JP2007331314A - Inkjet recorder and its controlling method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an inkjet recording technique whereby a detection accuracy for a tip part of a cut rolled sheet is enhanced, and whether or not cutting processing is required can be judged on the basis of a state of the detected tip part. <P>SOLUTION: The inkjet recorder carries out recording by delivering ink to a recording medium while moving a recording head with a plurality of nozzles back and forth by a carriage. The inkjet recorder comprises a detecting means which is carried on the carriage and detects the tip part of the recording medium, a determining means which determines a detection region for detecting the state of the tip part of the recording medium on the basis of the detection result, and a judging means which judges on the basis of the state of the recording medium detected in the determined detection region whether or not cutting processing of cutting the tip part of the recording medium by a cutter is required. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ink jet recording technique for performing recording by discharging ink.

  In a large-format printer that prints on roll paper, there are cases where an image cannot be printed correctly because the leading end cut according to the storage state of the roll paper is inappropriate for printing. Inappropriate states assumed here are dirt, tears, wrinkles, etc. at the tip.

  Conventionally, such a problem has been dealt with by cutting and discarding the leading end of the roll paper.

  However, the conventional countermeasures described above have the disadvantage that the roll paper is wasted because it is cut even when there is no problem with the roll paper. In addition, it is possible to leave the user whether or not to cut the leading edge of the roll paper. In this case, however, the user's judgment is required every time the roll paper is set, which reduces operability and convenience. It is not preferable.

For such a problem, a technique is described in which the contour of the leading end of the roll paper is detected and falls within the standard value range (see, for example, Patent Document 1).
JP 2001-146052 A

  However, even if the technique of the above-mentioned Patent Document 1 is used, the present situation is that it is not possible to cope with the deterioration of print quality due to dirt and wrinkles on the roll paper.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve the detection accuracy of the leading end portion of the cut roll paper and to determine whether or not the cutting process is necessary based on the detected state of the leading end portion. Is to realize.

  In order to solve the above problems and achieve the object, the present invention provides an inkjet recording apparatus that performs recording by ejecting ink onto a recording medium while reciprocally scanning a recording head having a plurality of nozzles with a carriage. A detecting unit mounted on a carriage for detecting a leading end portion of the recording medium; and a determining unit for determining a detection region for detecting a state of the leading end portion of the recording medium based on the detection result. And determining means for determining whether or not a cutting process for cutting the front end portion of the recording medium with a cutter is performed based on the state of the recording medium detected in the detection area.

  The present invention also provides a control method for an ink jet recording apparatus that performs recording by ejecting ink onto a recording medium while reciprocally scanning a recording head having a plurality of nozzles with a carriage, and includes a detection unit mounted on the carriage. A detecting step for detecting a leading end portion of the recording medium; a determining step for determining a detection region for detecting a state of the leading end portion of the recording medium based on the detection result; and a detection in the determined detection region. A determination step of determining whether or not a cutting process for cutting the leading end portion of the recording medium with a cutter is performed based on the state of the recording medium.

  According to the present invention, the detection accuracy of the leading end of the cut roll paper can be improved and the necessity of the cutting process can be determined based on the detected state of the leading end, so that the user can avoid waste of the roll paper. Usability and convenience can be improved.

  Hereinafter, an embodiment according to the present invention will be described in detail with reference to the drawings.

  The embodiment described below is an example as means for realizing the present invention, and should be appropriately modified or changed according to the configuration of the apparatus to which the present invention is applied and various conditions. It is not limited to the embodiment.

  In the present embodiment, “print” is not only formed when significant information such as characters and figures is formed, but also manifested so that humans can perceive it visually. Whether or not. That is, a case where an image, a pattern, a pattern, or the like is widely formed on a recording medium or a medium is processed is also expressed.

  “Paper” is not only paper used in general printers, but also widely represents cloth, plastic film, metal plate, glass, ceramics, wood, leather, etc. that can accept ink. To do.

  Furthermore, “ink” should be interpreted widely as the definition of “print” above, and is applied on paper to form images, patterns, patterns, etc., or process paper, or process ink. Represents a liquid that can be subjected to Examples of the ink treatment include solidification or insolubilization of the colorant in the ink applied to the paper.

  Further, the “nozzle” is a generic term for an ejection port or a liquid passage communicating with the nozzle and an element that generates energy used for ink ejection unless otherwise specified.

