JP2012162051A - Recorder and method of recording - Google Patents

Abstract

A recording apparatus capable of coping with a change in a conveyance speed of a recording medium is provided.
A conveying device that conveys a recording medium, a recording head that performs recording on the recording medium, a signal output device that outputs a detection pulse KP (k) as the recording medium is conveyed, and a detection pulse KP (k). A recording pulse generating device that generates the ejection timing pulse TP (k) at a corrected time interval Th (k) obtained by correcting the time interval T (k), and a recording head based on the ejection timing pulse TP (k). The recording pulse generator has a transport speed corresponding to the time interval T (k) of the detection pulse KP (k) for each time interval T (k) of the detection pulse KP (k). By adding the correction amount ΔT (k) calculated based on the time interval T (k) of the detection pulse KP (k), the time interval T (k) of the detection pulse KP (k) is corrected to the correction time interval Th ( k) Apparatus.
[Selection] Figure 8

Description

  The present invention relates to a recording apparatus, a recording method, and the like.

2. Description of the Related Art Conventionally, there are recording apparatuses that perform recording on a recording medium by transporting the recording medium with a rotationally driven transport apparatus and forming dots on the transported recording medium with a recording head. Some recording apparatuses use a pulse signal from an encoder that detects the conveyance amount of the recording medium as a dot formation trigger.
In such a recording apparatus, there is conventionally known a recording apparatus having a correction table in which correction values for correcting the positional deviation of the dots that accompany the rotation drive of the transport device are tabulated for one rotation of the rotation drive. (For example, refer to Patent Document 1).

JP 2008-110572 A

In Patent Document 1, the dot interval is calculated based on the result of reading a plurality of dots formed on the recording medium to be conveyed by the line sensor and the conveyance speed of the recording medium, and based on the calculated dot interval. It is described that a correction value is calculated. According to Patent Literature 1, the correction value changes according to the conveyance speed of the recording medium. That is, it is necessary to calculate a correction value for each conveyance speed of the recording medium.
In the recording apparatus described in Patent Document 1, since correction values are tabulated, a correction table must be provided for each conveyance speed of the recording medium. For this reason, when a new conveyance speed of the recording medium is added, a new correction table must be created and added.
As described above, the conventional recording apparatus has a problem that it is difficult to cope with the change in the conveyance speed of the recording medium.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  [Application Example 1] A transport device that transports a recording medium, a recording head that faces the recording medium and performs recording on the recording medium, a signal output device that outputs a pulse signal as the recording medium is transported, A recording pulse generation device that generates a recording pulse signal at a correction interval obtained by correcting an interval of the pulse signal; and a head driving device that drives the recording head based on the recording pulse signal, and the recording pulse generation The apparatus adds the correction amount calculated based on the conveyance speed corresponding to the interval of the pulse signal to the interval of the pulse signal by adding the correction amount calculated for each interval of the pulse signal to the interval of the pulse signal. A recording apparatus, wherein

The recording apparatus of this application example includes a transport device, a recording head, a signal output device, a recording pulse generation device, and a head driving device.
The transport device transports the recording medium.
The recording head performs recording on the recording medium while facing the recording medium.
The signal output device outputs a pulse signal as the recording medium is conveyed.
The recording pulse generator generates a recording pulse signal at a correction interval obtained by correcting the pulse signal interval.
The head driving device drives the recording head based on the recording pulse signal.
In this recording apparatus, the recording pulse generator adds the correction amount calculated based on the conveyance speed corresponding to the pulse signal interval to the pulse signal interval for each interval of the pulse signal. To the correction interval. That is, in this recording apparatus, recording can be performed at a correction interval corrected based on the conveyance speed corresponding to the pulse signal interval. For this reason, this recording apparatus can perform recording in consideration of a change in the conveyance speed of the recording medium. That is, this recording apparatus can easily cope with a change in the conveyance speed of the recording medium.

