showing the steps of the operation of the transport roller pressing means. It is.

  Here, when the medium is a normal medium such as a printing sheet, and as shown in FIG. 5, a plurality of sheets 53 are stacked and bundled in a booklet form like a passbook issued by a financial institution. A case where the booklet medium 51 is a booklet medium 51 having a transparent book cover 52 on the cover will be described. The booklet-like medium 51 is indicated by an arrow B from A which is an insertion opening in a state where the binding portion 54 binding the plurality of sheets 53 is centered. It shall be inserted in the direction to be transported and transported. 5A shows a state in which the first sheet 53 appears, and FIG. 5B shows a state in which printing is possible by turning the page from the state shown in FIG. 5A. Thus, the second and subsequent sheets 53 are shown. FIG. 5C is an enlarged view of the portion C in FIG. 5A, and the leading end portion (the left end portion in the figure) that is a predetermined distance range from the leading end of the booklet-shaped medium 51 has high transparency. It shows that the transparent portion 55 transmits light. Even in the state shown in FIG. 5B, the leading end portion of the booklet-shaped medium 51 is a transparent portion 55. Therefore, when the booklet-shaped medium 51 is inserted into the printing apparatus 10 in the state shown in FIG. 5B, the transparent portion 55 is inserted at the tip.

  First, a medium is inserted from A which is an insertion port of the printing apparatus 10 by an operator (step S1). When the medium is a booklet-shaped medium 51, the medium is inserted in a state as shown in FIG. The control device 30 determines the state of the medium detection sensor 15 (step S2). Specifically, when the medium detection sensor 15 is ON, the determination as to whether or not the medium detection sensor 15 is OFF is repeated and waits. Note that OFF means that the optical path from the light emitting side medium detection sensor 15a to the light receiving side medium detection sensor 15b is blocked by the medium. Further, the position of the medium detection sensor 15 is a distance longer than the length of the transparent portion 55 on the upstream side of the nip portion (medium abutting portion) of the conveyance roller 13 in the medium conveyance direction (the portion of the paper 53 in the transparent book cover 52). Can be detected).

  Then, when the medium detection sensor 15 is turned OFF, the control device 30 determines that the medium detection sensor 15 has detected the medium, drives the conveyance roller pressing force adjustment motor 27, and as shown in FIG. The pressing force of the conveying roller 13, that is, the pressing force that presses the lower roller 13b against the upper roller 13a is weakened (step S3). Specifically, as shown in FIG. 8B, the slide rack 25 is moved in the direction of the arrow by rotating the shaft of the conveying roller pressing force adjusting motor 27, and the lower end position of the spring 26 is lowered. Thus, the pressing force for pressing the lower roller 13b against the upper roller 13a is reduced.

  Subsequently, the control device 30 drives the medium alignment plate driving motor 22 to raise and close the medium alignment plate 17 as shown in FIG. 6B (step S4). That is, the medium transport path is closed.

  Further, the control device 30 drives the transport roller drive motor 21 to perform a certain amount of rotation of the transport roller 13 as shown in FIG. 6C (step S5). Specifically, the upper roller 13 a and the lower roller 13 b are simultaneously rotated by a certain amount, and the front end of the medium is brought into contact with the medium alignment plate 17. The fixed amount is a rotation amount corresponding to the distance from the center position of the upper roller 13a and the lower roller 13b to the medium alignment plate 17. Thereby, the skew correction of the medium is performed.

  And the control apparatus 30 judges the detection number of the skew detection sensor 16 (step S6). That is, as shown in FIG. 3, it is determined how many of the skew detection sensors 16 arranged in the left-right direction (main scanning direction) are turned off to detect the medium. Note that OFF means that the optical path from the light emission side skew detection sensor 16b to the light reception side skew detection sensor 16a is blocked by the medium. Then, based on the detection result of the skew detection sensor 16, specifically, based on the number of detections of the skew detection sensor 16, the control device 30 determines whether or not the skew amount of the medium is greater than or equal to the allowable value. Judging. Note that a plurality of skew detection sensors 16 are arranged at equal intervals so that the two skew sensors 16 can detect even the minimum length of the medium to be used in the scanning direction. . For example, an allowable skew is set by setting an allowable skew amount based on the relationship between the distance between the two skew sensors 16 and the rotation amount (medium transport amount) of the transport roller 13 for transporting the medium at the time of detection. It is determined whether or not the amount is a line amount.