[Schematic description of inkjet printer (FIG. 1)]
FIG. 1 is a perspective view showing an ink jet printer according to an embodiment of the present invention with an upper cover removed.

  As shown in FIG. 1, a manual insertion slot 88 is provided on the front surface of an inkjet printer (hereinafter referred to as printer) 2, and a roll paper cassette 89 that can be opened and closed to the front surface is provided below the manual insertion slot 88. As a result, a recording medium such as paper (hereinafter, paper) is supplied from the manual insertion slot 88 or the roll paper cassette 89 into the printer. The printer 2 includes an apparatus main body 94 supported by two leg portions 93, a stacker 90 for stacking discharged sheets, and an upper cover 91 that is transparent and can be opened and closed. Further, on the right side of the apparatus main body 94, an operation panel 12, an ink supply unit, and an ink tank are arranged.

  The printer 2 includes a transport roller 70 for transporting the paper in the arrow B direction (sub-scanning direction), and a carriage unit (hereinafter referred to as “reciprocating” in the width direction of the paper (arrow A direction, main scanning direction)). Carriage) 4 is provided. The printer 2 also includes a carriage motor (not shown) and a carriage belt 3 for reciprocating the carriage 4 in the direction of arrow A. In addition, the printer 2 supplies an ink jet recording head (hereinafter referred to as a print head) 11 mounted on the carriage 4 and a suction type for supplying ink and eliminating ink ejection defects due to clogging of ejection ports of the print head 11. And an ink recovery unit 9.

A print head 11 composed of six heads corresponding to six color inks is mounted on the carriage 4 in order to perform color recording on paper.
That is, the print head 11 ejects, for example, a K head that ejects K (black) ink, a C head that ejects C (cyan) ink, an M head that ejects M (magenta) ink, and a Y (yellow) ink. It is composed of a Y head. Further, the print head 11 includes an LC head that ejects LC (light color cyan) ink and an LM head that ejects LM (light color magenta) ink.

  As described above, after the sheet is conveyed to the predetermined recording start position by the conveyance roller 70, the operation of causing the carriage 4 to scan the print head 11 in the main scanning direction, and the operation of conveying the sheet by the conveyance roller 70 in the sub-scanning direction. Is repeated to record on the entire sheet.

  That is, the carriage 4 is moved in the direction of arrow A shown in FIG. 1 by the carriage belt 3 and a carriage motor (not shown), and recording is performed on the paper. When the carriage 4 is returned to the position before being scanned (home position), the sheet is conveyed in the sub-scanning direction (the direction of arrow B shown in FIG. 1) by the conveying roller. Thereafter, the carriage is scanned again in the direction of arrow A in FIG. 1 to record images, characters, etc. on the paper. When the above operation is repeated and the recording of one sheet is completed, the sheet is discharged into the stacker 90, and the recording for one sheet is completed.

[Description of Printer Control Circuit (FIG. 2)]
FIG. 2 is a block diagram showing a main control configuration of the printer shown in FIG.

  In FIG. 2, reference numeral 1 denotes a host device such as a personal computer (PC) that supplies image data, commands, and the like. The printer 2 receives image data, commands, parameters, an image processing LUT (lookup table), and the like from the PC 1 and records the received image data according to the commands, parameters, and image processing LUT.

  The PC 1 is a general one, has a keyboard and a display, and implements an interface with the user by application software, a printer driver dedicated to the printer, and dedicated printer control software (RIP or the like).

  A control unit 5 includes a CPU, an ASIC, a DMAC, a RAM, a ROM, and the like for controlling the entire printer 2. Reference numeral 4 denotes a carriage 4 on which the print head 11 is mounted, 6 denotes a carriage transport unit that reciprocates the carriage 4 in the main scanning direction, and 7 denotes a paper transport unit that moves the paper in the sub-scanning direction. Reference numeral 8 denotes a supply unit that supplies ink to the print head 11, and 9 denotes a recovery unit that recovers the print head 11 to a good state by performing surface cleaning, ink suction, ink droplet ejection, and the like of the print head 11. Reference numeral 10 denotes a power supply unit for supplying power to the print head 11 and the control unit 5 and other unit units. Reference numeral 12 denotes an operation panel unit having a display such as a key switch or LCD.

