JP3941680B2 - Medium edge setting device and image forming apparatus using the edge setting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an edge setting device suitable for setting the position of the edge of a sheet, for example, in a copying machine or a printer, and an image forming apparatus using the edge setting device.
[0002]
[Prior art]
  In image forming apparatuses such as copiers and printers, an optical sensor is mounted on a carriage, and light is applied to the paper while moving the carriage from one end to the other in the width direction of the paper, and the amount of reflected light is measured. A method of detecting both ends of a sheet by detection is known (for example, see Patent Document 1).
[0003]
[Patent Document 1]
      Japanese Patent Laid-Open No. 3-7371 (FIG. 4)
[0004]
[Problems to be solved by the invention]
  However, when there is dirt or a pattern on the paper, there is a problem that both ends of the paper cannot be set accurately. For example, as shown in FIG. 7A, when the low reflectance portion 101 such as a stain or a pattern is at the end of the paper P, if the detection means is moved from the left end of the paper P toward the right end, At the position P1, the amount of reflected light changes from a low level to a high level, and then at a position P2, it changes from a high level to a low level. Therefore, although the actual left end position of the paper P is the position P1 and the right end position is the position P3, the position P1 is set as the left end position and the position P2 is set as the right end position.
[0005]
  The present invention has been made to solve the above problems, and uses an edge setting device that can accurately set the edge position of a medium without being affected by dirt or a pattern of the medium such as paper. An object of the present invention is to provide an image forming apparatus.
[0006]
[Means for Solving the Problems and Effects of the Invention]
  In order to solve the above problem, the medium edge setting device according to claim 1,
  A medium edge setting device for detecting an edge of a medium and setting a position of the edge,
  Detecting means for detecting one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium;
  One end portion distance that is a distance from a predetermined center position representing the center in the width direction of the medium to the one end portion candidate position, and the other end portion from the center positionCandidateDistance calculating means for calculating the other end distance which is the distance to the position;
  End setting means for setting end positions on both sides of the medium based on a distance difference between the one end distance calculated by the distance calculating means and the other end distance;
  A distance difference determination means for determining whether or not a distance difference between the one end distance calculated by the distance calculation means and the other end distance is equal to or less than a first determination value;
  When the distance difference determining unit determines that the distance difference is equal to or less than the first determination value, the end setting unit sets the one end candidate position and the other end candidate position to the medium. One end position and the other end position, and when the distance difference determination means determines that the distance difference is greater than the first determination value, the one end distance and the other end distance Setting the one end position and the other end position of the medium as a distance from the center position of the medium to the end positions,
TheFeatures.
[0007]
  According to the medium edge setting device configured as described above, the detection unit detects the one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium. Then, the distance calculation means includes one end portion distance that is a distance from a predetermined center position representing the center in the width direction of the medium to one end portion candidate position, and the other end portion from the center position.CandidateThe other end distance, which is the distance to the position, is calculated. Furthermore, the end setting meansIf the distance difference determining means determines that the distance difference is equal to or smaller than the first determination value, each end candidate position is set as each end position of the medium, and the distance difference is greater than the first determination value. If it is determined that the distance is larger, the larger one of the one end distance and the other end distance is defined as the distance from the center position of the medium to each end position, and the one end position and the other end position of the medium are Set.
  For this reason, when the edge candidate position cannot be accurately detected due to dirt or a pattern, the distance difference determination unit determines that the distance difference is larger than the first determination value, and the one end distance and the other end distance are determined. Since the larger one is the distance from the center position of the medium to each end position, and the one end position and the other end position of the medium are set, a value close to the actual end position of the medium is set to each end section. Can be set as position.
[0008]
  Therefore, when the center position in the width direction of the medium is known by inserting the medium along a paper guide provided in a paper feed tray of an image forming apparatus such as a printer, the detection means accurately detects it. Since the end setting means sets the other end position based on the distance difference between the center position calculated by the distance calculation means and the one end candidate position by detecting the position of one end that can be created, The position of the other end can be set with high accuracy without being affected by the pattern or the pattern.
[0009]
[0010]
[0011]
[0012]
[0013]
  Further, in the medium edge setting device according to claim 1, the device further comprises:2As described in
  Conveying means for conveying the medium;
  When the distance difference determining unit determines that the distance difference is equal to or smaller than the first determination value, the end position of the medium is set based on the end distance, and the distance difference determining unit And a remeasurement command means for causing the transport means to transport the medium by a predetermined amount and then operating the detection means when it is determined that the distance difference is greater than the first determination value. It may be.
[0014]
  According to the edge setting device for a medium configured as described above, the edge setting means determines that the edge distance when the distance difference determination means determines that the distance difference is equal to or smaller than the first determination value. The edge position of the medium is set based on the above, and when the distance difference determining means determines that the distance difference is larger than the first determination value, the medium is conveyed by a predetermined amount to the conveying means, and then detected. Operate means.
[0015]
  For this reason, when the edge candidate position cannot be accurately detected due to dirt or a pattern, the distance difference determination unit determines that the distance difference is larger than the first determination value, and the conveyance unit conveys the medium by a predetermined amount. After that, since the detection means detects each end position, if the medium is transported and the dirt or the pattern disappears from the edge of the medium in the area detected by the detection means, each end position is detected normally. can do.
[0016]
  Claims2In the medium edge setting device according to claim 1, further comprising:3As described in
  When the number of times of detection, which is the number of times that the detecting means has operated before the one end position and the other end position are set by the edge setting means, is measured, and the number of times of detection is less than or equal to a second determination value Operates the remeasurement command means after the determination by the distance difference determination means, and when the number of times of detection is larger than the second determination value, the remeasurement command means after the determination by the distance difference determination means It is also possible to provide a counting means for prohibiting the operation and operating the end setting means.
[0017]
  According to the medium edge setting device configured as described above, the number of times of detection is counted, and when the number of times of detection is less than or equal to the second determination value, the remeasurement command means operates.
