Feed device and image formation system with the same

Abstract

To suppress sheets from being fed one over the other while suppressing an increase in power consumption.SOLUTION: A feed device comprises: a set plate; a feed part; a fan for blowing air to a sheet on the set plate; a heater for heating the air blown to the sheet; a control part; and a temperature / humidity sensor. On receiving a feed start instruction, the control part recognizes an internal environment of the feed device if a sheet to be fed by the feed part is coat paper, and performs condition determination processing as to whether the internal environment meets predetermined conditions. When determining that the predetermined conditions are met, the control part starts driving the fan and the heater and then causes the feed part to start feeding the sheet. When the feeding of the sheet is completed, the control part stops driving the heater and continues to drive the fan without reference to whether or not the internal environment meets the predetermined conditions.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a feeding device and an image forming system including the same.

Background Art

[0002] During printing by an image forming apparatus, sheets are fed one by one from a stack of a plurality of set sheets. The image forming apparatus prints an image on the fed sheet.

[0003] Here, there are various types of sheets. For example, when the sheet is coated paper, it is difficult to separate the set sheets from each other. If the set sheets are not separated from each other, there is a problem that double feeding occurs during sheet feeding.

[0004] Therefore, some conventional image forming apparatuses apply warm air to the set sheets to dehumidify them. Such an image forming apparatus is disclosed in, for example, Patent Document 1.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By applying warm air to the set sheets to dehumidify them, double feeding of the sheets is suppressed. However, there is a problem that power consumption increases.

[0007] The present invention has been made to solve the above problems, and an object thereof is to provide a feeding device capable of suppressing an increase in power consumption while suppressing double feeding of sheets and an image forming system including the same.

Means for Solving the Problems

[0008] In order to achieve the above object, a sheet feeding device according to a first aspect of the present invention includes a setting plate on which a sheet is set, a feeding unit that feeds the sheet from the setting plate, a fan that blows air onto the sheet on the setting plate, a heater that heats the air blown onto the sheet on the setting plate, a control unit that controls the feeding of the sheet by the feeding unit, and a temperature and humidity sensor that detects the internal temperature and internal humidity of the sheet feeding device. When receiving a feeding start command from the sheet feeding destination, if the sheet to be fed by the feeding unit is coated paper, the control unit recognizes the internal environment of the sheet feeding device based on the output of the temperature and humidity sensor, and performs a condition determination process on whether the internal environment satisfies a predetermined condition. When it is determined in the condition determination process that the predetermined condition is satisfied, the control unit starts driving the fan and the heater, and then starts feeding the sheet to the feeding unit. When the feeding of the sheet in the state where the fan and the heater are driven is completed, the control unit stops driving the heater regardless of whether the internal environment satisfies the predetermined condition, and continues driving the fan.

[0009] An image forming system according to a second aspect of the present invention includes the above sheet feeding device and an image forming device connected to the sheet feeding device. The sheet feeding device feeds a sheet to the image forming device. The image forming device performs printing on the sheet fed from the sheet feeding device.

Advantages of the Invention

[0010] In the configuration of the present invention, it is possible to suppress double feeding of the sheet while suppressing an increase in power consumption.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0012] Hereinafter, with reference to FIGS. 1 to 10, a feeding device 100 according to an embodiment of the present invention and an image forming system 100S including the same will be described.

[0013] <Configuration of the Image Forming System> The feeding device 100 has an appearance as shown in FIG. 1. The feeding device 100 is connected to the image forming device 1000 as shown in FIG. 2. By being connected to the image forming device 1000, the feeding device 100 constitutes an image forming system 100S together with the image forming device 1000. FIG. 2 is a schematic diagram of the image forming system 100S (that is, the feeding device 100 connected to the image forming device 1000). FIG. 2 corresponds to the case where the image forming system 100S is viewed from the front.

[0014] The feeding device 100 is installed on the floor together with the image forming device 1000. The direction perpendicular to the floor surface (flat surface) on which the feeding device 100 is installed is the vertical direction of the feeding device 100.

[0015] The feeding device 100 may be detachable from the image forming apparatus 1000. The feeding device 100 is, for example, an optional device. The feeding device 100 is arranged on the right side of the image forming apparatus 1000 when viewed from the front of the image forming apparatus 1000.

[0016] The feeding device 100 accommodates the sheet S. The type of the sheet S is not particularly limited. Various sheets S such as plain paper and coated paper can be accommodated in the feeding device 100. The feeding device 100 feeds the sheet S to the image forming apparatus 1000.

[0017] The feeding device 100 feeds the sheet S from the right side of the image forming apparatus 1000 toward the image forming apparatus 1000. In the following description, the symbol Df is attached to the feeding direction of the sheet S by the feeding device 100. The direction parallel to the feeding direction Df is the left - right direction of the feeding device 100. The upstream side of the feeding direction Df is the right side of the feeding device 100, and the downstream side of the feeding direction Df is the left side of the feeding device 100.

[0018] Note that the feeding direction Df is one direction of the horizontal direction orthogonal to the up - down direction. The direction orthogonal to the feeding direction Df horizontally corresponds to the width direction of the feeding device 100. In the following description, the symbol Dw is attached to the width direction of the feeding device 100. The width direction Dw is also the front - rear direction of the feeding device 100.

