JP2005004072A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of void due to the moisture absorption of paper by detecting and ejecting in advance a paper part which has absorbed moisture in an image forming apparatus using roll paper as a transfer material. <P>SOLUTION: In the image forming apparatus, a transfer means 36 transfers an image formed on an image carrier 33 to the transfer material supplied and transported by paper feeding/transporting means 70 to 75, and fixing means 34 and 35 fix the transferred image. The image forming apparatus is provided with means 76 and 77 for cutting and feeding the roll paper in accordance with a paper size by using a plurality of paper rolls 78 to 80 as the transfer material, and detects the moisture absorption level of the roll paper by utilizing temperature and humidity information from a temperature/humidity sensor 83 which is arranged in a paper feeding part 82. The moisture absorption time of the roll paper is calculated from the temperature and humidity information detected by the temperature/humidity sensor 83, so that the paper length part of the roll paper which has absorbed moisture is automatically cut and ejected in accordance with the calculated time. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine, a printer, a plotter, a facsimile machine, a printing machine, and the like, and in particular, image formation corresponding to the problem of moisture absorption when using a roll wound paper as a transfer material. Relates to the device.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an image forming apparatus such as a copying machine or a printer, an image carrier made up of a photosensitive member or the like is uniformly charged by a charging means, and then the image carrier is exposed by exposure of an original image or optical writing in accordance with an image signal. An electrostatic latent image is formed on the surface, the electrostatic latent image is visualized with a developer (for example, toner) of a developing unit, and the visualized image is fed and conveyed by a transfer material feeding and conveying unit The image is transferred onto the material by the transfer means, and the image transferred to the transfer material is fixed by the fixing means.
[0003]
In this type of image forming apparatus, when a roll-shaped paper (roll paper) is used as a transfer material, the roll paper is exposed to the outer periphery of the roll paper depending on the season if it is put in the machine for a long time. When the portion absorbs moisture and the absorbed paper portion is fed as transfer paper, the toner image is placed on the transfer paper when the transfer means transfers the image (toner image) from the image carrier to the transfer paper. There was a problem that it was white.
Therefore, conventionally, as a countermeasure, a heater is provided in a paper feeding unit that stores roll paper or the like, and the paper is always kept warm by the heater, thereby preventing moisture absorption and taking measures against white spots. However, when the heater is arranged in the sheet feeding unit, the cost of the image forming apparatus is high, and the heater is energized even when the image forming apparatus is not used.
[0004]
[Problems to be solved by the invention]
The present invention has been made in view of the above circumstances, and in an image forming apparatus using roll paper as a transfer material, a problem of white spots due to moisture absorption of the transfer paper is detected by detecting and discharging the moisture absorbed paper portion in advance. The purpose is to eliminate.
[0005]
[Means for Solving the Problems]
As a means for achieving the above object, according to the present invention, after the image carrier is uniformly charged by the charging means, the original image is exposed on the image carrier or optically written according to the image signal. An electrostatic latent image is formed, the electrostatic latent image is visualized by a developer of a developing unit, and the visualized image is transferred onto a transfer material fed and conveyed by a transfer material feeding and conveying unit. An image forming apparatus for transferring and fixing an image transferred to a transfer material by a fixing unit, wherein a roll (roll paper) is used as the transfer material, and a roll containing at least one roll paper A paper feeding unit and means for cutting and feeding the roll paper according to the paper size, a temperature / humidity sensor is disposed in the roll paper feeding unit, and the roll paper is detected by temperature / humidity information from the temperature / humidity sensor. Of moisture absorption detection In the image forming apparatus, the moisture absorption time of the roll paper is calculated from the temperature / humidity information detected by the temperature / humidity sensor, and the absorbed paper length of the roll paper is automatically cut and discharged according to the calculated time. It is characterized (claim 1).
[0006]
Further, according to the present invention, the image forming apparatus having the above configuration includes an operation unit input unit that inputs paper information such as a paper type, and automatically calculates the moisture absorption time of the roll paper in conjunction with the operation unit input unit. According to the calculation time, the sheet length portion of the roll sheet that has absorbed moisture is automatically cut and discharged (Claim 2).