  Application Example 2 A recording method for performing recording with a recording head on a recording medium transported by a transporting apparatus, wherein the interval between the pulse signals is set at every interval of a pulse signal output as the recording medium is transported. A recording method comprising: driving the recording head based on a recording pulse signal generated at a correction interval obtained by adding a correction amount calculated based on a corresponding conveyance speed to the interval of the pulse signal.

  In the recording method of this application example, for each pulse signal interval, the correction amount calculated based on the conveyance speed corresponding to the pulse signal interval is added to the pulse signal interval based on the recording pulse signal generated at the correction interval. Since the recording head is driven, it is possible to perform recording in consideration of the change in the conveyance speed of the recording medium. As a result, according to this recording method, it is possible to easily cope with a change in the conveyance speed of the recording medium.

1 is a front view illustrating a schematic configuration of an ink jet apparatus according to an embodiment. The perspective view which shows the rotating drum in this embodiment. The perspective view which shows the rotary scale and rotary encoder in this embodiment. 1 is a block diagram illustrating a schematic configuration of an ink jet apparatus according to an embodiment. FIG. 2 is a block diagram illustrating a schematic configuration of a head control unit according to the present embodiment. The timing chart which shows the example in the ideal state of the encoder signal in this embodiment. The timing chart which shows an example of the encoder signal in this embodiment. The timing chart which shows the encoder signal and discharge timing signal in this embodiment.

An embodiment will be described with reference to the drawings, taking an ink jet apparatus as one of recording apparatuses as an example. In addition, in each drawing, in order to make each structure the size which can be recognized, the structure and the scale of a member may differ.
As shown in FIG. 1, the ink jet apparatus 1 according to the present embodiment includes an apparatus main body 2, a medium supply apparatus 6, and a medium recovery apparatus 7.

  The ink jet apparatus 1 is a center drum type recording apparatus in which a plurality of ink jet heads (heads 76) are arranged in the circumferential direction, and UV ink (ultraviolet curing) is applied to a long recording medium A supplied in a roll-to-roll manner. Type ink). The recording medium A is, for example, a sheet-like material such as a label film or paper, and has various widths and thicknesses as the recording target. In the following description, the direction penetrating the paper surface in FIG. 1 is front and rear, the front side is “front”, and the back side is “rear”. Specifically, the extending direction of a rotating shaft (drum shaft 62) of the rotating drum 61, which will be described later, is assumed to be front and rear. In the medium feeding path L of the recording medium A, the medium supply device 6 side is also referred to as “upstream side”, and the medium recovery device 7 side is also referred to as “downstream side”.

The apparatus main body 2 performs printing (recording) on the recording medium A by an inkjet method. In the present embodiment, a center drum type apparatus main body 2 is employed. A technique for ejecting a liquid material such as ink from the inkjet head as droplets is called an inkjet technique. A method of arranging a liquid material such as ink at a predetermined position by using an ink jet technique is called a droplet discharge method or an ink jet method. These droplet discharge method and ink jet method are one of coating methods. In the present embodiment, the head 76 has a plurality of nozzles. The head 76 can eject ink as ink droplets from each of the plurality of nozzles.
The medium supply device 6 supplies the recording medium A to the device main body 2. The medium recovery device 7 recovers the recording medium A from the device body 2.

The recording medium A is set in the medium supply device 6 as a roll 11. The roll 11 is wound with a recording medium A before printing. The recording medium A is unwound from the roll 11 by the medium supply device 6 and then sent out toward the apparatus main body 2.
The recording medium A printed with ink is wound as a roll 21 by the medium recovery device 7 on the downstream side of the apparatus main body 2.
As described above, the inkjet apparatus 1 can perform printing on the recording medium A in a roll-to-roll form.

