JP2010284926A - Image recording apparatus and method for controlling image recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image recording apparatus capable of setting an accurate recording position to a recording medium by using an image reading sensor serving as a means for both reading an image and reading a paper end, and also capable of saving a space, and to provide a method for controlling the image recording apparatus. <P>SOLUTION: The image recording apparatus includes: a conveying part for conveying the recording medium; an image recording part for delivering ink on the recording medium conveyed to record the image; and an image inspecting part for taking the recorded image in for inspecting the quality of the image recording. The image recording apparatus further includes an end part detecting part which irradiates an side end of the recording medium with light by a specified angle of incidence and detects the end part of the recording medium based on the reflecting light from the recording medium. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image recording apparatus for recording an image on a recording medium and a control method for the image recording apparatus, and more particularly to a technique for detecting an end position of a conveyed recording medium.

  2. Description of the Related Art Image recording apparatuses that perform image recording on a continuous recording medium (continuous medium) in which paper, film, or the like is wound in a roll shape are known. In such an image recording apparatus, the direction orthogonal to the transport direction of the recording medium to be transported, that is, the left and right positions in the recording direction of the recording medium, is grasped, and the image recording start position and the image recording end position on the recording medium Need to know.

  The transport position of the recording medium to be transported changes due to variations in position caused when the individual image recording apparatuses are installed, variations due to the meandering of the recording medium, and the winding state of the roll paper. For this reason, it is necessary to detect a side end perpendicular to the conveyance direction of the recording medium with a sensor or the like to correct the image recording position.

In addition, there is a device having a function of reading a recorded image with a sensor for the purpose of confirming that the image recording has no defect and is normally recorded.
The above two functions can be performed by the same sensor by using, for example, a CIS (CONTACT IMAGE SENSOR) or a CCD area sensor as the reading sensor. In that case, in order to read the recorded image with high accuracy, the recording medium needs to be placed on the backing portion so that the recording medium is not distorted.

  There are many methods for detecting the edge of the recording medium, which illuminate the recording medium, read the reflected light with a sensor, and detect the difference in the electrical signal level resulting from the difference in light reflectance between the recording medium and its background. It is used. In this case, if the reflectance of the recording medium and the illumination light in the background are close, the end of the recording medium may not be detected.

  In order to solve this problem, for example, in the invention according to Patent Document 1, light sources are provided before and after the image reading sensor, and one of the light sources is positively shaded at the leading edge and the trailing edge of the paper. Discloses a technique for detecting the edge of a sheet by generating a timing to turn on only the paper.

JP 2008-17067 A

  However, in the above prior art, since it is necessary to positively generate a shadow on the paper edge, it is necessary to illuminate the paper edge from the inside to the outside of the paper. Must be provided. Moreover, it is necessary to illuminate the same area in a relatively wide range with two illuminations having an angle, and a device such as a CIS cannot be arranged to block the optical path.

Therefore, in order to read an image, it is necessary to place the sensor at a distant position via an optical device such as a mirror or a lens, and it is difficult to save the space of the device.
Therefore, in view of the above problems, the present invention provides an image recording apparatus and a control method for the image recording apparatus that can save both space and save both image reading and sheet side edge reading.

  In order to achieve the above object, an image recording apparatus according to one embodiment of the present invention includes a transport unit that transports a recording medium, an image recording unit that records an image by ejecting ink onto the transported recording medium, An image recording apparatus including an image inspection unit that captures a recorded image and inspects the quality of the image recording, and irradiates the side edge of the recording medium with light at a predetermined incident angle, from the recording medium And an edge detection unit that detects an edge of the recording medium based on the reflected light.

  In addition, a control method for an image recording apparatus according to another aspect of the present invention includes a conveyance process for conveying a recording medium, an image recording process for recording an image by ejecting ink onto the conveyed recording medium, An image recording apparatus control method for performing an image inspection process for capturing a recorded image and inspecting the quality of the image recording, wherein the recording medium is irradiated with light at a predetermined incident angle, and the recording is performed. An edge detection process for detecting an edge of the recording medium based on reflected light from the medium is performed.