  When it is determined that the distance difference is equal to or smaller than the first determination value, each end candidate position is set as each end position of the medium. When it is determined that the distance difference is larger than the first determination value, the transport unit transports the medium by a predetermined amount, and then the detection unit is operated.
[0018]
  On the other hand, when it is determined that the number of times of detection is greater than the second determination value, the operation of the re-measurement command unit is prohibited after the determination by the distance difference determination unit, and the end setting unit is operated, whereby the distance difference Is determined to be equal to or smaller than the first determination value, each end candidate position is set as each end position of the medium, and when it is determined that the distance difference is greater than the first determination value. The one end position and the other end position of the medium are set with the larger one of the one end distance and the other end distance as the distance from the center position of the medium to each end position.
[0019]
  For this reason, when the edge candidate position cannot be accurately detected due to dirt or a pattern, the distance difference determination unit determines that the distance difference is larger than the first determination value. Then, the detection means detects each end position. Therefore, when the medium is transported and the dirt or the pattern disappears from the edge of the medium in the area detected by the detection means, the position of each end can be normally detected. In addition, if dirt or a pattern is present at the edge of the medium in the area detected by the detection means even after the predetermined amount of conveyance by the conveyance means is repeated a predetermined number of times, the larger of the one end distance and the other end distance Since the one end position and the other end position of the medium are set as the distance from the center position of the medium to each end position, a value close to the actual end position of the medium can be set as each end position.
[0020]
  Claims4The edge setting device for a medium described in
  A medium edge setting device for detecting an edge of a medium and setting a position of the edge,
  Detecting means for detecting one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium;
  One end distance, which is a distance from a predetermined center position representing the center in the width direction of the medium to the one end candidate position, and another end distance, which is a distance from the center position to the other end position, are calculated. Distance calculating means to
  Distance difference determination means for determining whether or not a distance difference between the one end distance and the other end distance is equal to or less than a first determination value;
  Conveying means for conveying the medium in a direction orthogonal to the moving direction of the detecting means;
  When the distance difference determining means determines that the distance difference is less than or equal to the first determination value, the one end portion candidate position and the other end portion candidate position are set as the one end portion position and the other end of the medium, respectively. Set as a part position, and when the distance difference determination means determines that the distance difference is larger than the first determination value, the medium is conveyed by a predetermined amount to the conveyance means, and then the detection means And end setting means for operating the device.
[0021]
  According to the medium edge setting apparatus configured as described above, the detection unit detects the one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium.
Then, the distance calculation means calculates one end distance, which is a distance from a predetermined center position representing the center of the medium, to one end candidate position, and the other end distance, which is a distance from the center position to the other end position. To do.
[0022]
  Furthermore, when the distance difference determining unit determines that the distance difference is equal to or smaller than the first determination value, the edge setting unit determines the one end candidate position and the other end candidate position as one end position of the medium and The other end position is set, and when the distance difference determination unit determines that the distance difference is larger than the first determination value, the conveyance unit conveys the medium by a predetermined amount, and then the detection unit is operated.
[0023]
  For this reason, when the edge candidate position cannot be accurately detected due to dirt or a pattern, the distance difference determination unit determines that the distance difference is larger than the first determination value, and the conveyance unit conveys the medium by a predetermined amount. Then, since the detection means detects each end position, if the medium is transported and the dirt or pattern disappears from the edge of the medium in the area detected by the detection means, each end position is correctly detected. be able to.
[0024]
  Claims5The edge setting device for a medium described in
  A medium edge setting device for detecting an edge of a medium and setting a position of the edge,
  Detecting means for detecting one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium;
  One end distance, which is a distance from a predetermined center position representing the center in the width direction of the medium to the one end candidate position, and another end distance, which is a distance from the center position to the other end position, are calculated. Distance calculating means to
  Recognizing means for recognizing a medium width which is a length in the width direction of the medium;
  Conveying means for conveying the medium in a direction orthogonal to the moving direction of the detecting means;
  Distance sum determination means for determining whether or not a difference between the sum of the one end distance and the other end distance and the medium width recognized by the recognition means is equal to or less than a third determination value;
  When the distance sum determination means determines that the difference between the distance sum and the medium width is equal to or smaller than the third determination value, the one end candidate position and the other end candidate position are set as the medium. One end portion position and the other end portion position, and when the distance sum determining means determines that the difference between the distance sum and the medium width is larger than the third determination value, the conveying means And an end setting means for operating the detection means after the medium is conveyed by a predetermined amount.
[0025]
  According to the medium edge setting apparatus configured as described above, the detection unit detects the one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium.
Then, the distance calculation means calculates one end distance, which is a distance from a predetermined center position representing the center of the medium, to one end candidate position, and the other end distance, which is a distance from the center position to the other end position. To do.
[0026]
  Further, the edge setting means determines that the difference between the distance sum and the medium width recognized by the recognition means is less than or equal to the third determination value by the distance sum determination means. And the other end candidate position are set as the one end position and the other end position of the medium, respectively, and the both end distance determining means determines that the difference between the both end distance and the medium width is larger than the third determination value. Causes the transport means to transport a predetermined amount of medium, and then operates the detection means.
[0027]
  For this reason, when the edge candidate position cannot be accurately detected due to dirt or a pattern, the distance sum determining unit determines that the distance difference is larger than the third determination value, and the conveying unit conveys the medium by a predetermined amount. Then, since the detection means detects each end position, if the medium is transported and the dirt or pattern disappears from the edge of the medium in the area detected by the detection means, each end position is correctly detected. be able to.
[0028]
  As shown in FIG. 7B, when detecting the edge of both sides in the detection means for detecting the edge candidate position of the medium by detecting the amount of reflected light from the medium, as shown in FIG. When the rate part 102 is inside the paper P and the low reflectance part 103 is at the end of the paper P, if the detection means is moved from the left end of the paper P toward the right end, the position P11 is the first. The amount of reflected light changes from a low level to a high level, then first changes from a high level to a low level at a position P12, then changes again from a low level to a high level at a position P13, and at a position P14. Finally, it changes from a high level to a low level. For this reason, the situation where the position P11 is set as the left end position and the position P12 is set as the right end position can be considered.
