JP5811318B2 - Printing apparatus and printing method - Google Patents

Description

  The present invention relates to a printing apparatus that performs a paper feeding operation.

  2. Description of the Related Art Conventionally, printing apparatuses that perform printing by conveying a sheet to a recording head by a conveyance roller are known. For example, the printing apparatus includes a path (also referred to as a transport path) that connects a paper discharge port from a paper storage unit that stores paper to the bottom of the recording head, and the transport roller is included in the transport path. Has been placed. Further, after the paper set in the paper storage unit is taken out by the separation roller and sent by a predetermined distance downstream in the transport direction, the paper is transferred to the transport roller (this operation is also referred to as a paper feed operation). There is something.

  In addition, when the paper feeding operation is not performed appropriately, the internal roller may be driven again to perform the paper feeding operation (hereinafter, repeating the paper feeding operation in this way is a re-feeding operation or a retry operation. Also described.) In the paper feeding operation, the feed amount for feeding paper to each roller by a predetermined distance is set. However, when the roller slides against the paper, the feed amount decreases and the predetermined feed amount cannot be secured. There is. Therefore, in order to eliminate the failure of the paper feeding operation, there is a case where the same paper is fed by a predetermined distance by driving each roller again to increase the feed amount, and refeeding is performed to complete the paper feeding operation (for example, (See Patent Document 1).

Japanese Patent Application Laid-Open No. 2005-74766

  By feeding the paper by a predetermined distance by the re-feeding operation, it is possible to complete the feeding operation accurately. However, an unnecessary paper may be fed. For example, when the rotation of the separation roller is restarted by the re-feed operation, the paper other than the paper to be fed comes into contact with the separation roller, and the paper may be fed.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a printing apparatus and a printing method that prevent a sheet other than a sheet to be fed in a refeed operation from being fed.

  In order to solve the above-described problem, the present invention provides a printing apparatus that performs a paper feeding operation for feeding a paper to a predetermined position on a conveyance path by rotating a first roller, compared with the first roller. A second roller that is disposed downstream in the transport direction and transports the paper, and when the paper is not fed to the predetermined position after the paper feeding operation, the paper length L2 in the paper feed direction is equal to or greater than the second length. If the feed amount is L1 of one roller, the paper is fed in a first refeed operation that rotates the first roller and the second roller, and the paper length in the paper feed direction If L2 <feed amount L1 of the first roller, the first roller is not rotated, and the second paper refeeding operation in which the second roller is rotated refeeds the paper. And a paper feed operation executing means.

  Detailed configurations and effects of the present invention will be disclosed in the specification.

FIG. 2 is a perspective view of the printer 11 with an outer case removed. FIG. 4 is a side view showing a conveyance path of paper M formed inside the printer 11 and various rollers arranged in the conveyance path. 3 is a block configuration diagram illustrating a control block of the printer 11. FIG. 3 is a flowchart for explaining a printing operation in the printer. It is a figure explaining the paper feeding operation performed in step S1. It is a flowchart which shows the paper feeding operation | movement of step S1 in detail. It is a figure for demonstrating an irregular retry. FIG. 10 is a diagram illustrating a positional relationship between rollers and a sheet of a printer 11 according to a second embodiment. 10 is a flowchart illustrating in detail a sheet feeding operation according to a second embodiment.

Hereinafter, embodiments of the present invention will be described in the following order.
1. First embodiment:
2. Second embodiment:
3. Other embodiments:

1. First embodiment:
Hereinafter, a first embodiment of a printing apparatus according to the present invention will be described with reference to the drawings. Hereinafter, the printer 11 will be described as an example of the printing apparatus.

  FIG. 1 is a perspective view of the printer 11 with the outer case removed. As shown in FIG. 1, the printer 11 includes a substantially square box-shaped main body case 12 having an upper opening, and a carriage 14 extends along a main scanning direction X on a guide shaft 13 installed in the main body case 12. It is provided in a state where it can reciprocate. An endless timing belt 15 to which the carriage 14 is fixed on the back side is wound around a pair of pulleys 16 and 17 disposed on the inner surface of the back plate of the main body case 12, and one pulley 16 and the drive shaft are connected. The carriage 14 is configured to reciprocate in the main scanning direction X by forward / reversely driving a carriage motor (hereinafter also referred to as “CR motor 18”) as the driving means.