  According to the present invention, it is possible to detect the edge of the recording medium even when the difference in reflectance between the backing portion of the recording medium and the recording medium is small, and the recorded image can be read by the same sensor. Thus, an image recording apparatus and a control method for the image recording apparatus that can confirm the quality of the recorded image are realized.

It is the schematic of the side surface of an inkjet full line type printer apparatus. (A) is the schematic diagram which observed the upper periphery of the base drum from the top, (b) is the schematic diagram of the base drum periphery observed from the conveyance direction of the recording medium. It is a figure explaining that the edge part side surface of a recording medium is emphasized brightly and illuminated. It is a figure explaining the electric signal level of a detection part. It is a flowchart explaining the processing operation of 1st Embodiment. FIG. 6 is a schematic diagram of a periphery of a base drum observed from a recording medium conveyance direction for explaining a second embodiment. It is a flowchart explaining the processing operation of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the following description, an example in which the image recording apparatus of the present embodiment is configured as an ink jet full-line printer apparatus will be described.

  FIG. 1 is a schematic view showing a side surface of an ink jet full line type printer apparatus (hereinafter simply referred to as a printer apparatus). The printer apparatus 1 used in this embodiment includes at least a base drum 6, an image recording unit 16, image reading sensors 17 and 24, and external illuminations 18 and 25. Further, an unwinder unit 2 for supplying the recording medium 3 wound up in a roll shape to the printer device 1 is provided outside.

  The recording medium 3 is wound around a base drum 6 by a free roller 4 and a free roller 5. The base drum 6 is formed of, for example, a hollow cylinder made of aluminum, and is held rotatably with respect to the printer device 1. The recording medium 3 is conveyed in the direction of the arrow according to the rotation of the base drum 6, and the recording medium 3 is guided to the nip roller pair 8 and 9 via the free roller 7. The nip roller pairs 8 and 9 function as conveyance driving members that are rotationally driven by the nip roller driving unit 10 to sandwich the recording medium 3 and convey it to the downstream side. The recording medium 3 wound around the base drum 6 obtains a predetermined tension and conveyance speed by the conveyance force by the nip roller pairs 8 and 9 and the back tension generated by a braking mechanism (not shown) provided in the unwinder section 2. Yes.

  A cutter unit 14 including a cutter roller 11, an anvil roller 12, and a cutter blade 13 is disposed downstream of the nip roller pair 8 and 9. The recording medium 3 is cut into a predetermined length, and a sheet-like recording medium 15. And

  The image recording unit 16 is disposed on the base drum 6 and includes a nozzle row (not shown) that ejects ink and a drive unit that drives the nozzle row, and ejects ink to the recording medium 3 being conveyed. To record an image.

  The image reading sensor 17 is disposed downstream of the image recording unit 16 in the transport direction, and has a function of reading an image recorded on the recording medium 3 as electronic information. Information read by the image reading sensor 17 is normally used for confirming the quality of a recorded image. The sensor 17 also has a function of detecting the positions of the left and right end portions orthogonal to the conveyance direction of the recording medium 3.

  As a confirmation of the quality of the recorded image, for example, when dot recording is not performed on the recording medium 3 due to clogging of ink nozzles or the like, a line-shaped non-recording portion is generated in the conveyance direction of the recording medium 3 and the recording quality is deteriorated. Therefore, such a recording defect is detected. Note that detection processing of the left and right ends of the recording medium 3 by the image reading sensor 17 will be described in detail later.

  The external illumination 18 is an element constituting the present embodiment, and is a light source including, for example, a laser diode as a main component. The external illumination 18 irradiates the side end of the recording medium 3 with light at a predetermined incident angle, and detects the end of the recording medium 3 based on the reflected light from the recording medium 3.

