JP2009066955A - Print unit and inkjet recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To exactly record an image on each recording medium even when a page interval between the recording media is made narrower than one page. <P>SOLUTION: A print unit 3 includes a recording head 30 ejecting ink toward the recording medium K successively conveyed in a conveying direction X, a recording medium detection part 31 outputting the passing timing of the recording medium K at a predetermined position upstream from the recording head 30 in the conveying direction X, a counting part 32 counting down distances M between recording object areas R in a plurality of recording media K,... whose passing timing is output by the recording medium detection part 31 and an ink landing position T of the recording head 30 concurrently, and a control part 4 controlling the recording head 30 to eject the ink when the recording object area R in each recording medium K reaches the ink landing position T of the recording head 30 based on a counted value by the counting part 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a print unit and an inkjet recording apparatus.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus that records an image on a recording medium such as paper or cloth discharges ink from a recording head of a print unit toward the recording medium while sequentially conveying the recording medium by a conveying device. An image is recorded on the surface.

  In recent years, the following two types of techniques have been developed as techniques for controlling the ink ejection timing in accordance with the transport position of each recording medium in such an ink jet recording apparatus.

  Specifically, as shown in FIG. 4, in the inkjet recording apparatus 100 according to the first type of technology, the edge (trigger) of the recording medium K that is transported upstream of the recording head 101 in the transport direction X. A trigger detection unit (not shown) that detects K1 and outputs a trigger (print start) signal, and a delay counter that counts down the distance from the recording medium K detected at the edge K1 to the ink landing position of the recording head 101 (Not shown). According to such an inkjet recording apparatus 100, each recording medium K is controlled by the recording head 101 by controlling the ink ejection timing based on the output timing of the trigger signal and the distance from the recording medium K to the recording head 101. Ink can be ejected from the recording head 101 when transported to the ink landing position (see, for example, Patent Document 1).

Further, as shown in FIG. 5, in the ink jet recording apparatus 200 according to the second type of technology, image data is inserted by inserting white data (data indicating that ejection is not performed) by a predetermined width between pages of each recording medium. A personal computer (not shown) to be generated is connected. According to the ink jet recording apparatus 200, when the recording medium K is transported to the ink landing position of the recording head 201 by transporting the recording medium with the page width P11 matched to the predetermined width, Ink can be ejected.
Japanese Unexamined Patent Publication No. 7-47670

  However, in the ink jet recording apparatus 100 according to the first type of technology, when the edge K1 of the recording medium K is detected by the trigger detection unit, the distance from the recording medium K to the ink landing position of the recording head 101. Since the delay counter counts down, the recording medium K whose distance is being counted down (hereinafter referred to as the recording medium K on the previous page) has not yet passed through the ink landing position of the recording head 101, and a new recording medium K (hereinafter referred to as the recording medium K). When the trigger detection unit detects the edge K1 of the recording medium K on the next page), the delay counter counts down the distance on the recording medium K on the next page, and as a result, ink is ejected on the recording medium K on the previous page. The timing will be out of control. That is, in the inkjet recording apparatus 100, if the page interval P10 of the recording medium K to be conveyed is narrower than that of one recording medium K, an image cannot be accurately recorded on each recording medium. Further, if the trigger detection unit is disposed away from the recording head 101, it is necessary to widen the page interval of the recording medium K so as to delay the detection timing of the edge K1 of the recording medium K of the next page. In addition, there is a restriction that the position where the trigger detection unit is disposed is close to the recording head 101.

  Further, in the ink jet recording apparatus 200 according to the second type of technology, since white data is inserted to generate image data, the load on the personal computer is heavy especially when recording different images for each page. turn into. Further, since the ink ejection timing is not controlled in accordance with the actual transport position of the recording medium K of each page, if the page interval of the recording medium K shifts, the image recording position shifts. Become.

  An object of the present invention is to provide a print unit and an ink jet recording apparatus capable of accurately recording an image on each recording medium even when the page interval of the recording medium is narrower than one page.

The invention according to claim 1 is the print unit,
A recording head that ejects ink toward a recording medium that is sequentially conveyed in the conveying direction;
Passage timing output means for outputting the passage timing of the recording medium at a predetermined position upstream in the transport direction from the recording head;
Count means for counting down in parallel the distances between the recording target areas in the plurality of recording media whose passage timings are output by the passage timing output means and the ink landing positions of the recording heads;
And a control unit that enables the recording head to eject ink when a recording target area on each recording medium reaches an ink landing position of the recording head based on a count value by the counting unit. .