According to the present invention, the image forming apparatus having the above-described configuration includes an operation unit input unit that inputs paper information such as a paper thickness or a paper width, and automatically operates the moisture absorption time of the roll paper in conjunction with the operation unit input unit. The paper length portion of the roll paper that has absorbed moisture is automatically cut and discharged according to the calculation time (claim 3).
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention, and shows an example of a digital copying machine using paper (roll paper) wound in a roll shape as a transfer material. FIG. 2 shows a schematic configuration of the main part of the control unit of the electrical system of the digital copying machine.
This copier mainly comprises a main body-side paper supply section (paper feed tray) 82, an image forming section (image forming unit) 81, a document feeder (ADF) 11 mounted on the upper portion of the main body, and a reading section 17. Has been.
[0008]
A document transport device (ADF) 11 transports a sheet-shaped document S to a reading position, and an operation mode (rear discharge mode / front discharge) set in advance according to the thickness (strength of stiffness) of the document S. Mode / winding mode), the document S after reading is conveyed in the direction a and discharged to the first document discharge tray 26 at the rear (rear side) of the apparatus, or the document S after reading inversion is c direction. To the second document discharge tray 12 at the front (front side) of the apparatus, or after reading the document S guided to the first document discharge tray 26 at the rear of the apparatus by the take-up and storage guide 27 b It winds in the direction. Further, when the user rotates and moves the winding and storing guide 27 upward, the trailing end of the document after winding is separated from the apparatus housing, and the document S is moved from above or from the side of the storing guide 27 at the user operation position. It is taken out. Here, the front of the apparatus (front side) is the direction of the display screen of the operation unit 51, and the rear of the apparatus (back side) is the opposite side of the display screen of the operation unit 51, that is, in the rear paper discharge mode. This is the first document discharge tray 26 side for discharging the document S.
[0009]
The upper unit of the ADF 11 is connected to the lower unit by a connecting member such as a hinge (not shown) so as to be opened and closed in the vertical direction. An operation unit 51 and a second document discharge tray 12 are mounted on the upper part of the upper unit so as to face the front of the apparatus, and a winding storage guide 27 swings between the upper surface and the rear surface of the unit at the rear end. Supported as possible. The take-up storage guide 27 is connected to the upper unit by a connecting means including a support member that supports the support shaft 29, and can be rotated around the support shaft 29. It is configured to be movable between a position (a set position of the winding storage guide 27 shown in FIG. 1) and a take-out position in front of the apparatus (front side). The second document discharge tray 12 is made of a metal wire formed in a comb-teeth shape. The second document discharge tray 12 is inclined at the upper part of the upper unit from the rear to the front of the unit. Then, it is stored so as to be removable at the user operation position in front of the apparatus.
[0010]
As shown in FIG. 2, the operation unit 51 includes a key group 30 such as a start key, a numeric keypad, a clear / stop key, an initial setting key, a mode key, and a liquid crystal touch panel 57, and sets each operation mode by a user operation. And an operation start / stop instruction. Further, the liquid crystal touch panel 57 has an input operation unit including function keys that appear as appropriate for each screen, and a display unit that displays a message indicating the number of copies, device status, and the like. The setting content of the operation mode by the user operation is transmitted from the operation unit 51 to the main controller 61.
[0011]
The reading unit 17 is a scanner unit including a mirror, a light source, an imaging lens, a shading plate, a photoelectric conversion element (CCD image sensor), a scanner motor, and the like (not shown). Light is irradiated from above the transport path, and the reflected light is imaged on the light receiving surface of the CCD image sensor via a mirror and an imaging lens, and the image surface is sequentially converted into an image signal (image data).
[0012]
A branching claw (not shown) is disposed in the vicinity of the downstream side of the conveyance roller 14 (near the conveyance roller 14 between the conveyance roller 14 and the first document discharge tray 26), and is based on a preset operation mode. It is driven by a suction / release operation of a solenoid mechanism (not shown). The branching claws branch the read document to the second document discharge tray 12 side in the front discharge mode, and the read document in the first document discharge tray 26 in the rear discharge mode and the winding mode. Branch to the side.