  The host device 20 is constituted by, for example, a personal computer and has a function of outputting image data to be recorded to the printer device 1. The control unit 19 controls the operation control of the printer device 1 and the unwinder 2.

Hereinafter, an image recording operation according to the present embodiment will be described.
First, recording data and a recording instruction for image recording are output from the upper device 20 to the control unit 19. The control unit 19 performs command analysis on the received image data, converts it into drawing data suitable for image recording, and starts operation control of the main body of the printer device 1 and the unwinder 2.

  First, rotation of the cutter roller 11 and the anvil roller 12 is started, and then the nip roller pair 8 and 9 is rotated. The nip roller pairs 8 and 9 sandwich the recording medium 3 and convey the recording medium 3 by its rotation. The unwinder 2 has a brake function (not shown) and applies a back tension to the recording medium 3. As a result, a certain tension is applied to the recording medium 3 between the pair of nip rollers 8 and 9 and the unwinder 2.

  Further, the recording medium 3 is wound around the base drum 6 in a wide range by the free rollers 4 and 5. As described above, since a constant tension is applied to the recording medium 3, a vertical drag is applied to the outer peripheral surface of the base drum 6. As a result, a predetermined frictional force is generated between the base drum 6 and the recording medium 3, slippage between the base drum 6 and the recording medium 3 is suppressed, the recording medium 3 is held in close contact with the base drum 6, and It is transported at a stable speed.

Then, ink for image recording is ejected from the image recording unit 16, whereby a high-quality image is formed on the recording medium 3.
Here, it is necessary to make the ink ejection position from the image recording unit 16 coincide with the position of the recording medium 3. In particular, when a roll-shaped continuous recording medium is used, left and right deviations easily occur with respect to the transport direction. The reason is due to variations in the setting of the recording medium 3 with respect to the unwinder 2 by the user or variations in winding of the roll paper itself. For the above reason, in order to detect a left-right shift with respect to the conveyance direction of the set recording medium 3, the end position of the recording medium 3 is read by a sensor, and the result is reflected in the ink ejection position from the image recording unit 16. It will be necessary.

  In this embodiment, the image reading sensor 17 is a CIS type sensor used in a scanner or the like, and has a function of detecting the position of the end of the recording medium 3 and an image recorded by the image recording unit 16 as electronic data. As well as the ability to read as In order to read an image recorded by the image reading sensor 17, the recording light being conveyed is scanned and read line by line using illumination light incorporated in the image reading sensor 17, and the printer apparatus as described above. 1 recording quality is ensured.

  Further, as described above, since the recording medium 3 is held in close contact with the base drum 6, it is possible to read image data without the recording medium 3 being lifted or distorted. However, when the image reading sensor 17 is used on the base drum 6 for the purpose of detecting the position of the end portion of the recording medium 3, there is a problem as described later, and this embodiment solves this problem.

Next, the operation principle of this embodiment will be described with reference to FIG.
FIG. 2A is a schematic view of the upper periphery of the base drum 6 observed, and the conveyance direction of the recording medium 3 is indicated by an arrow. FIG. 2B is a schematic diagram of the periphery of the base drum 6 observed from the downstream side in the conveyance direction of the recording medium 3.

  Further, as described above, the base drum 6 is an aluminum hollow cylinder, and its surface is processed in a smooth state so as to function as a backing portion when an image is recorded on the recording medium 3. . Therefore, the surface of the base drum 6 has a very high reflectance with respect to the illumination light built in the image reading sensor 17 when reading the recording medium 3. Even when the recording medium 3 is white paper, the recording medium 3 has a very high reflectance with respect to the illumination light built in the image reading sensor 17. For this reason, when the illumination light is applied from the vertical direction to the recording surface of the recording medium 3 using the internal illumination of the image reading sensor 17 in an attempt to detect the boundary between the recording medium 3 and the base drum 6, Since the surface of the base drum 6 that is the backing portion and the reflectance of the recording medium 3 are combined, there is a case where reading cannot be performed correctly.

