JP4734524B2 - Image recording device - Google Patents

Description

  The present invention relates to an image recording apparatus that records an image on a recording medium conveyed by a pair of conveying rollers.

  Some photographic processing apparatuses, which are one of image recording apparatuses, include a conveyance roller that conveys photographic paper and a pulse motor that drives the conveyance roller (see, for example, Patent Document 1). In the drive control of the motor of the photographic processing apparatus, the motor is stopped in the interval between the photographic processing and the photographic processing. However, if the power supply to the motor is completely cut off, the load to be driven by the motor is an external force. There is a possibility of moving from a predetermined position due to an influence or the like. For this reason, it is known that even when the motor is stopped, the power supply is not interrupted, but a current value of about 50% at full power is supplied to the motor.

Also, in recent years, since higher conveyance accuracy is required in image recording apparatuses, a conveyance roller that conveys a recording medium is often driven by a DC servo motor.
JP 2001-13593 A

  Here, some image recording apparatuses such as a photographic processing apparatus and an ink jet printer convey a roll-shaped recording medium to the downstream side while being unwound by a pair of conveying rollers, and supply the recording medium to an image recording unit. . In this image recording apparatus, in a standby state in which no image is recorded (for example, before image recording is started, between image recording and image recording, etc.), the recording medium needs to be held without being conveyed by a pair of conveying rollers. There is. For example, the conveyance roller pair is arranged above the roll-shaped recording medium, and the recording medium is conveyed to the downstream side while being unwound while pulling up the recording medium in the direction opposite to the gravity direction by the conveyance roller pair. In other words, the holding force required to hold the recording medium in a standby state in which the recording medium is not conveyed is considered to vary depending on the width size and thickness of the recording medium and the winding diameter (remaining amount) of the winding portion.

  In addition, when the holding force of the conveying roller pair in the standby state is set to be constant regardless of the type of the recording medium, the holding force is set according to the type of the recording medium that requires the largest holding force. However, various problems occur in this case. That is, when the width of the recording medium on which the image is recorded is narrow, the holding force at the pair of conveying rollers in the standby state may be relatively small, but the holding force is set to be larger than necessary. As a result, the motor generates more heat than necessary and chatter vibration occurs. Moreover, it becomes a problem also from an energy-saving side.

  Therefore, a main object of the present invention is to provide an image recording apparatus capable of making the holding force of the recording medium on the conveying roller pair in the standby state appropriate.

Means for Solving the Problems and Effects of the Invention

  The image recording apparatus of the present invention is disposed above the recording medium supply unit into which the winding unit of the recording medium wound in a roll shape is loaded and the lower end of the winding unit in the vertical direction, A conveying roller pair that sandwiches the recording medium unwound from the winding unit, a motor that drives the conveying roller pair, and a conveying state in which the conveying roller pair conveys the recording medium while being unwound from the winding unit, And a control means for controlling the motor so that the pair of transport rollers is in a standby state in which the pair of transport rollers hold the recording medium without transporting, and the control means includes the pair of transport rollers. The control of the motor in the standby state is changed based on at least one of the width size and thickness of the recording medium loaded in the recording medium supply unit and the winding diameter of the winding unit. Yes.

  According to this configuration, since the control of the motor when the conveyance roller pair is in the standby state is changed based on at least one of the width size and thickness of the recording medium and the winding diameter of the winding portion, Regardless of the type or the like, the holding force of the recording medium by the conveying roller pair in the standby state is appropriate. Therefore, it is possible to prevent the motor from generating more heat than necessary and chatter vibration in the standby state. It is also effective in terms of energy saving.

  In the image recording apparatus of the present invention, the control means controls the motor when the pair of transport rollers is in a standby state, the width size and thickness of the recording medium loaded in the recording medium supply unit, and the winding. You may change based on all the winding diameters of a rotation part.

  In the image recording apparatus of the present invention, the motor is a DC servo motor, and the control means records the parameters of the motor when the conveyance roller pair is in a standby state, loaded in the recording medium supply unit. You may change based on at least 1 of the width size and thickness of a medium, and the winding diameter of the said winding part.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an ink jet printer according to an embodiment of the present invention.

  An ink jet printer 1 shown in FIG. 1 includes a paper supply unit 4, a transport roller unit 5, an ink jet printing unit 6, a cutting unit 7, a dot impact printing unit 8, and a discharge in a substantially rectangular housing 30. And a roller unit 9. The housing 30 is provided with a paper feed tray 31 for manually feeding a predetermined length of paper and a discharge tray 32 for receiving the paper discharged from the discharge roller unit 9. The operation of each part of the ink jet printer 1 is controlled by the controller 20 disposed in the housing 30.