  Here, when the number of detection of the skew detection sensor 16 is 0, the control device 30 further determines whether or not the number of retries has expired (step S7), that is, the number of retries has not expired, that is, If it has not been completed, the process returns to step S5 and a certain amount of rotation of the transport roller 13 is repeated. The number of retries is set in advance.

  Even if the upper roller 13a and the lower roller 13b are rotated by a certain amount, the actual transport distance changes for each medium due to a change in friction between the upper roller 13a and the lower roller 13b and the medium. For this reason, in many cases, the medium does not reach the position detected by the skew detection sensor 16 in the first conveyance. Therefore, the medium is retried, that is, the upper roller 13a and the lower roller 13b are rotated by a certain amount. It is necessary to redo the contact of the front end of the head with the medium alignment plate 17.

  However, when the medium is a booklet-shaped medium 51, the leading end portion is a transparent portion 55 and the skew detection sensor 16 is close to the medium alignment plate 17, so that it is shown in FIG. As described above, even when the front end of the booklet-shaped medium 51 abuts against the medium alignment plate 17, the skew detection sensor 16 is not turned off and the booklet-shaped medium 51 cannot be detected.

  Further, when the number of detection of the skew detection sensor 16 is determined in step S6 and the number of detection of the skew detection sensor 16 is two or more, the control device 30 determines that the medium does not include the transparent portion 55, That is, it is determined that the medium is a normal medium (step S8). Since the plurality of skew detection sensors 16 arranged in the left-right direction, that is, in the medium width direction, detect the medium, the control device 30 determines that the skew amount of the medium is less than the allowable value. Then, it is determined that the skew correction of the medium has been normally completed (step S9), the conveying roller pressing force adjusting motor 27 is driven, and the pressing force of the conveying roller 13, that is, the lower roller 13b is changed to the upper roller. The pressing force pressed against 13a is increased (step S10). Specifically, as shown in FIG. 8A, the slide rack 25 is moved in the direction of the arrow by rotating the shaft of the conveying roller pressing force adjusting motor 27, and the lower end position of the spring 26 is raised. Thus, the pressing force for pressing the lower roller 13b against the upper roller 13a is increased.

  Subsequently, the control device 30 drives the medium alignment plate driving motor 22 to lower the medium alignment plate 17 to open (step S11). That is, the medium conveyance path is opened. Then, the control device 30 drives the transport roller drive motor 21 to rotate the transport roller 13 to feed the medium (step S12), and transport the medium to the lower side of the print head 11. Specifically, the medium is transported downstream in the transport direction until the medium width sensor 24 attached to the print head 11 detects the medium. In this case, since the pressing force of the transport roller 13 is strong, skew does not occur when the medium is transported downstream in the transport direction. Here, the medium width sensor 24 detects the leading edge of the medium. When the medium is detected by the medium detection sensor 15, the print head 11 is moved in advance so that the medium width sensor 24 is arranged on the medium.

  When the medium width sensor 24 detects the medium (step S13), the control device 30 drives the print head 11, starts the printing operation (step S14), and ends the process.

  In addition, when the number of detection by the skew detection sensor 16 is determined in step S6 and the number of detection is 1, the control device 30 determines that the medium is a normal medium that does not include the transparent portion 55 ( Step S15). Since only one of the skew detection sensors 16 arranged side by side in the width direction of the medium detects the medium, the control device 30 determines that the skew amount of the medium is equal to or greater than an allowable value. The medium is skewed, that is, it is determined that the medium is not parallel to the medium alignment plate 17 (step S16), the conveyance roller pressing force adjusting motor 27 is driven, and the conveyance roller 13 The pressing force, that is, the pressing force for pressing the lower roller 13b against the upper roller 13a is increased (step S17).

  Subsequently, the control device 30 drives the transport roller drive motor 21, rotates the transport roller 13 in the reverse direction, and retracts a certain amount of medium upstream in the transport direction (step S18). Then, the control device 30 determines whether or not the number of retries has expired (step S19). If the number of retries has not expired, that is, if it has not been completed, the control device 30 returns to step S3, and thereafter Repeat the operation. On the other hand, when the number of retries has expired, a certain amount of reverse rotation of the transport roller 13 is performed (step S20). Specifically, the upper roller 13a and the lower roller 13b are simultaneously reversely rotated by a certain amount to convey the medium upstream in the conveying direction.

