JP5361415B2 - Image recording apparatus and control method of image recording apparatus - Google Patents

Description

  The present invention relates to an image recording apparatus that corrects an attachment position of a line sensor including an image sensor incorporated in the apparatus, and a control method for the image recording apparatus.

  In general, an image recording apparatus represented by a printer apparatus or a copying apparatus conveys a recording medium and records an image during the conveyance. For example, in an ink jet image recording apparatus, image recording is performed by ejecting ink from nozzles of a recording head onto a recording medium such as printer paper conveyed to a conveying unit such as a platen.

  When performing such image recording, if the recording medium to be transported is misaligned in the direction (main scanning direction) perpendicular to the transport direction (sub-scanning direction), ink is not ejected to the transport system. It is necessary to detect the position of the side edge of the medium. In general, an image sensor, an optical line sensor, or the like is used as a device for detecting the side edge of the recording medium.

  In such a detection apparatus, the end position of the medium is determined based on a level difference between reflected light from a recording medium and a member supporting the recording medium, for example, a conveyor belt. Since the recording head performs a recording process based on the detection result, if the relative position between the detection result and the recording head is shifted, there is a risk that ink is ejected to the transport system.

  Therefore, it is necessary to correct the relative position between the side edge detector and the recording head. As a correction method, for example, a method of actually performing a recording operation, measuring an output test image with a scale or the like, and obtaining a correction value from the measurement result is performed. However, this method requires time for correction processing, and variation in measurement results becomes a problem.

  Therefore, for example, in the invention described in Patent Document 1, in order to correct the mounting position of the CCD that reads the print image, the test image is read by the CCD, the measured margin length is compared with the specified value, and the correction amount is automatically set. Disclosure techniques are disclosed.

JP 2000-203133 A

  However, in the method of measuring and comparing only the margin length, if the conveyance position when the test image is printed and the conveyance position when the test image is read are shifted, the amount of deviation due to the deviation of the conveyance position is included in the measured margin length. In addition, the relative positional deviation between the sensor and the recording head cannot be accurately corrected.

  Accordingly, the present invention has been made in view of the above problems, and for example, even if the transport position is deviated, an image recording apparatus capable of automatically correcting the relative positional deviation between the sheet end detection sensor and the recording head, and An image recording apparatus control method is provided.

In order to achieve the above object, an image recording apparatus according to an aspect of the present invention includes a transport mechanism for transporting a recording medium, and nozzles formed by a plurality of nozzles in a direction orthogonal to the transport direction of the recording medium. In an image recording apparatus having at least one recording unit in which rows are arranged, and performing recording processing on the recording medium by discharging ink from the plurality of nozzles, the side end position of the recording medium and the recording A side edge detection unit for detecting a side edge position of an image, and a side edge position (X11 ′) read by the side edge detection unit when a test image whose margin length is known in advance is recorded by the recording unit. The side edge position (X12) of the recorded image when the test image is recorded and the side edge detection unit when the recording medium on which the test image is recorded are read again by the side edge detection unit. From the side length position (X21 ') of the recording medium read by the output portion and the side end position (X22') of the recorded image, the margin length (X22'-X21 ') of the recording medium is obtained from the side. The image forming apparatus includes at least a correction unit that corrects a relative positional deviation between the end detection unit and the recording unit.

According to another aspect of the present invention, there is provided a control method for an image recording apparatus, comprising: a transport mechanism for transporting a recording medium; and a nozzle formed by a plurality of nozzles in a direction orthogonal to the transport direction of the recording medium. In a control method of an image recording apparatus having at least one recording unit in which rows are arranged, and performing recording processing on the recording medium by discharging ink from the plurality of nozzles,
Side edge detection process for detecting a side edge position and a margin length of the recording medium, and a side edge position read by the side edge detection process when a test image with a known margin length is recorded in advance by the recording unit And a relative margin between the side edge detector and the recording unit is corrected based on a margin length of the recording medium obtained by reading the recording medium on which the test image is recorded again by the side edge detector. And an image recording apparatus control method for performing at least correction processing.