  The paper supply unit 4 is loaded with a long paper 2 formed with a winding part 2a wound in a roll shape, and the winding part 2a of the paper 2 is configured to be rotatable about the axis. 3 is held.

  The transport roller unit 5 includes a transport roller pair 40 that transports the paper 2 to the downstream side while being unwound from the winding unit 2 a of the paper supply unit 4. The configuration of the transport roller unit 5 will be described in detail later.

  The ink jet printing unit 6 has two print heads 11, 12, a carriage 13, a printing table 14, and a suction fan 15. The two print heads 11 and 12 are separated by a predetermined distance along the conveyance direction of the paper 2 (the direction from right to left in FIG. 1 and referred to as “sub-scanning direction” in the following description). Are arranged. The two print heads 11 and 12 are provided with a large number of ejection nozzles (not shown) that can eject color ink. The carriage 13 is for holding the two print heads 11 and 12, and is a direction orthogonal to the sub-scanning direction (in FIG. 1, a direction perpendicular to the paper surface, and will be referred to as a “main scanning direction” in the following description). ). Accordingly, the print heads 11 and 12 eject ink toward the surface of the paper 2 while reciprocating in the main scanning direction as the carriage 13 reciprocates.

  The printing stand 14 has a paper support surface that is disposed on substantially the same surface as the transport surface of the paper 2, and supports the paper 2 that is disposed to face the print heads 11 and 12. A large number of suction holes (not shown) are uniformly formed in the printing table 14 over almost the entire width of the printing table 14. The suction fan 15 is disposed at a position facing the print heads 11 and 12 across the conveyance path of the paper 2. The suction fan 15 is for sucking the sheet 2 on the surface of the printing table 14 by generating a suction force capable of sucking air from the surface side of the printing table 14 into the suction holes. Accordingly, the sheet 2 facing the print heads 11 and 12 is sucked by the suction fan 15 disposed on the back side of the sheet 2 and is brought into close contact with the printing table 14, and is spaced from the print heads 11 and 12. Becomes constant. For this reason, when the sheet 2 is curled, it is possible to suppress a printing defect caused by a change in the distance between the print heads 11 and 12 due to a part of the sheet 2 being greatly separated from the printing table 14. .

  The cutting unit 7 has a moving blade 7 a disposed above the conveyance path of the paper 2 and a fixed blade 7 b disposed below. Both the movable blade 7 a and the fixed blade 7 b are rectangular blades having a width slightly larger than the width of the paper 2. The moving blade 7a can be moved toward or away from the fixed blade 7b by a motor (not shown) controlled by the controller 20, and the printed blade that has been transported from the upstream side through the transport path is printed. The sheet 2 can be cut along the width direction by the interaction with the fixed blade 7b. By cutting in this way, the printed paper 2 having a predetermined length is divided.

  The dot impact printing unit 8 performs printing by a number of thin pins selectively hitting the paper 2 via an ink ribbon. As shown in FIG. 2, the dot impact printing unit 8 includes two roller pairs 8a and 8b and a dot head 8e, and the sheet 2 conveyed by the two roller pairs 8a and 8b by the dot head 8e. Additional information such as the date and time when the printing was performed and the serial number are printed. The two roller pairs 8a and 8b are driven by a pulse motor 8d via a belt 8c that is stretched over rollers 8a 'and 8b' that are coaxially fixed to one of the rollers.

  The discharge roller unit 9 discharges the printed paper 2 to the outside of the housing 30. As shown in FIG. 2, the discharge roller unit 9 has a roller pair 9a and a decurling roller 9b disposed on the upstream side of the roller pair 9a. The roller pair 9a is driven by a pulse motor 9d through a belt 9c that is stretched around a roller 9a 'that is coaxially fixed with one of the rollers.

  The controller 20 performs predetermined processing on an image signal supplied from an input interface (not shown) and supplies a print signal including image data corresponding to an image to be printed to the inkjet printing unit 6. Further, the controller 20 is configured to convey the sheet 2 by the conveyance roller unit 5 and the discharge roller unit 9, to move the carriage 13 or to discharge ink from the print heads 11 and 12, to cut the sheet 2 by the cutting unit 7, The printing timing by the dot impact printing unit 8 can be controlled.

  Further, in the control of the transport roller unit 5, the controller 20 appropriately changes the parameters of the DC servo motor 54 that drives the transport roller pair 40 as will be described later. That is, the controller 20 appropriately changes the parameters of the DC servo motor 54 between a transport state in which the transport roller pair 40 transports the paper 2 and a standby state in which the transport roller pair 40 sandwiches the paper 2 without transporting the paper 2. In the standby state, the controller 20 changes the parameters of the DC servo motor 54 based on the width size and thickness of the paper 2 and the winding diameter of the winding portion 2a.