[0013]
On the other hand, a document table 20 is disposed on the front upper surface of the lower unit, and a first document discharge tray 26 is protruded and attached to the rear rear surface of the unit. The document table 20 places the document S on the image surface upward, and guides the document S inserted from the front of the apparatus to the nip portion of the transport roller 13.
The registration sensor 18 is an optical reflective sensor disposed in the vicinity of the upstream of the reading unit 17. The registration sensor 18 detects that the leading edge of the document has reached the reading unit 17 and is turned on. Become. Based on the rear end detection timing of the registration sensor 18, the branch claw restoration process and the conveyance motor 43 stop process in the rear paper discharge mode are performed.
[0014]
The first document discharge tray 26 is made of a metal wire that is inclined so as to become higher toward the downstream in the transport direction and is formed in a comb-like shape, and is discharged in a stretched state from the discharge port downstream of the transport roller 14 to the rear of the apparatus. Store the original as it is. When the take-up and storage guide 27 is in the take-up position, the comb-like wire of the first document discharge tray 26 is also used as a receiving port (guide means) of the take-up and storage guide 27.
The transport driving rollers 13 to 15 and the backup roller 16 are stepping motors, and are supplied with a power supply voltage from the apparatus main body, and both rotate forward and backward by driving the transport motor 43.
[0015]
On the other hand, the image forming unit 81 is centered on a drum-shaped photoconductor 33 that is an image carrier, and a charging charger that uniformly charges the photoconductor 33 in the order of the electrophotographic process around the photoconductor 33. 31, a writing unit (not shown) for forming an electrostatic latent image on the photosensitive member 33 by optical writing in accordance with an image signal from the document reading unit 17, and developing the electrostatic latent image on the photosensitive member 33 with a developer (for example, A developing unit 32 that develops the toner image with a toner), a transfer charger 36 that transfers the developed image on the photosensitive member to a transfer material, a separation charger 37 that separates the transferred transfer material from the photosensitive member, and the like are provided. Has been. The writing unit constitutes a laser writing optical system including a laser output unit (including a laser diode, a collimating lens, a polygon mirror, etc.), an imaging lens, a mirror, or the like, or is connected to a light emitting diode (LED) array. An LED array writing optical system combining an image element array and the like is configured.
[0016]
A paper feed unit (paper feed tray) 82 is provided in the lower part of the image forming unit 81, and transfer paper (first paper) wound in a plurality of rolls as a transfer material is provided in the paper feed tray 82. (Third roll paper) 78 to 80 are mounted so as to be freely drawn out, and a vertical transport unit (including paper feed rollers 71 to 75 and paper feed cutters 76 and 77), which is a common transfer material paper feed transport means, is provided. Then, the transfer sheet cut according to the length of the original from the selected roll sheet is fed and conveyed to the transfer position side of the photoconductor 33. Further, downstream of the transfer position of the photosensitive member 33 in the transport direction, a transport unit (transport belt or transport roller) (not shown), a fixing unit (such as the fixing roller 35 and the pressure roller 34), and discharge rollers 38 and 39 are included. A paper discharge unit and paper discharge trays 40 and 41 are provided in this order. In addition, as the first to third roll papers 78 to 80, paper types (plain paper, tressing paper, film, recycled paper, etc.), paper widths, or paper thicknesses which are different are loaded, which will be described later. The operation unit 51 is appropriately selected by the liquid crystal touch panel 57 or the like.
[0017]
With the above configuration, the first to third roll papers 78 to 80 have the original length detected on the ADF 11 side (or the paper type and paper size (paper width and length) input from the operation unit 51). Accordingly, it is selected / cut and conveyed to the transfer position of the photosensitive member 33 by the vertical conveying unit. On the other hand, on the side of the photosensitive member 33 that is rotationally driven in the sub-scanning direction, an electrostatic latent image is formed by optical writing in the main scanning direction by the writing unit, and a toner image is formed by developing by the developing unit 32. . The cut transfer paper transported by the vertical transport unit is synchronized with the leading edge of the toner image by a registration roller 70 driven at the same speed as the photoreceptor 33 and a transport means (transport belt or transport roller) (not shown). The toner image is transferred and transferred. The transferred transfer paper is subjected to a fixing process by the fixing unit, and is then discharged onto the discharge trays 40 and 41 via the discharge rollers 38 and 39 according to the size of the transfer sheet.