  In the present embodiment, although detailed drawings and descriptions of the mechanism unit are omitted, the printer 2 operates as a serial printer.

  In this embodiment, the print head 11 is detachable with respect to the carriage 4. The carriage 4 is an electrical contact, a joint portion such as a tube for supplying ink, a member for supporting and fixing the print head 11, and the carriage transport unit 6. And a connection part. The carriage 4 is supported by a rail (not shown) of the carriage transport unit 6 and is connected to a motor (not shown) of the carriage transport unit 6 by a timing belt (not shown) of the carriage transport unit 6. The carriage 4 reciprocates in the main scanning direction. Further, an encoder sensor (not shown) is mounted on the carriage 4, and an encoder linear scale (not shown) is provided in the main scanning direction inside the carriage transport unit 6, and the print head 11 mounted on the carriage 4. Can be detected and its moving speed can be controlled.

  The paper transport unit 7 controls the rotation of the transport roller 70 with a motor (not shown) and a rotary encoder (not shown) in order to move the paper in the sub-scanning direction.

  The ink supply unit 8 connects an ink tank (not shown) and the print head 11 with an ink tube or the like, and supplies ink from the ink tank to the print head. Further, a valve mechanism is provided in the middle of the ink tube, and ink leakage from the ink tube and the print head is prevented by closing the valve when the print head 11 is replaced or the ink tank is replaced. A motor is used as a drive source for moving the valve mechanism, and a photo interrupter is used as a position sensor to detect the open / closed state of the valve.

  The recovery unit 9 has a wiping mechanism for wiping the surface of the print head 11, a capping mechanism for sealing the surface of the print head with a member, and a suction pump mechanism for sucking ink from the nozzles of the print head 11. Further, the recovery unit 9 includes a motor that drives these mechanisms, a drive transmission mechanism, and a position sensor that detects the state of each part of the mechanism unit.

  The power supply unit 10 is turned on / off by an AC switch, a soft switch on the operation panel 12, and the like, and the control unit 5 is supplied with power of 3.3V and 5V as a logic power supply. Further, the power supply unit 10 supplies power of a voltage of 24 V to the actuators (motors, etc.) of each unit via the I / O control unit & driver unit 26 in the control unit. In addition, the head power of the print head 11 is supplied from the power supply unit 10 at a set voltage value via a head power control unit in the control unit.

  The control unit 5 includes a sequence control unit 21 that manages the overall operation, an image processing unit 22 that performs conversion processing from image data to recording data, and a timing control unit 23 that adjusts the timing of recording data in accordance with the operation of the printer 2. Prepare. Further, the control unit 5 is an I / O that performs interface and drive control with the head drive unit 24 that controls drive data, drive pulses, drive voltage, and the like of the print head 11, and sensors and actuators (motors, etc.) of the internal unit of the printer 2. O control unit & driver unit 25 and the like.

  The control unit 5 is physically a circuit board. The sequence control unit 21 is a CPU, a ROM that stores a control program for the CPU and various data, a RAM that is used as a work area for the CPU and stores various data, and an I / F unit that controls an interface with the PC 1 serving as a host device. Etc. The image processing unit 22, the timing control unit 23, and the head drive unit 24 are mainly configured by a memory such as an ASIC and a RAM, and the I / O control unit & driver unit 25 is an electric circuit such as a general-purpose LSI or a transistor. Composed.

  The image processing unit 22 converts the luminance image data (RGB color component data) from the PC 1 into density image data (K, C, M, Y, LC, LM components) corresponding to ink colors based on the image processing LUT. A color conversion processing unit 41 is provided. The image processing unit 22 also includes an output γ processing unit 42 that converts density image data from the color conversion processing unit 41 based on output γ characteristics of the printer. Further, the image processing unit 22 includes a binarization processing unit 43 that converts density image data (multi-value data) from the output γ processing unit 42 into binary image data.

  The timing control unit 23 sets the arrangement order of binary image data (raster direction (main scanning direction) order) corresponding to each ink color processed by the image processing unit 22 in the order (column column) of the print head 11 in the nozzle arrangement direction. An HV conversion unit 47 that converts in the direction (sub-scanning direction) is provided. In addition, the timing control unit 23 includes a memory unit 48 that stores image data converted in the column direction. Further, the timing control unit 23 controls the read timing from the memory unit 48 for each image data corresponding to each ink color according to the position and moving direction of the print head 11 and adjusts so that the recording by each ink does not shift. A registration adjustment unit 49 is provided.