  When the medium is discharged from A, which is the insertion port of the printing apparatus 10 (step S21), the control apparatus 30 ends the process.

  In step S7, it is determined whether the number of retries has expired. If the number of retries has expired, the control device 30 determines the state of the medium detection sensor 15 (step S23). This is because the conveyance retry, that is, the rotation of the upper roller 13a and the lower roller 13b by a certain amount and the contact of the front end of the medium with the medium alignment plate 17 is repeated a predetermined number of times. This is because the number of detections of the skew detection sensor 16 is 0, so that the medium detection sensor 15 located upstream of the skew detection sensor 16 in the transport direction confirms the presence or absence of the medium.

  If the medium detection sensor 15 is ON, the control device 30 saves the error (step S22) and ends the process. The fact that neither the skew detection sensor 16 nor the medium detection sensor 15 detects the medium even after the conveyance retry is performed for a preset number of times is obviously an irregular phenomenon, and the medium is special. Or there is a possibility that a malfunction has occurred in the elements such as the skew detection sensor 16 and the medium detection sensor 15 and the circuit in the control device 30, so that the conveyance roller 13 is rotated in the reverse direction and the medium is inserted. It is necessary to save the error of discharging from the mouth A.

  On the other hand, when the medium detection sensor 15 is OFF, since the medium detection sensor 15 has detected the medium, the control device 30 determines that the tip portion is the medium of the transparent portion 55. That is, it is determined that the medium is the booklet-shaped medium 51 (step S24).

  Subsequently, as shown in FIG. 7E, the control device 30 drives the conveying roller pressing force adjusting motor 27 to push the pressing force of the conveying roller 13, that is, the lower roller 13b against the upper roller 13a. The pressing force to be pressed is increased (step S25), and the medium alignment plate drive motor 22 is driven to lower the medium alignment plate 17 to open (step S26).

  Subsequently, the control device 30 drives the transport roller drive motor 21 to perform a certain amount of minute rotation of the transport roller 13 (step S27). Specifically, the transport roller 13 is rotated by a certain minute rotation amount, for example, about 1/360 rotations, and the booklet medium 51 is transported downstream in the transport direction by a slight distance.

  And the control apparatus 30 judges the detection number of the skew detection sensor 16 (step S28). Here, when the number of detections of the skew detection sensor 16 is 0, the control device 30 further determines whether or not the number of retries has expired (step S29), that is, the number of retries has not expired, that is, If it has not been completed, the process returns to step S27, and a certain amount of minute rotation of the transport roller 13 is repeated. That is, the operation of transporting the booklet medium 51 little by little in the transport direction is repeatedly performed by the preset number of retries until detected by the skew detection sensor 16. If the number of retries has expired, the retry is terminated and the routine proceeds to step S20, where a certain amount of reverse rotation of the transport roller 13 is performed, and when the booklet medium 51 is discharged from A, the processing is terminated. To do.

  On the other hand, when the number of detections of the skew detection sensor 16 is determined and the number of detection is one, the control device 30 drives the transport roller drive motor 21 again to perform a certain amount of slight rotation of the transport roller 13. Perform (step S30). Specifically, the transport roller 13 is rotated by a fixed minute rotation amount, for example, a constant multiple of 1/360 rotations, for transporting the booklet-like medium 51 downstream in the transport direction by a distance that allows the skew amount. Let

  Subsequently, the control device 30 determines again the detection number of the skew detection sensor 16 (step S31). When the number of detections is 1, the control device 30 determines that the skew amount of the booklet medium 51 is equal to or greater than the allowable value and the booklet medium 51 is skewed. When it is determined that the sheet is not parallel to the medium alignment plate 17 (step S32), the process proceeds to step S20 to perform a certain amount of reverse rotation of the transport roller 13, and the booklet medium 51 is discharged from A. The process is terminated.