  A recording head (recording means) 19 for ejecting ink is provided below the carriage 14. Further, in the lower position facing the recording head 19 in the main body case 12, the recording head 19 and a sheet M as a target are disposed. The platen 20 that defines the interval is arranged extending in the X direction. In addition, on the carriage 14, black and color ink cartridges 21 and 22 are detachably loaded. The recording head 19 ejects (discharges) ink of each color supplied from the ink cartridges 21 and 22 from nozzles for each color.

  On the back side of the printer 11, only the topmost sheet among the paper feed tray 23 and the many sheets M stacked on the paper feed tray 23 is separated and the sub-scanning direction Y (upstream in the transport direction) is separated. An automatic sheet feeder is provided to supply in the direction from the side to the downstream side.

  Further, a paper feed motor (hereinafter referred to as “PF motor 25”) is disposed at the lower right side of the main body case 12 in FIG. 1, and when the PF motor 25 is driven, a transport roller and a discharge roller (both are both). 2) is driven to rotate, and the sheet M is conveyed in the sub-scanning direction Y. In the printer 11, a printing operation for ejecting ink from the nozzles of the recording head 19 toward the paper M while reciprocating the carriage 14 in the main scanning direction X, and a predetermined conveyance amount of the paper M in the sub-scanning direction Y are performed. By repeating the paper feeding operation transported in (1) substantially alternately (however, each operation timing partially overlaps), printing of characters, images, etc. is performed on the paper M.

  Further, a linear encoder 26 that outputs a number of pulses proportional to the moving distance of the carriage 14 is installed in the printer 11 so as to extend along the guide shaft 13, and is obtained using the output pulse of the linear encoder 26. Based on the movement position, movement direction, and movement speed of the carriage 14, speed control and position control of the carriage 14 are performed.

  FIG. 2 is a side view showing a conveyance path of the paper M formed inside the printer 11 and various rollers arranged in the conveyance path. As shown in FIG. 2, a conveyance path for discharging the paper M stacked on the paper feed tray 23 to the outside of the printer 11 through the platen 20 is formed inside the printer 11. In addition, on the transport path, on the upstream side in the transport direction of the paper feed tray 23, a separation roller 33 (first roller) that takes out the paper M to be transported from the plurality of papers M stacked on the paper feed tray 23. ) Is arranged. Then, on the downstream side of the separation roller 33 in the conveyance direction, the conveyance roller (the first conveyance roller 31 (second roller), the first conveyance roller 31, the second conveyance roller) before and after sandwiching the recording position of the recording head 19 (that is, the platen 20) in the conveyance direction The second transport roller 32) and the paper discharge roller 34 are arranged in a rotatable state.

  The separation roller 33 is provided between the paper feed tray 23 and the upstream side in the transport direction of the first transport roller 31 and is rotated by power transmitted from the PF motor 25 via a clutch unit (not shown). Moreover, in this embodiment, the rotation direction cross section of the separation roller 33 is a half-moon shaped cross section in which a part of the circumference is cut, and the length of the circumference is L1. Therefore, when the separation roller 33 contacts the paper M on the paper feed tray 23 and rotates once, the paper M is wound in the transport direction by the rotation of the separation roller 33, and ideally downstream in the transport direction. Is sent by a distance L1. On the other hand, in a period in which the circumferential portion of the separation roller 33 releases contact with the paper M (for example, a period in which a part of the circumferential portion is cut away from the paper M), the separation roller 33 and Since it does not contact the paper M, the paper M is not sent. Hereinafter, the position at which the separation roller 33 starts to contact the paper M and starts feeding is referred to as a home position.

  The transport roller is configured by a first transport roller 31 and a second transport roller 32 that are respectively disposed on the transport path. Each transport roller is composed of a pair of a drive roller 31A (32A) and a driven roller 31B (32B). In this embodiment, the driving force of the PF motor 25 (see FIG. 1) is transmitted to the transport roller, and both the driving rollers 31A (32A) are rotationally driven. Therefore, the paper M separated by the separation roller 33 is transferred to the first transport roller 31 and transported in the left direction (sub-scanning direction Y) in FIG.