[Detect paper edge]
Next, a method for detecting the leading edge of the sheet by the printer of this embodiment will be described.

  FIG. 3 is a view showing a carriage peripheral portion in the printer of the present embodiment.

  In FIG. 3, 51 is a platen, 52 is an optical sensor such as a reflective sensor, and 53 is paper. The optical sensor 52 is disposed on the downstream side (or upstream side or one side of the main scanning direction A) of the paper 53 in the carriage 4 in the conveyance direction (sub-scanning direction B). The conveyance roller 70 sequentially stores position information using the rotary encoder described above. Although the transport roller 70 and the paper 53 are slightly slipped, they basically operate in conjunction with each other. Therefore, the control unit 5 calculates the relative position (paper feed amount) of the paper 53 with respect to the print head 11 from the position information (direction and movement amount) of the transport roller 70.

  FIG. 4 is a schematic configuration diagram of the optical sensor of FIG.

  In FIG. 4, 54 is a light emitting LED, and 55 is a phototransistor. Light emitted from the light emitting LED 54 is reflected by the surface of the paper 53 and received by the phototransistor 55. When the distance between the paper 53 and the optical sensor 52 varies, the amount of light received by the phototransistor 55 changes. Therefore, the distance between the paper 53 and the optical sensor 52 can be detected by obtaining the change in the amount of light.

  Next, a process for determining whether or not to cut the front end of the paper using the optical sensor will be described.

  FIG. 5 is a flowchart showing the paper tip cutting necessity determination process according to the present embodiment. The following steps are realized by the sequence controller 21 of the control unit 5 executing a program stored in the ROM when the printer is turned on.

Step5-1 (tip detection)
In a state where the paper 53 is discharged to the downstream of the optical sensor 52, first, the carriage 4 is driven to move the optical sensor 52 to a position within the printable range of the paper 52, and an output value in that state is obtained. Remember.

  Next, the carriage 4 is driven out of the range where the paper 53 is set, and the output value in that state is stored.

  The average value of these two output values is used as a reference value for detecting the state of the leading end of the sheet.

  Next, the carriage 4 is driven to move the optical sensor 52 to a position where the optical sensor 52 is within the printable range of the paper 53, and the paper 53 is pulled back so that the output value of the optical sensor 52 falls below the reference value. The position of the leading edge of the paper.

  FIG. 6 is a diagram for explaining the leading edge detection process in Step 5-1 of FIG. 5, and shows the relationship between the position (a) of the sheet leading edge and the output value (b) of the sensor. In FIG. 6, a paper front end portion and 66 are detection areas (hereinafter referred to as spot diameters) of the optical sensor 52. Reference numeral 67 denotes a position where the output value of the sensor is below the reference value, that is, a position corresponding to the leading edge of the paper.

Step5-2 (Detection area determination)
FIG. 7 is a schematic diagram showing the state detection area of the front end of the paper, and 71 shows the detection direction of the paper on the reference side (paper transport direction side) in the front end detection in Step 5-1 (actually, the carriage 4 is The operation of fixing and relatively pulling back the paper 53 is performed). Reference numeral 72 denotes a non-reference side (paper width direction side, also referred to as BP) detection direction of the paper (actually, the carriage 4 is driven in the paper width direction). Reference numeral 73 denotes a state detection area at the leading edge of the sheet. The state detection area of the front end of the paper detects the front end of the paper and is set to a position at a predetermined distance from the detected front end of the paper in the direction opposite to the paper transport direction B.

  The predetermined distance is desirably 1/2 or more of the spot diameter 66. Further, it is necessary to make the area smaller than the margin area set by the printer in order to secure the printing area of the paper.

  In this embodiment, since the spot diameter 66 is 4 mm and the margin area is 5 mm, the state detection area 73 is set at a position of 3 mm.

Step5-3 (tip state detection)
The carriage 4 is scanned in the state detection area determined in Step 5-2, and the output value is stored.

  Here, the number of detected points and the carriage speed for scanning are determined in advance according to the paper state to be detected.

  In order to detect stains and tears at the leading edge of the paper, it is sufficient to obtain information of pitch intervals of several mm. In this embodiment, it is sufficient if the 15 inch / s carriage 4 is driven and data can be acquired at intervals of 2 ms (the data acquisition interval at this time is 0.762 mm, and the number of detection points varies depending on the paper width). .