The invention according to claim 2 is the print unit according to claim 1,
The passage timing output means detects a conveyed recording medium at the predetermined position and outputs a passage timing.

The invention according to claim 3 is the print unit according to claim 1 or 2,
The counting means ends the countdown for the recording medium when the recording target area on the recording medium has passed the ink landing position of the recording head.

The invention according to claim 4 is the print unit according to any one of claims 1 to 3,
A page memory for storing image data of at least two pages of the recording medium;
The control means includes
When the recording target area on the recording medium reaches the ink landing position of the recording head, ink is applied to the recording head based on the image data of the corresponding page portion of the image data of each page of the recording medium in the page memory. It is characterized by discharging.

Invention of Claim 5 is a printing unit as described in any one of Claims 1-4,
The counting means includes
It has a plurality of delay counters that respectively count down in parallel the distances between the recording target areas in the plurality of recording media whose passage timings are output by the passage timing output means and the ink landing positions of the recording heads. To do.

A sixth aspect of the present invention is the print unit according to any one of the first to fifth aspects,
The counting means includes
An encoder is provided that outputs a pulse signal for each predetermined conveyance amount of the recording medium.

The invention according to claim 7 is the ink jet recording apparatus,
The print unit according to any one of claims 1 to 6,
And a transport device that transports the recording medium in the transport direction.

  According to the first aspect of the present invention, with respect to the recording media that are sequentially conveyed, the passage timing on the upstream side in the conveyance direction from the recording head is output, and the recording target areas in the plurality of recording media to which the passage timing is output The distance from the ink landing position of the recording head is counted down in parallel, and based on this count value, the recording head can eject ink when the recording target area on the recording medium reaches the ink landing position of the recording head. Therefore, even when the passage timing of the newly conveyed recording medium is output in a state where the recording medium counting down the distance to the ink landing position of the recording head has not yet passed the ink landing position of the recording head, the previous page For each recording medium and the recording medium on the next page, the distance to the ink landing position is counted down. It is possible. Therefore, even if the page interval of the recording medium is narrower than that of one page, an image can be accurately recorded on each recording medium.

  According to the invention of claim 2 or 3, the same effect as that of the invention of claim 1 can be obtained.

  According to the fourth aspect of the invention, the page memory stores image data for at least two pages of the recording medium, and when the recording target area on the recording medium reaches the ink landing position of the recording head, the page memory Since the recording head ejects ink based on the image data of the corresponding page portion among the image data of each page of the recording medium in the recording medium, even when a different image is output to the recording medium of each page The page interval of the medium can be made narrower than one page.

  According to the invention described in claims 5 to 7, the same effect as that of the invention described in any one of claims 1 to 4 can be obtained.

The ink jet recording apparatus according to the present invention will be described below.
FIG. 1 is a side view showing a schematic configuration of an ink jet recording apparatus 1 according to the present embodiment. In the present embodiment, the ink jet recording apparatus 1 will be described as a one-pass type ink jet recording apparatus, that is, an ink jet recording apparatus that completes image recording while the recording medium K is transported once.

  The ink jet recording apparatus 1 records an image on a recording target area R (see FIG. 3) of a recording medium K based on image data transmitted from a personal computer (not shown), and faces each other as shown in FIG. The transport apparatus 2 and the print unit 3 are provided.

  Among them, the transport device 2 sequentially transports a plurality of recording media K in the transport direction X by the rotation of the transport rollers 20. In the present embodiment, the recording medium K is affixed to the surface of the long mount D at predetermined page intervals P as shown in FIG. It is designed to be conveyed following.

  The print unit 3 includes a plurality of recording heads 30 extending in the width direction Y of the mount D, that is, the direction orthogonal to the transport direction X.

  The recording heads 30 are provided with a plurality of nozzles 300 that eject ink toward the recording medium K that is sequentially conveyed by the conveying device 2. These nozzles 300,... Are configured to eject ink droplets based on ejection propriety data generated for each nozzle 300 based on image data and drive waveforms. More specifically, the recording head 30 is provided with a piezo element (not shown) for discharging the ink in the nozzle 300, and the piezo element vibrates based on the drive waveform and discharge enable / disable data. Thus, the ink in the nozzle 300 is vibrated or ejected. In the present embodiment, a plurality of recording heads 30 are described as being linearly arranged in the width direction Y, but may be arranged in other forms such as a staggered pattern. good. Further, the extending direction of the recording head 30 does not have to be orthogonal to the transport direction X as long as it intersects the transport direction X.

Next, the functional configuration of the print unit 3 will be described.
FIG. 2 is a block diagram illustrating a schematic configuration of the print unit 3.

  As shown in this figure, the print unit 3 includes a recording medium detection unit 31, a count unit 32, a page memory 33, and a control unit 4 in addition to the recording head 30 described above.

  Among these, the recording medium detection unit 31 outputs the passage timing of the recording medium K at a predetermined position upstream of the recording head 30 in the conveyance direction X. In the present embodiment, the recording medium 30, ... Is arranged on the upstream side in the transport direction X so as to face the mount D (recording medium K), and detects the transported recording medium K and outputs a detection signal. More specifically, the recording medium detection unit 31 in the present embodiment detects the edge (trigger) K1 on the leading end side of the recording medium K in the transport direction X. Further, the interval between the recording medium detection unit 31 and the recording head 30 is wider than the two recording media K arranged at the page interval P as shown in FIG. Note that the recording medium detection unit 31 that detects the recording medium K in this way detects the edge K1 of the recording medium K based on the difference in reflectance between the mount D and the recording medium K, or the recording medium K. What detects a predetermined mark provided in advance at the edge K1 can be used.

  The count unit 32 includes an encoder 320 and three delay counters 321,.

  The encoder 320 outputs a pulse signal for each predetermined conveyance amount of the recording medium K. Note that the encoder 320 in the present embodiment is a rotary encoder that rotates in accordance with the transport amount of the mount D (recording medium K) and outputs a pulse signal for each predetermined rotation amount. As shown, it is provided on a roller 320a that rotates following the board D (recording medium K) being conveyed.

  The three delay counters 321,... Are detected by the recording medium detection unit 31 based on the pulse signal from the encoder 320 and the position of the recording target region R in the recording medium K set in the image data. The distance M between the leading edge R1 of the recording target region R of the plurality of recording media K,... And the ink landing position T of the recording head 30 is counted down in parallel. Each delay counter 321 ends the countdown for the recording medium K when the recording target region R of the recording medium K has passed the ink landing position T. Here, the ink landing position T is a position where the ink ejected from the recording head 30 lands by design, and is not the landing position of the scattered ink when the actually ejected ink is scattered. In addition, as such a delay counter 321, what was implement | achieved by hardware, such as an electric circuit, may be used, and what is implement | achieved by software may be used.

  The page memory 33 stores image data to be output to the recording medium K for each page. When the same image is recorded on the recording medium K for each page, the page memory 33 stores image data for one page.

  The control unit 4 includes a CPU, ROM, RAM, a conventionally known hardware circuit, and the like, and drives and controls each unit of the print unit 3. Specifically, the control unit 4 generates ejection propriety data for each nozzle 300 based on the image data, and outputs the ejection feasibility data and the above-described drive waveform to each recording head 30. The recording head 30 performs image recording. Further, the control unit 4 in the present embodiment moves the recording head 30 when the recording target area R of each recording medium K reaches the ink landing position T of the recording head 30 based on the count value by the counting unit 32. Ink discharge is enabled, and when the ink landing position T has been passed, the recording head 30 is prohibited from discharging ink.

  Next, the operation of the above inkjet recording apparatus 1 will be described with reference to FIG. In FIG. 3, for the sake of simplicity, only one recording head 30 in the print unit 3 is illustrated.

  First, when image data is transmitted from the personal computer to the inkjet recording apparatus 1, the image data is stored in the page memory 33 for each page of the recording medium K.

  Next, when the transport device 2 of the inkjet recording apparatus 1 starts transporting the mount D and the recording medium K, the encoder 320 rotates following the mount D (recording medium K) and outputs the rotation amount as a pulse signal. . Further, the recording medium detection unit 31 detects the edge K1 on the leading end side of the recording medium K in the transport direction X (hereinafter referred to as recording medium Ka for convenience).