  The paper discharge roller 34 is disposed near the paper discharge port, and discharges the paper M on which an image has been formed by the recording head 19 to the outside of the printer 11. The paper discharge roller 34 includes a pair of a driving roller 34A and a driven roller 34B, and the driven roller 34B follows the rotation of the driving roller 34A to discharge the paper M.

A paper detection sensor 35 is provided at a position slightly upstream of the second transport roller 32 in the transport direction. The paper detection sensor 35 is composed of, for example, a contact type sensor (switch type sensor). The paper detection sensor 35 is turned on when the leading edge of the fed paper M hits a detection lever (not shown) and is displaced, and the trailing edge of the paper M passes. It turns off when the detection lever returns to the original standby position by spring force. The paper detection sensor 35 can determine whether or not the paper M exists in the transport path, and can detect that the paper feeding operation has been performed.
The paper detection sensor 35 only needs to be able to detect the edge of the paper M, and a non-contact sensor such as an optical sensor can also be used.

  FIG. 3 is a block diagram illustrating a control block of the printer 11. As shown in FIG. 3, the printer 11 is provided with a control unit 37 composed of a microcomputer or the like that performs overall control of driving of the printer 11. The control unit 37 is based on the input from the paper detection sensor 35, the linear encoder 26 (strictly, the light receiving side), and the input from the operation buttons 38 provided on the exterior case (not shown). The drive of the recording head 19 and the PF motor 25 is controlled. Furthermore, the display on the monitor 39 provided in the exterior case (not shown) is controlled based on each input.

FIG. 4 is a flowchart for explaining a printing operation in the printer 11.
Hereinafter, in step S1, the separation roller 33 is driven to take out the paper M placed on the paper feed tray 23, and the paper M is sent to the first conveyance roller 31 by feeding a predetermined distance downstream in the conveyance direction ( Hereinafter, such an operation is referred to as a paper feeding operation and a paper feeding process.) In step S2, the carriage 14 moves the recording head 19 in the main scanning direction (x direction) with respect to the fed paper M, and the transport roller moves the paper M in the sub operation direction (y direction). Then, an image forming operation (image forming process) is performed. In step S3, the sheet M on which the image is formed is discharged from the discharge port.

  FIG. 5 is a diagram illustrating the paper feeding operation executed in step S1. As shown in FIG. 5A, in the paper feeding operation, the paper M taken out from the paper feeding tray 23 (hereinafter referred to as paper M1 is used to distinguish from the paper M2 stacked on the paper feeding tray 23. ) On the downstream side in the transport direction (hereinafter also simply referred to as a paper leading end Me) is sent to the point P0 (hereinafter, the distance that the paper M is fed in this way is also referred to as the paper feeding distance P). .) In this embodiment, since the sheet feeding operation is completed by one rotation of the separation roller 33, ideally, the feed amount L1 = P. The feed amount L1 indicates the distance that the separation roller 33 sends the paper tip Me to the point P0. Therefore, when the separation roller 33 rotates n times and the paper M1 tip is sent to the point P0, L1 = Li × n (however, , Li is a feed amount in one rotation of the separation roller 33). Similarly, even when the separation roller 33 feeds the paper M1 to the paper feed distance P with less than one rotation, the ideal feed amount L1 is set by the circumference according to the rotation angle of the separation roller 33. Since the paper detection sensor 35 is disposed at the point P0, when the paper leading edge Me reaches the point P0, the paper detection sensor 35 detects the paper M1, and the control unit 37 determines the completion of the paper feeding operation. . Therefore, in the present embodiment, the paper feed distance P can be the distance between the paper detection sensor 35 and the separation roller 33 on the transport path.

  In the course of the paper feeding operation, the separation roller 33 may slide with respect to the paper M1, and the feed amount L1 of the separation roller 33 may not become P. For example, the sheet M1 does not follow the rotation of the separation roller 33, and the sheet leading end Me does not reach the point P0 even if the separation roller 33 is rotated once (FIG. 5B). In such a case, the control unit 37 rotates the separation roller 33 again and performs a retry operation (refeed operation) that repeats the paper feed operation.

  Here, in the retry operation, after the rotation of the separation roller 33 is completed, the separation roller 33 is rotated again. Therefore, it is possible that the paper M (M2) other than the paper to be fed is fed. For example, the separation roller 33 sends the paper M1 by the retry operation, but before the paper leading edge Me reaches P0, the separation roller 33 comes into contact with the next paper M2 and starts feeding the paper M2. . For this reason, in the present embodiment, the retry operation mode is changed according to the conditions so that the paper M2 that is not a paper supply target in the retry operation is not fed.