  Therefore, the present embodiment is characterized in that illumination is performed from the side surface of the end of the recording medium 3. That is, the external illumination 18 using a laser diode is arranged in the lateral direction of the image reading sensor 17, and the illumination light is applied to the end side surface of the recording medium 3.

  When such illumination is performed, diffuse diffuse reflection occurs between the surface of the recording medium 3, the side surface of the end portion, and the surface of the base drum 6. By detecting this diffuse reflection component by the image reading sensor 17 in the direction perpendicular to the paper surface, the diffuse reflection light from the end of the recording medium 3 is emphasized, and the end side surface of the recording medium 3 can be detected. That is, a phenomenon occurs in which the light reflected from the side surface of the end of the recording medium 3 is further reflected in the vertical direction by the base drum 6.

  As a result, as shown in FIG. 3, the end side surface 22 of the recording medium 3 is brightly highlighted and illuminated. In this state, by performing the reading process by the image reading sensor 17, the electric signal level becomes high at the end portion of the recording medium 3 as shown in FIG. 4, and if the threshold value is set at an appropriate signal level, it corresponds. The position of the side edge of the paper can be known from the position of the sensor pixel.

By using this method, for example, the position of the end of the recording medium 3 can be detected even when the light reflectivity of the base drum 6 that is the backing portion and the recording medium 3 is combined.
The external illumination 18 is configured to illuminate a gap between the recording medium 3 and the image reading sensor 17 as shown in FIG. Therefore, for example, the CIS can be used for the image reading sensor 17 to cope with a case where the gap with the recording medium 3 is small. As a result, even in a small space, a configuration that combines image reading and detection of the end of the recording medium 3 becomes possible.

Next, the processing operation for detecting the edge of the recording medium in the present embodiment will be described with reference to a flowchart.
Here, the initial operation of the printer apparatus 1 has been completed, and a description will be given since it is in a state of waiting for a recording command from the host apparatus 20.
FIG. 5 is a flowchart for explaining the processing operation of this embodiment. First, when an image recording command is output from the above-described host apparatus 20 to the printer apparatus 1, the printer apparatus 1 detects the end of the recording medium 3. In order to perform position detection, the external illumination 18 is turned on, and the built-in illumination of the image reading sensor 17 is turned off (step (hereinafter referred to as S) 1).

  Next, the reflected light of the external illumination 18 with respect to the base drum 6 and the recording medium 3 is read by the image reading sensor 17 (S2). As described above, the end of the recording medium 3 is shined by being emphasized by diffuse diffuse reflection of light, and its position is detected by the image reading sensor 17.

  Next, from the position of the end of the recording medium 3 detected by the above process and the width information of the recording medium 3 registered in the control unit 19 in advance, the control unit 19 arranges an image recording range, A recording start position is determined (S3).

  Next, the conveyance of the recording medium 3 is started (S4), the external illumination 18 is turned off, the internal illumination of the image reading sensor 17 is turned on, and the image reading sensor 17 is set to a state in which an image can be read ( S5).

  Next, image recording is started (S6), and the recorded image is read by the image reading sensor 17 (S7). Based on the data read in this way, the printer apparatus 1 confirms the recording quality as described above.

  Thereafter, the end of the image recording job is determined (S8). If the image recording job is not ended (S8 is NO), the above process is repeated, and when the image recording job is ended (S8 is YES), the printer apparatus 1 ends the conveyance process of the recording medium 3.

  As described above, according to the present embodiment, the end of the recording medium 3 can be detected and the image quality can be confirmed even when the backing portion of the recording medium 3 and the reflectance of the recording medium 3 are antagonistic. Therefore, it is possible to realize an image recording apparatus that can also serve as the image reading sensor 17 and a space-saving method, and a control method for the image recording apparatus.