  According to the present invention, even if the transport position is deviated, an image recording apparatus capable of automatically correcting a relative position shift between the side edge detection unit and the recording unit and preventing ink discharge to the transport system, and an image A method for controlling a recording apparatus is provided.

1 is a conceptual block configuration diagram of an image recording apparatus according to an embodiment. (A) is a schematic diagram from the side surface side of an image forming apparatus, (b) is a schematic diagram from the upper surface of a part of image forming apparatus. It is a figure which shows the structure of test image data. It is a figure which shows typically the recording processing operation | movement of the test image data at the time of the correction process of the image recording device which concerns on this embodiment. It is a figure which shows typically the reading operation at the time of the correction process of the image recording device which concerns on this embodiment. It is a flowchart explaining the control processing of the image recording device which concerns on this embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a conceptual block diagram of an image recording apparatus according to this embodiment. FIG. 2 is a schematic diagram of the image recording apparatus according to the present embodiment, FIG. 2A is a schematic view from the side of the image recording apparatus, and FIG. 2B is a part of the image recording apparatus. It is a schematic diagram from the upper surface. In the arrows of X, Y, and Z shown in the above drawings, X indicates the main scanning direction (direction orthogonal to the recording medium conveyance direction), and Y indicates the sub-scanning direction (recording medium conveyance direction). Z indicates the direction orthogonal to the XY plane.

  The image recording apparatus 1 according to the present embodiment includes at least a feeding unit 2, a side edge detection unit 3, a transport unit 4, an image recording unit 5, and a control unit 6. Here, at least one feeding unit 2 is disposed on the most upstream side of the conveyance path of the recording medium 8, and the conveyance unit 4 is disposed on the downstream side of the conveyance path from the feeding unit 2. In addition, the side edge detection unit 3 is disposed on the upstream side of the image recording unit 5, and the image recording unit 5 is disposed to face the conveyance unit 4.

  The feeding unit 2 includes at least one feeding tray 2a for stacking and storing a plurality of recording media 8, a feeding mechanism 2b disposed above the feeding tray 2a, and conveyance of the feeding mechanism 2b. A registration roller pair 2c disposed on the downstream side of the path. The feeding unit 2 constitutes the feeding mechanism 2b with the recording medium 8 loaded and stored in the feeding tray 2a according to an instruction from the control unit 6, for example, by rotating a pickup roller one by one on the downstream side of the conveying path. Carry out. The unloaded recording medium 8 has its skew corrected by the registration roller pair 2 c and is conveyed to the conveying unit 4.

  The conveyance unit 4 includes, for example, a driving roller 10a, a driven roller 10b, and a conveyance member 11 that is an endless belt provided on both the rollers 10a and 10b. In addition, a platen (not shown) having a plurality of holes is provided above the endless belt, and a suction fan (not shown) is further provided below the platen.

  Here, the conveyance information generation unit 12 is connected to the rotation shaft of the driven roller 10b, and the conveyance drive unit 13 is connected to the rotation shaft of the drive roller 10a. In addition, the conveyance information generation part 12 is comprised by the rotary encoder, for example. Moreover, the conveyance drive part 13 is comprised by the motor driven by the instruction | indication of the control part 6, for example.

  In accordance with an instruction from the control unit 6, the transport unit 4 sucks and holds the recording medium 8 fed from the feed unit 2 on the endless belt of the transport member 11 by driving the suction fan, and the transport drive unit 13 is endless. By rotating the belt, the recording medium 8 is transported to the downstream side of the transport path. At this time, the rotary encoder constituting the conveyance information generation unit 12 generates a pulse signal corresponding to the moving amount of the endless belt, that is, the conveyance amount of the recording medium 8 as the conveyance information of the recording medium 8, and the control unit 6. To notify.