The medium feeding path L of the recording medium A includes a feeding path L1 from the medium feeding device 6 to the apparatus main body 2, an arc-shaped printing feeding path L2 that is close to a circle formed in the apparatus main body 2, and the apparatus main body 2. It can be divided into a recovery feed path L3 leading to the medium recovery device 7.
The recording medium A supplied from the medium supply device 6 through the supply feed path L1 is fed along the print feed path L2 in the apparatus main body 2, and is used for printing in this portion. In addition, the recording medium A that has been printed is collected by the medium collection device 7 through the collection feeding path L3.

The apparatus main body 2 includes a medium feeding mechanism (medium feeding means) 41, a plurality of carriage units 42, and a UV irradiation unit 44.
The medium feeding mechanism 41 has a rotating drum 61 and a feeding roller 18. The rotary drum 61 has a cylindrical drum body 71. The medium feeding mechanism 41 feeds the recording medium A along the arc-shaped print feeding path L2 along the outer periphery of the drum main body 71. The feeding roller 18 feeds the recording medium A to the lower outer peripheral surface 71 a of the drum body 71.
Each of the plurality of carriage units 42 faces the print feed path L <b> 2 and is arranged radially with respect to the rotary drum 61. Each carriage unit 42 has a plurality of heads 76. Each head 76 faces the drum body 71.
The UV irradiation unit 44 faces the recovery feeding path L3 and irradiates the recording medium A with ultraviolet light for curing the UV ink applied to the recording medium A.

Here, the rotating drum 61 has a drum shaft 62 as shown in FIG. The drum shaft 62 is a rotation shaft for rotating the drum main body 71.
The drum shaft 62 is provided with a rotary scale 81 as shown in FIG. A plurality of scales 83 are engraved radially on the rotary scale 81. These scales 83 serve as indicators of the amount of rotation of the drum shaft 62. The amount of rotation of the drum shaft 62 can be detected by detecting the scale 83 carved in the rotary scale 81 with a detector having an optical sensor or the like. In the present embodiment, a rotary encoder 85 is employed as a detector that detects the scale 83. Each time the rotary encoder 85 detects the scale 83 carved in the rotary scale 81, the rotary encoder 85 outputs a detection pulse that is a pulse signal.

Moreover, the inkjet apparatus 1 has the control part 111 which controls operation | movement of said each structure, as shown in FIG. The control unit 111 includes a CPU (Central Processing Unit) 113, a drive control unit 115, and a memory unit 117. The drive control unit 115 and the memory unit 117 are connected to the CPU 113 via the bus 119.
In addition, the inkjet device 1 includes a drum drive motor 121, an input device 129, and a display device 131.
The drum drive motor 121 is connected to the control unit 111 via the input / output interface 133 and the bus 119. The input device 129 and the display device 131 are also connected to the control unit 111 via the input / output interface 133 and the bus 119, respectively.

The drum drive motor 121 generates power for rotationally driving the drum main body 71.
The input device 129 is a device for inputting various setting conditions. The display device 131 is a device that displays setting conditions, printing status, and the like. An operator who operates the inkjet device 1 can input various information via the input device 129 while confirming information displayed on the display device 131.
The head 76, the UV irradiation unit 44, the head 76, and the rotary encoder 85 are also connected to the control unit 111 via the input / output interface 133 and the bus 119, respectively.

The CPU 113 performs various arithmetic processes as a processor. The drive control unit 115 controls driving of each component. The memory unit 117 includes a RAM (Random Access Memory), a ROM (Read Only Memory), and the like. In the memory unit 117, an area for storing program software 135 in which the operation control procedure in the inkjet apparatus 1 is described, a data expansion unit 137 that is an area for temporarily expanding various data, and the like are set. Examples of data developed in the data development unit 137 include drawing data indicating a pattern to be drawn, program data such as drawing processing, and the like.
The drive control unit 115 includes a motor control unit 141, a head control unit 145, an irradiation control unit 147, and a display control unit 151.