[0019] The image forming apparatus 1000 prints an image on the sheet S fed from the feeding device 100. The printing method of the image forming apparatus 1000 is an electrophotographic method. The printing method of the image forming apparatus 1000 may be an ink - jet method.

[0020] <Configuration of the image forming apparatus> The image forming apparatus 1000 conveys the sheet S fed from the feeding device 100 along the conveyance path. The image forming apparatus 1000 prints an image on the sheet S being conveyed. In FIG. 2, the conveyance path of the sheet S is indicated by a dashed arrow.

[0021] The image forming apparatus 1000 includes a photoreceptor drum 1001 and a transfer roller 1002. The photoreceptor drum 1001 carries a toner image on its circumferential surface. The transfer roller 1002 is pressed against the photoreceptor drum 1001 to form a transfer nip therebetween. The transfer roller 1002 rotates together with the photoreceptor drum 1001. When the sheet S being conveyed enters the transfer nip, transfer processing for the sheet S is performed, and the toner image is transferred to the sheet S.

[0022] Although not shown, the image forming apparatus 1000 further includes a charging device, an exposure device, and a developing device. The charging device charges the circumferential surface of the photoreceptor drum 1001. The exposure device forms an electrostatic latent image on the circumferential surface of the photoreceptor drum 1001. The developing device develops the electrostatic latent image on the circumferential surface of the photoreceptor drum 1001 into a toner image.

[0023] The image forming apparatus 1000 includes a fixing roller pair 1003. The fixing roller pair 1003 includes a heating roller and a pressure roller. The heating roller incorporates a heater. The pressure roller is pressed against the heating roller to form a fixing nip therebetween. The pressure roller rotates together with the heating roller. When the sheet S being conveyed enters the fixing nip, fixing processing for the sheet S is performed, and the toner image is fixed to the sheet S. The sheet S that has passed through the fixing nip is discharged to a discharge tray ET.

[0024] Note that the image forming apparatus 1000 includes a feed roller 1004. The feed roller 1004 feeds the sheet S from a sheet cassette CA within the main body of the image forming apparatus 1000 to a conveyance path. That is, the image forming apparatus 1000 can also print on the sheet S set in the sheet cassette CA.

[0025] Also, the image forming apparatus 1000 includes an image reading device 1005. The image reading device 1005 reads a document and generates image data of the document. The image forming apparatus 1000 can print an image based on the image data of the document on the sheet S (i.e., copy the document).

[0026] <Configuration of the Feeding Device> As shown in FIG. 3, the feeding device 100 includes a front frame Ff and a rear frame Fr that are arranged to face each other in the width direction Dw. The front frame Ff and the rear frame Fr are made of sheet metal. The front frame Ff is arranged on the front side, and the rear frame Fr is arranged on the rear side.

[0027] The feeding device 100 has a sheet storage area in the region between the front frame Ff and the rear frame Fr in the width direction Dw. The sheet storage area is covered by an upper surface cover CV (see FIGS. 1 and 2) from above. That is, the feeding device 100 includes the upper surface cover CV. The upper surface cover CV corresponds to the "cover".

[0028] The upper surface cover CV is rotatably supported with respect to the front frame Ff and the rear frame Fr. The upper surface cover CV is rotatable about an axis extending in the width direction Dw. The upper surface cover CV rotates with the left end as a fulcrum and the right end swinging up and down. In other words, the upper surface cover CV opens and closes with respect to the upper opening of the sheet storage area. Further in other words, the upper surface cover CV is supported so as to be openable and closable.

[0029] The feeding device 100 includes a set plate 1. The set plate 1 is made of sheet metal. The set plate 1 is arranged between the front frame Ff and the rear frame Fr in the width direction Dw. The sheet S is set on the set plate 1. That is, the area on the set plate 1 is the sheet storage area. When there are a plurality of sheets S, the sheets S are stacked in the vertical direction on the set plate 1.

[0030] When the user sets the sheet S on the set plate 1, the upper surface cover CV is opened and closed. By rotating the right end of the upper surface cover CV upward from the state where the upper surface cover CV is closed, the upper surface cover CV can be opened. By rotating the right end of the upper surface cover CV downward from the state where the upper surface cover CV is opened, the upper surface cover CV can be closed.

[0031] When the upper cover CV is opened, the sheet storage area on the set plate 1 is exposed. As a result, the sheet S can be set on the set plate 1. When the upper cover CV is closed, it covers the sheet storage area on the set plate 1.

[0032] The feeding device 100 includes a lifting mechanism 2. The configuration of the lifting mechanism 2 is shown in FIG. 4. The lifting mechanism 2 moves the set plate 1 in the vertical direction. That is, the set plate 1 is supported so as to be reciprocally movable in the vertical direction. By raising the set plate 1, the lifting mechanism 2 holds the vertical position of the uppermost sheet S set on the set plate 1 at a predetermined position.

[0033] The lifting mechanism 2 includes a wire 20 connected to the set plate 1. The number of wires 20 is four. One end of each wire 20 is connected to each of the four corners of the set plate 1. A take-up drum 21 and a relay pulley 22 are assigned to each wire 20. Each wire 20 is wound around the corresponding relay pulley 22. And the other end of each wire 20 is connected to the corresponding take-up drum 21.

[0034] Each take-up drum 21 is rotatably supported around the same axis extending in the width direction Dw. That is, each take-up drum 21 is attached to the same rotation shaft 210 and rotates together with the rotation shaft 210. The rotation shaft 210 is connected to a take-up motor (not shown) and rotates when the take-up motor is driven. By the forward and reverse rotation of each take-up drum 21, the wire 20 is wound and fed out. That is, the set plate 1 moves up and down.

[0035] As shown in FIGS. 2 and 3, the feeding device 100 includes a feeding unit 3. The feeding unit 3 corresponds to the "feeding section". The feeding unit 3 feeds the sheet S from the set plate 1 by performing a feeding operation. By the feeding unit 3, the sheet S on the set plate 1 is fed from the feeding device 100 to the image forming device 1000. The feeding unit 3 includes a pickup roller 31 and a pair of conveying rollers 32.

[0036] The pickup roller 31 is rotatably supported. The pickup roller 31 is disposed at a position where it can contact the downstream end portion of the sheet S in the feeding direction Df from above in a state where the sheet S is set on the set plate 1. The pickup roller 31 contacts the sheet S set on the set plate 1 from above and rotates in that state, thereby pulling out the sheet S from the set plate 1.

[0037] The pair of conveying rollers 32 is rotatably supported. The pair of conveying rollers 32 is a pair of rollers that are in pressure contact with each other. The pair of conveying rollers 32 is disposed on the downstream side of the pickup roller 31 in the feeding direction Df. The pair of conveying rollers 32 nips the sheet S pulled out from the set plate 1 by the pickup roller 31 and rotates. Thereby, the pair of conveying rollers 32 conveys the sheet S toward the image forming apparatus 1000. The number of the pair of conveying rollers 32 installed is not particularly limited and can be changed according to the conveyance path length of the sheet S from the pickup roller 31 to the image forming apparatus 1000 or the like.

[0038] Note that the elevating mechanism 2 raises the set plate 1 to bring the uppermost sheet S on the set plate 1 into contact with the pickup roller 31. When the feeding of the sheet S from the feeding device 100 to the image forming apparatus 1000 is continuously performed, the elevating mechanism 2 repeatedly raises and stops raising the set plate 1. Thereby, the contact between the uppermost sheet S on the set plate 1 and the pickup roller 31 is maintained.

[0039] As shown in FIGS. 3 and 5, the feeding device 100 includes width direction regulating cursors 4 and 5. The width direction regulating cursors 4 and 5 are supported so as to be reciprocally movable in the width direction Dw. The width direction regulating cursors 4 and 5 are arranged to face each other with a space therebetween in the width direction Dw. The width direction regulating cursors 4 and 5 move in the width direction Dw by a user's operation.

[0040] The width direction regulating cursors 4 and 5 move in the width direction Dw in conjunction with each other. When the width direction regulating cursor 4 moves rearward, the width direction regulating cursor 4 moves forward, narrowing the interval between the width direction regulating cursors 4 and 5 in the width direction Dw. When the width direction regulating cursor 4 moves forward, the width direction regulating cursor 5 moves rearward, widening the interval between the width direction regulating cursors 4 and 5 in the width direction Dw.

[0041] By moving in the width direction Dw, the width direction regulating cursors 4 and 5 contact the edge of the sheet S on the set plate 1 from the width direction Dw. The width direction regulating cursor 4 contacts the edge of the sheet S on the set plate 1 from the front side by moving from the front side toward the rear side. The width direction regulating cursor 5 contacts the edge of the sheet S on the set plate 1 from the rear side by moving from the rear side toward the front side. Thereby, the width direction regulating cursors 4 and 5 regulate the displacement of the sheet S in the width direction Dw on the set plate 1.

[0042] The feeding device 100 further includes a rear end regulating cursor RC. The rear end regulating cursor RC is supported so as to be reciprocally movable in the left-right direction. The rear end regulating cursor RC moves in the left-right direction by a user's operation. The rear end regulating cursor RC contacts the rear end edge of the sheet S on the set plate 1 by moving from the upstream side to the downstream side in the feeding direction Df. Thereby, the rear end regulating cursor RC regulates the displacement of the sheet S on the set plate 1 to the upstream side in the feeding direction Df.

[0043] Incidentally, when viewed from above, the set plate 1 has openings (reference numerals omitted) on the movement paths of the width-direction regulating cursors 4 and 5, and also has an opening (reference numeral omitted) on the movement path of the rear-end regulating cursor RC. Therefore, even when the width-direction regulating cursors 4 and 5 move in the width direction Dw, they do not contact the set plate 1. Even when the rear-end regulating cursor RC moves in the left-right direction, it does not contact the set plate 1. That is, when viewed from above, even if the sheet S is small with respect to the set plate 1, the width-direction regulating cursors 4 and 5 can be brought into contact with the edge of the sheet S without contacting the set plate 1, and the rear-end regulating cursor RC can be brought into contact with the edge of the sheet S without contacting the set plate 1. In FIG. 5, hatching is applied to the set plate 1.

[0044] As shown in FIGS. 6 and 7, the feeding device 100 includes a dehumidifying unit D. The dehumidifying unit D blows heated air to the sheet storage area on the set plate 1. That is, the dehumidifying unit D blows warm air onto the sheet S on the set plate 1. Thereby, the dehumidifying unit D dehumidifies the sheet S on the set plate 1.

[0045] The dehumidifying unit D includes a fan 6 and a heater 7. The fan 6 blows air onto the sheet S on the set plate 1 when driven. The heater 7 is disposed on the air flow path generated by the fan 6. The heater 7 heats the air blown onto the sheet S on the set plate 1. Thereby, when the fan 6 and the heater 7 are driven, warm air hits the sheet S on the set plate 1, and dehumidification of the sheet S on the set plate 1 is performed.

[0046] The fan 6 and the heater 7 are disposed on the rear width-direction regulating cursor 5. In this configuration, the width-direction regulating cursor 5 corresponds to the "regulating cursor".

[0047] Note that the fan 6 and the heater 7 are arranged outside the width direction Dw of the width direction regulating cursor 5. The outside of the width direction Dw of the width direction regulating cursor 5 means the side opposite to the sheet accommodation region side in the width direction Dw of the width direction regulating cursor 5 (that is, the rear side of the width direction regulating cursor 5). For this reason, a vent 50 penetrating in the width direction Dw is formed in the width direction regulating cursor 5. Then, through the vent 50, the warm air generated by the fan 6 and the heater 7 flows into the sheet accommodation region on the setting plate 1.

[0048] For example, the number of fans 6 is two. The two fans 6 are arranged along the feeding direction Df. On the other hand, the number of heaters 7 is one. The one heater 7 is assigned to the fan 6 located on the downstream side in the feeding direction Df among the two fans 6. That is, one fan 6 heats the air blown by the fan 6 located on the downstream side in the feeding direction Df among the two fans 6.

[0049] Further, as shown in FIG. 8, the feeding device 100 includes a feeding control unit 10. The feeding control unit 10 corresponds to the "control unit". The feeding control unit 10 includes a processing circuit 101 such as a CPU and an ASIC. Further, the feeding control unit 10 includes a storage unit 102 such as a ROM, a RAM, an HDD, and an SSD.

[0050] The feeding control unit 10 is connected to the main control unit MC of the image forming apparatus 1000. The feeding control unit 10 communicates with the main control unit MC. The main control unit MC receives job settings regarding a job (hereinafter simply referred to as a job) involving feeding of the sheet S by the feeding device 100 from the user. For example, the image forming apparatus 1000 is provided with an operation panel (not shown), and the operation panel receives job settings from the user. The main control unit MC recognizes the content of the job settings received by the operation panel.

[0051] The main control unit MC transmits a control instruction based on a job setting specified by the user to the feed control unit 10. The feed control unit 10 controls the sheet S feeding process by the feeder 100 (in other words, the sheet S feeding process from the feeder 100 to the image forming apparatus 1000) based on the control instruction from the main control unit MC.

[0052] For example, a sheet S feeding start command is transmitted from the main control unit MC to the feed control unit 10. That is, the feed control unit 10 receives the feed start command from the image forming apparatus 1000 which is the destination of the sheet S. After receiving the feed start command, the feed control unit 10 causes the feed unit 3 to start feeding the sheet S. That is, the feed control unit 10 rotates the rotating bodies (pickup roller 31 and conveying roller pair 32) of the feed unit 3. Also, the feed control unit 10 raises the set plate 1 and brings the topmost sheet S on the set plate 1 into contact with the pickup roller 31. Thereby, the sheet S on the set plate 1 is fed to the image forming apparatus 1000.

[0053] The feed control unit 10 controls the dehumidification process of the sheet S by the dehumidification unit D. That is, the feed control unit 10 controls the driving of the fan 6. The feed control unit 10 controls the driving of the heater 7. The dehumidification process of the sheet S by the dehumidification unit D will be described in detail later.

[0054] The feeder 100 is provided with a temperature and humidity sensor 11. The temperature and humidity sensor 11 detects the internal temperature and internal humidity of the feeder 100. The temperature and humidity sensor 11 is connected to the feed control unit 10. The feed control unit 10 detects the internal temperature and internal humidity of the feeder 100 based on the output of the temperature and humidity sensor 11.

[0055] The sheet feeding device 100 is provided with a temperature sensor 12. The temperature sensor 12 detects the external temperature of the sheet feeding device 100. The temperature sensor 12 is connected to the sheet feeding control unit 10. The sheet feeding control unit 10 detects the external temperature of the sheet feeding device 100 based on the output of the temperature sensor 12. In some cases, the image forming apparatus 1000 is provided with an outside air temperature detection sensor and is connected to the main control unit MC. In this case, the temperature sensor 12 may be omitted, and information indicating the outside air temperature (i.e., the external temperature of the sheet feeding device 100) may be transmitted from the main control unit MC to the sheet feeding control unit 10.

[0056] The sheet feeding device 100 is provided with an open / close sensor 13. The open / close sensor 13 outputs a value according to the open / closed state of the upper cover CV. For example, when the upper cover CV is opened, the output value of the open / close sensor 13 changes. The open / close sensor 13 is connected to the sheet feeding control unit 10. The sheet feeding control unit 10 detects that the upper cover CV has been opened and detects that the upper cover CV has been closed based on the output of the open / close sensor 13.

[0057] The sheet feeding device 100 is provided with a heater temperature sensor 70 (e.g., a thermistor). The heater temperature sensor 70 detects the temperature of the heater 7. The heater temperature sensor 70 is connected to the sheet feeding control unit 10. The sheet feeding control unit 10 detects the temperature of the heater 7 based on the output of the heater temperature sensor 70.

[0058] <Drying process of the sheet> The types of sheets S used in the job are various. For example, coated paper may be used. When the sheet S used in the job is coated paper, depending on the internal temperature and internal humidity of the sheet feeding device 100, the moisture of the sheet S increases, making it difficult for the sheets S stacked on the set plate 1 to separate from each other. As a result, in the feeding of the sheet S from the set plate 1, double feeding, in which a plurality of sheets S are fed overlapping each other, is likely to occur.

[0059] In order to suppress such inconveniences, a dehumidifying unit D is provided in the sheet feeding device 100. Then, the dehumidifying unit D dehumidifies the sheet S on the setting plate 1. Thereby, double feeding of the sheet S is suppressed.

[0060] Here, if the dehumidifying unit D is continuously driven regardless of the internal environment of the sheet feeding device 100, the power consumption increases. Also, if the dehumidifying unit D is continuously driven regardless of the type of the sheet S, the power consumption increases. Therefore, the sheet feeding control unit 10 performs control along the flowcharts shown in FIGS. 9 and 10.

[0061] Hereinafter, with reference to the flowcharts shown in FIGS. 9 and 10, the flow of the process performed by the sheet feeding control unit 10 will be described.

[0062] When the sheet feeding control unit 10 receives a sheet feeding start command from the sheet feeding destination of the sheet S (that is, the image forming apparatus 1000), the flow shown in FIG. 9 starts. Note that at the start of the flow shown in FIG. 9, the fan 6 may be driven or may not be driven. On the other hand, the heater 7 is not driven.

[0063] In step S1, the sheet feeding control unit 10 determines whether the sheet S to be fed by the sheet feeding unit 3 is coated paper. In other words, the sheet feeding control unit 10 determines whether the sheet S set on the setting plate 1 is coated paper. More specifically, the sheet feeding control unit 10 determines whether the sheet S used in the job is coated paper. If the sheet feeding control unit 10 determines in step S1 that the sheet S to be fed by the sheet feeding unit 3 is coated paper, the process proceeds to step S2.

[0064] For example, the operation panel of the image forming apparatus 1000 receives the type of the sheet S on the setting plate 1 from the user. When the sheet S is set on the setting plate 1, the user inputs the type of the sheet S set on the setting plate 1 to the operation panel. The main control unit MC transmits the type of the sheet S input to the operation panel to the feeding control unit 10. Thereby, the feeding control unit 10 recognizes the type of the sheet S set on the setting plate 1.

[0065] In step S2, the feeding control unit 10 recognizes the internal environment of the feeding device 100 based on the output of the temperature and humidity sensor 11. Then, the feeding control unit 10 performs a condition determination process on whether the internal environment of the feeding device 100 satisfies a predetermined condition. That is, when the sheet S to be fed to the feeding unit 3 is coated paper, the feeding control unit 10 performs the condition determination process.

[0066] When performing the condition determination process, the feeding control unit 10 obtains the absolute humidity based on the output of the temperature and humidity sensor 11. The feeding control unit 10 acquires the absolute humidity based on the output of the temperature and humidity sensor 11 as the internal environment of the feeding device 100. Then, the feeding control unit 10 performs, as the condition determination process, a process of determining that the predetermined condition is satisfied when the absolute humidity based on the output of the temperature and humidity sensor 11 is higher than the threshold humidity. The feeding control unit 10 determines that the predetermined condition is not satisfied when the absolute humidity based on the output of the temperature and humidity sensor 11 is equal to or lower than the threshold humidity. The condition determination process is, in other words, a process of determining whether the state is such that double feeding of the sheet S is likely to occur. The state in which double feeding of the sheet S is likely to occur is a state in which the absolute humidity based on the output of the temperature and humidity sensor 11 is higher than the threshold humidity.

[0067] In step S2, when the feeding control unit 10 determines that the predetermined condition is satisfied, the process proceeds to step S3. In other words, when the feeding control unit 10 determines that the absolute temperature based on the output of the temperature and humidity sensor 11 is higher than the threshold humidity, the process proceeds to step S3. Further in other words, when the feeding control unit 10 determines that the state is such that double feeding of the sheet S is likely to occur, the process proceeds to step S3.

[0068] In step S3, the feeding control unit 10 starts driving the fan 6 (Fan: ON). The feeding control unit 10 drives the fan 6 at a predetermined reference rotational speed. Note that the feeding control unit 10 drives the fan 6 by performing PWM control. At this time, the feeding control unit 10 also starts driving the heater 7 (Heater: ON). If the fan 6 and the heater 7 are driven normally, the warm air hits the sheet S on the setting plate 1 and the sheet is dehumidified.

[0069] Note that the feeding control unit 10 measures a first elapsed time, which is the elapsed time since the start of driving the heater 7 when it is determined that a predetermined condition is satisfied in the condition determination process. That is, when shifting to step S3, the feeding control unit 10 starts measuring the first elapsed time.

[0070] In step S4, the feeding control unit 10 determines whether the temperature (HT) of the heater 7 is higher than the threshold temperature (Tt). If the feeding control unit 10 determines that the temperature of the heater 7 is higher than the threshold temperature (HT > Tt), it shifts to step S5. The threshold temperature is a temperature 10° higher than the external temperature of the feeding device 100 (external temperature + 10°C). That is, the threshold temperature changes according to the external temperature of the feeding device 100.

[0071] In step S5, the feeding control unit 10 causes the feeding unit 3 to start feeding the sheet S. That is, when it is determined that a predetermined condition is satisfied in the condition determination process, the feeding control unit 10 causes the feeding unit 3 to start feeding the sheet S after starting the driving of the fan 6 and the heater 7. Note that the feeding control unit 10 causes the feeding unit 3 to feed the sheet S with the upper cover CV closed.

[0072] In step S6, when the feeding of the sheet S is completed, the feeding control unit 10 stops the feeding operation of the feeding unit 3.

[0073] In step S1, when the feed control unit 10 determines that the sheet S to be fed by the feed unit 3 is not coated paper, the process proceeds to step S7. In step S7, the feed control unit 10 does not drive the fan 6 (fan: OFF). Then, the process proceeds to step S5.

[0074] In addition, in step S7, if the fan 6 is in operation, the feed control unit 10 stops the drive of the fan 6. Also, in step S7, if the drive of the fan 6 has been stopped, the feed control unit 10 maintains the stopped state of the drive of the fan 6. In any case, when the sheet S to be fed by the feed unit 3 is not coated paper, the feed control unit 10 does not drive the fan 6 and the heater 7.

[0075] In step S2, even when the feed control unit 10 determines that a predetermined condition is not satisfied, the process proceeds to step S7. That is, when it is determined in the condition determination process that the predetermined condition is not satisfied, the feed control unit 10 does not drive the fan 6 and the heater 7 even if the sheet S to be fed by the feed unit 3 is coated paper.

[0076] In step S4, when the feed control unit 10 determines that the temperature of the heater 7 is equal to or lower than the threshold temperature (HT ≤ Tt), the process proceeds to step S8.

[0077] In step S8, the feed control unit 10 determines whether the first elapsed time has reached the first threshold time. When the feed control unit 10 determines that the first elapsed time has not reached the first threshold time, the process proceeds to step S4. When the feed control unit 10 determines that the first elapsed time has reached the first threshold time, the process proceeds to step S9.

[0078] In step S9, the feeding control unit 10 performs error notification processing to notify that an abnormality has occurred in the heater 7. That is, when the temperature of the heater 7 reaches the threshold temperature before the first elapsed time reaches the first threshold time, the feeding control unit 10 causes the feeding unit 3 to start feeding the sheet S. On the other hand, when the temperature of the heater 7 does not reach the threshold temperature even when the first elapsed time reaches the first threshold time, the feeding control unit 10 performs error notification processing.

[0079] As error notification processing, the feeding control unit 10 performs processing to transmit to the main control unit MC that an abnormality has occurred in the heater 7. When receiving an error notification from the feeding control unit 10, the main control unit MC performs processing such as displaying an error message on the operation panel.

[0080] When the feeding of the sheet S is completed, the process proceeds from step S6 to step S10 (see FIG. 10).

[0081] In step S10, the feeding control unit 10 determines whether the fan 6 is driven. The fact that the fan 6 is driven at this time means that the heater 7 is also driven. On the other hand, the fact that the fan 6 is not driven at this time means that the heater 7 is not driven either.

[0082] In step S10, if the feeding control unit 10 determines that the fan 6 is not driven, the process proceeds to step S11. In step S11, the feeding control unit 10 enters a standby state and waits until a new feeding start command is received. At this time, the feeding control unit 10 does not drive the fan 6 and the heater 7. That is, the feeding control unit 10 does not drive the heater 7 from the end of the feeding of the sheet S until the next feeding start command is received. When the feeding control unit 10 receives the next feeding start command, the flow in FIG. 9 starts.

[0083] In step S10, if the feed control unit 10 determines that the fan is driving, the process proceeds to step S12. In step S12, the feed control unit 10 stops the driving of the heater 7 (Heater: OFF). At this time, regardless of whether the internal environment of the feeding device 100 satisfies the predetermined conditions (that is, regardless of whether the absolute humidity based on the temperature and humidity sensor 11 is higher than the threshold humidity), the feed control unit 10 stops the driving of the heater 7. However, the feed control unit 10 continues to drive the fan 6. That is, at this point, the fan 6 is driving while the heater 7 has stopped driving.

[0084] In addition, the feed control unit 10 measures the second elapsed time, which is the elapsed time since the driving of the heater 7 was stopped. That is, when the process proceeds to step S12, the feed control unit 10 starts measuring the second elapsed time.

[0085] In step S13, the feed control unit 10 determines whether the second elapsed time has reached the second threshold time. If the feed control unit 10 determines that the second elapsed time has reached the second threshold time, the process proceeds to step S14. In step S14, the feed control unit 10 stops the driving of the fan 6 (Fan: OFF). Then, the process proceeds to step S11.

[0086] In step S13, if the feed control unit 10 determines that the second elapsed time has not reached the second threshold time, the process proceeds to step S15. In step S15, the feed control unit 10 determines whether the upper cover CV has been opened. The feed control unit 10 detects that the upper cover CV has been opened based on the output of the open / close sensor 13.

[0087] In step S15, if the feed control unit 10 determines that the upper cover CV has not been opened, the process proceeds to step S16. In step S16, the feed control unit 10 determines whether it has received the next feed start command (that is, a new feed start command) from the main control unit MC.

[0088] In step S16, when the feeding control unit 10 determines that it has received the next feeding start command from the main control unit MC, it proceeds to step S1 (see FIG. 9). On the other hand, when the feeding control unit 10 determines that it has not received the next feeding start command from the main control unit MC, it proceeds to step S13. That is, after stopping the driving of the heater 7, when the second elapsed time reaches the second threshold time before receiving the next feeding start command from the main control unit MC, the feeding control unit 10 stops the driving of the fan 6.

[0089] In step S15, when the feeding control unit 10 determines that the upper cover CV has been opened, it proceeds to step S17. In step S17, the feeding control unit 10 switches the rotation speed of the fan 6 to low speed while driving the fan 6 (Fan: Low speed). The feeding control unit 10 drives the fan 6 at a rotation speed slower than the reference rotation speed, which is the rotation speed of the fan 6 before the upper cover CV is opened. Thereafter, it proceeds to step S13. That is, after stopping the driving of the heater 7, when the upper cover CV is opened before receiving the next feeding start command from the main control unit MC and before the second elapsed time reaches the second threshold time, the feeding control unit 10 drives the fan 6 at a rotation speed slower than before the upper cover CV was opened.

[0090] In this embodiment, when it is determined in the condition determination process that a predetermined condition is satisfied, the feeding control unit 10 starts feeding the sheet S to the feeding unit 3 after starting the driving of the fan 6 and the heater 7. That is, the feeding control unit 10 starts feeding the sheet S to the feeding unit 3 while dehumidifying the sheet S to be fed to the feeding unit 3. Thereby, double feeding of the sheet S can be suppressed.

[0091] Here, in the present embodiment, when the feeding control unit 10 receives a feeding start command from the feeding destination of the sheet S, the feeding control unit 10 performs a condition determination process to determine whether to drive the fan 6 and the heater 7. Further, when the feeding of the sheet S is completed, the feeding control unit 10 stops the driving of the heater 7 regardless of whether the internal environment of the feeding device 100 satisfies a predetermined condition. That is, the feeding control unit 10 does not drive the heater 7 at least until the next feeding start command is received after the feeding of the sheet S is completed. Thereby, an increase in power consumption due to an increase in the driving time of the heater 7 is suppressed. As a result, it is possible to suppress the occurrence of double feeding of the sheet S while suppressing an increase in power consumption in the feeding device 100.

[0092] In the present embodiment, when the feeding of the sheet S is completed, the driving of the heater 7 is immediately stopped, but the driving of the fan 6 is continued. Thereby, overshoot of the heater 7 can be suppressed.

[0093] Also, in the present embodiment, as described above, the feeding control unit 10 determines that a predetermined condition is satisfied when the absolute humidity is higher than the threshold humidity. Thereby, it is possible to easily perform the dehumidification process when the double feeding of the sheet S is likely to occur.

[0094] Also, in the present embodiment, as described above, when the sheet S to be fed to the feeding unit 3 is not coated paper, the feeding control unit 10 does not drive the fan 6 and the heater 7. Further, when it is determined in the condition determination process that the predetermined condition is not satisfied, the feeding control unit 10 does not drive the fan 6 and the heater 7 even if the sheet S to be fed to the feeding unit 3 is coated paper. That is, the fan 6 and the heater 7 are driven only when the double feeding of the sheet S is likely to occur. Thereby, power consumption can be further suppressed.

[0095] Also, in the present embodiment, when the temperature of the heater 7 reaches the threshold temperature before the first elapsed time reaches the first threshold time, the feeding control unit 10 causes the feeding unit 3 to start feeding the sheet S. On the other hand, when the temperature of the heater 7 does not reach the threshold temperature even when the first elapsed time reaches the first threshold time, the feeding control unit 10 performs a process of notifying an error. Here, if an abnormality such as a disconnection occurs in the heater 7, the temperature of the heater 7 will not reach the threshold temperature. Therefore, when the temperature of the heater 7 does not reach the threshold temperature even when the first elapsed time reaches the first threshold time, it is preferable to perform a process of notifying an error.

[0096] Also, in the present embodiment, as described above, after stopping the driving of the heater 7, when the second elapsed time reaches the second threshold time before receiving the next feeding start command from the feeding destination of the sheet S, the feeding control unit 10 stops the driving of the fan 6. Thereby, it is possible to suppress the fan 6 from continuing to drive unnecessarily.

[0097] Also, in the present embodiment, as described above, after stopping the driving of the heater 7, before receiving the next feeding start command from the feeding destination of the sheet S and before the second elapsed time reaches the second threshold time, when it is detected based on the output of the opening / closing sensor 13 that the upper cover CV has been opened, the feeding control unit 10 drives the fan 6 at a rotation speed slower than before the upper cover CV was opened. Here, the fact that the upper cover CV has been opened means that the work of setting the sheet S on the setting plate 1 is being performed. When the sheet S is being set, if an air flow is generated on the setting plate 1, the workability is poor. Therefore, the rotation speed of the fan 6 is reduced. Thereby, a decrease in workability can be suppressed.

[0098] Also, in the present embodiment, as described above, the fan 6 and the heater 7 are arranged at the width direction regulating cursor 5. Thereby, it is possible to easily apply warm air to the sheet S.

[0099] Also, in the present embodiment, as described above, the heater 7 is assigned only to the fan 6 located on the downstream side in the feeding direction Df. Thereby, power consumption can be further suppressed. Here, the pickup roller 31 contacts the front end side of the sheet S (downstream side in the feeding direction Df). In this configuration, if the dehumidification of the front end side of the sheet S is insufficient, double feeding of the sheet S is likely to occur. Therefore, it is preferable to heat the air blown by the fan 6 located on the downstream side in the feeding direction Df.

[0100] The embodiments disclosed this time should be considered as illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and further includes all modifications within the meaning and scope equivalent to the claims.

Explanation of Reference Numerals

[0101] 1 Set plate 3 Feeding unit (feeding section) 5 Width direction regulating cursor (regulating cursor) 6 Fan 7 Heater 10 Feeding control unit (control unit) 11 Temperature and humidity sensor 13 Opening and closing sensor 100 Feeding device 100S Image forming system 1000 Image forming apparatus CV Upper surface cover (cover) S Sheet

Claims

1. A setting plate on which a sheet is set, A feeding unit that feeds the sheet from the setting plate, A fan that blows air onto the sheet on the setting plate, A heater that heats the air blown onto the sheet on the setting plate, A control unit that controls the feeding of the sheet by the feeding unit, A temperature and humidity sensor that detects the internal temperature and internal humidity of the feeding device, and When receiving a feeding start command from the sheet feeding destination, if the sheet to be fed by the feeding unit is coated paper, the control unit recognizes the internal environment of the feeding device based on the output of the temperature and humidity sensor, and performs a condition determination process on whether the internal environment satisfies a predetermined condition. When it is determined in the condition determination process that the predetermined condition is satisfied, the control unit starts driving the fan and the heater, and then starts feeding the sheet to the feeding unit. When the feeding of the sheet in the state where the fan and the heater are driven is completed, the control unit stops driving the heater regardless of whether the internal environment satisfies the predetermined condition, and continues driving the fan. A feeding device.

2. The internal environment is absolute humidity, The control unit determines that the predetermined condition is satisfied when the absolute humidity is higher than a threshold humidity. The feeding device according to claim 1.

3. When the sheet to be fed to the feeding unit is not the coated paper, the control unit does not drive the fan and the heater. The feeding device according to claim 1.

4. When it is determined in the condition determination process that the predetermined condition is not satisfied, the control unit does not drive the fan and the heater even if the sheet to be fed to the feeding unit is the coated paper. The feeding device according to claim 1.

5. The control unit measures a first elapsed time, which is the elapsed time since the start of driving the heater when it is determined in the condition determination process that the predetermined condition is satisfied. When the temperature of the heater reaches a threshold temperature before the first elapsed time reaches a first threshold time, the control unit starts feeding the sheet to the feeding unit. When the first elapsed time reaches the first threshold time but the temperature of the heater does not reach the threshold temperature, the control unit performs a process of notifying an error. The feeding device according to claim 1.

6. The control unit measures a second elapsed time, which is the elapsed time since the driving of the heater was stopped. After the driving of the heater is stopped and before the next sheet feeding start command is received, when the second elapsed time reaches a second threshold time, the control unit stops the driving of the fan. The sheet feeding device according to claim 1. **Claim 7** A cover that is supported so as to be openable and closable, An opening / closing sensor that detects the opening and closing of the cover, and When the cover is opened, an area on the setting plate is exposed to enable setting of the sheet, and when the cover is closed, the area on the setting plate is covered. The control unit causes the feeding unit to feed the sheet with the cover closed. After the driving of the heater is stopped and before the next sheet feeding start command is received and before the second elapsed time reaches the second threshold time, when it is detected based on the output of the opening / closing sensor that the cover has been opened, the control unit drives the fan at a rotational speed slower than before the cover was opened. The sheet feeding device according to claim 6. **Claim 8** A regulating cursor that regulates displacement of the sheet in the width direction by contacting the edge of the sheet on the setting plate from the width direction orthogonal to the feeding direction. The fan and the heater are arranged on the regulating cursor. The sheet feeding device according to claim 1. **Claim 9** The number of the fans is two, while the number of the heaters is one. The two fans are arranged along the feeding direction. One heater heats the air blown by the fan located on the downstream side in the feeding direction among the two fans. The sheet feeding device according to claim 8. **Claim 10** A sheet feeding device according to any one of claims 1 to 9, An image forming device connected to the sheet feeding device, and The sheet feeding device feeds the sheet to the image forming device, The image forming device performs printing on the sheet fed from the sheet feeding device. An image forming system.

Images