  When the state is determined by repeatedly detecting the leading end of the sheet at a plurality of points, it is necessary to repeatedly detect the state of the leading end of the sheet and move the carriage. On the other hand, by detecting the area at a predetermined distance from the leading edge of the sheet detected at a certain point while driving the carriage 4, the time required to grasp the state of the leading edge can be shortened. .

Step5-4 (Determination of necessity of cutting)
Here, it is determined whether or not the leading edge of the sheet needs to be cut.

  8 and 9 are diagrams showing the relationship between the sheet position (a) and the sensor output value (b) when the state of the leading end of the sheet is normal and abnormal.

  In FIG. 8, when the state of the leading end of the sheet is normal, the output value in the sheet width region is stable in a flat shape and does not fall below the reference value set in Step 5-1.

  On the other hand, for example, when a tear occurs at the leading end of the sheet, as shown in FIG. 9, when a part of the leading end of the sheet is torn, the output value of the torn portion 74 rapidly decreases, and Step 5- Below the reference value set in 1.

  In this way, when the sensor output value falls below the reference value set in Step 5-1, it is determined that the front end of the sheet needs to be cut.

  According to the determination of necessity of cutting, the state of the front end of the sheet is determined using the output value of the optical sensor 52 mounted on the carriage 4, and the fluctuation of the sheet height (distance between the sensors) is detected. be able to. In addition, it is possible to detect a state where dirt or the like is attached to the leading edge of the paper.

Step5-5 (cut)
If it is determined in Step 5-4 that cutting is necessary, the leading edge of the paper is cut along the paper width direction on the platen using a cutter (not shown) attached to the printer body.

  The amount of cut at the leading edge of the paper depends on the use environment, paper condition, etc., but it is sufficient to cut approximately one turn of the roll paper.

  Next, the operation of the printer body when setting paper will be described.

  FIG. 10 is a flowchart showing the operation of the printer main body when paper is set. FIG. 11 is a diagram showing the sheet detection position in the processing in each step of FIG.

  10 and 11, in Step 10-1 (reference value determination), the reference value used for detecting the state of the leading end of the sheet is determined in the same manner as in Step 5-1 above.

  In Step 10-2 (Detection of paper reference side edge), the reference side edge position of the paper is detected.

  In Step 10-3 (paper reference side leading edge detection), the reference side leading edge position of the paper is detected.

  In Step 10-4 (paper skew detection), a state where the paper is set obliquely is detected.

  In Step 10-5 (paper non-reference side edge detection), the non-reference side edge position of the paper is detected.

  In Step 10-6 (Detection of leading edge of paper non-reference side), the leading edge position of the paper on the non-reference side is detected.

  In Step 10-7 (pre-cut detection), it is determined whether or not it is necessary to cut the leading edge of the sheet from the state of the leading edge of the sheet.

[Second Embodiment]
Next, as a second embodiment, a method of detecting the left and right edges of a sheet and determining the state detection area of the leading end of the sheet using output values at both ends will be described.

  One possible cause of the abnormal state of the leading edge is that the paper has been cut obliquely during the previous printing. There is also a state where the paper is set obliquely (skew).

  The skew is generated by a user operation at the time of paper setting. In particular, in the case of a large format printer, it is necessary to allow a predetermined amount from the viewpoint of convenience at the time of paper setting.

  For example, as shown in FIG. 12, when the front end of the sheet is set obliquely, it is determined that pre-cut is not necessary according to the flow of FIG. 10 described above, but as shown in FIG. When set, it is determined that pre-cutting is necessary. Therefore, it is necessary to allow a predetermined amount of skew to prevent erroneous precuts. Therefore, in the present embodiment, the left end and the right end of the sheet are detected, and the state detection area is determined using the output values at both ends.

  FIG. 14 is a flowchart showing processing for detecting the left and right edges of a sheet and determining the state detection area using output values at both ends.

  In FIG. 14, Steps 5-1, 5-3, 5-4, and 5-5 are the same as the processing described in FIG.

  In Step 14-1 (BP side leading edge detection), the left edge and the right edge of the sheet are detected, and then the leading edge is detected at a predetermined position on the non-reference side (for example, a position of 10 mm). Note that BP represents a non-reference side opposite to the reference side. The reference value used for tip detection is equivalent to Step 5-1 in FIG.

  In Step 14-2 (determination of detection area), the output value in the tip detection in Step 5-1 of FIG. 5 is compared with the output value in the BP side tip detection in Step 14-1. Then, as a result of the comparison, the value located further upstream in the paper transport direction B is determined as the leading edge of the paper, and a predetermined distance (for example, 3 mm) from that position is determined as the state detection region.

  FIG. 15 shows the respective detection operations in the leading edge detection (a) in Step 5-1 and the BP side leading edge detection (b) in Step 14-1, comparing the output values at the time of each detection, and further upstream in the paper transport direction. The value located in the position is set as the leading edge of the sheet, and a predetermined distance from the position is determined as the state detection region.

[Third Embodiment]
Next, as a third embodiment, a method for detecting a sheet height variation and determining a sheet state from the detected variation amount will be described.

  Another factor that causes the leading edge state to be abnormal is the wavy state of the paper.

  When the paper is in a wavy state, the landing position of the ink droplets is deviated from the target position, which causes a drop in print quality such as ruled line deviation and color change. Therefore, it is desirable to cut the paper.

  However, when the paper is in a wavy state, the amount of change is small compared to the change in the output value due to paper tearing or the like, and therefore does not fall below the reference value determined in Step 5-1 of FIG.

  Therefore, in this embodiment, the wavy state is determined by detecting the height fluctuation of the state detection region at the tip.

  Specifically, the following steps are added in the cut determination at Step 5-4 in FIG.

  First, the relationship between the height fluctuation and the sensor output fluctuation will be described.

  Since the optical sensor 52 described in FIG. 4 is a simple combination of a light emitting element and a light receiving element, when the height of the paper changes, the direction of reflection changes, and even if the amount of emitted light is constant, the amount of received light is small. Change.

  FIG. 16 shows the height fluctuation and the sensor output fluctuation (relative value). As can be seen from the figure, the sensor output value fluctuates with the paper height fluctuation.

  FIG. 17 shows the relationship between the paper position (a), height fluctuation (b), and sensor output value (c) when the paper is in a wavy state. The output value of the sensor varies corresponding to the amount and position.

  The landing position of the ink droplet based on the height variation is determined by the carriage speed at the time of printing, the ink ejection speed, and the height variation amount.

  Here, for example, if the height variation tolerance is set to 0.2 mm, the sheet is cut when the height variation exceeds the tolerance, and the sheet is not cut if the height variation is less than that. Good.

[Other Embodiments]
The embodiment according to the present invention has been described in detail using specific examples. However, the present invention can take an embodiment as a system, apparatus, method, program, storage medium (recording medium), or the like. is there. Specifically, the present invention may be applied to a system composed of a plurality of devices, or may be applied to an apparatus composed of a single device.

  It goes without saying that the object of the present invention can be achieved even if any part of the illustrated functional blocks and operations is realized by a hardware circuit or by software processing using a computer.

  Note that the present invention includes a case where the present invention is achieved by supplying a software program for realizing the functions of the above-described embodiments directly or remotely to a system or apparatus. In that case, a computer such as a system reads and executes the program code.

  Accordingly, since the functions of the present invention are implemented by computer, the program code installed in the computer also implements the present invention. In other words, the present invention includes a computer program itself for realizing the functional processing of the present invention.

1 is a perspective view showing an ink jet printer according to an embodiment of the present invention with an upper cover removed. FIG. 2 is a block diagram illustrating a main control configuration of the printer illustrated in FIG. 1. It is a figure which shows the carriage peripheral part in the printer of this embodiment. It is a schematic block diagram of the optical sensor of FIG. 6 is a flowchart illustrating processing for determining whether or not to cut a front end portion of a sheet according to the present embodiment. It is a figure explaining the front-end | tip detection process in Step5-1 of FIG. FIG. 6 is a schematic diagram illustrating a state detection region at the leading end of a sheet. It is a figure which shows the output value of a sensor when the state of a paper front-end | tip part is normal. It is a figure which shows the output value of a sensor when the state of a paper front-end | tip part is abnormal. 6 is a flowchart illustrating the operation of the printer main body when setting paper according to the present embodiment. It is a figure which shows the detection position of the paper in the process in each step of FIG. FIG. 6 is a schematic diagram illustrating a state detection region of a paper front end when the paper front end is set obliquely. FIG. 6 is a schematic diagram illustrating a state detection region of a paper front end when the paper front end is set obliquely. 10 is a flowchart illustrating processing for determining whether or not a front end portion of a sheet needs to be cut according to a second embodiment. It is a figure which shows each detection operation | movement by the front-end | tip detection (a) of Step5-1, and the BP side front-end | tip detection (b) of Step14-1. It is a figure which shows the relationship between the height fluctuation | variation of a paper, and the output fluctuation | variation of a sensor. It is a figure which shows the output fluctuation | variation of the sensor accompanying the height fluctuation | variation in case a paper is a wavy state.