Next, a second embodiment of the present invention will be described.
In the second embodiment, the entire system of the printer apparatus 1 is the same as that in FIG. 1 described in the first embodiment. However, in the second embodiment, the external illumination 18 is deleted and image reading is performed. The only difference is that the sensor has a built-in illumination.

  FIG. 6 is a diagram for explaining the characteristics of the second embodiment, and is a schematic view of the periphery of the base drum 6 observed from the downstream side in the conveyance direction of the recording medium 3. In the first embodiment described above, the external illumination 18 is used when detecting the edge of the recording medium 3, but in the second embodiment, as described above, the same effect can be obtained by controlling the built-in illumination of the image reading sensor. It is a configuration to obtain.

  The image reading sensor 24 is a CIS, and a sensor unit that actually reads light, an illumination unit using white, red, blue, and green three primary color LEDs, and a lens are integrated in a sensor housing. . The image reading sensor 24 is opposed to the recording medium 3 with close contact or a slight clearance to read an image.

  As described above, the illumination unit built in the image reading sensor 24 is composed of white or three primary color LEDs, but a plurality of LEDs are arranged so that light is uniformly applied to the image area to be read, and the emitted LED Light is diffused by a diffusion plate or the like and used for illumination. The plurality of LEDs are generally controlled to be lit simultaneously, but can be individually lit by changing the internal configuration of the image reading sensor 24.

  This will be specifically described below. The image reading sensor 24 is provided with a plurality of illumination LEDs 25. Here, the following description will be given on the assumption that the number of illumination LEDs 25 is five of 25a to 25e. Moreover, these lighting LEDs 25a to 25e are individually controlled to be turned on and off independently, and can be controlled based on a command from the outside.

  Therefore, when detecting the end of the recording medium 3, only two of the plurality of illumination LEDs 25a to 25e built in the image reading sensor 24 are arranged. That is, only the illumination LEDs 52a and 52e shown in FIG. 6 are turned on, and the three illumination LEDs 25b to 25d are kept off. The image reading sensor 24 has a reading width that exceeds the width of the recording medium 3, and the illumination LEDs 25 a and 25 e at both ends of the image reading sensor 24 are located outside the width of the recording medium 3. .

As a result, as described in the first embodiment, the edge is emphasized by diffuse diffuse reflection of light, and the position of the edge of the recording medium 3 can be detected by the image reading sensor 24.
In the description of the above embodiment, among the plurality of illumination LEDs 25a to 25e built in the image reading sensor 24, the two LEDs arranged at both ends of the sensor are lit, but one illumination LED 25a is used. Or it is good also as a structure which lights 25e. Moreover, the edge detection illumination is not limited to one, and may be plural as necessary.

In the image reading process, the illumination LEDs 25a to 25e are all turned on to perform the image reading process and maintain the recording quality of the printer apparatus 1.
The illumination LED of the image reading sensor 24 has three primary colors of white, red, blue, and green as described above. However, the LED used for detecting the edge of the paper may be any color. There is no.

Next, the process of the second embodiment will be described with reference to the flowchart shown in FIG.
As in the first embodiment described above, when an image recording command is output from the host device 20 to the printer device 1, the printer device 1 detects the position of the end of the recording medium 3, and thus the image reading sensor 24. Only the internal illuminations 25a and 25e located at both ends of the built-in illumination are turned on, and the other LEDs 25b to 25d are turned off (step (hereinafter referred to as ST) 1).

  Next, the image reading sensor 24 reads the reflected light from the both ends of the image reading sensor 24 with respect to the base drum 6 and the recording medium 3 (ST2). As described above, the end portion of the recording medium 3 is shined by being emphasized by diffuse diffuse reflection of light, and its position can be detected.