  Next, a detailed configuration of the transport roller unit 5 will be described with reference to FIG. FIG. 2 is a diagram showing a detailed configuration inside the ink jet printer shown in FIG.

  The conveyance roller unit 5 is disposed between the conveyance roller pair 40 disposed upstream of the lower end portion of the winding unit 2a in the vertical direction on the upstream side of the ink jet printing unit 6, and between the paper supply unit 4 and the conveyance roller pair 40. The turn roller 44 is disposed, and a pressure roller pair 45 disposed on the downstream side of the inkjet printing unit 6.

  The pair of transport rollers 40 is disposed below the transport path of the paper 2 and changes the transport direction of the paper 2 to the horizontal direction, and disposed between the advance roller 41 and the advance roller 41 disposed above the transport path of the paper 2. And driven rollers 42 and 43 capable of sandwiching the sheet 2. The conveyance roller pair 40 sandwiches the paper 2 between the advance roller 41 and the driven rollers 42 and 43, thereby conveying the paper 2 to the downstream side while being unwound from the winding portion 2a.

  The pressure roller pair 45 includes a driving roller 46 disposed below the conveyance path of the sheet 2 and a driven roller 47 disposed above the conveyance path of the sheet 2 and capable of sandwiching the sheet 2 between the driving roller 46. have. Accordingly, the pressure roller pair 45 sandwiches the paper 2 conveyed between the inkjet printing unit 6 and the cutting unit 7. The pressure roller pair 45 is disposed between the ink jet printing unit 6 and the cutting unit 7 so that the image printing by the ink jet printing unit 6 and the cutting of the paper 2 by the cutting unit 7 can be appropriately performed. Become.

  Here, the advance roller 41 is driven by a DC servo motor 54 via a belt 53 that is stretched around a roller 51 that is coaxially fixed thereto. A belt 57 is stretched between a roller 52 fixed coaxially with the advance roller 41 and a roller 56 fixed coaxially with the drive roller 46 of the pressure roller pair 45. The upper portion of the belt 57 is pressed downward by the roller 55. Accordingly, the driving roller 46 of the pressure roller pair 45 is driven by the transmission of the driving force of the DC servo motor 54.

  Incidentally, the print head 12 of the inkjet printing unit 6 is provided with a leading edge detection sensor 61 for detecting the leading edge of the paper 2. Here, since the leading edge detection sensor 61 reciprocates along the main scanning direction together with the print head 12, it can also detect the width size of the paper 2. A rear end detection sensor 62 for detecting the rear end of the sheet 2 is provided on the upstream side of the advance roller 41. The leading edge detection sensor 61 and the trailing edge detection sensor 62 are both reflection sensors, and can detect the presence or absence of the sheet 2 at the detection position of each sensor.

  Next, the operation of the ink jet printer 1 will be described.

  First, when the winding portion 2a of the paper 2 is loaded in the paper supply unit 4 and the leading end of the paper 2 is disposed between the advance roller 41 and the driven roller 42, the advance roller 41 is driven, whereby the paper The two tips are automatically loaded (temporarily conveyed) to the detection position of the tip detection sensor 61. Thereafter, the advance roller 41 is driven in the opposite direction, whereby the sheet 2 is rewound, and the leading end of the sheet 2 is disposed at a standby position between the driven roller 42 and the driven roller 43. In this way, with the leading edge of the paper 2 placed at the standby position, the standby state is maintained in which the paper 2 is not conveyed by the advance roller 41 and the driven rollers 42 and 43. Thereafter, the image is printed on the sheet 2 by alternately repeating the conveyance of the sheet 2 by a predetermined distance and the forward movement or backward movement of the print heads 11 and 12.

  Accordingly, the controller 20 conveys the sheet 2 downstream while unwinding from the winding part 2a of the sheet supply unit 4 by sandwiching the sheet 2 between the advance roller 41 and the driven rollers 42 and 43 of the conveyance roller unit 5. The DC servo is set so as to take either a transporting state in which the paper 2 is held between the advance roller 41 and the driven rollers 42 and 43 without holding the paper 2 downstream. The motor 54 is controlled. In the standby state immediately after auto loading, the sheet 2 is sandwiched between the advance roller 41 and the driven roller 42.

  That is, the standby state is a state in which the paper 2 is not transported immediately after auto-loading and before printing is started, and the front end of the paper 2 is arranged at the standby position, and the paper 2 is transported after printing is started. And a state where printing is performed without being performed.