The motor control unit 141 controls driving of the drum drive motor 121 based on a command from the CPU 113.
The head controller 145 controls driving of the head 76 based on a command from the CPU 113.
The irradiation control unit 147 controls the light emission state of the light source in the UV irradiation unit 44 based on a command from the CPU 113.
The display control unit 151 controls driving of the display device 131 based on a command from the CPU 113.

As shown in FIG. 5, the head controller 145 includes an ejection timing signal generator 171, a drive controller 173, and a head drive circuit 175.
The discharge timing signal generation unit 171 outputs a discharge timing signal TS. In the ejection timing signal TS, a pulse-like ejection timing pulse, which will be described later, appears at a timing when ink droplet ejection is permitted. Ink droplet ejection is permitted based on the rise of the ejection timing pulse. In other words, in the present embodiment, while the CPU 113 instructs the head 76 to execute printing, the ejection of ink droplets from the head 76 is permitted every time the ejection timing pulse rises.

Encoder signal EP and correction signal HS are input to discharge timing signal generation unit 171. The encoder signal EP is output from the rotary encoder 85. In the encoder signal EP, every time the scale 83 of the rotary scale 81 is detected, a detection pulse that is a pulse-like signal appears.
The correction signal HS is a signal indicating a correction amount with respect to a pulse interval that is an interval between adjacent detection pulses in the encoder signal EP, and is output from the CPU 113. The encoder signal EP is also input to the CPU 113. The CPU 113 generates a correction signal HS based on the input encoder signal EP.

The discharge timing signal generation unit 171 outputs a discharge timing pulse at a correction pulse interval obtained by correcting the pulse interval in the encoder signal EP based on the correction signal HS.
The ejection timing signal TS is input to the drive control unit 173. The drive control unit 173 receives the ejection timing signal TS and the print command signal IS. The print command signal IS is a signal output from the CPU 113 and indicates information that instructs the head 76 whether or not to execute printing. The drive control unit 173 outputs the ejection timing signal TS to the head drive circuit 175 when the print command signal IS instructs the head 76 to execute printing (hereinafter referred to as an ON state).
The head driving circuit 175 drives the head 76 based on the input ejection timing signal TS, and ejects ink droplets from the nozzles. At this time, the head 76 selectively ejects ink droplets at each rising edge (or falling edge) of the ejection timing pulse based on the bitmap-like print data.
As described above, printing on the recording medium A can be performed.

By the way, originally, when the rotary drum 61 is rotationally driven, a detection pulse KP corresponding to the detection of the scale 83 appears in the encoder signal EP at every predetermined rotation angle. Therefore, originally, if ink droplets are ejected from the head 76 toward the recording medium A for each detection pulse KP, the recording medium A has a predetermined interval P (distance) as shown in FIG. ) To form dots Dt.
The interval P originally does not change depending on the rotation speed of the rotary drum 61. In this case, originally, when the rotary drum 61 is rotationally driven at a constant speed, the encoder signal EP output from the rotary encoder 85 includes a detection pulse KP corresponding to the detection of the scale 83 as shown in FIG. Appear at regular intervals S (time).
The interval P is an interval related to the distance. The interval S is a time interval. In the following, in order to distinguish between an interval related to distance and an interval related to time, an interval related to distance is called a distance interval, and an interval related to time is called a time interval.

  As described above, originally, when the rotary drum 61 is rotationally driven at a constant speed, the detection pulse KP corresponding to the detection of the scale 83 appears at a constant time interval S. However, in practice, the interval between adjacent dots Dt may vary. This may occur due to the accuracy of the rotary drum 61, the rotary scale 81, the rotary encoder 85, and the like, the mounting accuracy of these components, and the like. Due to these factors, the distance interval L between the adjacent dots Dt may be larger than the distance interval P or smaller than the distance interval P as shown in FIG. In the example shown in FIG. 7A, the distance interval L (1) between the first dot Dt (1) and the second dot Dt (2) is the amount of deviation of ΔL (1) from the distance interval P. large. Similarly, the distance interval L (2) between the second dot Dt (2) and the third dot Dt (3) is smaller than the distance interval P by a deviation amount ΔL (2).