[0029]
  Because of this, the claims1~ Claim5In the medium edge setting device according to claim 1, further comprising:6As described in
  In the case where there are a plurality of edge candidate positions, the detecting means sets the edge candidate position having the longest distance from the center position on the one end side from the center position as the one edge candidate position of the medium, and The end candidate position having the longest distance from the center position on the other end side from the position may be set as the other end candidate position.
[0030]
  According to the edge setting device for a medium configured as described above, when there are a plurality of edge candidate positions, the detection means has an edge candidate having the largest distance from the center position on the one end side from the center position. The position is the one end candidate position of the medium, and the end candidate position having the largest distance from the center position on the other end side from the center position is the other end candidate position.
[0031]
  For this reason, in the case shown in FIG. 7B, the position P11 is set as one end candidate position, and the position P14 is set as the other end candidate position. The detection of the end candidate position by the means is not affected.
  And claims7The image forming apparatus described in
  An image forming apparatus that detects an edge of the medium and forms an image on the medium based on the position of the edge,
  Claims 1 to6It is provided with the edge part setting apparatus of the medium in any one.
[0032]
  According to the image forming apparatus configured as described above, claims 1 to 1.6The edge position of the medium can be set by any one of the edge setting devices.
  For this reason, it is possible to correctly set the edge position of the medium and form an image.
[0033]
DETAILED DESCRIPTION OF THE INVENTION
    (Embodiment 1)
  Embodiment 1 of the present invention will be described below with reference to the drawings.
  This embodiment is an example when the present invention is applied to a multi-function device having a printer function, a copy function, a scanner function, a facsimile function, a telephone function, etc. FIG. 1 is a perspective view of the multi-function device 1. .
[0034]
  As shown in FIG. 1, the multi-function device 1 is provided with a paper feeding device 2 at the rear end, an ink jet printer 3 is provided at the lower front side of the paper feeding device 2, and a copy function is provided above the printer 3. A reading device 4 for the facsimile function is provided. A paper discharge tray 5 is provided on the front side of the printer 3, and an operation panel 6 is provided on the upper surface of the front end of the reading device 4.
[0035]
  The paper feeding device 2 includes an inclined wall portion 66 that holds the paper in an inclined posture, and an extended paper guide plate 67 that is detachably attached to the inclined wall portion 66, so that a plurality of sheets can be stacked. it can.
  The stacking surface on which the sheets are stacked on the inclined wall portion 66 is provided with a pair of sheet guides 61 that can move in the left-right direction for guiding the position for loading the sheets.
[0036]
  Thus, the left and right edges of the paper P can be guided according to the widthwise dimension of the paper P stacked between the pair of paper guides 61, and the paper P can be set at the center of the stacking surface in the width direction.
  Each of the paper guides 61 is provided with a paper guide position sensor 64 (see FIG. 3). The paper guide position sensor 64 is composed of a potentiometer, for example, and detects the position of the paper guide 61 by detecting the amount of deviation of the paper guide 61 from the reference position. The distance from the reference position of the paper guide 61 to the origin position of the carriage 11 is set to a predetermined distance.
[0037]
  Further, the inclined wall portion 66 is provided with a paper feed motor (not shown), a paper feed roller (not shown), and the like. When the paper feed roller is rotated by the driving force of the paper feed motor, the paper feed is rotated. The roller sends the paper P toward the printer 3.
  Next, the printer 3 will be described. FIG. 2 is a plan view showing the internal structure of the printer 3.
[0038]
  As shown in FIG. 2, the printer 3 includes a print head 10, a carriage 11 on which the print head 10 is mounted, a guide mechanism 12 that guides and supports the carriage 11 so as to be movable in the horizontal direction that is the scanning direction, and the carriage 11 in the horizontal direction. A carriage moving mechanism 13 that moves the paper P, a paper transport mechanism 14 that transports the paper P fed by the paper feeder 2, a maintenance mechanism 15 for the print head 10, and the like are provided.
[0039]
  The printer 3 is provided with a rectangular parallelepiped frame 16 that is long in the left-right direction and has a small vertical width. A guide mechanism 12, a carriage moving mechanism 13, a paper transport mechanism 14, a maintenance mechanism 15 and the like are attached to the frame 16. Further, the print head 10 and the carriage 11 are accommodated inside the frame 16 so as to be movable in the left-right direction.
[0040]
  A paper inlet and a paper outlet (not shown) are formed in the rear plate 16a and the front plate 16b of the frame 16, and the paper P fed by the paper feeder 2 is introduced into the frame 16 from the paper inlet. Then, the paper is transported forward by the paper transport mechanism 14 and discharged from the paper discharge port to the front paper discharge tray 5 (see FIG. 1). A platen 17 having a plurality of ribs is attached to the bottom surface of the frame 16, and printing by the print head 10 is performed on the paper P moving on the platen 17 inside the frame 16.
[0041]
  The print head 10 is provided with four sets of ink nozzle groups 10a to 10d facing downward, and ink of four colors (black, cyan, yellow, magenta) is ejected downward from these ink nozzle groups 10a to 10d. Thus, printing on the paper P is possible. Since the four sets of ink nozzle groups 10a to 10d are provided on the lower side of the print head 10, in FIG.
[0042]
  The four color ink cartridges 21 a to 21 d mounted on the cartridge mounting portion 20 on the front side of the frame 16 are connected to the print head 10 via four flexible ink tubes 22 a to 22 d passing through the inside of the frame 16. Four colors of ink are supplied to the print head 10.
[0043]
  In addition, two left and right FPCs 23 and 24 (flexible print circuit) are disposed inside the frame 16, and the left FPC 23 is integrally connected to the print head 10 and connected to the two ink tubes 22a and 22b. The right FPC 24 is connected to the print head 10 integrally with the two ink tubes 22c and 22d. The FPCs 23 and 24 are provided with a plurality of signal lines that electrically connect a processing execution device 70 (not shown in FIG. 2) to be described later and the print head 10.