  Here, in the standby state, the holding force (holding torque) for holding the sheet 2 by the advance roller 41 and the driven rollers 42 and 43 is controlled by changing the parameter of the DC servo motor 54. Parameters of the DC servo motor 54 used to control the holding force for holding the paper 2 by the advance roller 41 and the driven rollers 42 and 43 include a proportional gain coefficient, an integral gain coefficient, a differential gain coefficient, an integral limit coefficient, There are differential sampling factors and so on. For example, when the value of the proportional gain coefficient is increased, the holding force of the sheet 2 between the advance roller 41 and the driven rollers 42 and 43 is increased. When the value of the proportional gain coefficient is decreased, the advance roller 41 and the driven roller 42 are increased. , 43, the holding force of the sheet 2 becomes small.

  In the present embodiment, the controller 20 determines between the advance roller 41 and the driven rollers 42 and 44 based on the width size and thickness of the paper 2 loaded in the paper supply unit 4 and the winding diameter of the winding unit 2a. The proportional gain coefficient, which is a parameter of the DC servo motor 54, is changed so that the holding force of the sheet 2 in the above becomes appropriate.

  That is, when the winding unit 2a of the paper 2 is loaded into the paper supply unit 4, the type (for example, width size and thickness) of the paper 2 is set for the ink jet printer 1, and therefore the controller 20 changes the proportional gain coefficient according to the type. Further, as described above, the width size of the paper 2 can be detected by the leading edge detection sensor 61. Therefore, the controller 20 performs proportional gain based on the width size of the paper 2 detected by the leading edge detection sensor 61. The coefficient can be changed.

  Further, the winding diameter of the winding portion 2a changes with the printing operation on the paper 2. Here, the controller 20 detects the winding diameter of the winding unit 2a based on the usage amount of the paper 2 (the winding is performed by subtracting the usage amount of the paper 2 from the length of the paper 2 of the new winding unit 2a). Therefore, the proportional gain coefficient is changed as the winding diameter of the winding portion 2a changes.

  As described above, in the ink jet printer 1 according to the present embodiment, the control of the DC servo motor 54 when the transport roller pair 40 is in the standby state controls the width size and thickness of the paper 2 and the winding portion 2a. Since it is changed based on the winding diameter, the holding force of the sheet 2 by the conveying roller pair 40 in the standby state can be made appropriate. Therefore, it is possible to prevent the motor from generating more heat than necessary and chatter vibration in the standby state. It is also effective in terms of energy saving.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. . For example, in the above-described embodiment, the motor that drives the conveyance roller pair 40 is the DC servo motor 54, and the control of the DC servo motor 54 in the standby state determines the width size and thickness of the paper 2 and the winding portion 2a. Although it is changed based on the winding diameter, the control of the DC servo motor 54 may be changed based on at least one of the width size and thickness of the paper 2 and the winding diameter of the winding portion 2a. Further, in the control of the DC servo motor 54 in the standby state, the proportional gain coefficient of the DC servo motor 54 is changed, but other parameters may be changed. Further, the motor that drives the conveying roller pair 40 is a pulse motor, and the control of the pulse motor in the standby state is changed based on at least one of the width size and thickness of the paper 2 and the winding diameter of the winding portion 2a. May be.

1 is a diagram illustrating a schematic configuration of an ink jet printer according to an embodiment of the present invention. It is a figure which shows the detailed structure inside the ink jet type printer of FIG.

Explanation of symbols

1 Inkjet printer (image recording device)
2 Paper (recording medium)
2a Winding unit 4 Paper supply unit (recording medium supply unit)
20 controller (control means)
40 Conveying roller pair 54 DC servo motor (motor)

Claims (3)

A recording medium supply unit loaded with a winding unit of a recording medium wound in a roll;
A pair of conveying rollers that are disposed above the lower end of the winding part in the vertical direction and sandwich the recording medium unwound from the winding part;
A motor for driving the conveying roller pair;
The motor so that the conveyance roller pair is in a conveyance state in which the recording medium is conveyed while being unwound from the winding unit, or a standby state in which the conveyance roller pair holds the recording medium without conveying it. And control means for controlling
The control means controls the motor when the pair of transport rollers is in a standby state, and controls at least one of the width size and thickness of the recording medium loaded in the recording medium supply unit and the winding diameter of the winding unit. The image recording apparatus is characterized in that the image recording apparatus is changed on the basis of the two.   The control means controls the motor when the conveying roller pair is in a standby state to all of the width size and thickness of the recording medium loaded in the recording medium supply unit and the winding diameter of the winding unit. The image recording apparatus according to claim 1, wherein the image recording apparatus is changed based on the change. The motor is a DC servo motor;
The control means sets the parameter of the motor when the pair of transport rollers is in a standby state as at least one of the width size and thickness of the recording medium loaded in the recording medium supply unit and the winding diameter of the winding unit. The image recording apparatus according to claim 1, wherein the image recording apparatus is changed on the basis of the two.

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