  FIG. 6 is a flowchart showing in detail the sheet feeding operation in step S1. Hereinafter, the sheet feeding operation according to the present embodiment will be described with reference to the flowchart shown in FIG. When a print command is input to the printer 11, in step S <b> 11, the control unit 37 drives the separation roller 33 and the transport rollers 31 and 32 to execute a paper feeding operation. Further, the control unit 37 implements a refeed operation execution means of the present invention by the processing shown in FIG.

  In step S12, the control unit 37 determines whether or not the paper leading end Me has reached the point P0. That is, the control unit 37 monitors the input of the paper detection sensor 35. If the paper detection sensor 35 detects the paper M and the input signal changes to high (step S12: YES), the paper is fed in step S13. End the operation. In the present embodiment, the control unit 37 stops the rotation of the separation roller 33 and delivers the paper M to the first transport roller 31.

  On the other hand, when the paper leading end Me has not reached the point P0 even after the predetermined period has elapsed or the separation roller 33 has rotated once (step S12: NO), the control unit 37 determines that a paper feed failure has occurred, A retry operation is performed in the following processing.

  Therefore, the control unit 37 determines the current number of retries in step S14, and if the number of retries is equal to or less than the threshold value n (step S14: YES), the control unit 37 proceeds to step S16. In the determination of the number of retries in step S14, the control unit 37 determines whether or not the paper to be fed is jammed. In other words, when the paper M is jammed, the paper M is not fed even if the retry operation is repeated (the number of retries> n). Make a notification.

In step S <b> 16, the control unit 37 performs the first retry operation (first refeed operation) or the second retry operation (second refeed operation) based on the condition shown in the following equation (1). )

Paper length L2 <feed amount L1 of separation roller (1)

Here, the length in the transport direction of the sheet M1 is a value determined by the control unit 37 based on the size of the sheet M selected on the property screen at the start of printing, for example. For example, when “A4” is selected as the paper M (paper size: 210 mm × 297 mm) and the paper M is fed with the short side (side of 210 mm) intersecting the transport direction (y direction), the transport direction The length L2 at this point is “297 mm”.

  If the length L2 of the paper M in the transport direction is equal to or greater than the feed amount L1 (step S16: NO), the control unit 37 selects a normal retry operation in step S17. In the normal retry operation, the separation roller 33 and the transport rollers 31 and 32 are rotated to feed the paper M downstream in the transport direction as in the normal paper feed operation. In this embodiment, since the outer periphery of the separation roller 33 has a fan shape, after the separation roller 33 is rotated to the home position, the separation roller 33 is brought into contact with the paper M again to perform a refeed operation. In step S12, if the paper M is detected by the paper detection sensor 35, the process advances to step S13 to end the paper feeding operation. Of course, the normal retry operation is repeated until the paper detection sensor 35 detects the paper M (step S12: YES).

  On the other hand, when the length L2 in the transport direction of the sheet M is equal to or greater than the feed amount L1 (step S16: YES), the control unit 37 proceeds to step S18 and selects the irregular retry operation. In this irregular retry operation, a retry operation is performed so that a sheet not to be fed (M2 in FIG. 5) is not fed.

  FIG. 7 is a diagram for explaining the irregular retry. FIG. 7A is a flowchart (step S181) for explaining the irregular retry operation executed in step S18. FIG. 7B is a diagram for explaining the irregular retry operation. In the irregular retry operation illustrated in FIG. 7, the control unit 37 stops the rotation of the separation roller 33 and rotates only the first transport roller 31 and the second transport roller 32 to perform the paper feeding operation. That is, in this irregular retry operation, the sheet M1 is fed only by the first transport roller 31 and the separation roller 33 is not involved. Therefore, in the irregular retry operation, since the separation roller 33 does not rotate, it is possible to prevent the paper (M2) that is not the paper feed target from being fed.

  Thereafter, returning to step S12, when the paper detection sensor 35 detects the paper M (step S12: YES), the paper feeding operation is terminated (step S13), and the process proceeds to step S2 in FIG. On the other hand, when the paper detection sensor 35 does not detect the paper M (step S12: NO), the irregular retry operation is repeated again (step S18).

