JP2007245352A - Image recording device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enhance throughput while enhancing the reliability in image forming. <P>SOLUTION: The conditions such as the end portion (reference) position, the end portion slant traveling, the head slant traveling, the head condition (corrugation) of the record paper of the side near the standby position (a home position) of a carriage are detected by a detecting means mounted on the carriage in paper condition detecting movement, and execution/nonexecution of the front end alignment (precut) when setting the paper is automatically controlled based on the detected data. Further, the head condition detecting (corrugation detecting) position is front end margin or lower. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a large copying machine or a plotter that forms an image on a sheet.

  Generally, as a means for printing on a recording paper, there are recording methods such as a thermal type and an ink jet type, but an ink jet recording apparatus is inexpensive and can output a high quality image on plain paper. Widely used.

  Among inkjet recording apparatuses, in particular, a recording apparatus that requires high-quality printing for outputting a photographic image and a recording apparatus that is used for the purpose of outputting a drawing or the like requires high-precision printing quality. In this type of recording apparatus, in a series of initial operations before printing / printing, detection of the position where the recording paper is set (paper end position) and detection of the width of the recording paper are performed. The positional deviation of the image with respect to the recording paper is corrected.

In order to detect the position of the recording paper, a reflection type optical sensor that can detect the recording paper without contact is generally used. Usually, such a sensor is provided on a side surface of a unit for holding a recording head called a carriage. It is also possible to detect the position of the end of the recording paper by scanning the recording paper and know the width of the recording paper from the detected end position. (Reference 1)
In the above recording apparatus, when roll paper is used as recording paper, it is necessary to first cut a predetermined length in order to align the leading edge of the recording paper at the time of setting. This is an operation called trimming cut or precut, but in this example it is precut.

  In this operation, since the recording start position is determined by the position data of the leading edge of the recording paper by the detecting means, printing outside the paper (platen printing) is prevented when the leading edge of the recording paper is slanted or uneven (waving). It is to do. This platen printing not only causes image loss, but also significantly deteriorates the quality such as ink transfer to the back surface after the next page.

The recording paper may be cut by having a cutting means on the carriage and cutting the carriage by scanning the carriage, or as a cutting device by cutting the cutting portion (cutter blade) independently. . Since this cutting position is misaligned due to the characteristics of the roll paper (material and stiffness of the base material), after cutting, the sensor is moved onto the recording paper to detect the leading position of the next page when the recording paper is back-fed. Yes. (Reference 2)
Further, the cutting operation and the recording medium on which the image data is recorded are cut and cut for each page.
JP 2000-109243 A Japanese Patent Laid-Open No. 10-15886 JP 2002-225363 A

  In the case of the above apparatus, the following problems occur.

  Since a predetermined length is cut (precut) every time the roll-shaped recording paper is set, for example, precutting is performed every time the paper type is changed or the roll width is changed, and the recording paper is wasted. If you have multiple kitchens, you can reduce the waste by using a fixed device, paper type, and size as much as possible. Wastefulness increases due to frequent replacement.

  In order to improve this, Japanese Patent Application Laid-Open No. 2002-225363 proposes a method of detecting the tip state by two sensors on the conveyance path and controlling the cut / not, but in this method, a plurality of sensors are used. Not only does this increase the cost, but the state of the paper between the sensors is unknown and the platen printing described above occurs especially when there is a recess.

  SUMMARY OF THE INVENTION In view of the above, the present invention provides an image recording apparatus capable of improving productivity (throughput) while maintaining high image quality while preventing complexity and cost increase of the apparatus or lowering of reliability. is there.

In order to solve the above problems, the present invention
Image recording apparatus comprising a carriage on which a recording head for recording an image on a roll-shaped recording paper is mounted, a cutting means for the recording medium, and a detecting means for detecting each end position of the recording paper on the carriage In
When the roll-shaped recording medium is set in the apparatus, the recording paper width direction (direction perpendicular to the conveyance direction) end position X ₁ , the same end position X ₂ after a predetermined amount of conveyance, and the left and right head positions Y ₁ , Y ₂ , Each detection of the presence / absence (leading state) of the inside of the vicinity of the leading end of the paper is performed, and the execution / non-execution of the cutting operation (precutting or trimming cut) for leading end alignment by the cutting means is automatically controlled based on the respective detection data. It is characterized by.

In the cutting operation control, the difference ΔXa (skew amount) between the recording paper edge positions X ₁ and X ₂ is within the threshold (A ₀ ), and the reference position X ₀ set in advance in the apparatus. The difference ΔXb (position shift amount) is less than or equal to the threshold value (B ₀ ), the difference ΔYc (start position skew amount) between the head positions Y ₁ and Y ₂ is less than or equal to the threshold value (C ₀ ), It is also preferable to perform control so that the cutting operation is not performed when Δ is not present, and ΔYc (leading skew amount) is greater than or equal to the threshold value (C ₀ ) or there is a recess in the leading state.

Further, as the detection operation, the recording paper leading position Y ₁ on the side close to the standby position (home position) of the carriage is detected → paper end position detection X ₁ → paper end position detection X ₂ after a predetermined amount of conveyance → paper width detection → It is also preferable to perform detection in the order of detection of the leading position Y ₂ on the opposite side and detection of the presence or absence of paper (leading state detection) a predetermined amount S inside from the leading edge of the paper.

  Further, the predetermined amount S at the time of detecting the leading state may be set smaller than the leading edge margin set in the apparatus.

According to the present invention,
The detection means on the carriage detects the leading edge (straightness) and skew state of the recording paper and automatically determines whether or not to pre-cut based on this data. It is possible to minimize the waste of recording paper while preventing (platen printing). In addition, the detection operation of the recording paper state is performed by one detection means, and the detection order is also performed so that the recording paper feed operation and the carriage scanning operation are minimized. Is possible.

  In addition, the cutting operation of the recording paper requires a cutting operation, a discharging operation thereof, and a detection operation of the head of the next page after cutting. Since these operations can be omitted, throughput can be improved while maintaining reliability.

  Hereinafter, an embodiment of a recording apparatus provided with a recording material conveying apparatus of the present invention will be described with reference to a perspective view showing a schematic configuration of the entire recording apparatus in FIG.

  In this example, the recording material is a rolled recording paper conveyance device, but may be a cut recording paper conveyance device, and the dimensions, materials, shapes, and relative dimensions of the components described in the embodiment. The invention should be changed as appropriate according to the configuration of the apparatus to which the invention is applied, such as the arrangement, and various conditions, and is not intended to limit the scope of the invention to the following embodiments.

  The apparatus 1 is roughly divided into a roll paper holder unit 10 for rotatably holding a roll-shaped recording paper Pr, an image forming unit 20 for forming an image while holding the recording paper fed therefrom, It comprises a paper discharge unit 30 for cutting the recording paper and discharging it outside the apparatus.

  The roll paper holder portion 10 is configured to hold the roll paper Pr rotatably by a spool shaft 11 and a pair of spool flanges 12L and 12R, and both ends of the spool shaft 11 are received by spool bearing portions 13L and 13R. In order to facilitate the replacement work of the roll paper Pr, there are slide slopes 13′L and 13′R in front of the bearing portions 13L and 13R, and the operator can roll paper Pr along the slope. Desorption of. Under the roll paper Pr, a pair of paper feed guides is provided to support when an operator feeds paper to an image forming unit 20 described later.

  The image forming unit 20 includes a LF roller 21 for conveying a predetermined amount of recording paper at the time of image formation, a plurality of pinch rollers 22 that are driven and rotated by a predetermined pressure F, and a suction hole 23a. A carriage 40 that holds the platen 23 and the recording head 41 for sucking the ink and reciprocatingly scans in the direction X perpendicular to the paper transport direction Y (referred to as sub-scanning) (referred to as main scanning). Consists of

  The recording head 41 is a well-known ink jet system, and ink droplets are directed toward the recording paper Pr by a head driving signal based on image data periodically generated in a reciprocating movement operation in the main scanning direction of the carriage 40 that holds the recording head 41. Discharge and record an image. In forming an image on a recording sheet, an image is recorded on a recording material while a predetermined amount of conveyance (referred to as band conveyance) by the LF roller 21 and recording by the carriage 40 are alternately repeated.

  A cutter unit 50 that cuts the roll paper Pr while traveling in the main scanning direction −X (left to right) is detachably provided at the left end of the carriage 40.

  The cutter unit 50 will be described with reference to the cutter unit configuration diagram of FIG.

  A cutter blade 51 is fixed to the cutter unit 50 to directly contact the roll paper Pr and cut the roll paper Pr. A portion of the platen 23 where the cutter blade 51 travels is formed with a cutter groove 23b into which the tip of the cutter blade 51 enters.

  A cutter slider 53 that can move up and down is arranged inside the cutter holder 52, and a guide roller 54 that is rotatably held with the cutter blade is attached to the cutter slider 53, and moves up and down in conjunction with the cutter slider 53. . When the cutter blade 51 moves to the storage position 51 ′, the guide roller 54 is pushed upward and stored along the guide rib 23c formed on the platen 23.

  A cutter spring 55, which is a compression coil spring, is provided on the upper part of the cutter slider 53, and the cutter blade 51 is urged downward by the cutter spring 55. This urging force F is the tension on the recording paper at the time of cutting. It becomes.

  A claw portion 53a is provided at the upper end portion of the cutter slider 53, and the claw portion 53a is selectively locked with the ribs 52b and 52c of the cutter holder 52 to fix the vertical position. When the recording paper is cut, when the carriage 40 overruns to the leftmost portion of the main body 1, the claw portion 53a is pushed and released by the projection 2 provided on the wall, and the claw portion 53a is engaged with the rib 52c. The cutter spring 55 is moved downward to a stop position (cutting position), and the above-described cutting operation is performed.

  A recording paper detection unit 60 is provided at the left end of the carriage 40. The recording paper detection unit 60 will be described with reference to the schematic diagram of the recording paper detection unit of FIG.

  The recording paper detection unit 60 is an optical sensor, which irradiates light onto the surface of the recording paper Pr from a light emitting diode (LED) that is a light emitting unit 61, and receives light reflected from the recording paper Pr as a light receiving unit 62. This is a reflective optical sensor that detects a recording paper Pr by detecting it with a phototransistor (or photodiode). The recording paper detection unit 60 can be any sensor as long as it can detect the presence or absence of recording paper.

  Next, the paper setting operation will be described with reference to the paper setting flowchart of FIG. 4 and the diagram showing the recording paper detection position of FIG.

  First, the operator releases the nip of the pinch roller 22 with a release lever (not shown), and feeds the roll paper Pr to the image forming unit 20. The right end of the roll paper Pr is aligned with the set mark 31a of the roll paper cover 31, and the pinch roller 22 is turned on by the release lever. Starting from this operation, the following paper edge detection operation is started. The following is called a pre-feed operation.

  In order to shorten the detection operation time, the detection operation from the right side to the left side of the recording paper Pr is performed with the side closer to the standby position (referred to as the home position) of the carriage 40 in this example as the right and the far side as the left. When the home position is reversed left and right, it is desirable to perform a left-to-right detection operation.

<Detection operation (1)>
The carriage 40 moves in the + X direction and stops at a position where the recording paper detection unit 60 is located on the right end of the paper (viewed from the front side of the main body). While detecting by the recording paper detection unit 60, the LF roller 21 back-feeds the recording paper Pr in the −Y direction, thereby detecting the paper right leading position Y1.

<Detection operation (2)>
Again, the recording sheet Pr to a predetermined position in the + Y direction to the feed to stop, while the detection by the recording sheet detector 60 the carriage 40 detects the paper right end position (reference position) X ₁ by scanning in the -X direction.

<Detection operation (3)>
Next, when the recording paper Pr is fed by a predetermined amount L (300 mm in this example) in the + Y direction and stopped, the carriage 40 reciprocates on the recording paper Pr while being detected by the recording paper detection unit 60, similarly to the above. detecting the paper right end position X _2.

<Detection operation (4)>
Next, the paper width detection is detected by the carriage 40 scanning in the + X direction while the recording paper detection unit 60 detects the recording paper Pr.

<Detection operation (5)>
The carriage 40 moves in the −X direction and stops at a position where the recording paper detection unit 60 is located on the upper left end of the paper (viewed from the front side of the main body). Then the recording sheet Pr while detected by the recording sheet detector 60 detects the Kamihidari head position Y ₂ by backfeed the -Y direction.

<Detection operation (6)>
Of Kamimigi head position Y ₁ and Kamihidari head position Y _2, a paper from the more the position (closer to the LF roller) upstream to a position where the recording sheet detector 60 position is paper inside the predetermined amount S + Y direction Feed.

  Thereafter, the carriage 40 scans in the −X direction while detecting by the recording paper detection unit 60, thereby detecting the presence / absence of the paper in the entire paper width.

  The predetermined amount S depends on the detection range of the recording paper detection unit 60 = the output diameter. In this example, the predetermined amount S is set to 2 mm in consideration of a margin because the spot diameter is Φ3 mm.

  The predetermined amount S is set to be equal to or less than the front end margin (5 mm in this example) of the apparatus. This ensures that there is a recording sheet at the print start position, and there is no platen printing.

  The head detection position is preferably determined according to the spot diameter and the tip margin setting.

  When the above series of detection operations is completed, the recording paper Pr is back-fed to the standby position in the -Y direction and stopped, and the carriage is also moved to the standby position in the -X direction and stopped to enter a standby state.

  Here, various determinations are performed by the calculation of the CPU based on the detection data.

<Declination check>
First, the skew amount ΔXa is determined based on the following equation.

Skew amount ΔXa = | X ₁ −X ₂ |> Threshold A ₀ (1 mm in this example)
In the case of, prompt the operator to reset. If this is within the threshold A _0,
<Reference position deviation judgment>
Deviation amount from reference position ΔXb = | X ₀ −X ₁ |> threshold B ₀ (5 mm in this example)
* If X ₀ is a preset reference position, the operator is prompted to reset it as described above.

<Declination of head skew>
Next, the head skew amount ΔYc = | Y ₁ −Y ₂ |> threshold value C ₀ (20 mm in this example)
In this case, a pre-cut operation (cut operation + discharge operation + next page head detection operation) described later is performed.

Here, the value of the threshold value C ₀ is set to a value (upper limit) that does not cause any trouble such as JAM on the downstream conveyance (discharge) route. Note that this setting value can be changed by the user if it is less than the upper limit.

<Paper edge condition judgment>
Further, when a concave portion (paperless portion) is detected in the detection operation (6), the pre-cut operation is performed as described above.

  If there is no recess, the pre-cut operation is not performed, and the recording paper is back-fed in the −Y direction to the standby position and enters a standby state.

When the print signal is input, the print start position is determined by the position on the upstream side (side closer to the LF roller) of the right end position X ₁ and the leading positions Y ₁ and Y ₂ , and the printing operation is performed.

  The above operation is called “automatic precut mode” and will be described with reference to the recording paper state and the precut correlation diagram of FIG.

If the recording paper first skew amount as the upper side figure of a state where there is a significantly oblique state or recess in the threshold C ₀ or more, it performs the pre-cut operation + discharge operation + next page top detection operation.

State, that is the recording paper first skew amount other than the above as the lower side Fig. Is the threshold value C ₀ or less, in the case of a state in which there is a protrusion, not pre-cut.

  Most roll papers have their leading edges aligned properly, and when the roll paper is reset, the previous cutting operation is included, so the leading edges are always aligned, so there are very few cases of pre-cutting operations.

  However, in the case of straightness from the top page to the top state, a “forced precut mode” may be provided to forcibly perform the pre-cut.

  Next, the precut operation will be described.

  The pre-cut operation includes a cut operation, a discharge operation, and a next page head detection operation.

First, the pre-cut operation feeds from the head positions Y ₁ and Y ₂ to a position that is a predetermined amount (this is called a pre-cut amount and is 100 mm in this example). When the cut position and _{Y 3 | Y 1, Y 2} -Y 3 | = 100mm
Next, the above-described cutting operation (carriage overrun to cut to cutter storage) is performed.

Next, the paper discharge operation is performed by pushing out the trailing edge of the first recording sheet (cutting downstream side) with the leading edge of the succeeding recording sheet (cutting upstream side). In addition, as the paper discharge operation, extrusion amount: 390 mm in this example
Feed L1: 20mm → Wait: 0.5s → Feed L2: 20mm → Wait: 0.5s → Feed L3: 350mm
→ Back feed to standby position → Wait until next job Here, feeding is divided into three times because the leading edge of the subsequent recording sheet contacts the trailing edge of the leading recording sheet, that is, paper discharge Thus, the paper discharge operation is performed more reliably even with a smaller push-out amount (paper discharge amount).

  The total feed amount in this example is 390 mm. However, as this length increases, the required time of feed (+ Y direction) + back feed (−Y direction) is required, resulting in a decrease in throughput. Accordingly, it is desirable that each feed amount, the number of times, and the total feed amount are set to optimum values depending on conditions of the paper discharge mechanism.

Thereafter, while detecting the head position of the subsequent (next page) by the aforementioned operation, the back-feeding waiting state to the standby position Y _0.

  Although the above operation is a pre-cut operation, the time required for this series of operations is about 50 s in this example, and omitting this will greatly improve the throughput.

  The cutting operation after printing is the same as described above.

  As described above, the paper state detection operation is performed by one detection means, and the detection order is also performed so that the recording paper feed operation and the carriage scanning operation are minimized. Is possible.

  In addition, the cutting operation of the recording paper requires a cutting operation, its discharging operation, and a detection operation at the top of the next page after cutting. Since these operations can be omitted, the waste of the recording paper is reduced while improving the reliability. Throughput can be greatly improved. This content can be applied regardless of the size of the apparatus and the type and size of the recording paper.

Example explanatory drawing (perspective view showing a schematic configuration of the entire apparatus). Example explanatory drawing (cutter unit block diagram). FIG. 3 is an explanatory diagram of an embodiment (schematic diagram of a recording paper detection unit). FIG. 3 is an explanatory diagram of an embodiment (sheet setting flowchart). FIG. 4 is an explanatory diagram of an embodiment (recording paper detection position). FIG. 3 is an explanatory diagram of an embodiment (correlation diagram between a recording sheet state and a precut operation).

Explanation of symbols

Pr Recording paper A ₀ Skew amount threshold value B ₀ Right end position deviation amount threshold value C ₀ Leading skew amount threshold value X Main scanning direction X ₁ , X ₂ Paper right end position ΔXa Skew amount ΔXb Right end position deviation amount Y Transport direction ( (Sub-scanning direction)
Y ₀ standby initial position Y ₁ , Y ₂ recording paper leading position △ Yc leading skew amount
S Start state detection position (amount from the start position of the paper)
1 body
10 Roll holder
11 Spool shaft
20 Image forming unit
21 LF roller
23 Suction platen
40 Carriage
41 Recording head
50 Cutter unit
60 Recording paper detector

Claims (4)

Image recording apparatus comprising a carriage on which a recording head for recording an image on a roll-shaped recording paper is mounted, a cutting means for the recording medium, and a detecting means for detecting each end position of the recording paper on the carriage In
When the roll-shaped recording medium is set in the apparatus, the recording paper width direction (direction perpendicular to the conveyance direction) end position X ₁ , the same end position X ₂ after a predetermined amount of conveyance, and the left and right head positions Y ₁ , Y ₂ , Each detection of the presence / absence (leading state) of the inside of the vicinity of the leading end of the paper is performed, and the execution / non-execution of the cutting operation (precutting or trimming cut) for leading end alignment by the cutting means is automatically controlled based on the respective detection data. An image recording apparatus. In the cutting operation control, the difference ΔXa (skew amount) between the recording paper edge positions X ₁ and X ₂ is within the threshold (A ₀ ), and the difference Δ from the reference position X ₀ set in advance in the apparatus Xb (position shift amount) is less than or equal to the threshold value (B ₀ ), the difference ΔYc (start position skew amount) between the head positions Y ₁ and Y ₂ is less than or equal to the threshold value (C ₀ ), and there is no recess in the head state. 2. The control according to claim 1, wherein the cutting operation is not performed, and the control is performed so that the cutting operation is performed when ΔYc (leading skew amount) is equal to or greater than a threshold value (C ₀ ) or there is a recess in the leading state. Image recording device. As the detection operation, the recording paper leading position Y ₁ near the carriage standby position (home position) detection → paper end position detection X ₁ → paper end position detection X ₂ after feeding a predetermined amount → paper width detection → opposite side The image recording apparatus according to claim 1, wherein detection is performed in the order of detection of the leading position Y _{2 of the} paper → detection of the presence or absence of paper (leading state detection) within a predetermined amount S from the leading edge of the paper.   The image recording apparatus according to claim 1, wherein the predetermined amount S at the time of detecting the leading state is smaller than a leading edge margin set in the apparatus.

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