  Next, any one of the three delay counters 321,... (Hereinafter referred to as delay counter 321a for convenience) is included in the recording medium Ka set in the pulse signal from the encoder 320 and the image data. The distance M between the edge R1 of the recording target region R on the recording medium Ka and the ink landing position T of the recording head 30 based on the position of the recording target region R in FIG. Start the countdown.

  Here, in a state where the recording target region R of the recording medium Ka has not reached the ink landing position T, that is, in a state where the delay counter 321a counts down the distance Ma to the ink landing position T with respect to the recording medium Ka. When the unit 31 detects the edge K1 on the leading end side of a new recording medium K (hereinafter referred to as recording medium Kb for convenience), one of the three delay counters 321,. (Hereinafter referred to as a delay counter 321b for convenience) in the recording medium Kb based on the pulse signal from the encoder 320 and the position of the recording target region R in the recording medium Kb set in the image data. Counting the distance M between the edge R1 of the recording target region R and the ink landing position T of the recording head 30 (hereinafter referred to as the distance Mb for convenience) To start down.

  Further, the recording target area R of the recording media Ka and Kb does not reach the ink landing position T, that is, the delay counters 321a and 321b count down the distances Ma and Mb to the ink landing position T for the recording media Ka and Kb. When the recording medium detection unit 31 detects the edge K1 on the leading end side of a new recording medium K (hereinafter referred to as a recording medium Kc for convenience), the delay counter of the three delay counters 321,. Any one other than 321a and 321b (hereinafter referred to as a delay counter 321c for convenience) is the position of the recording target region R within the recording medium Kc set in the pulse signal from the encoder 320 and the image data. Based on the above, the distance M between the edge R1 of the recording target region R on the recording medium Kc and the ink landing position T of the recording head 30 (hereinafter, referred to as “M To start the countdown of the convenience to the distance Mc).

  When the recording target region R on the recording medium Ka of the previous page reaches the ink landing position T, the control unit 4 enables the recording head 30 to eject ink and reads out image data of the corresponding page portion from the page memory 33. Ejection availability data for each nozzle 300 is generated, and ink is ejected based on the ejection availability data and the drive waveform. When the recording medium Ka has passed the ink landing position T, the control unit 4 prohibits the recording head 30 from ejecting ink. Further, the delay counter 321a finishes the countdown for the recording medium Ka, and the recording medium detection unit 31 enters the countdown standby state for the recording medium K to be detected next.

  Thereafter, by repeating the above-described operation, an image is recorded on each recording medium K (see the recording medium K at the right end in the figure).

  According to the above-described ink jet recording apparatus 1, for the recording media K,... That are sequentially transported, a plurality of recording media whose passage timings are output upstream of the recording head 30 in the transport direction X are output. The distance M between the recording target region R in K,... And the ink landing position T of the recording head 30 is counted down in parallel, and based on this count value, the recording target region R in the recording medium K becomes the ink of the recording head 30. Since the recording head 30 can eject ink when the landing position T is reached, the recording medium Ka that is counting down the distance M to the ink landing position T of the recording head 30 still determines the ink landing position T of the recording head 30. Even if the passage timing of the newly conveyed recording media Kb and Kc is output without passing, the recording medium of the previous page is output. And a, and a recording medium Kb of the next page can be further about the recording medium Kc of the next page, respectively counts down the distance Ma~Mc to the ink landing position T. Therefore, even when the page interval P between the recording media K,... Is narrower than that of one page of the recording medium K, an image can be accurately recorded on each recording medium K. As a result, the image recording efficiency is improved. Can be made.

  Further, even if the recording medium detection unit 31 is disposed away from the recording head 30, the recording head for each recording medium K,... That has not reached the ink landing position T after being detected by the recording medium detection unit 31. Since the distances M up to 30 can be counted down, the recording medium detection unit 31 can be arranged at an arbitrary position, unlike the conventional case. Therefore, the degree of freedom in designing the print unit 3 and the inkjet recording apparatus 1 can be increased.

  Further, since the page interval P of the recording medium K,... Can be made narrower than one page without inserting white data and generating image data, the load on the personal computer for generating image data is reduced. can do.

  Further, since the discharge timing can be controlled in accordance with the actual transport position of the recording medium K,... For each page, the image can be recorded at an accurate position regardless of the page interval P of the recording medium K,. Can do.