[0018]
Next, the hardware configuration of the electrical control system shown in FIG. 2 will be described.
In addition to the operation unit 51 and the ADF 11, an image processing unit (not shown) is connected to the main controller 61 that controls the entire digital copying machine. These distributed control devices and the main controller 61 exchange machine states, operation commands, and the like as necessary. Furthermore, a conveyance motor 43 necessary for conveying the document S, a sheet feeding motor 84 necessary for feeding and conveying the transfer sheet, sheet feeding cutters 76 and 77 for cutting roll sheets, and various motors (not shown) (photosensitive member, developing roller, Fixing rollers, conveying means, driving motors for each part such as a discharge roller), various clutches, and the like are connected to the main controller 61 via an input / output unit (I / O) 63. A registration sensor 18 that detects document position information necessary for driving the conveyance motor 43 and various clutches is connected to the main controller 61 via an input / output unit (I / O) 63. Further, an optical reflection type document size sensor 64 for detecting the size of the document to be inserted / conveyed is provided in the document insertion portion of the ADF 11. A temperature / humidity sensor 83 is disposed in the paper feed tray 82 that stores the first to third roll papers 78 to 80, and the temperature / humidity sensor 83 is connected via an input / output unit (I / O) 63. Connected to the main controller 61.
[0019]
The main controller 61 includes a central processing unit (CPU) including a microprocessor (microcomputer), a memory (RAM / ROM), various control circuits, an A / D converter, a clock, a counter, a timer, and the like. 18, 64, 83 detection signals, status signals of various motors such as the conveyance motor 43 and paper feed motor 84, status signals of various clutches, setting signals of the operation unit 51, and the like. Control of various motors such as drive control of various clutches, control of various parts such as charging, writing, developing, and transfer, and display control of the liquid crystal touch panel 57 in the operation unit 51 are performed. In addition, the memory (RAM / ROM) of the main controller 61 includes operation modes (including front discharge mode / rear discharge mode / winding mode and correction mode) input and set from the operation unit 51, and paper information. (Paper type (plain paper, tressing paper, film, recycled paper, etc.), paper size (paper width, length), paper thickness, etc.) are stored, and the stored contents are stored each time the operation mode or paper information is changed. Configured to update.
[0020]
A paper feed motor 84 for rotating the paper feed rollers 71 to 75 is connected to the main controller 61 via an input / output unit (I / O) 63. The count value of the number is in accordance with the transport amount of the paper feed rollers 71 to 75, and by multiplying the transport amount per pulse of the paper feed rollers 71 to 75 by the count value, the length of the roll paper fed out. You can ask for it. Therefore, when the number of counted pulses is compared with a preset setting value (measured original length detected at the time of inserting the original or the length according to the paper size set on the operation unit), they match. Stops the paper feed motor 84 and cuts one of the roll papers 78 to 80 by one of the paper feed cutters 76 and 77. As a result, a cut transfer sheet having the same length as the document length stored in the memory or the set sheet size can be obtained.
[0021]
On the other hand, if the counted number of pulses does not match the preset value, it is determined that there is a deviation in the conveyance due to the rotation of the paper feed motor 84, and correction processing is performed. In other words, the number of document lines stored in the memory (or the set paper size length) is L, the counted number of pulses is X, and the document length detected at the time of document insertion (or the set paper size length). If the number of pulses corresponding to is P,
L1 = L * (X / P)
After the roll paper is conveyed only by this amount, the paper feed motor 84 is stopped and the roll paper is cut by the paper feed cutters 76 and 77. As a result, it is possible to absorb the conveyance deviation and obtain a cut transfer sheet having the same length as the document length (or the set sheet size length) stored in the memory.