  As described above, in the printer 11 according to the first embodiment, when a paper feed failure occurs, the paper feed failure is determined based on the relationship between the paper length L2 and the feed amount L1 of the separation roller 33. Select the mode of retry operation to cancel. That is, when the paper length L2 is equal to or less than the feed amount L1, the paper M is fed again without rotating the separation roller 33 in the retry operation. Therefore, it is possible to prevent paper M other than the paper supply target from being fed regardless of the size of the paper M to be fed.

2. Second embodiment:
The condition for selecting the retry operation may be determined based on the relationship between the paper length L2 and the paper feed distance P in addition to the relationship between the paper length L2 and the feed amount L1 of the separation roller 33. FIG. 8 is a diagram illustrating a positional relationship between the rollers of the printer 11 and the paper M according to the second embodiment.

In the printer 11 shown in the second embodiment, when the paper M satisfying the paper feed distance P> paper length L2 is printed, the separation roller 33 and the first transport roller 31 cooperate to perform a paper feed operation. That is, as shown in FIG. 8, when feeding the paper M1 that satisfies the paper feed distance P> L2, even if the separation roller 33 is fed until the contact between the paper M1 and the separation roller 33 is released, The paper leading end Me has not reached the point P0. Therefore, the printer 11 is configured to send the paper M1 to the paper feed distance P by the rotation of the first transport roller 31 even after the contact between the separation roller 33 and the paper M1 is released. After the contact between the separation roller 33 and the sheet M1 is released, the part of the circumference of the separation roller 33 that is cut is positioned so as to face the sheet M2. Therefore, the sheet M2 and the separation roller 33 are located. And keeps rotating to the home position without abutting.
Note that the paper feed distance P may be an actual path distance in addition to the linear distance as shown in FIG. 8 because it may be a distance at which the leading end Me of the paper M1 is fed.

  When the retry operation is performed in the printer 11 having such a configuration, the retry operation is repeated for a predetermined period, whereby the separation roller 33 rotates beyond the home position and the circumferential portion comes into contact with the sheet M2 again. In some cases, the paper M2 is fed. Therefore, in the second embodiment, a retry operation for preventing the above problem is performed.

  FIG. 9 is a flowchart for explaining in detail the sheet feeding operation according to the second embodiment. The process shown in FIG. 9 differs in conditions for determining the retry operation as compared to the first embodiment.

  When a print command is input to the printer 11, in step S <b> 21, the control unit 37 drives the separation roller 33 and the transport rollers 31 and 32 to execute a paper feeding operation. In step S22, the control unit 37 determines whether or not the paper leading end Me has reached the point P0. Therefore, when the paper leading end Me has not reached the point P0 even after the predetermined period has elapsed or the separation roller 33 has rotated once (step S22: NO), the control unit 37 determines that a paper feed failure has occurred, and A retry operation is performed in the above process.

In step S24, the controller 37 determines the current number of retries. If the number of retries is equal to or less than the threshold value n (step S24: YES), the control unit 37 proceeds to step S26. In step S26, the control unit 37 selects either the normal retry operation or the irregular retry operation based on the condition shown in the following equation (2).

Paper length L2 <paper feed distance P (2)

Here, since the paper feed distance P has a different value for each printer 11, it is necessary to set in advance according to the shape of the printer 11 to be used. Further, the length of the paper M in the transport direction is determined based on the paper shape set as a print target, as in the first embodiment.

  If the length L2 of the paper M in the transport direction is equal to or longer than the paper feed distance P (step S26: NO), the control unit 37 selects a normal retry operation in step S27. For paper M where paper length L2> feed distance P, the paper M is fed by the rotation of the separation roller 33, so the normal retry operation is the same as that described in the first embodiment. In step S22, if the paper M is detected by the paper detection sensor 35, the flow advances to step S23 to end the paper feeding operation.