  The page memory 33 stores image data for at least two pages of the recording medium, and the control unit 4 detects the recording medium in the page memory 33 when the recording medium K reaches the ink landing position T of the recording head 30. Of the image data of each page of K, since the recording head 30 ejects ink based on the image data of the corresponding page portion, even when different images are output to the recording medium K of each page, The page interval of the recording medium K can be made smaller than one page.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  For example, in the above embodiment, the print unit 3 has been described as including three delay counters 321, but it may be provided as two or four or more. However, the number of delay counters 321 is preferably larger than the number of recording media K that can be conveyed and at least one portion can exist in the interval between the recording medium detection unit 31 and the recording head 30.

  Further, although it has been described that the distance M from the recording medium K detected by the recording medium detection unit 31 to the recording head 30 is counted down based on the rotation amount of the encoder 320, the conveyance speed by the conveyance device 2 is made constant. The countdown may be performed based on the elapsed time after the recording medium K is detected by the recording medium detection unit 31.

  In addition, it has been described that the recording medium detection unit 31 detects the recording medium K and outputs the passage timing of the recording medium K on the upstream side of the recording head 30, but the length of the recording medium K in the transport direction X is described. In addition, the passage timing of the recording medium K may be automatically output every time the mount D is conveyed by the total of the page interval of the recording medium K.

  The recording medium K has been described as being attached to the surface of the mount D. However, the recording medium K may be set at predetermined intervals by a command signal from a personal computer or the like in the mount D having a uniform surface. Good. In this case, the recording medium detection unit 31 may detect the set area of the recording medium K by detecting a predetermined mark provided in advance on the mount D, or may be on the setting in the transport direction X. The passing timing of the set area of the recording medium K may be automatically output every time the mount D is conveyed by the total of the length of the recording medium K and the page interval of the recording medium K.

1 is a side view showing a schematic configuration of an ink jet recording apparatus according to the present invention. FIG. 2 is a block diagram illustrating a schematic configuration of a print unit according to the present invention. It is a figure for demonstrating the space | interval of a recording medium. It is a figure for demonstrating the conventional inkjet recording device. It is a figure for demonstrating the conventional inkjet recording device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus 2 Conveyance apparatus 3 Print unit 4 Control part (control means)
30 Recording Head 31 Recording Medium Detection Unit (Passing Timing Output Unit)
32 Count unit (counting means)
33 page memory 320 rotary encoder 321 delay counter K recording medium R recording target area T ink landing position X transport direction

Claims (7)

A recording head that ejects ink toward a recording medium that is sequentially conveyed in the conveying direction;
Passage timing output means for outputting the passage timing of the recording medium at a predetermined position upstream in the transport direction from the recording head;
Count means for counting down in parallel the distances between the recording target areas in the plurality of recording media whose passage timings are output by the passage timing output means and the ink landing positions of the recording heads;
And a control unit that enables the recording head to eject ink when a recording target area on each recording medium reaches an ink landing position of the recording head based on a count value by the counting unit. Print unit. The print unit according to claim 1,
The printing unit, wherein the passage timing output means detects a transported recording medium at the predetermined position and outputs a passage timing. The print unit according to claim 1 or 2,
The printing unit according to claim 1, wherein the counting unit ends the countdown for the recording medium when the recording target area on the recording medium has passed the ink landing position of the recording head. In the printing unit as described in any one of Claims 1-3,
A page memory for storing image data of at least two pages of the recording medium;
The control means includes
When the recording target area on the recording medium reaches the ink landing position of the recording head, ink is applied to the recording head based on the image data of the corresponding page portion of the image data of each page of the recording medium in the page memory. A print unit that discharges water. In the printing unit as described in any one of Claims 1-4,
The counting means includes
It has a plurality of delay counters that respectively count down in parallel the distances between the recording target areas in the plurality of recording media whose passage timings are output by the passage timing output means and the ink landing positions of the recording heads. To print unit. In the printing unit as described in any one of Claims 1-5,
The counting means includes
A print unit comprising an encoder that outputs a pulse signal for each predetermined conveyance amount of a recording medium. The print unit according to any one of claims 1 to 6,
An ink jet recording apparatus comprising: a transport device that transports a recording medium in the transport direction.

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