  In addition, when the number of detection of the skew detection sensor 16 is determined in step S28 and step S31 and the number of detection is two or more, the control device 30 indicates that the skew amount of the booklet-shaped medium 51 is less than the allowable value. Then, it is determined that the skew correction of the booklet-shaped medium 51 has been normally completed (step S33), and the conveyance roller drive motor 21 is driven and the conveyance roller 13 is rotated as shown in FIG. Then, the medium is fed (step S34). Then, the process proceeds to step S13, and as shown in FIG. 7G, when the medium width sensor 24 detects the booklet-like medium 51, the control device 30 drives the print head 11 to start the printing operation. The process ends. After determining that the number of detections of the skew detection sensor 16 is zero and the leading end portion is the medium of the transparent portion 55 and then opening (opening) the medium alignment plate 17, the plurality of skew detection sensors 16 are set in advance. It is determined that it is within the allowable skew feeding amount based on whether it is detected while the transport roller 13 is rotating (medium transport). In that case, the leading end portion of the booklet-shaped medium 51 in the transparent book cover 52 is detected.

Next, a flowchart will be described.
Step S1: A medium is inserted from A.
Step S2: The state of the medium detection sensor 15 is determined. When the medium detection sensor 15 is OFF, the process proceeds to step S3, and when the medium detection sensor 15 is ON, the determination as to whether or not the medium detection sensor 15 is OFF is repeated and waits.
Step S3: The pressing force of the transport roller 13 is weakened.
Step S4 The medium alignment plate 17 is raised and closed.
Step S5 A certain amount of rotation of the transport roller 13 is performed.
Step S6: The number of detection by the skew detection sensor 16 is determined. If the number of detection of the skew detection sensor 16 is zero, the process proceeds to step S7, and if the number of detection of the skew detection sensor 16 is two or more, the process proceeds to step S8, where the number of detection of the skew detection sensor 16 is If there is one, the process proceeds to step S15.
Step S7: It is determined whether or not the number of retries has expired. If the number of retries has expired, the process proceeds to step S23, and if the number of retries has not expired, the process returns to step S5.
Step S8: It is determined that the medium is a normal medium.
Step S9: It is determined that the medium skew correction has been normally completed.
Step S10: The pressing force of the conveying roller 13 is increased.
Step S11: The medium alignment plate 17 is lowered and opened.
Step S12: Medium feeding is performed.
Step S13: The medium width sensor 24 detects the medium.
Step S14 The printing operation is started and the process is terminated.
Step S15: It is determined that the medium is a normal medium.
Step S16: It is determined that the medium is not parallel to the medium alignment plate 17.
Step S17: The pressing force of the transport roller 13 is increased.
Step S18: A certain amount of medium is retracted upstream in the transport direction.
Step S19: It is determined whether or not the number of retries has expired. If the number of retries has expired, the process proceeds to step S20, and if the number of retries has not expired, the process returns to step S3.
Step S20 A certain amount of reverse rotation of the transport roller 13 is performed.
Step S21: The medium is ejected from A, and the process ends.
Step S22: The error is saved and the process is terminated.
Step S23: Determine the state of the medium detection sensor 15. When the medium detection sensor 15 is OFF, the process proceeds to step S24, and when the medium detection sensor 15 is ON, the process proceeds to step S22.
Step S24: It is determined that the tip portion is the medium of the transparent portion 55.
Step S25: The pressing force of the conveying roller 13 is increased.
Step S26: The medium alignment plate 17 is lowered and opened.
Step S27 A certain amount of minute rotation of the transport roller 13 is performed.
Step S28: The detection number of the skew detection sensor 16 is determined. If the number of detection of the skew detection sensor 16 is 0, the process proceeds to step S29. If the number of detection of the skew detection sensor 16 is 1, the process proceeds to step S30, and the number of detection of the skew detection sensor 16 is 2. If the number is greater than or equal to, the process proceeds to step S33.
Step S29: It is determined whether or not the number of retries has expired. If the number of retries has expired, the process proceeds to step S20, and if the number of retries has not expired, the process returns to step S27.
Step S30 A certain amount of minute rotation of the transport roller 13 is performed.
Step S31: The number of detection by the skew detection sensor 16 is determined. When the number of detection of the skew detection sensor 16 is one, the process proceeds to step S32, and when the number of detection of the skew detection sensor 16 is two or more, the process proceeds to step S33.
Step S32: It is determined that the booklet medium 51 is not parallel to the medium alignment plate 17.
Step S33: It is determined that the skew correction of the booklet medium 51 has been completed normally.
Step S34 The medium is fed.