  Next, as described above, the control unit 19 sets the image recording range from the position of the end of the recording medium 3 detected by the above process and the width information of the recording medium 3 registered in the control unit 19 in advance. Then, the recording position of the image is determined (ST3).

  Next, conveyance of the recording medium 3 is started (ST4), all the internal illuminations 25a to 25e of the image reading sensor 24 are turned on, and the image reading sensor 24 is set to a state in which image reading processing is possible (ST5). ).

  Next, the image recording unit 16 starts ejecting ink and performs image recording on the recording medium 3 (ST6). The recorded image is conveyed immediately below the image reading sensor 24, and the recorded image information is read (ST7).

  Thereafter, the end of the image recording job is determined (ST8). If the image recording job has not ended (NO in ST8), the above process is repeated, and when the image recording job ends (YES in ST8), the printer apparatus 1 ends the conveyance process of the recording medium 3.

  As described above, according to the second embodiment, the image reading sensor 24 can be used for both confirmation of image quality and edge detection of the recording medium, and the external illumination 18 used in the first embodiment is deleted. Therefore, it is possible to further save the space of the printer device 1.

  Furthermore, the present invention is not limited to the above-described embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, the present invention can make various inventions by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, in the present invention, some components may be deleted from all the components shown in the embodiment.

DESCRIPTION OF SYMBOLS 1 Printer apparatus 2 Unwinder 3 Recording medium 4 Free roller 5 Free roller 6 Base drum 7 Free roller 8, 9 Nip roller pair 10 Nip roller drive part 11 Cutter roller 12 Anvil roller 13 Cutter blade 14 Cutter part 15 Sheet-like recording medium 16 Image Recording unit 17 Image reading sensor 18 External illumination 19 Control unit 20 Host device 22 End side surface 24 of recording medium Image reading sensor 25, 25a to 25e LED for illumination

Claims (9)

A transport unit that transports a recording medium; an image recording unit that records an image by ejecting ink onto the transported recording medium; and an image inspection unit that captures the recorded image and inspects the quality of the image recording. An image recording device,
An image comprising an end detection unit that irradiates light on a side end of the recording medium at a predetermined incident angle and detects an end of the recording medium based on reflected light from the recording medium. Recording device.   2. The image recording apparatus according to claim 1, wherein the irradiation light of the edge detection unit is a laser beam.   2. The image recording apparatus according to claim 1, wherein the image inspection unit also serves as the end detection unit.   The image inspection unit is provided with a plurality of illuminations in a direction orthogonal to the conveyance direction of the recording medium, and substantially all of the plurality of illuminations are used when inspecting the quality of the image recording. The image recording apparatus according to claim 3, wherein at least one end of the plurality of illuminations is used when detecting a portion.   5. The image recording according to claim 4, wherein among a plurality of illuminations provided in the conveyance direction of the recording medium, the illumination at at least one end is disposed outside the width of the recording medium. apparatus.   4. The image inspection unit according to claim 3, wherein the image reading timing differs between the quality inspection of the image recording and the edge detection of the recording medium, and the illumination light is controlled according to the timing. The image recording apparatus according to 4 or 5. A transport process for transporting a recording medium, an image recording process for recording an image by ejecting ink onto the transported recording medium, and an image inspection process for inspecting the quality of image recording by capturing the recorded image A method for controlling an image recording apparatus, comprising:
An image in which edge detection processing is performed to irradiate light on a side edge of the recording medium at a predetermined incident angle and detect an edge of the recording medium based on reflected light from the recording medium. Control method of recording apparatus.   The method of controlling an image recording apparatus according to claim 7, wherein the image inspection process also serves as the edge detection process.   In the image inspection process, a plurality of illuminations provided in the conveyance direction of the recording medium are used, and when inspecting the quality of the image recording, all of the plurality of illuminations are used, and an end of the recording medium is used. The method for controlling an image recording apparatus according to claim 7, wherein illumination of at least one end of the plurality of illuminations is used when detecting the image.

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