[0044]
  The guide mechanism 12 is formed in the front portion in the frame 16 and the guide shaft 25 which is disposed in the left-right direction at the rear portion in the frame 16 and whose left and right end portions are connected to the left plate 16 c and the right plate 16 d of the frame 16. The rear end portion of the carriage 11 is slidably fitted on the guide shaft 25, and the front end portion of the carriage 11 is slidably engaged with the guide rail 26. Yes.
[0045]
  The carriage moving mechanism 13 is pivotably attached to the carriage motor 30 mounted forward on the rear side of the right end portion of the rear plate 16a of the frame 16, the drive pulley 31 that is rotationally driven by the carriage motor 30, and the left end portion of the rear plate 16a. The driven pulley 32 is supported, and a belt 33 that is hung on the pulleys 31 and 32 and fixed to the carriage 11. A carriage feed encoder 39 for detecting the movement amount of the carriage 11 (print head 10) is provided in the vicinity of the carriage motor 30.
[0046]
  The paper transport mechanism 14 includes a paper transport motor 40 attached leftward to a portion of the left side plate 16c of the frame 16 that projects to the rear side of the rear side plate 16a, and a left and right side below the guide shaft 25 inside the frame 16. A registration roller 41 that is disposed in a direction and is rotatably supported by left and right side plates 16c and 16d, a drive pulley 42 that is driven to rotate by a paper transport motor 40, and a left end of the registration roller 41. And a belt 44 hung on the pulleys 42 and 43. When the paper transport motor 40 is driven, the registration roller 41 rotates to transport the paper P in the front-rear direction. become. In FIG. 2, the registration roller 41 is emphasized, but actually, the registration roller 41 is arranged below the guide shaft 25.
[0047]
  The paper transport mechanism 14 includes a paper discharge roller 45 that is disposed on the front side of the frame 16 in the left-right direction, and whose left and right ends are rotatably supported by the left side plate 16c and the right side plate 16d, and a driven pulley. 43, a driven pulley 46 provided integrally with the output roller 45, a driven pulley 47 connected to the left end portion of the paper discharge roller 45, and a belt 48 hung on the pulleys 46, 47. Then, the paper discharge roller 45 rotates and the paper can be discharged to the front paper discharge tray 5 side.
[0048]
  An encoder disk 51 is fixed to the driven pulley 43, and a photo interrupter 52 having a light emitting part and a light receiving part is attached to the left side plate 16c so as to sandwich the encoder disk 51. Based on the detection signal from the paper transport encoder 50 (photo interrupter 52), the paper transport motor 40 is driven and controlled by the processing execution device 70 described later.
[0049]
  The maintenance mechanism 15 has a wiper 15a for wiping off the head surface of the print head 10, two caps 15b capable of sealing two sets of the four ink nozzle groups 10a to 10d, and a common drive for driving the wipers 15a and 15b. The wiper 15a, the cap 15b, the drive motor 15c, and the like are attached to the attachment plate 15d, and the attachment plate 15d is fixed to the right portion of the bottom plate of the frame 16 from the lower surface side. Since the cap 15b is provided on the lower side of the print head 10, in FIG. 2, the transparent position is indicated by a dotted line.
[0050]
  As shown in FIG. 2, a media sensor 68 capable of detecting the leading edge, the trailing edge, and the edge in the width direction of the paper P is provided at the left edge of the print head 10. The media sensor 68 is an optical sensor including a light emitting portion 68a (light emitting element) and a light receiving portion 68b (light receiving element), and is attached downward to a sensor attachment portion 10e protruding to the left side of the print head 10.
[0051]
  Further, a registration sensor 69 (see FIG. 3, not shown in FIG. 2) that can detect the presence / absence of the paper P, the leading edge, and the trailing edge upstream of the media sensor 68 in the sheet conveyance direction (left side in FIG. 2). More specifically, it is attached to the front end portion of the upper cover that forms the transport path of the sheet feeding device 2.
[0052]
  The registration sensor 69 includes, for example, a detector that protrudes from the paper conveyance path and is rotated by the paper being conveyed, a photo interrupter that detects the rotation of the detector with a light emitting portion and a light receiving portion, and a paper conveyance device. A mechanical sensor having a torsion spring biased toward the road side can be used. The detector is integrally provided with a shielding portion. When the detector is rotated by the paper P being conveyed, the shielding portion is placed in a space other than between the light emitting portion and the light receiving portion of the photo interrupter. As a result, the transmission of light from the light emitting unit to the light receiving unit is not blocked, and the registration sensor 69 is turned on. In addition, when the paper P is not transported and the detector is biased toward the paper transport path by the torsion spring, the shielding unit is disposed between the light emitting unit and the light receiving unit of the photo interrupter and receives light from the light emitting unit. When the transmission of light to the part is interrupted, the registration sensor 69 is turned off.
[0053]
  Next, the process execution device 70 will be described. FIG. 3 is a block diagram illustrating a schematic configuration of the process execution device 70.
  As shown in FIG. 3, the processing execution device 70 includes a microcomputer having a CPU 71, a ROM 72, a RAM 73, and an EEPROM 74, and includes a paper guide position sensor 64, a registration sensor 69, a media sensor 68, a paper transport encoder 50, an operation. The panel 6, the carriage feed encoder 39, and the like are electrically connected.
[0054]
  Further, the processing execution device 70 is electrically connected to drive circuits 76 a to 76 c for driving the paper feed motor 65, the paper transport motor 40, and the carriage motor 30, and a print drive circuit 76 d for driving the print head 10. And a personal computer 77 (PC 77) is connectable.
[0055]
  Further, the processing execution device 70 sends a carriage control command signal for bringing the relative positional relationship between the carriage 11 and the paper P closer to the target positional relationship to the carriage moving mechanism 13 based on the detection result of the paper P by the media sensor 68. Output. The carriage moving mechanism 13 drives the carriage motor 30 based on the received carriage control command signal, thereby moving the carriage 11 so that the relative positional relationship between the carriage 11 and the paper P approaches the target positional relationship.