  As described above, in the skew correction device and the printing apparatus 10 having the skew correction device according to the present embodiment, the medium is the transparent portion 55 through which the transparent book cover 52 is applied and the tip portion transmits light. Even in the case of the booklet-shaped medium 51, as in the case of a normal medium such as a printing paper, it is possible to correct the skew of the medium and determine whether or not the skew correction is appropriately performed. it can. Therefore, even if the medium is the booklet-shaped medium 51, printing can be performed after correcting the skew as in the case of the normal medium. Even if the skew correction is performed, if the medium is skewed, the medium is discharged without printing, so that the operation becomes easy.

  Next, a second embodiment of the present invention will be described. In addition, about the thing which has the same structure as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operations and effects as those of the first embodiment is omitted.

  FIG. 11 is a side perspective view showing a main part of a skew feeding correction apparatus and a printing apparatus having the skew feeding correction apparatus according to the second embodiment of the present invention, and FIG. 12 is a skew perspective view according to the second embodiment of the present invention. It is a block diagram which shows the function structure of a printing apparatus which has a line correction apparatus and this skew correction apparatus.

  In the present embodiment, as shown in FIG. 11, the printing apparatus 10 includes an upper roller drive motor 21 a for driving the upper roller 13 a as a transport roller drive motor 21 for driving the transport roller 13, and a lower roller motor 21 a. A lower roller drive motor 21b for driving the side roller 13b, and the upper roller 13a as the first roller and the lower roller 13b as the second roller are independently driven and rotated. Be able to.

  For this purpose, as shown in FIG. 12, the control device 30 in the present embodiment is a circuit that outputs a drive signal that drives and rotates the upper roller drive motor 21a as the transport roller drive driver 45. It has a driver 45a and a lower roller drive driver 45b which is a circuit for outputting a drive signal for driving and rotating the lower roller drive motor 21b.

  Since the configuration of other points is the same as that of the first embodiment, description thereof is omitted.

  Next, the operation of the skew feeding correction apparatus and the printing apparatus 10 having the skew feeding correction apparatus in the present embodiment will be described.

  FIG. 13 is a diagram showing a booklet-shaped medium according to the second embodiment of the present invention, FIG. 14 is a first diagram showing the operation of the skew feeding correction apparatus according to the second embodiment of the present invention, and FIG. FIG. 16 shows the operation of the skew feeding correction apparatus according to the second embodiment of the invention, and FIG. 16 shows the skew feeding correction apparatus and the printing apparatus having the skew feeding correction apparatus according to the second embodiment of the present invention. It is a flowchart which shows operation | movement. In FIG. 13, (a) is a first view showing the state of the medium, (b) is a second view showing the state of the medium, and (c) to (e) are first to third views of the medium. FIG. 14 is an enlarged view of a main part, and in FIGS. 14 and 15, (a) to (f) are diagrams illustrating steps of the operation of the skew feeding correction device.

  In the present embodiment, the operation when the medium is a normal medium such as a printing paper is the same as that in the first embodiment, so the description thereof is omitted, and the book cover 52 having a transparent medium is used. Only the operation when it is discriminated that the front end portion is the booklet-like medium 51 having the transparent portion 55 that transmits light will be described. Therefore, here, it is determined whether or not the number of retries has expired in step S7 of the flowchart in the first embodiment, and only the operation when the number of retries has expired will be described.

  In addition, here, as shown in FIG. 13, the medium is a book in which a plurality of sheets 53 are stacked and bundled in a booklet like a passbook issued by a financial institution, and is transparent on the cover. A case where the booklet medium 51 is provided with a book cover 52 will be described. The booklet-like medium 51 is inserted in the direction indicated by the arrow B from the insertion opening A in a state where the booklet medium 51 is spread so that the binding portion 54 binding the plurality of sheets 53 is centered. And shall be transported. 13A shows a state in which the first sheet 53 appears, and FIG. 13B shows a state in which printing is possible by turning the page from the state shown in FIG. 13A. Thus, the second and subsequent sheets 53 are shown.

  FIG. 13C is a first enlarged view of the portion C in FIG. 13A, and a leading end portion (left end portion in the drawing) that is a predetermined distance range from the leading end of the booklet-shaped medium 51 is shown in FIG. The transparent portion 55 has high transparency and transmits light, and the front end of the book cover 52 and the front end of the paper 53 are parallel to each other. FIG. 13D is a second view in which the portion C in FIG. 13A is enlarged. When the transparent portion 55 is large, that is, the distance from the front end of the book cover 52 to the front end of the paper 53 is increased. Shows the long case. Further, FIG. 13E is a third enlarged view of the portion C in FIG. 13A, and shows a case where the front end of the book cover 52 and the front end of the paper 53 are not parallel but skewed. Show. In the present embodiment, when the booklet-like medium 51 with the transparent book cover 52 is detected in the first embodiment, the skew feeding amount exceeds the allowable range. When the paper 53 is obliquely covered in the transparent book cover 52 shown in d) and (e), the book cover 52 is made independent by driving the medium that sandwiches and transports the booklet-like medium 51. The user wants to align the inner paper 53.