Explanation of symbols

1 PC (personal computer)
2 Inkjet recording apparatus 3 Carriage belt 4 Carriage 5 Control unit 6 Carriage transport unit 7 Paper transport unit 8 Ink supply unit 9 Recovery unit 10 Power supply unit 11 Print head 12 Operation panel unit 21 Sequence control unit 22 Image processing unit 23 Timing processing unit 24 Head drive unit 25 I / O control unit & driver unit 41 Color conversion processing unit 42 Output gamma processing unit 43 Binary conversion processing unit 47 HV conversion unit 48 Memory unit 49 Registration adjustment unit 51 Platen 52 Optical sensor 53 Paper 54 For light emission LED
55 Phototransistor 70 Conveying roller 88 Manual feed port 89 Roll paper cassette 90 Stacker 91 Upper cover 93 Leg 94 Device body

Claims (12)

An inkjet recording apparatus that performs recording by ejecting ink onto a recording medium while reciprocally scanning a recording head having a plurality of nozzles with a carriage,
A detecting means mounted on the carriage for detecting the leading end of the recording medium;
Determining means for determining a detection region for detecting the state of the tip of the recording medium based on the detection result;
An ink-jet printing apparatus comprising: a determination unit configured to determine whether or not a cutting process for cutting a front end portion of the recording medium with a cutter based on a state of the recording medium detected in the determined detection region; Recording device.   The determining means sets a reference value for detecting the state of the recording medium in the detection area, using each detection result within the recordable range and outside the recordable range of the recording medium by the detecting means. The inkjet recording apparatus according to claim 1.   3. The ink jet recording apparatus according to claim 2, wherein the determination unit determines that the cutting process of the leading end portion of the recording medium is necessary when a detection result by the detection unit falls below the reference value. 4. . The detection means detects both ends in the width direction orthogonal to the conveyance direction of the recording medium,
4. The inkjet recording apparatus according to claim 1, wherein the determination unit determines the detection area using a detection result of the both ends. 5. The detecting means detects a distance between the recording surface of the recording medium,
The inkjet recording apparatus according to claim 1, wherein the determination unit determines the state of the recording medium based on the detection result of the distance.   The ink jet recording apparatus according to claim 1, wherein the recording medium is a paper medium that is continuously fed from a roll paper in accordance with a recording operation. A control method for an ink jet recording apparatus that performs recording by ejecting ink onto a recording medium while reciprocally scanning a recording head having a plurality of nozzles with a carriage,
A detection step of detecting a leading end portion of the recording medium by detection means mounted on the carriage;
A determination step for determining a detection area for detecting the state of the tip of the recording medium based on the detection result;
A determination step of determining whether or not a cutting process for cutting the front end portion of the recording medium with a cutter is performed based on the state of the recording medium detected in the determined detection area. .   The determining step sets a reference value for detecting the state of the recording medium in the detection area, using each detection result within the recordable range and outside the recordable range of the recording medium by the detection unit. The method according to claim 7.   9. The method according to claim 8, wherein the determination step determines that the cutting process of the leading end portion of the recording medium is necessary when a detection result by the detection unit falls below the reference value. The detection means detects both ends in the width direction orthogonal to the conveyance direction of the recording medium,
The method according to any one of claims 7 to 9, wherein the determining step determines the detection area using detection results of the both ends. The detecting means detects a distance between the recording surface of the recording medium,
The method according to claim 7, wherein the determination step determines a state of the recording medium based on a detection result of the distance.   The method according to any one of claims 7 to 11, wherein the recording medium is a paper medium that is continuously fed from a roll paper in accordance with a recording operation.

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