[0056]
  Next, the paper edge setting process executed by the process execution device 70 will be described with reference to FIG.
  FIG. 4 is a flowchart showing the paper edge setting process.
  When this paper edge setting process is executed, the process execution device 70 first acquires information on the paper center position in S100. Here, the setting position of the paper guide 61 is detected by the paper guide position sensor 64, and the paper center position information is obtained by calculating the paper center position. Here, since the absolute position from the origin position of the carriage 11 to each of the sheet guides 61 can be obtained by the sheet guide position sensor 64, the average position (center position) thereof is set as the sheet center position.
[0057]
  Thereafter, a paper edge detection process is performed in S110. Here, after the carriage 11 is moved to the left end of the paper P, the light emitting unit 68a of the media sensor 68 irradiates the paper P while moving rightward, and the light receiving unit 68b receives the reflected light. The amount of reflected light is detected, and the position data of the carriage 11 detected by the carriage feed encoder 39 from the left end to the right end of the paper P, and the amount of reflected light at that position, that is, the output value (voltage) of the media sensor 68 Value) is stored in the RAM 73.
[0058]
  Next, the process proceeds to S120, the position where the light quantity changes is obtained from this light quantity data, and the position where the distance from the paper center position is the largest among the positions where the light quantity has changed from a low level to a high level is determined as the left edge of the paper P. Among the positions where the light quantity changes from a high level to a low level, the position with the longest distance from the paper center position is set as the right edge candidate position of the paper P.
[0059]
  Then, the process proceeds to S130, and 1 is added to the value of the measurement count storage area CNT provided in the RAM 73.
  Thereafter, in S140, the distance from the paper center position to the right edge candidate position (hereinafter referred to as the right edge distance, which corresponds to A in FIG. 4) and the distance from the paper center position to the left edge candidate position ( Hereinafter, the left end distance is obtained (corresponding to B in FIG. 4).
[0060]
  Next, in S150, it is determined whether or not the difference between the right end distance and the left end distance (corresponding to | A−B | in FIG. 4) is a predetermined value (for example, 5 mm) or less. If it is determined that the difference between the right edge distance and the left edge distance is equal to or less than a predetermined value (S150: YES), the process proceeds to S160, the right edge candidate position is set as the right edge position, and the left edge candidate position is set as the left edge position. Set. Thereafter, the process proceeds to S170, the value of the measurement count storage area CNT is set to 0, and the paper edge setting process is ended.
[0061]
  On the other hand, if it is determined in S150 that the difference between the right end distance and the left end distance is greater than a predetermined value (S150: NO), the process proceeds to S180, and the value of the measurement count storage area CNT is set to a specified number (for example, 3 times) Determine whether or not
If it is determined that the value of the measurement count storage area CNT is equal to or less than the specified count (S180: YES), the process proceeds to S190, the paper P is fed by a predetermined amount (for example, 20 mm), and then the process proceeds to S110. Process.
[0062]
  In S180, if it is determined that the value of the measurement count storage area CNT is larger than the specified count (S180: NO), the process proceeds to S200 to determine whether the right end distance is equal to or greater than the left end distance. . If it is determined that the right edge distance is greater than or equal to the left edge distance (S200: YES), the process proceeds to S210, the right edge candidate position is set as the right edge position, and the position obtained by subtracting the right edge distance from the paper center position is the left edge position. Set as. Thereafter, the process proceeds to S170, the value of the measurement count storage area CNT is set to 0, and the paper edge setting process is ended.
[0063]
  On the other hand, if it is determined in S200 that the right end distance is smaller than the left end distance (S200: NO), the process proceeds to S220, and the position obtained by adding the left end distance from the paper center position is set as the right end position. The copy candidate position is set as the left end position. Thereafter, the process proceeds to S170, the value of the measurement count storage area CNT is set to 0, and the paper edge setting process is ended.
[0064]
  In the first embodiment, the processing of S110 to S120 is the detection means of the present invention, the processing of S140 is the calculation means of the present invention, the processing of S150 is the distance difference determination means of the present invention, and S160 and S200 to The process of S220 corresponds to the edge setting means of the present invention, the process of S190 corresponds to the conveying means of the present invention, and the processes of S130, S170 and S180 correspond to the counting means of the present invention.
[0065]
  The predetermined value in S150 is the first determination value of the present invention, and the specified number of times in S180 is the second determination value of the present invention.
As described above, according to the medium edge setting device configured as described above, when the difference between the right edge distance and the left edge distance is small (S150: YES), the right edge candidate position and the left edge candidate position are normal. It is determined that the detected value is a right end position and a left end position (S160). On the other hand, if the difference between the right edge distance and the left edge distance is large (S150: NO), the right edge candidate position and the left edge candidate position are normally detected because there is dirt or a pattern on the edge of the paper P. It is determined that the value is not set, and the paper is fed by a predetermined amount (S190), and the paper edge is detected again (S110).
[0066]
  For this reason, if the paper P is transported so that dirt or a pattern disappears from the edge of the paper P in the area detected by the processing of S110, each edge position can be detected normally.
  Furthermore, when the paper edge detection is repeated and the specified number of times is exceeded (S180: NO), the right edge distance and the left edge distance are compared (S200). If the left edge distance is large, the true right edge is the paper. It is estimated that it is at a position away from the center by the left end portion distance, and this position is set as the right end (S220). When the right edge distance is large, it is estimated that the true left edge is at a position away from the paper center by the right edge distance, and this position is set as the left edge (S210).
[0067]
  For this reason, even when dirt or a pattern or the like is present on the paper P in most of the area detected by the processing of S110, a value close to the actual edge position of the paper P can be set as the edge position.
    (Embodiment 2)
  Embodiment 2 of the present invention will be described below with reference to the drawings. The configurations of the multi-function device 1, the printer 3, and the process execution device 70 according to the second embodiment of the present invention are the same as those of the first embodiment.