In this case, even if the rotary drum 61 is rotationally driven at a constant speed, in the encoder signal EP output from the rotary encoder 85, as shown in FIG. 7B, the time interval T between adjacent detection pulses KP is equal to the time interval T. It varies. In the example shown in FIG. 7B, the time interval T (1) between the first detection pulse KP (1) and the second detection pulse KP (2) is larger than the time interval S by ΔT (1). . Similarly, the time interval T (2) between the second detection pulse KP (2) and the third detection pulse KP (3) is smaller than the time interval S by ΔT (2).
Note that the order of the detection pulses KP can be defined by determining the scale 83 as a starting point among the plurality of scales 83 in the rotary scale 81. This can be realized, for example, by employing a rotary encoder 85 having a Z phase.

In the present embodiment, the value of the distance interval L (k) and the deviation amount ΔL (k) are stored in the memory unit 117 shown in FIG.
Note that the value of the distance interval L (k) and the amount of deviation ΔL (k) over one rotation of the rotary scale 81 can be grasped from the test pattern printed on the recording medium A. The test pattern can be printed by forming dots Dt for each detection pulse KP output from the rotary encoder 85 when the rotary drum 61 is rotationally driven at an arbitrary speed. Then, the value of the distance interval L (k) and the deviation amount ΔL (k) can be grasped by detecting the dot Dt in this test pattern, for example, with an optical microscope.
Further, the value of the deviation amount ΔL (k) is calculated by the following equation (1).
ΔL (k) = P−L (k) (1)
For this reason, when the distance interval L (k) is larger than the distance interval P, the deviation amount ΔL (k) is a negative value. On the other hand, when the distance interval L (k) is smaller than the distance interval P, the shift amount ΔL (k) is a positive value.

As described above, the CPU 113 generates the correction signal HS. In addition to the encoder signal EP, data indicating the time interval T (k) is input to the CPU 113. The CPU 113 generates the correction signal HS based on the input encoder signal EP and data indicating the time interval T (k).
In the correction signal HS, data indicating the correction amount ΔT (k) for the time interval T (k) in the encoder signal EP is described. The correction amount ΔT (k) is calculated by the following equation (2). The correction amount ΔT (k) is calculated by the CPU 113.
ΔT (k) = ΔL (k) / V (k) (2)
Here, in Equation (2), V (k) is the conveyance speed of the recording medium A in the distance interval L (k). The conveyance speed V (k) is calculated by the following equation (3). The conveyance speed V (k) is calculated by the CPU 113.
V (k) = L (k) / T (k) (3)

Then, the ejection timing signal generator 171 shown in FIG. 5 adds the correction amount ΔT (k) to the time interval T (k) described in the correction signal HS, thereby adjusting the time interval T (k) to the correction time. The interval Th (k) is corrected. That is, the correction time interval Th (k) is calculated by the following equation (4). The correction time interval Th (k) is calculated by the CPU 113.
Th (k) = T (k) + ΔT (k) (4)
The discharge timing signal generator 171 (FIG. 5) outputs the discharge timing pulse TP (k) at the correction time interval Th (k) as shown in FIG.
In the present embodiment, the output of the first ejection timing pulse TP (1) is delayed until the third detection pulse KP (3) is output after the first detection pulse KP (1) is output. To do.
The drive control unit 173 to which the ejection timing signal TS is input outputs the ejection timing signal TS to the head driving circuit 175 when the print command signal IS is in an on state.

  In the present embodiment, the rotary drum 61 corresponds to the transport device, the head 76 corresponds to the recording head, the rotary encoder 85 corresponds to the signal output device, the ejection timing signal generation unit 171 corresponds to the recording pulse generation device, A head driving circuit 175 corresponds to the head driving device. The detection pulse KP (k) corresponds to the pulse signal, the correction time interval Th (k) corresponds to the correction interval, the ejection timing pulse TP (k) corresponds to the recording pulse signal, and the correction amount ΔT (k). Corresponds to the correction amount.