The side edge detection unit 3 detects the side edge position of the recording medium 8 conveyed by the conveyance unit 4 and notifies the control unit 6 of the detection information.
The image recording unit 5 includes at least one recording unit 17-1 to 17-n (n ≧ 2, n is an integer) including nozzle rows formed by a plurality of nozzles in a direction orthogonal to the transport direction. Prepare. The nozzle array, for example, causes ink stored in a plurality of ink chambers to be ejected by a volume change caused by deformation of a piezoelectric member (for example, a piezo element (PZT)) provided for each ink chamber.

  The control unit 6 includes at least a storage unit 15 that stores setting values and the like of the present embodiment, and a correction processing unit 16 for performing correction processing of the side edge detection unit 3, and includes operation processing according to the present embodiment. The overall control of the image recording apparatus 1 is performed. Specifically, the control unit 6 has a control function and an arithmetic function, for example, from an MPU (Micro Processor Unit) and a ROM (Read Only Memory) storing a control program, a RAM (Random Access Memory), and the like. And a processing unit including a correction process, and a storage unit 15 configured to store, for example, a setting value related to the control of the image recording apparatus 1, for example, constituted by a non-insertable memory.

  The control unit 6 is configured to store a control program in advance in, for example, a ROM, and causes the MPU to read and execute the control program, thereby causing the correction processing unit 16 to function.

  The nonvolatile memory in the storage unit 15 includes recording units 17-1 to 17-n from a detection position of a recording medium front end detection unit (not shown) that is disposed on the upstream side of the conveyance path from the side end detection unit 3. The information corresponding to the separation distances to the plurality of nozzle formation positions is converted into the accumulated value of the number of pulse signals of the rotary encoder in the conveyance information generation unit 12 of the conveyance unit 4 and stored in advance. That is, the ejection timing of the ink droplets from the nozzles is set with reference to the detection position of the recording medium leading edge detection unit.

  The information corresponding to the separation distance will be described by taking the recording unit 17-1 as an example. The tip of the recording medium 8 is located at a plurality of nozzle formation positions of the recording unit 17-1 from a detection position of a recording medium tip detection unit (not shown). Is the cumulative value of the number of pulse signals generated by the rotary encoder in the transport information generation unit 12 when the transport information is transported.

  For example, the control unit 6 determines that the cumulative value of the number of pulse signals generated by the rotary encoder in the transport information generation unit 12 is triggered by the detection information detected by the medium front end detection unit. When the accumulated value of the number of pulse signals corresponding to the plurality of nozzle formation positions of the recording unit 17-1 stored in the nonvolatile memory of the control unit 8 coincides with the recording unit 17-1, the recording unit 17-1 is controlled to perform the recording process. .

  The host device 18 is connected as an external device of the image recording apparatus 1 of the present embodiment via, for example, a LAN (Local Area Network). The host device 18 corresponds to a user computer that causes the image recording apparatus 1 of the present embodiment to perform recording processing, and notifies the image recording apparatus 1 of the present embodiment of job information as information relating to the recording processing. To do.

Next, correction processing performed by the correction processing unit 16 in order to correct the relative positional deviation between the side edge detection unit 3 and the image recording unit 5 performed in the image recording apparatus 1 will be described.
FIG. 3 shows the configuration of the test image data 20. As shown in the figure, the test image data 20 is set with a specified value α as left and right margin values with respect to the transport direction. FIG. 4 is a diagram schematically showing the recording processing operation of the test image data 20, and the recorded image 21 shows the result of recording the test image data 20 on the recording medium 8. Further, β1 indicates a deviation width between an ideal transport position 22 indicated by a dotted line and a position where the recording medium 8 is actually transported during the recording process.

  Also, in the figure, the XY coordinates are coordinates with the left end of the image recording unit 5 as the origin, and X12 indicated by the XY coordinates is the left end nozzle position from which ink was ejected when recording the recorded image 21.

  Further, the X′Y coordinate shown in the figure is a coordinate with the left end of the side edge detection unit 3 as the origin, and X11 ′ shown in the X′Y coordinate is actually transported by the recording medium 8 during the recording process. The left end position is indicated by the position detected by the side end detection unit 3.