[0068]
  The difference between the image forming apparatus system according to the second embodiment and the first embodiment is a paper edge setting process. Therefore, the description of the configuration of the multi-function device 1, the printer 3, and the processing execution device 70 of the second embodiment is omitted, and the paper edge setting processing in the second embodiment will be described below.
[0069]
  FIG. 5 is a flowchart showing the paper edge setting process in the second embodiment.
  When this paper edge setting process is executed, the process execution device 70 first acquires information on the set paper width in S300. Here, the set paper width information is obtained by detecting the set position of the paper guide 61 by the paper guide position sensor 64. Alternatively, the set paper width may be set based on information about the paper size transmitted from the personal computer 77.
[0070]
  Thereafter, a paper edge detection process is performed in S310. Here, after the carriage of the paper P is moved to the left end, the light emitting portion 68a of the media sensor 68 irradiates the paper P while moving in the right direction, and the light receiving portion 68b receives the reflected light. The amount of reflected light is detected and the position data of the carriage 11 detected by the carriage feed encoder 39 from the left end to the right end of the paper P and the amount of reflected light at that position, that is, the output value (voltage value) of the media sensor 68. Are stored in the RAM 73.
[0071]
  Next, the process proceeds to S320, the position where the light quantity changes is obtained from the light quantity data, and the position where the distance from the paper center position is the largest among the positions where the light quantity has changed from a low level to a high level is determined as the left edge of the paper P. Among the positions where the light quantity changes from a high level to a low level, the position with the longest distance from the paper center position is set as the right edge candidate position of the paper P.
[0072]
  Then, the process proceeds to S330, and 1 is added to the value of the measurement count storage area CNT provided in the RAM 73.
Thereafter, in the process of S340, a preset paper center position (in the second embodiment, this paper center position does not need to coincide with the actual center position of the paper P and is temporarily set. From the paper center position to the left edge candidate position (hereinafter referred to as the left edge portion), and the distance from the paper center position to the left edge candidate position (hereinafter referred to as A in FIG. 5). Distance (corresponding to B in FIG. 5)).
[0073]
  Next, in the process of S350, the right end distance storage area An that stores the right end distance for each measurement count and the left end distance storage area Bn that stores the left end distance for each measurement count (n is the number of measurements). N = 1, 2, 3,...), The right end distance and the left end distance are stored respectively.
[0074]
  That is, for example, when the specified number of times in S390 is 3, the right end distance storage areas A1, A2, A3 for storing the right end distance and the left end distance measured 1-3 times in the RAM 73 and the left end Division distance storage areas B1, B2, and B3 are provided. For example, the right end distance and the left end distance detected in the second measurement are stored in the right end distance storage area A2 and the left end distance storage area B2, respectively.
[0075]
  Thereafter, in S360, it is determined whether or not the difference between the distance sum of the right end distance and the left end distance (corresponding to A + B in FIG. 5) and the set sheet width is equal to or less than a predetermined value (for example, 5 mm). . If it is determined that the difference between the distance sum and the set paper width is equal to or smaller than the predetermined value (S360: YES), the process proceeds to S370, the right end candidate position is set as the right end position, and the left end candidate position is set as the left end position. To do. Thereafter, the process proceeds to S380, the values of the measurement count storage area CNT, the right end distance storage areas A1, A2, and A3, and the left end distance storage areas B1, B2, and B3 are set to 0, and the paper end setting process ends.
[0076]
  On the other hand, if it is determined in S360 that the difference between the sum of distances and the set sheet width is larger than the predetermined value (S360: NO), the process proceeds to S390, and the value of the measurement count storage area CNT is set to a specified number (for example, 3). Times) Determine whether or not.
If it is determined that the value of the measurement count storage area CNT is equal to or less than the specified count (S390: YES), the process proceeds to S400, and after a certain amount (for example, 20 mm) of paper P has been sent, the process proceeds to S310 and the paper end detection is performed again. Process.
[0077]
  If it is determined in S390 that the value of the measurement count storage area CNT is larger than the specified count (S390: NO), the process proceeds to S410, and the right end distance storage areas A1, A2, A3 and the left end distance storage area The largest value among B1, B2, and B3 is stored in the maximum distance storage area C provided in the RAM 73 (corresponding to C in FIG. 5).
[0078]
  Thereafter, the process proceeds to S420, and it is determined whether or not the value of the maximum distance storage area C is less than or equal to half of the set sheet width. If it is determined that the value of the maximum distance storage area C is equal to or less than half of the set sheet width (S420: YES), the process proceeds to S430, and the position obtained by adding the value of the maximum distance storage area C from the sheet center position is set as the right end position. The position obtained by subtracting the value of the maximum distance storage area C from the sheet center position is set as the left end position. Thereafter, the process proceeds to S380, the values of the measurement count storage area CNT, the right end distance storage areas A1, A2, and A3, and the left end distance storage areas B1, B2, and B3 are set to 0, and the paper end setting process ends.
[0079]
  On the other hand, if it is determined in S420 that the value of the maximum distance storage area C is larger than half of the set sheet width (S420: NO), the process proceeds to S440, and the right edge distance storage areas A1, A2, A2 from the sheet center position. The position where the largest value is added in A3 is set as the right end position, and the position obtained by subtracting the largest value in the left end distance storage areas B1, B2, B3 from the sheet center position is set as the left end position. Thereafter, the process proceeds to S380, the values of the measurement count storage area CNT, the right end distance storage areas A1, A2, and A3 and the left end distance storage areas B1, B2, and B3 are set to 0, and the paper end setting process ends.
[0080]
  In the second embodiment, the processing of S310 to S320 is the detection means of the present invention, the processing of S340 is the calculation means of the present invention, the processing of S360 is the distance sum determination means of the present invention, and the processing of S300 is In the recognition means of the present invention, the process of S370 corresponds to the edge setting means of the present invention, the process of S400 corresponds to the transport means of the present invention, and the processes of S330, S380 and S390 correspond to the counting means of the present invention.
[0081]
  Further, the predetermined value in S360 is the third determination value of the present invention, and the specified number of times in S390 is the second determination value of the present invention.
As described above, according to the medium edge setting device configured as described above, when the difference between the sum of the distance between the right edge distance and the left edge distance and the set sheet width is small (S360: YES), the right edge candidate The position and the left end candidate position are determined to be normally detected values, and are set as the right end position and the left end position, respectively (S370). On the other hand, if the difference between the distance sum and the set paper width is large (S360: NO), the right end candidate position and the left end candidate position are normal because there is dirt or a pattern on the paper edge on the paper P. It is determined that the detected value is not detected, the sheet is fed by a predetermined amount (S400), and the end of the sheet is detected again (S310).
[0082]
  Further, when the paper edge detection is repeated and the specified number of times is exceeded (S390: NO), half of the set paper width is compared with the maximum of the right edge distance and the left edge distance, and the set paper width is compared. Set the right and left end positions within the range that does not exceed.
For this reason, even if the paper center position does not coincide with the actual center position of the paper P and is set temporarily, if the paper width information is acquired, stains, pictures, etc. If it is at the edge, the paper P is conveyed and the paper edge is detected again. As a result, if dirt or a pattern disappears from the edge of the paper P in the area detected by the process of S310, the position of each edge can be normally detected.
[0083]
    (Embodiment 3)
  The third embodiment of the present invention will be described below with reference to the drawings. The configurations of the multi-function device 1, the printer 3, and the processing execution device 70 according to the third embodiment of the present invention are the same as those of the first embodiment.
[0084]
  The difference between the image forming apparatus system according to the third embodiment and the first embodiment is a paper edge setting process. For this reason, the description of the configuration of the multi-function device 1, the printer 3, and the processing execution device 70 of the third embodiment is omitted, and the paper edge setting processing in the third embodiment will be described below.
[0085]
  FIG. 6 is a flowchart showing the paper edge setting process in the third embodiment.
  When this paper edge setting process is executed, the process execution device 70 first acquires information on the paper center position in S500. Here, the setting position of the paper guide 61 is detected by the paper guide position sensor 64, and the paper center position information is obtained by calculating the paper center position.
[0086]
  Thereafter, a paper edge detection process is performed in S510. Here, after the carriage of the paper P is moved to the left end, the light emitting portion 68a of the media sensor 68 irradiates the paper P while moving in the right direction, and the light receiving portion 68b receives the reflected light. The amount of reflected light is detected and the position data of the carriage 11 detected by the carriage feed encoder 39 from the left end to the right end of the paper P and the amount of reflected light at that position, that is, the output value (voltage value) of the media sensor 68. Are stored in the RAM 73.
[0087]
  Next, the process proceeds to S520, where the light quantity change position is obtained from the light quantity data, and the position where the distance from the paper center position is the largest among the positions where the light quantity has changed from a low level to a high level is determined. The left end candidate position.
Thereafter, in S530, a distance from the paper center position to the left edge candidate position (hereinafter, left edge distance, corresponding to B in FIG. 6) is calculated.
[0088]
  In S540, the position obtained by adding the left edge distance from the paper center position is set as the right edge position, the left edge candidate position is set as the left edge position, and the paper edge setting process is terminated.
In the third embodiment, the processing of S510 to S520 corresponds to the detection means of the present invention, the processing of S530 corresponds to the calculation means of the present invention, and the processing of S540 corresponds to the edge setting means of the present invention.
[0089]
  As described above, according to the medium edge setting device configured as described above, the left edge candidate position is detected while moving from the left edge toward the right edge, and the one having the longest distance from the paper center position is detected as the left edge of the paper P. It is set as a candidate position (S520). Then, the position obtained by adding the left end distance from the sheet center position is set as the right end position (S540).
[0090]
  For this reason, when the center position in the width direction of the paper P is known by inserting the paper P along a paper guide provided in a paper tray of an image forming apparatus such as a printer, it can be accurately detected. Since the position of the left end is detected and the position obtained by adding the left end distance from the center position is set as the right end position, the right end position can also be set with high accuracy.
[0091]
  [Modification]
  Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments, and various forms can be taken as long as they belong to the technical scope of the present invention. Not too long.
[0092]
  For example, in the above-described embodiment, an example in which the configuration as the image forming apparatus of the present invention is applied to the multi-function device 1 is illustrated. However, as long as it has a function of detecting the edge of the paper while moving in the width direction of the paper, it can be similarly applied to a copying machine, a printer, a facsimile, and the like having an image forming function.
[0093]
  In the above-described embodiment, the paper edge setting process of FIGS. 4 to 6 is illustrated as being executed by a computer system including the process execution device 70 of the printer 3. However, these processes may be executed by another computer system connected to the printer 3 via a wired / wireless signal transmission path.
[0094]
  The sheet guide 61 is connected to a pair of horizontally long racks (not shown) arranged on the back side of the stacking surface, and is configured so that the pair of racks mesh with a pinion (not shown) provided on the back side, The pair of paper guides 61 may be configured to be movable in the left-right direction by interlocking the pinion and the rack.
[0095]
  If the sheet guide 61 is configured to move left and right evenly with respect to the determined sheet center position in this way, the sheet center position is not obtained from the position of the sheet guide 61 but simply the carriage 11. What is necessary is just to set the design value of the absolute position of the paper center position with respect to the origin.
[Brief description of the drawings]
FIG. 1 is a perspective view of a multi-function device 1 according to an embodiment.
FIG. 2 is a plan view illustrating an internal structure of the printer 3 according to the embodiment.
FIG. 3 is a block diagram illustrating a schematic configuration of a process execution device 70 according to the embodiment.
FIG. 4 is a flowchart showing a paper edge setting process procedure according to the first embodiment.
FIG. 5 is a flowchart showing a paper edge setting process procedure according to the second embodiment.
FIG. 6 is a flowchart showing a paper edge setting process procedure according to the third embodiment.
FIG. 7 is a diagram illustrating a problem of paper edge detection.
[Explanation of symbols]
  DESCRIPTION OF SYMBOLS 1 ... Multifunctional device, 2 ... Paper feeder, 3 ... Printer, 4 ... Reading apparatus, 5 ... Paper discharge tray, 6 ... Operation panel, 10 ... Print head, 10a-10d ... Ink nozzle group, 10e ... Sensor mounting part , 11 ... Carriage, 12 ... Guide mechanism, 13 ... Carriage moving mechanism, 14 ... Paper transport mechanism, 15 ... Maintenance mechanism, 15a ... Wiper, 15b ... Cap, 15c ... Drive motor, 15d ... Mounting plate, 16 ... Frame, 16a ... rear side plate, 16b ... front side plate, 16c ... left side plate, 16d ... right side plate, 17 ... platen, 20 ... cartridge mounting part, 21a-21d ... ink cartridge, 22a-22d ... ink tube, 23 ... FPC, 24 ... FPC , 25 ... guide shaft, 26 ... guide rail, 30 ... carriage motor, 31 ... drive pulley, 32 ... driven pulley, 39 ... carriage 40: paper feed motor, 41: registration roller, 42: driving pulley, 43 ... driven pulley, 44 ... belt, 45 ... paper discharge roller, 46 ... driven pulley, 47 ... driven pulley, 48 ... belt , 50 ... Encoder for paper conveyance, 51 ... Encoder disk, 52 ... Photo interrupter, 61 ... Paper guide, 64 ... Paper guide position sensor, 65 ... Paper feed motor, 66 ... Inclined wall, 67 ... Expansion paper guide plate, 68 ... Media sensor, 68a ... Light emitting part, 68b ... Light receiving part, 69 ... Registration sensor, 70 ... Process execution device, 71 ... CPU, 72 ... ROM, 73 ... RAM, 74 ... EEPROM, 76a to 76c ... Drive circuit, 76d ... Print drive circuit, 77 ... personal computer.

Claims (7)

A medium edge setting device for detecting an edge of a medium and setting a position of the edge,
Detecting means for detecting one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium;
One end distance that is a distance from a predetermined center position that represents the center in the width direction of the medium to the one end candidate position, and another end distance that is a distance from the center position to the other end candidate position A distance calculating means for calculating;
End setting means for setting end positions on both sides of the medium based on a distance difference between the one end distance calculated by the distance calculating means and the other end distance;
A distance difference determination means for determining whether or not a distance difference between the one end distance calculated by the distance calculation means and the other end distance is equal to or less than a first determination value;
When the distance difference determining unit determines that the distance difference is equal to or less than the first determination value, the end setting unit sets the one end candidate position and the other end candidate position to the medium. One end position and the other end position, and when the distance difference determination means determines that the distance difference is greater than the first determination value, the one end distance and the other end distance Setting the one end position and the other end position of the medium as a distance from the center position of the medium to the end positions,
A device for setting an edge of a medium. Conveying means for conveying the medium;
When the distance difference determining unit determines that the distance difference is equal to or smaller than the first determination value, the end position of the medium is set based on the end distance, and the distance difference determining unit If it is determined that the distance difference is greater than the first determination value, the remeasurement command unit causes the transport unit to transport the medium by a predetermined amount, and then operates the detection unit.
The medium edge setting device according to claim 1, further comprising: When the number of times of detection, which is the number of times that the detecting means has operated before the one end position and the other end position are set by the edge setting means, is measured, and the number of times of detection is less than or equal to a second determination value Operates the remeasurement command means after the determination by the distance difference determination means, and when the number of times of detection is larger than the second determination value, the remeasurement command means after the determination by the distance difference determination means 3. The medium edge setting device according to claim 2, further comprising a counting unit that prohibits the operation of the medium and operates the edge setting unit. A medium edge setting device for detecting an edge of a medium and setting a position of the edge,
Detecting means for detecting one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium;
One end distance, which is a distance from a predetermined center position representing the center in the width direction of the medium to the one end candidate position, and another end distance, which is a distance from the center position to the other end position, are calculated. Distance calculating means to
Distance difference determination means for determining whether or not a distance difference between the one end distance and the other end distance is equal to or less than a first determination value;
Conveying means for conveying the medium in a direction orthogonal to the moving direction of the detecting means;
When the distance difference determining means determines that the distance difference is less than or equal to the first determination value, the one end portion candidate position and the other end portion candidate position are set as the one end portion position and the other end of the medium, respectively. Set as a part position, and when the distance difference determination means determines that the distance difference is larger than the first determination value, the medium is conveyed by a predetermined amount to the conveyance means, and then the detection means End setting means for operating,
A device for setting an edge of a medium, comprising: What end setting device Der medium to set the position of the end portion to detect the edge of the medium,
Detecting means for detecting one end candidate position and the other end candidate position of the medium while moving in the width direction of the medium;
One end distance, which is a distance from a predetermined center position representing the center in the width direction of the medium to the one end candidate position, and another end distance, which is a distance from the center position to the other end position, are calculated. Distance calculating means to
Recognizing means for recognizing a medium width which is a length in the width direction of the medium;
Conveying means for conveying the medium in a direction orthogonal to the moving direction of the detecting means;
Distance sum determination means for determining whether or not a difference between the sum of the one end distance and the other end distance and the medium width recognized by the recognition means is equal to or less than a third determination value;
When the distance sum determination means determines that the difference between the distance sum and the medium width is equal to or smaller than the third determination value, the one end candidate position and the other end candidate position are set as the medium. One end portion position and the other end portion position, and when the distance sum determining means determines that the difference between the distance sum and the medium width is larger than the third determination value, the conveying means An end setting means for causing the medium to be conveyed by a predetermined amount and then operating the detection means;
A device for setting an edge of a medium, comprising: In the case where there are a plurality of edge candidate positions, the detecting means sets the edge candidate position having the longest distance from the center position on the one end side from the center position as the one edge candidate position of the medium, and On the other end side from the position, the end candidate position having the longest distance from the center position is set as the other end candidate position.
The medium edge setting device according to claim 1, wherein: An image forming apparatus that detects an edge of the medium and forms an image on the medium based on the position of the edge,
An image forming apparatus comprising the medium edge setting device according to claim 1.

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