[0022]
As described above, as an embodiment of the image forming apparatus according to the present invention, an example of a digital copying machine using roll paper has been described. In this type of image forming apparatus, when roll paper 78 to 80 is used as a transfer material, If the roll paper is kept in the machine for a long time, depending on the season, the portion exposed to the outer periphery of the roll paper 78 to 80, particularly the portion exposed to the outer peripheral surface of each roll paper 78 to 80, the feed roller 72, When the portion drawn to 73 and 75 absorbs moisture, and the absorbed paper portion is fed as transfer paper, the toner is transferred when the transfer charger 36 transfers the toner image from the photosensitive member 33 to the transfer paper. There was a problem in that the image was not white on the transfer paper and was white. Therefore, in the present invention, the temperature / humidity sensor 83 is disposed in the vicinity of the roll paper 78 to 80 in the paper feed unit (paper feed tray) 82, and the temperature / humidity sensor 83 is connected via the input / output unit (I / O) 63. The main controller 61 is connected. The main controller 61 is configured to detect the moisture absorption of the roll paper 78 to 80 based on the temperature and humidity information from the temperature and humidity sensor 83, and the moisture absorption of the roll paper 78 to 80 based on the temperature and humidity information detected by the temperature and humidity sensor 83. The time is calculated, and the paper length portion of the roll paper that has absorbed moisture is automatically cut by the paper feed cutters 76 and 77 in accordance with the calculated time.
[0023]
More specifically, information input to the controller 61 from the greenhouse sensor 83 is digitized by an A / D converter (not shown) in the controller 61 and input to the CPU. The CPU converts the input data into temperature / humidity data, sets a moisture absorption determination time corresponding to the temperature / humidity from a data table set in advance and stored in the memory, and starts a timer. If the count of the timer exceeds the set time, the roll paper is affected by moisture absorption. Therefore, the paper portion affected by moisture absorption at the start of printing by the image forming unit 81 is detected by the paper feed rollers 72, 73 or 75. The sheet is fed out and the absorbed portion is cut by the paper feed cutter 76 or 77 to discharge the blank paper, and then printing is started. If the timer count does not exceed the set time, the sheet is not yet affected by moisture absorption, and a normal printing operation is started.
[0024]
Here, FIGS. 3 and 4 show an example of a control flow processed by the CPU of the controller 61, and show a control example of the moisture absorption determination described above. That is, the information of the greenhouse sensor 83 is read and converted into temperature / humidity data (S11), and the moisture absorption determination time (timer count value) corresponding to the temperature / humidity is set in advance from a data table stored in the memory. Set (S12), start the timer (S13). Then, it is determined whether or not the moisture absorption time (timer count) exceeds a set value (S14), and if it exceeds, a blank paper discharge flag is set (S15). When an image output request is made (S21), it is determined whether or not the blank paper discharge flag is set (S22). If the blank paper discharge flag is set, the roll paper 78 to 80 is set. The paper is fed by the paper feed rollers 72, 73, or 75 by the cut size of the roll paper selected from the above, cut by the paper feed cutter 76 or 77, and discharged as white paper (S23), and then the printing operation is performed. (S24). If the moisture absorption time does not exceed the determination time and the blank paper discharge flag is not set, the normal printing operation is started as it is (S25). With the above control operation, the moisture-absorbed portion of the roll paper is not used for image transfer but is discharged as a white paper to the paper discharge unit, so that the problem of white spots due to moisture absorption of the transfer paper can be solved.
[0025]
Next, FIG. 5 shows a display example of the liquid crystal touch panel 57 of the operation unit 51, and is an example in which the liquid crystal touch panel 57 is used as an operation unit input means for paper type and paper thickness.
As shown in FIG. 5, the type of roll paper (plain paper, tressing paper, film, recycled paper, etc.) and the thickness of the roll paper are input by the liquid crystal touch panel 57 of the operation unit 51 and stored in the memory of the controller 61. The In this example, the moisture absorption time of each sheet based on the sheet type and sheet thickness information is calculated as described above from the data table that is created in advance based on the sheet type and sheet thickness information and stored in the memory. Set the judgment time. Thereafter, the control flow shown in FIGS. 3 and 4 is executed to correspond to the paper portion affected by moisture absorption. In other words, the moisture absorption time of the roll paper is automatically calculated in conjunction with the paper information such as the paper type and paper thickness input from the liquid crystal touch panel 57 of the operation unit 51, and the control flow shown in FIGS. According to the calculated time, the paper length portion of the roll paper that has absorbed moisture is automatically cut and discharged. As a result, the moisture absorption part of the roll paper is cut according to the paper type and paper thickness, and it is discharged as blank paper without being used for image transfer. And the problem of white spots due to moisture absorption of the transfer paper can be solved. In the above example, the paper information such as the paper type and the paper thickness is used. However, the moisture absorption time of the roll paper may be automatically calculated according to the paper information combined with the paper width.