  In the present embodiment, for each time interval T (k) of the detection pulse KP (k), the correction amount ΔT (k) calculated based on the transport speed V (k) corresponding to the time interval T (k) is The ejection timing pulse TP (k) can be generated at the correction time interval Th (k) added to the time interval T (k). The head 76 can be driven based on the ejection timing pulse TP (k). That is, in the present embodiment, recording can be performed at the corrected time interval Th (k) corrected based on the transport speed V (k) corresponding to the time interval T (k) of the detection pulse KP (k). For this reason, it is possible to perform recording in consideration of the change in the conveyance speed V (k) of the recording medium A. As a result, it is possible to easily cope with a change in the conveyance speed V (k) of the recording medium A.

In the present embodiment, a form in which the recording medium A is conveyed using the rotary drum 61 is employed. However, the conveyance form is not limited to this. As a transport mode, for example, a belt transport mode in which the recording medium A is transported by driving the endless belt while the recording medium A is placed on the endless belt may be employed. Further, as a transport mode, for example, a roller transport mode in which the recording medium A is transported by driving these rollers in a state where the recording medium A is sandwiched between a pair of rollers in contact with each other may be employed.
In the present embodiment, an inkjet method is employed as a method for recording (printing). However, the recording method is not limited to this. As a method for performing recording, for example, a dispensing method in which ink is applied to the recording medium A using a syringe, a dispenser, or the like may be employed. Further, as a recording method, for example, an electrophotographic recording method may be employed.

  Further, in this embodiment, an example in which the conveyance speed V (k) is calculated from the results of the distance interval L (k) and the time interval T (k) is adopted, but the value of the conveyance speed V (k) is acquired. The method of performing is not limited to this, and a method using a speed measuring device that directly measures the conveyance speed V (k) may be employed. According to this method, the processing load on the CPU 113 can be reduced.

  In the present embodiment, an example in which the ejection timing pulse TP (k) is output for each detection pulse KP is employed. However, the frequency with which the ejection timing pulse TP (k) is output is not limited to this. As a frequency of outputting the ejection timing pulse TP (k), for example, a frequency of outputting a plurality of ejection timing pulses TP (k) within one time interval T (k) may be employed. According to this, the number of dots Dt per unit length, that is, the recording resolution (DPI (Dot Per Inch)) can be increased. This can be realized, for example, by multiplying the encoder signal EP.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet apparatus, 2 ... Apparatus main body, 41 ... Medium feed mechanism, 61 ... Rotating drum, 62 ... Drum shaft, 71 ... Drum main body, 76 ... Head, 81 ... Rotary scale, 83 ... Scale, 85 ... Rotary encoder, 111 ... Control unit 113 ... CPU 115 ... Drive control unit 145 ... Head control unit 171 ... Discharge timing pulse generation unit 173 ... Drive control unit 175 ... Head drive circuit, A ... Recording medium, L ... Media feed path .

Claims (2)

A transport device for transporting the recording medium;
A recording head that faces the recording medium and performs recording on the recording medium;
A signal output device that outputs a pulse signal along with the conveyance of the recording medium;
A recording pulse generator for generating a recording pulse signal at a correction interval obtained by correcting the interval of the pulse signal;
A head driving device for driving the recording head based on the recording pulse signal,
The recording pulse generator adds the correction amount calculated based on the conveyance speed corresponding to the pulse signal interval to the pulse signal interval for each interval of the pulse signal. To the correction interval,
A recording apparatus. A recording method for recording with a recording head on a recording medium conveyed by a conveying device,
A correction amount calculated based on the conveyance speed corresponding to the pulse signal interval is generated at a correction interval obtained by adding the pulse signal interval to each pulse signal interval output as the recording medium is conveyed. Driving the recording head based on a recording pulse signal;
And a recording method.