  In step S7 of the flowchart in the first embodiment, it is determined whether or not the number of retries has expired. If the number of retries has expired, the control device 30 determines the state of the medium detection sensor 15 (step S7). S41). This is because the conveyance retry, that is, the rotation of the upper roller 13a and the lower roller 13b by a certain amount and the contact of the front end of the medium with the medium alignment plate 17 is repeated a predetermined number of times. This is because the number of detections of the skew detection sensor 16 is 0, so that the medium detection sensor 15 located upstream of the skew detection sensor 16 in the transport direction confirms the presence or absence of the medium.

  When the medium detection sensor 15 is OFF, as shown in FIG. 14A, the medium detection sensor 15 detects the medium. It is determined that it is a medium. That is, it is determined that the medium is the booklet-shaped medium 51 (step S42).

  On the other hand, when the medium detection sensor 15 is ON, the control device 30 saves an error (step S57) and ends the process. The fact that neither the skew detection sensor 16 nor the medium detection sensor 15 detects the medium even after the conveyance retry is performed for a preset number of times is obviously an irregular phenomenon, and the medium is special. Or there is a possibility that a malfunction has occurred in the elements such as the skew detection sensor 16 and the medium detection sensor 15 and the circuit in the control device 30, so that the conveyance roller 13 is rotated in the reverse direction and the medium is inserted. It is necessary to save the error of discharging from the mouth A.

  Subsequently, as shown in FIG. 14B, the control device 30 drives the conveying roller pressing force adjusting motor 27, and the pressing force of the conveying roller 13, that is, the lower roller 13b is set against the upper roller 13a. The pressing force to be pressed is increased (step S43), and the control device 30 further drives the upper roller driving motor 21a and the lower roller driving motor 21b to rotate the upper roller 13a and the lower roller 13b in reverse by a certain amount. Let That is, a certain amount of reverse rotation of the transport roller 13 is performed (step S44). The fixed amount is specifically a rotation amount corresponding to the distance that the booklet-like medium 51 is caught in the transport roller 13.

  Subsequently, as shown in FIG. 14C, the control device 30 drives the conveying roller pressing force adjusting motor 27 to weaken the pressing force of the conveying roller 13 (step S45). Only the upper roller drive motor 21a is driven, and only the upper roller 13a is rotated by a certain amount. That is, only a certain amount of rotation is performed only on the upper roller 13a (step S46). Thereby, as shown in FIG. 13D, when the transparent portion 55 is large, or as shown in FIG. 13E, the front end of the book cover 52 and the front end of the paper 53 are not parallel, and Even when the paper is being carried out, the paper 53 moves relative to the book cover 52 in the direction of the arrow B, so that the transparent portion 55 is small, as shown in FIG. The front end of the book cover 52 and the front end of the paper 53 are corrected to be in a parallel state.

  Subsequently, the control device 30 determines the detection number of the skew detection sensor 16 (step S47). Here, when the number of detection of the skew detection sensor 16 is 1 or more, the control device 30 proceeds to step S57, performs error saving, and ends the processing. Since the medium is determined to be the booklet-like medium 51 in step S42, the transparent portion 55 is present at the tip portion, and in the state as shown in FIG. 14C, the skew detection sensor 16 should not be turned off. In other words, one or more skew detection sensors 16 are turned off even though the number of detection of the skew detection sensor 16 should be zero, that is, the number of detection of the skew detection sensor 16 is one. This means that there is a suspicion that the skew detection sensor 16 malfunctions, and therefore it is necessary to perform error evacuation in which the conveyance roller 13 is rotated in the reverse direction and the medium is ejected from the insertion port A.

  On the other hand, when the number of detections of the skew detection sensor 16 is determined to be 0 in step S47, the control device 30 drives the conveyance roller pressing force adjustment motor 27 as shown in FIG. The pressing force of the conveying roller 13, that is, the pressing force pressing the lower roller 13b against the upper roller 13a is increased (step S48), and the medium alignment plate 17 is lowered by driving the medium alignment plate driving motor 22. In this state, the upper roller driving motor 21a and the lower roller driving motor 21b are driven to move the upper roller 13a and the lower roller 13b to a certain minute rotation amount, for example, 1/360. Rotate about the rotation, that is, perform a certain amount of minute rotation of the transport roller 13 (step S50), and transport the booklet-shaped medium 51 by a small distance downstream in the transport direction.

  Subsequently, the control device 30 determines the number of detections of the skew detection sensor 16 (step S51). Here, when the number of detections of the skew detection sensor 16 is 1 or less, the control device 30 determines whether or not the number of retries has expired since the skew amount of the booklet-shaped medium 51 is greater than or equal to an allowable value. (Step S52), if the number of retries has not expired, that is, if it has not been completed, the process returns to step S50, and a certain amount of minute rotation of the transport roller 13 is repeated. That is, the operation of transporting the booklet medium 51 by a small distance downstream in the transport direction is repeatedly performed for a preset number of retries until two or more skew detection sensors 16 detect it. If the number of retries has expired, the control device 30 ends the retry, proceeds to step S57, saves an error, and ends the process.

  On the other hand, when the number of detections of the skew detection sensor 16 is determined and the number of detections is 2 or more, the control device 30 determines that the skew amount of the booklet-like medium 51 is less than the allowable value, and FIG. As shown in e), it is determined that the skew correction of the booklet-shaped medium 51 has been normally completed (step S53). Subsequently, the control device 30 drives the upper roller driving motor 21a and the lower roller driving motor 21b, rotates the conveying roller 13, feeds the medium (step S54), and feeds the booklet-shaped medium 51 to the print head 11. Transport to below. Specifically, the booklet medium 51 is transported downstream in the transport direction until the medium width sensor 24 attached to the print head 11 detects the booklet medium 51.

  Then, as shown in FIG. 15F, when the medium width sensor 24 detects the medium (step S55), the control device 30 drives the print head 11 to start the printing operation (step S56). Exit.

Next, a flowchart will be described.
Step S41: Determine the state of the medium detection sensor 15. When the medium detection sensor 15 is OFF, the process proceeds to step S42, and when the medium detection sensor 15 is ON, the process proceeds to step S57.
Step S42: It is determined that the tip portion is the medium of the transparent portion 55.
Step S43: The pressing force of the conveying roller 13 is increased.
Step S44 A certain amount of reverse rotation of the transport roller 13 is performed.
Step S45: The pressing force of the transport roller 13 is weakened.
Step S46: A certain amount of rotation is performed only on the upper roller 13a.
Step S47: The number of detection by the skew detection sensor 16 is determined. When the number of detection of the skew detection sensor 16 is zero, the process proceeds to step S48, and when the number of detection of the skew detection sensor 16 is one or more, the process proceeds to step S57.
Step S48: The pressing force of the transport roller 13 is increased.
Step S49 The medium alignment plate 17 is lowered and opened.
Step S50 A certain amount of minute rotation of the transport roller 13 is performed.
Step S51: The number of detection by the skew detection sensor 16 is determined. When the number of detection of the skew detection sensor 16 is 1 or less, the process proceeds to step S52, and when the number of detection of the skew detection sensor 16 is 2 or more, the process proceeds to step S53.
Step S52: It is determined whether or not the number of retries has expired. If the number of retries has expired, the process proceeds to step S57, and if the number of retries has not expired, the process returns to step S50.
Step S53: It is determined that the skew correction of the booklet medium 51 has been completed normally.
Step S54: Medium feeding is performed.
Step S55 The medium width sensor 24 detects the medium.
Step S56 The printing operation is started and the process is terminated.
Step S57: The error is saved and the process is terminated.

  Thus, in the present embodiment, the upper roller 13a and the lower roller 13b of the transport roller 13 can be independently driven and rotated, so that the medium is a booklet. In the case of the medium 51, by rotating only the upper roller 13a, the leading end of the book cover 52 and the leading end of the sheet 53 are aligned, and the sheet feeding is performed in a state where the sheet 53 is not parallel to the medium alignment plate 17. Can be greatly reduced.