[0026]
【The invention's effect】
As described above, in the image forming apparatus according to the present invention, the moisture absorption time of the roll paper is calculated from the temperature / humidity information detected by the temperature / humidity sensor, and the moisture absorption sheet length portion of the roll paper is determined according to the calculation time. Since the paper is automatically cut and discharged, the problem of white spots due to moisture absorption of the transfer paper can be solved.
The image forming apparatus according to the present invention further includes an operation unit input unit for inputting paper information such as a paper type, a sheet thickness, and a paper width, and interlocks with the operation unit input unit to reduce the moisture absorption time of the roll paper. Automatically calculates and automatically absorbs the paper length that is absorbed by the roll paper according to the calculation time, so it can be handled even if the paper type, paper thickness, paper width, etc. change. The problem of white spots due to moisture absorption of the paper can be solved.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an image forming apparatus showing an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a schematic configuration of a control unit of the image forming apparatus illustrated in FIG.
FIG. 3 is a diagram showing an example of a control flow processed by the controller shown in FIG. 2;
4 is a diagram showing an example of a control flow processed by the controller shown in FIG. 2. FIG.
FIG. 5 is a diagram illustrating a display example of a liquid crystal touch panel of an operation unit used as an operation unit input unit for paper type, paper thickness, and the like.
[Explanation of symbols]
11: ADF
17: Reading unit 30: Key group 31: Charging charger (charging means)
32: Development unit (development means)
33: Photoconductor (image carrier)
34: Pressure roller 35: Fixing roller 36: Transfer charger (transfer means)
37: separation charger 38, 39: paper discharge roller 40, 41: paper discharge tray 43: document transport motor 51: operation unit 57: liquid crystal touch panel 61: main controller 63: input / output unit (I / O)
64: Document size sensor 70: Registration rollers 71-75: Paper feed rollers 76, 77: Paper feed cutters 78-80: Roll paper 81: Image forming unit 82: Paper feed tray (paper feed unit)
83: Temperature / humidity sensor 84: Paper feed motor

Claims (3)

After the image carrier is uniformly charged by the charging means, an electrostatic latent image is formed on the image carrier by exposure of the original image or optical writing according to the image signal, and the electrostatic latent image is developed. The developer is visualized by the developer, the visualized image is transferred onto the transfer material fed and conveyed by the transfer material feeding and conveying means, and the image transferred to the transfer material is transferred by the fixing means. An image forming apparatus for fixing, wherein a roll-rolled paper (roll paper) is used as the transfer material, and a roll paper feeding unit that stores one or more of the roll paper, and roll paper according to the paper size. In an image forming apparatus comprising a means for cutting and feeding, a temperature / humidity sensor disposed in the roll paper feed unit, and detecting the moisture absorption of the roll paper based on temperature / humidity information from the temperature / humidity sensor;
Image forming is characterized in that the moisture absorption time of the roll paper is calculated from the temperature / humidity information detected by the temperature / humidity sensor, and the paper-absorbed length of the roll paper is automatically cut and discharged according to the calculated time. apparatus. The image forming apparatus according to claim 1.
An operation unit input means for inputting paper information such as a paper type is provided. In conjunction with the operation unit input means, the moisture absorption time of the roll paper is automatically calculated, and the paper length of the roll paper absorbed according to the calculation time is calculated. An image forming apparatus characterized in that a portion is automatically cut and discharged. The image forming apparatus according to claim 1.
An operation unit input means for inputting paper information such as paper thickness or paper width is provided. In conjunction with the operation unit input means, the moisture absorption time of the roll paper is automatically calculated, and the roll paper is absorbed according to the calculation time. An image forming apparatus that automatically cuts and discharges a long paper portion.

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