Therefore, γ shown in the figure indicates the relative positional deviation between the side edge detection unit 3 to be corrected and the image recording unit 8, and the left margin of the recorded image 21 is expressed by the following equation.
α−β1 = X12− (X11 ′ + γ) (Equation 1)
On the other hand, FIG. 5 schematically shows an operation of reading the recording medium 8 recorded in FIG. In this case, β2 shown in FIG. 5 indicates a deviation between the ideal transport position 22 and the position where the recording medium 8 is actually transported when the recorded image 21 is read by the side edge detection unit 3.

  5 indicates the left end position of the recording medium 8 read by the side end detection unit 3. X22 'indicates the left end position of the recorded image 21 read by the side end detection unit 3. From this, the left margin of the recorded image 21 is expressed by the following equation.

α−β1 = X22′−X21 ′ (2)
Therefore, the relative positional deviation amount γ between the side edge detection unit 3 and the image recording unit 20 is obtained as follows from (Equation 1) and (Equation 2).

γ = (X12−X11 ′) − (X22′−X21 ′) (Equation 3)
Next, the control process of this embodiment is demonstrated using the flowchart shown in FIG.

First, the conveyance of the recording medium 8 is started (step (hereinafter referred to as S) 1), and the left end position X11 ′ of the recording medium 8 is detected by the side edge detection unit 3 and stored in the storage unit 15 (S2).
Next, the control unit 6 prints test image data in which the left end nozzle position for ink ejection is X12 (S3). That is, by the above process, the recording image 21 shown in FIG. 4 is printed on the recording medium 8 and the left end position X11 ′ of the recording medium 8 is stored in the storage unit 15.

  Next, the control unit 6 conveys the recording medium 8 on which the printing has been performed again, conveys the reading position of the side end detection unit 3 (S4), and the side end detection unit 3 causes the left end position X21 ′ of the recording medium 8 to be conveyed. Then, the left end position X22 ′ of the recorded image 21 is detected and recorded in the recording unit 15 (S5). That is, by the above process, the recording image 21 shown in FIG. 5 is printed on the recording medium 8, and the left end position X 21 ′ of the recording medium 8 and the left end position X 22 ′ of the recording image 21 are recorded on the recording unit 15.

Next, the control unit 6 calculates the correction value (X22′−X21 ′) − (X12−X11 ′) by the processing of the correction processing unit 16 and records it in the recording unit 15 (S6).
As described above, the correction processing according to the present embodiment is performed by the image recording apparatus 1, whereby the relative positional deviation between the side edge detection unit 3 and the image recording unit 6 can be corrected. The side edge detection unit 3 may be constituted by a scanner such as a CCD that reads a recorded image on the recording medium 8.

  Further, 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, and different components in each embodiment may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Image recording apparatus 2 Feeding part 2a Feeding tray 2b Feeding mechanism 2c Registration roller pair 3 Side edge detection part 4 Conveying part 5 Image recording part 6 Control part 8 Recording medium 10a Drive roller 10b Follower roller 11 Conveying member 12 Conveying information Generation unit 13 Transport drive unit 15 Storage unit 16 Correction processing units 17-1 to 17-n Recording unit 18 Host device 20 Test image data 21 Recorded image 22 Transport position

Claims (1)

A transport mechanism for transporting the recording medium; and at least one recording unit in which a nozzle array formed by a plurality of nozzles is arranged in a direction orthogonal to the transport direction of the recording medium, In an image recording apparatus that performs recording processing on the recording medium by discharging ink from nozzles,
A side edge detector for detecting a side edge position of the recording medium and a side edge position of the recorded image ;
The side end position (X11 ′) read by the side end detection unit when a test image whose margin length is known in advance is recorded by the recording unit and the side of the recording image when the test image is recorded The end position (X12) , the side end position (X21 ') of the recording medium read by the side end detection unit and the recording image when the recording medium on which the test image is recorded are read again by the side end detection unit Correction means for correcting a relative positional shift between the side edge detection unit and the recording unit from the margin length (X22′-X21 ′) of the recording medium obtained by the side edge position (X22 ′) of the recording medium;
An image recording apparatus comprising: