JP2001146052A - Method for trimming/cutting roll sheet and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for trimming/cutting a roll sheet automatically in which individual roll sheet can be cut by a correct amount automatically including a zero cut amount. SOLUTION: In an imaging apparatus where a roll sheet can be used as a recording medium, innermost part at the forward end of a roll sheet is detected by means of a sensor and then the forward end of the roll sheet is trimmed and cut based on the detected position. When the contour at the forward end of the roll sheet falls within a regulated range, trimming/cutting is omitted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus using a roll paper as a recording medium and having an automatic cut function.

[0002]

2. Description of the Related Art Since the leading end of a new roll paper is stopped with a tape or the like, the leading end is often broken when the tape is peeled off, or the leading end of the roll paper itself is often not cut properly. Therefore, when the roll paper is set, it is necessary to cut the paper so-called trimming cut in order to align the leading ends. As a trimming cutting method, there are a method in which a user determines a cutting position and manually performs the cutting, and a method in which the cutting is automatically performed.

[0003]

When the user performs trimming cut manually, there is no guarantee that the cut amount will be within an appropriate range. Therefore, the cut amount is smaller than the cut amount guaranteed by the performance of the cutter. When the trimming is performed by the amount, there is a concern that a defect such as a cutter jam due to a defective cut may occur. When the cutter jam occurs, the leading end of the roll paper is naturally not cut cleanly, so the trimming cut must be performed again. On the contrary, in order to avoid such a situation, there is a case where an unnecessary amount is trimmed.
In this case, the roll paper is wasted.

[0004] Even when the trimming cut is performed automatically, when the used roll paper is set again,
In many cases, the trimming cut is not necessary (the tip has been cut cleanly when used last time), and performing the trimming cut uniformly will again waste roll paper.

The present invention has been made under such a background. It is an object of the present invention to provide an automatic trimming and cutting of roll paper, including the case where the cut amount is zero. It is an object of the present invention to provide an automatic trimming and cutting method for roll paper that can be cut with an appropriate cutting amount according to the present invention, and an image forming apparatus that performs the method.

[0006]

[Means for Solving the Problems]

[Claims] An image forming apparatus according to the present invention is an image forming apparatus capable of using roll paper as a recording medium, in which a conveying unit for conveying the recording medium and a print head are mounted, and the image forming apparatus is substantially parallel to the recording medium conveying direction. A carriage that reciprocates in a direction perpendicular to the carriage, a cutter mounted on the carriage and cuts the roll paper on the platen along the carriage movement direction, and detects a portion of the leading end of the roll paper that enters the innermost portion. The apparatus includes a roll paper leading edge detecting means and a control means for trimming and cutting the leading edge of the roll paper based on the position of the detected portion.

The innermost part of the leading edge of the roll paper is detected, and the leading edge of the roll paper is trimmed and cut based on this position. It is possible to perform trimming cut with an optimum cut amount for roll paper.

Preferably, the roll paper leading end detecting means detects whether or not the detected contour of the leading end of the roll paper falls within a range of a predetermined standard value, and the control means keeps it. In this case, the trimming cut of the roll paper is omitted. As a result, it is possible to prevent the trimming cut from being performed uniformly even when there is no problem in the linearity and the perpendicularity of the leading end of the roll paper, thereby suppressing wasteful consumption of the roll paper.

[0009] As a specific embodiment, the roll paper leading end detecting means has a first sensor for detecting a recording medium mounted on a carriage. By judging the output of the first sensor in combination with the conveyance of the recording medium by the recording medium conveyance means, a portion of the leading end of the roll paper that enters the innermost part is detected.

Further, a second fixedly disposed device for detecting that a recording medium has been set on the platen.
When the second sensor detects that the roll paper has been set, the roll paper leading edge detection means may perform the detection.

Preferably, the skew detecting means detects whether the recording medium is skewed, and the roll paper leading end detecting means detects "no skew" by the skew detecting means. Thereafter, a portion which is located inside the leading end portion of the roll paper is detected. This makes it possible to avoid performing trimming cut of the skewed roll paper.

The method for trimming and cutting roll paper according to the present invention is a method for trimming and cutting roll paper in an image forming apparatus capable of using roll paper as a recording medium, wherein (a) a direction substantially perpendicular to the recording medium transport direction. In addition to detecting the left and right corners of the roll paper by moving the roll paper by sequentially positioning the recording medium sensors at the left and right ends of the roll paper, the detected left and right corners are used. (B) scanning the position inside the recording medium transport direction by a predetermined amount from the reference position with the recording medium sensor to detect the presence or absence of a recording medium absence area. (C) If the result of step (c) is that there is an area without a recording medium, the left and right end positions of the area without a recording medium are determined. The intermediate position between the left and right ends of the image is calculated, and the obtained intermediate position is set as a new reference position, and the process returns to step (b). (D) As a result of step (c), if there is no area without a recording medium, (E) scanning the position outside the recording medium conveyance direction by a predetermined amount from the reference position with the recording medium sensor to detect the presence / absence of a recording medium presence area; If there is an area, trimming of roll paper is performed based on the current reference position. (F) As a result of step (d), if there is no area with a recording medium, trimming of roll paper is executed. Is omitted.

[0013] This makes it possible to automatically and accurately detect the portion of the leading end of the roll paper that has entered the inside, and to determine an appropriate trimming cut position based on the position of that portion.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

First, an outline of a printing operation of an ink-jet plotter will be described as an example of an image forming apparatus to which the present invention is applied. However, the present invention is not limited to the inkjet plotter, but can be applied to any image forming apparatus that employs automatic trimming and cutting of roll paper.

FIG. 1 is a diagram showing the appearance of an ink jet plotter to which the present invention is applied. In this figure, the cover is opened, the inner carriage 104 and the print head 106 and the cutter unit 10 mounted thereon are mounted.
3 is shown. The cutter unit 103 cuts the roll paper along the cutter groove 105 in a direction orthogonal to the medium transport direction. In this plotter, after the setting of the medium is completed, printing is performed according to image data from a host computer (not shown). The medium is recorded on the platen by the print head 106, and is driven and conveyed by a conveying roller and a pinch roller (not shown) to move on the platen. Above the platen, for example, two mutually parallel guide shafts are installed in parallel with the platen. A carriage 104 is attached to the guide shaft so as to be reciprocally movable via a slide bearing, so that the carriage 104 can be moved in parallel along the guide shaft.

As shown in more detail in FIG. 2, the carriage 104 has a plurality of print heads 106 for discharging ink. The carriage 104 includes a carriage motor 201 and a carriage drive belt 203.
Accordingly, the print head 106 operates in accordance with the control of the control unit (not shown), and can reciprocate the mounted print head 106 in parallel with the guide shaft. At a predetermined position below the platen, a media sensor 210 for detecting the presence or absence of a medium through an opening of the platen is fixedly arranged. Further, a media sensor 202 for detecting the width of the medium and the like is mounted on the carriage 104.

In such a configuration, the print head 106 moves right and left along with the carriage 104 along the guide shaft. At this time, ink is ejected from a nozzle (not shown) to form an image corresponding to the nozzle width. Next, the medium is transported by the nozzle width by the transport roller and the pinch roller. By repeating this, image formation of one page is performed.

The details of the cutting of the media according to the embodiment of the present invention will be described below.

As the type of media in the ink jet plotter, cut paper and roll paper can be used. The procedure for setting each medium is described below.

First, in the case of cut paper, the cut paper is placed on the upper surface of the platen from the front of the plotter in FIG. When setting the cut sheet, the pinch roller is not in contact with the transport roller, so that the medium can be easily inserted between the pinch roller and the transport roller. After the cut sheet is set on the platen, the user operates a key provided on the operation panel to start loading the cut sheet.

At the time of loading the cut sheet, first, the length of the sheet in the sheet feeding direction (hereinafter, X direction) is detected. The presence or absence of the medium is detected by the media sensor 210 on the platen, and the transport roller is rotated forward (rotated in the direction in which the cut paper is discharged toward the front side of the apparatus) to transport the cut paper and detect the rear end of the media. . In this embodiment, a reflection type optical sensor is used as the media sensor 210, and its purpose is to detect the presence / absence of a medium on the platen and to detect the rear end of the medium. If the object can be achieved, any detecting means other than the reflection type optical sensor may be used.

Next, the carriage 104 is moved on the cut sheet in order to detect the leading end of the cut sheet, and the transport roller is rotated in the reverse direction (rotated in the direction in which the cut sheet is drawn into the inner side of the apparatus). As described above, the media sensor 202 is provided on the carriage 104. In the present embodiment, the media sensor 202 also uses a reflection type optical sensor. The media sensor 202 detects the leading edge of the media and detects the media width direction (hereinafter, Y direction).
It is also used to detect the length. By detecting the leading edge of the cut sheet, the length of the cut sheet in the feed direction is detected. The length of the cut sheet in the feed direction is (feed amount from the position where the trailing edge of the cut sheet is detected to the position where the leading edge is detected) +
(Mechanical distance from the media sensor 210 to the media sensor 202 on the carriage 104).

Next, detection in the Y direction, that is, detection of the width of the cut sheet is performed. The detection of the width of the cut sheet on the platen is performed by the media sensor 202 on the carriage 104. The carriage 104 is capable of moving horizontally above the cut sheet placed on the platen along the guide shaft in the Y direction of the cut sheet. The media sensor 202 detects the left and right ends of the cut sheet while moving the carriage 104 to detect the width of the cut sheet. Thus, the length between the left and right ends is set as the width of the cut sheet.

Finally, skew detection is performed. The skew detection method is as follows. The coordinates of the left and right edges of the cut sheet when a certain amount of cut paper is conveyed in the X direction are detected with respect to the coordinates of the left and right edges of the cut sheet in the Y direction detected for the first time. If the sheet is not skewed, the coordinates of the left and right ends before and after the cut sheet is conveyed are almost the same (within the allowable range of the apparatus), but are not the same (out of the allowable range of the apparatus). Is assumed to be skewed. The cause of the skew is basically caused by a defective setting of the cut sheet of the user. Therefore, when the sheet is skewed, the user is prompted to reset the cut sheet.

The above operation is executed, and if there is no problem, the setting of the cut sheet is completed, and the operation shifts to the print standby state.

Next, when the medium is roll paper, the length in the X direction is not detected in the X direction because there is a portion wound around a roll. Regarding the detection in the Y direction and the detection of the skew, the operation is the same as that for the cut sheet.

The most different point in the loading sequence between the roll paper and the cut paper is the trimming cut portion. Trimming cut is not required when the perpendicularity of the corners and the linearity of each side are guaranteed like cut paper.However, in the case of roll paper, especially for new roll paper, the linearity and There is no guarantee that the right angle is maintained, and a trimming cut is required.

However, for example, when the used roll paper is used again, for example, the medium to be used is switched from roll paper to cut paper, and then to the previous roll paper, the cut after the previous printing is completed. In some cases, the linearity and the perpendicularity of the tip portion are good. Therefore, it is preferable that the state of the leading end portion of the roll paper can be recognized.

Next, a specific processing procedure for that will be described with reference to FIG.
This will be described with reference to the flowchart of FIG. This process can be executed every time printing is performed on roll paper, but it requires a corresponding processing time.
Executed when the medium is switched to roll paper. Normally, the device can recognize the exchange or switching of the roll paper in accordance with the operation of the user.

In order to properly detect the state of the leading end of the roll paper, first, the coordinates (Rx, Rx,
Ry) and (Lx, Ly) are detected (S11, S1).
2). For example, the media sensor 202 is placed on the left end of the roll paper, the roll paper is moved in the X direction, and the position of the roll paper in the X direction at the time when the output of the media sensor 202 changes is determined. This position is a temporary reference position. That is,
It is assumed that the reference position coordinates (Px, Py) are (0, Ly). Ly is recognized when the right and left ends of the roll paper are detected. Next, the media sensor 202 is placed on the right end of the roll paper, and the roll paper is moved in the X direction.
The position of the roll paper in the X direction at the time when the output of No. 02 changes is determined. If the X value of the position coordinates is negative, the coordinates of the right end corner are set as a new temporary reference position. That is, the reference position coordinates (Px, Py) are set to (0, Ry). Ry is also recognized when the right and left ends of the roll paper are detected. If the X value is positive, the reference position is not changed. In addition, the positive or negative of X value (large or small)
Is "large" on the side where the roll paper is discharged and "small" on the side where it is pulled in. After all, the one that enters the inside of the roll paper among the left and right end corners becomes the temporary reference position (S13).
The reference position coordinates (Px, Py) are for determining the cut position of the roll paper. The X coordinate is important,
The Y coordinate is not particularly important.

From the state where the temporary reference position of the roll paper obtained in this way is aligned with the position of the media sensor 202 in the X direction, a predetermined standard value T [m
m] of the roll paper (S14). (Here, the standard value is ± T [mm].) Then, the carriage 10 is detected by the media sensor 202 in order to detect the presence or absence of roll paper.
4 is moved in the Y direction, and it is checked whether or not there is an area where roll paper is not detected (S15). If there is, the shape of the leading end of the roll paper has the pattern shown in FIG. In this case, the Y-coordinates Ay and By at both ends of the area where the roll paper is not detected by the media sensor 202 and the coordinate Cy located in the middle are obtained (S16, S17, S18). The corresponding X coordinates of the obtained coordinates Ay, By, and Cy are obtained, and the position having the smallest X coordinate among them is set to the reference position (S19, S13), and the above operation is repeated.
The position having the smallest X coordinate is set as the final reference position.
Although it depends on the size of the standard value T, it is not always guaranteed that this reference position is the position where it enters the innermost end of the roll paper. However, if T is about several millimeters, it can be considered that the final reference position is a position where the final reference position almost enters the innermost position.

When there is no area where roll paper is not detected at the time of the first execution of step S15, the X coordinate value of the temporary reference position has the smallest value, and the shape of the leading end of the roll paper is shown in FIGS. This corresponds to the pattern of c). This temporary reference position is defined as a final reference position.

Next, the roll paper is moved by T [mm] in a direction in which the roll paper is pulled in from the state in which the reference position of the roll paper is adjusted to the X direction position of the media sensor 202, and the media sensor 202 in this state. The carriage 104 is moved in the Y direction to detect the presence or absence of roll paper (S2
0). Then, it is checked whether or not there is an area for detecting roll paper (S21). If there is, the leading end shape of the roll paper matches the pattern shown in FIGS. 8B, 8C, or 8D, so that trimming cut is necessary. The trimming cut is executed based on the reference position at this time (S22).

On the other hand, when there is no area for detecting the roll paper, the contour of the front end of the roll paper is the standard value ± T of the front end.
It is within the range of [mm], and there is no need for trimming cut (S23). That is, nothing needs to be done in step 23.

By the above operation, the reference position for determining the trimming cut position is determined.

FIG. 5 shows the construction of the cutter unit 103 and its related parts. First, the trimming cut operation by the cutter unit 103 is performed by first moving the cutter 504 from the cutter unit 103 mounted on the carriage 104.
The carriage 104 is moved so that the cutter unit 103 abuts against the cutter draw-out abutting portion 503 on the left side of the main body. When the stopper 502 is abutted against the abutting portion 503 for extracting the cutter, the stopper 502 is released and the cutter 504 is pulled out. The cutter 504 moves along the cutter groove 105 provided on the platen as the carriage 104 moves. When the cutter 504 moves along the cutter groove 105, the roll paper is cut.

Here, when cutting the leading end of the roll paper, it is desirable that the reference position of the leading end of the roll paper is closer to the apparatus side (discharge direction) than the position of the cutter groove 105. Although this depends on the performance of the cutter, it is intended to prevent the occurrence of edge jams at the ends and cutter jams due to defective cutting when cutting is performed in accordance with the reference position.

After the cutting, as shown in FIG. 6, a cutter roller lifting rib 60 provided on the other end of the platen is provided.
When the roller 501 is pushed up by 1, the cutter 504 is pulled into the cutter unit 103,
The stopper 502 (FIG. 5) is set.

When the carriage 104 finally returns to the home position, the trimming cut operation is completed.
After the end of the trimming cut, the leading end of the medium is positioned at a predetermined position, and the process shifts to a normal print standby state.

While the preferred embodiment of the present invention has been described above, various modifications and changes are possible. For example,
Although two sensors 202 and 210 are used as media sensors, the number of sensors may be one if the sensor 202 detects the presence or absence of the media and the rear end of the media.

[0042]

According to the present invention, the minimum trimming cut amount and the number of times can be determined by judging the necessity and necessity of trimming cut when using roll paper and optimizing the cut position at the time of trimming cut. Is realized, which has a positive effect on the saving of media and the durability of the cutter.

[Brief description of the drawings]

FIG. 1 is a diagram showing the appearance of an ink jet plotter to which the present invention is applied.

FIG. 2 is a diagram showing a configuration of a main part inside the inkjet plotter shown in FIG.

FIG. 3 is a flowchart illustrating an example of a procedure for trimming and cutting a medium (roll paper) according to an embodiment of the present invention.

FIG. 4 is a diagram showing a state (shape) of a leading end portion of a medium (roll paper) before trimming cut.

FIG. 5 is a diagram for explaining the operation of the cutter unit according to the embodiment of the present invention.

FIG. 6 is another diagram for explaining the operation of the cutter unit according to the embodiment of the present invention.

[Explanation of symbols]

 103 ... Cutter unit 104 ... Carriage 105 ... Cutter groove 106 ... Print head 201 ... Carriage motor 202 ... Media sensor 203 ... Carriage drive belt 501 ... Roller 502 ...・ Stopper (claw) 503 ・ ・ ・ Abutting part 504 ・ ・ ・ Cutter blade 601 ・ ・ ・ Roller pushing up rib

Claims (6)

[Claims] An image forming apparatus capable of using roll paper as a recording medium, a conveying means for conveying the recording medium, a carriage mounted with a print head and reciprocating in a direction substantially perpendicular to the recording medium conveying direction. A cutter mounted on the carriage for cutting the roll paper on the platen along the carriage moving direction; a roll paper leading end detecting means for detecting a portion of the leading end of the roll paper that is inserted into the inside; Control means for trimming and cutting the leading end of the roll paper based on the position of the cut portion. 2. The roll paper tip detecting means detects whether or not the detected contour of the roll paper tip falls within a range of a predetermined standard value. 2. The image forming apparatus according to claim 1, wherein trimming cut of said roll paper is omitted. 3. The roll paper leading end detecting means has a first sensor for detecting a recording medium mounted on a carriage, and the first sensor is moved in a carriage moving direction and the first sensor is moved by the recording medium conveying means. The image according to claim 1, wherein a portion of the leading end portion of the roll paper that enters the inside is detected by determining an output of the first sensor in combination with conveyance of a recording medium. Forming equipment. 4. A printer according to claim 1, further comprising a second sensor fixedly disposed in the apparatus for detecting that the recording medium has been set on the platen, and that the roll paper has been set by the second sensor. The image forming apparatus according to claim 1, wherein the detection is performed by the roll paper leading edge detection unit when the detection is performed. 5. A skew detecting means for detecting whether or not the recording medium is skewed, wherein the roll paper leading end detecting means detects the absence of skew by the skew detecting means. The image forming apparatus according to any one of claims 1 to 4, wherein an innermost part of the leading end of the roll paper is detected. 6. A method for trimming and cutting roll paper in an image forming apparatus capable of using roll paper as a recording medium, the method comprising: (a) using a recording medium sensor movable in a direction substantially perpendicular to a recording medium conveyance direction. By moving the roll paper by sequentially positioning the recording medium sensors at the left and right ends of the roll paper, the left and right corners of the roll paper are detected, and the inner one of the detected left and right corners is used as a reference position. (B) scanning the position inside the recording medium conveyance direction by a predetermined amount from the reference position with the recording medium sensor to detect the presence or absence of a recording medium absence area; and (c) step (c). As a result of c), if there is a recording medium-less area, the left and right end positions of the recording medium-less area are obtained, and the intermediate position of the left and right ends is obtained. The position is set as a new reference position, and the process returns to step (b). (D) As a result of step (c), if there is no area with no recording medium, a predetermined amount outside the current reference position in the recording medium transport direction. (E) scanning the position of the recording medium with the recording medium sensor to detect the presence or absence of the recording medium presence area, and (e) as a result of step (d), if the recording medium presence area exists, the roll based on the current reference position. As a result of the step of trimming and cutting the paper and (f) the step (d), if there is no recording medium area,
A step of omitting the execution of the trimming of the roll paper.