  In the case where the medium is not the booklet-like medium 51 but a normal medium, or the booklet-like medium 51 is not provided with the book cover 52, the flowchart in the first embodiment. If it is determined in step S6 that the number of detection of the skew detection sensor 16 is one or more, skew correction can be performed normally and printing can be performed accurately.

  In the first and second embodiments, even if the medium is a medium having a transparent portion 55 having a high transmittance at the tip portion, for example, a booklet medium 51 having a transparent book cover 52 on the cover, A skew correction device that corrects skew of a medium and enables printing and a printing apparatus having the skew correction device have been described. The present invention relates to a dot impact printer that performs printing by a wire dot method, an inkjet method, and the like. The present invention can be applied to an apparatus that performs printing on a medium, such as an inkjet printer that performs printing, a thermal printer that performs printing by a thermal method, or a thermal transfer method. Also, the present invention can be applied when a medium is inserted in an image reading apparatus or an image processing apparatus.

  Furthermore, the number of the medium detection sensors 15 and the skew detection sensors 16 is not limited to the description of the first and second embodiments, and can be arbitrarily changed according to the skew correction angle. it can. In addition, it is possible to adopt a method of opening / closing the medium alignment plate 17 and increasing / decreasing the pressing force of the conveying roller 13 by switching the mode with one motor.

  Further, the block diagrams shown in FIGS. 4 and 12 can be easily changed in configuration and the sensor state can be detected depending on the performance of the microcomputer used.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

  The present invention can be used for a skew correction device and a printing apparatus having the skew correction device.

DESCRIPTION OF SYMBOLS 10 Printing apparatus 11 Print head 13a Upper side roller 13b Lower side roller 15a Light emission side medium detection sensor 15b Light reception side medium detection sensor 16a Light reception side skew detection sensor 16b Light emission side skew detection sensor 17 Medium alignment plate 30 Controller 51 Booklet-like medium 52 Book cover 55 Transparent part

Claims (4)

Transport means for transporting the medium along the transport path;
Medium alignment means disposed on the downstream side of the conveying means in the conveying path and opening and closing the conveying path;
A second medium detecting means disposed between the conveying means and the medium aligning means in the conveying path;
First medium detection means disposed upstream of the second medium detection means in the transport path;
A control device for controlling the operations of the conveying means and the medium aligning means based on the detection results of the first and second medium detecting means;
The control device, said medium based on a detection result of the first and second media sensing means is a transparent portion judgment means for judging whether or not provided with a transparent portion to the tip portion, said first After the medium detection means detects the medium, the medium alignment means closes the conveyance path, the medium is conveyed downstream by the conveyance means and brought into contact with the medium alignment means, and the second medium detection means When the medium is not detected , the transparent portion determining means determines that the medium has a transparent portion at the tip portion, and the transparent portion determining means has the transparent portion at the tip portion. If it is determined that the after opening the conveyance path to the medium aligning means, to transport the medium to the downstream by the conveying means to said second medium detection means detects said medium, said second medium Leaving a skew determining means for skew amount of the medium based on a detection result of means determines a whether or tolerance, the skew amount of the oblique determination means the medium is larger than the allowable value The skew correction apparatus, wherein the medium is conveyed upstream by the conveying means. Said conveying means comprising a first roller and the second roller facing each other, the pressing force of the second roller against the first roller, Ri strength changeable der by the conveying roller pressing means, the first roller and the second roller Can be rotated independently of each other,
When the transparent portion determining means determines that the medium has a transparent portion at the leading end portion, the control device reduces only the first roller by reducing the pressing force of the second roller against the first roller. The second medium detecting unit rotates the first roller and the second roller by rotating the first medium aligning unit to rotate the first roller and the second roller with a strong pressing force of the second roller against the first roller. There skew correction apparatus according to claim 1, Ru is conveyed to the medium downstream to the detection of the medium. The skew determination means rotates the first roller and the second roller with a strong pressing force of the second roller against the first roller, and the medium is detected until the second medium detection means detects the medium. After transporting downstream, if it is determined that the skew amount of the medium is greater than or equal to an allowable value based on the detection result of the second medium detection means, the operation of transporting the medium downstream is performed a preset number of times. The skew feeding correction device according to claim 2 , wherein the skew feeding correction device repeats within the range up to A printing apparatus having the skew correction device according to any one of claims 1 to 3 and having a print head disposed downstream of the medium alignment unit.

Images