  On the other hand, when the length L2 in the transport direction of the paper M is equal to or shorter than the paper feed distance P (step S26: YES), the control unit 37 proceeds to step S28 and selects the irregular retry operation. For the paper M where the paper length L2 <the paper feeding distance P, the separation roller 33 is separated from the paper M during the paper feeding process, and a period during which paper feeding is performed only by the first transport roller 31 occurs. This aspect is the same as that shown in the first embodiment. That is, in the irregular retry operation according to the second embodiment, the control unit 37 stops the rotation of the separation roller 33 and rotates only the first transport roller 31 and the second transport roller 32 to feed the sheet. I do. That is, in this irregular retry operation, the sheet M is fed only by the first transport roller 31.

  Thereafter, returning to step S22, when the paper detection sensor 35 detects the paper M (step S22: YES), the paper feeding operation is terminated (step S23), and the process proceeds to step S2 in FIG. On the other hand, if the paper detection sensor 35 does not detect the paper M (step S22: NO), the irregular retry operation is repeated again (step S28).

  As described above, in the printer 11 according to the second embodiment, even when the paper length L2 feeds the paper M shorter than the paper feed distance P inside the printer 11, the feeding operation is performed in the retry operation. It is possible to prevent paper M that is not a paper target from being fed.

3. Other embodiments:
There are various embodiments of the present invention.
The shape of the separation roller 33 is not limited to a shape in which a part of the circumference is cut. That is, the separation roller 33 may have a circular cross section in the rotation direction.
The number of transport rollers used by the printer 11 is not limited to that shown in the embodiment.

  Needless to say, the present invention is not limited to the above embodiments. That is, the mutually replaceable members and configurations disclosed in the above embodiments are applied by changing their combinations as appropriate. The members and configurations disclosed in the examples can be replaced with the members and configurations interchangeable with each other as appropriate, and the combination thereof is changed and applied. It is one of the present invention that a person skilled in the art can appropriately substitute the members and configurations that can be assumed as substitutes for the members and configurations disclosed in the above-described embodiments based on the above, and change the combination to apply. It is disclosed as an example.

  DESCRIPTION OF SYMBOLS 11 ... Printer, 12 ... Main body case, 13 ... Guide shaft, 14 ... Carriage, 15 ... Timing belt, 16, 17 ... Pulley, 18 ... CR motor, 19 ... Recording head, 20 ... Platen, 21, 22 ... Ink cartridge, 23 ... Paper feed tray, 25 ... PF motor, 26 ... Linear encoder, 31 ... First transport roller, 32 ... Second transport roller, 33 ... Separation roller, 34 ... Paper discharge roller, 35 ... Paper detection sensor, 37 ... Control unit, 38 ... Operation buttons, 39 ... Monitor

Claims (3)

A printing apparatus that performs a paper feeding operation of rotating a first roller to feed a paper to a predetermined position on a conveyance path,
A second roller that is disposed downstream of the first roller in the conveying direction and conveys the paper;
A third roller that is disposed downstream of the second roller in the transport direction and transports the paper;
A paper detection sensor that is disposed at the predetermined position on the third roller side relative to the second roller and outputs a signal for completing a paper feeding operation by detecting paper;
When the paper feeding operation is executed and the paper is not sent to the paper detection sensor ,
Paper length L2 in the paper feed direction ≧ first roller feed amount L1,
If so, the paper is fed in a first refeed operation that rotates the first roller and the second roller,
Paper length L2 in the paper feed direction <feed amount L1 of the first roller,
If so, refeed operation execution means for feeding the paper in a second refeed operation in which the first roller is not rotated but the second roller is rotated is provided. Characteristic printing device.   The refeed operation execution means performs an error notification indicating a paper feed failure when either the first refeed operation or the second refeed operation is repeated a predetermined number of times. The printing apparatus according to claim 1. Rotate the first roller and the second roller on the downstream side of the transport path compared to the first roller to rotate the paper to the downstream side of the transport path compared to the second roller on the transport path A paper feeding step for performing a paper feeding operation for feeding paper to a paper detection sensor arranged on a third roller side ;
When the paper feeding operation is executed and the paper is not sent to the paper detection sensor ,
Paper length L2 in the paper feed direction ≧ first roller feed amount L1,
If the rotation of the first roller, is feeding the sheet in the first re-feeding operation to perform a rotation of said second roller,
Paper length L2 in the paper feed direction <feed amount L1 of the first roller,
If so, a refeed operation step of feeding the paper in a second refeed operation that does not rotate the first roller but rotates the second roller;
And an image forming step of carrying out printing by conveying the fed paper.

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