Image forming system and method for controlling the image forming system

Abstract

This image forming system detects the moisture content of each individual sheet of paper, enabling stable paper feeding. [Solution] The image forming system 1 of the present invention comprises an image forming unit 17 that forms an image on a sheet of paper 90, a paper feeding unit 24 that feeds one sheet of paper 90 at a time from a stack of multiple sheets of paper 90 to the image forming unit 17, a detection unit 34 that detects the amount of moisture in the paper 90 fed by the paper feeding unit 24, and a control unit 21 that adjusts the paper feeding conditions when the paper feeding unit 24 feeds paper based on the amount of moisture detected by the detection unit 34.

Description

Technical Field

[0001] The present invention relates to an image forming system and a method for controlling the image forming system.

Background Art

[0002] In an image forming apparatus such as a printer or a copying machine, it is important to prevent double feeding of sheets from the paper feeding unit to the image forming unit.

[0003] In relation to this, Patent Document 1 below discloses a technique for detecting the moisture content of a sheet and controlling the humidity of the sheet fed from a paper feed tray. According to the technique of Patent Document 1, adsorption between sheets is prevented by optimally adjusting the humidity of the sheet, and stable paper feeding can be performed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, since the above technique estimates the moisture content of a sheet based on ambient temperature information and humidity information, it cannot detect the moisture content of each sheet in a stack of sheets composed of a plurality of sheets. Even for sheets in the same stack, if the positions of the sheets in the stack are different, the moisture content of the sheets may be different. Therefore, in the above technique, the humidity of the sheet may not be optimally adjusted, and there is a possibility that sufficiently stable paper feeding cannot be performed, which is not preferable.

[0006] The present invention has been made in view of the above problems. Therefore, an object of the present invention is to provide an image forming system and a method for controlling the image forming system that can detect the moisture content of each sheet and achieve sufficiently stable paper feeding. [Means for solving the problem]

[0007] The above objectives of the present invention are achieved by the following means.

[0008] (1) An image forming system comprising: an image forming unit that forms an image on paper; a paper feeding unit that feeds one sheet of paper at a time from a stack of multiple sheets of paper to the image forming unit; a detection unit that detects the amount of moisture in the paper fed by the paper feeding unit; and a control unit that adjusts the paper feeding conditions when the paper feeding unit is feeding paper based on the amount of moisture detected by the detection unit.

[0009] (2) The image forming system according to (1) above, wherein the paper feeding unit is configured to separate the top sheet of paper from the stack by blowing air onto the paper, and the control unit adjusts the air volume or the air blowing time as the paper feeding conditions.

[0010] (3) The image forming system according to (1) or (2) above, wherein the paper feeding unit has an air supply unit that blows air onto the paper, and the control unit controls the operation of the air supply unit so that the amount of air increases as the amount of moisture increases.

[0011] (4) The image forming system according to (1) or (2) above, wherein the paper feeding unit has an air supply unit that blows air onto the paper, and the control unit controls the operation of the paper feeding unit such that the air blowing time increases as the amount of moisture increases.

[0012] (5) The image forming system according to (1) or (2) above, wherein the paper feeding unit includes a plurality of air supply units that blow air onto the paper, and the control unit controls the operation of the plurality of air supply units such that the number of air supply units that blow air onto the paper increases as the amount of moisture increases.

[0013] (6) The image forming system according to (1) or (2) above, wherein the paper feeding unit is configured to separate the top sheet of paper from the stack of paper by blowing air onto the paper, and the control unit adjusts the paper feeding conditions based on the amount of moisture in the part of the paper to which the air is blown.

[0014] (7) The image forming system according to (6) above, wherein the detection unit detects the amount of moisture in multiple locations on the paper, and the control unit calculates the amount of moisture in the paper by giving the maximum weight to the amount of moisture in the locations included in the area to which the air is blown, and adjusts the paper feeding conditions.

[0015] (8) The image forming system according to (6) above, wherein the detection unit detects the amount of moisture in the portion of the paper to which the air is blown, and the control unit adjusts the paper feeding conditions based on the amount of moisture in the portion of the paper.

[0016] (9) The image forming system according to (1) or (2) above, wherein the control unit adjusts the paper feeding conditions each time a sheet of paper is fed from the paper feeding unit to the image forming unit.

[0017] (10) The image forming system according to (1) or (2) above, wherein the detection unit is disposed between the image forming unit and the paper feeding unit.

[0018] (11) The image forming system according to (1) or (2) above, wherein the detection unit detects the amount of moisture in the paper being transported within the image forming system.

[0019] (12) A control method for an image forming system having an image forming unit that forms an image on paper and a paper feeding unit that feeds one sheet of paper at a time to the image forming unit from a stack of multiple sheets of paper, the method comprising: (a) detecting the amount of moisture in the paper fed by the paper feeding unit, and (b) adjusting the paper feeding conditions when the paper feeding unit feeds the paper based on the amount of moisture detected in step (a). [Effects of the Invention]

[0020] According to the present invention, sufficiently stable paper feeding is achieved.

Brief Description of the Drawings

[0021] The advantages and features provided by one or more embodiments of the present invention will be more fully understood from the following detailed description and the accompanying drawings, which are for illustrative purposes only and are not intended to define the limitation of the present invention. [Figure 1] It is a diagram showing a schematic configuration of an image forming system. [Figure 2] It is a cross-sectional view showing a configuration of a paper feeding unit of a paper feeding device. [Figure 3] It is a perspective view showing a configuration of a paper feeding unit of a paper feeding device. [Figure 4A] It is a diagram for explaining a paper feeding operation of a paper feeding unit. [Figure 4B] It is a diagram following FIG. 4A. [Figure 4C] It is a diagram following FIG. 4B. [Figure 4D] It is a diagram following FIG. 4C. [Figure 5] It is a flowchart showing a procedure of paper feeding control processing.

Modes for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the scope of the present invention is not limited to the disclosed embodiments.

[0023] In the description of the drawings, the same elements are denoted by the same reference numerals, and duplicate descriptions are omitted. Also, the dimensional ratios in the drawings are exaggerated for convenience of explanation and may be different from the actual ratios. In the drawings, the vertical direction is the Z direction, the front and back directions of the image forming apparatus are the Y direction, and the direction orthogonal to the Y direction and the Z direction is the X direction. The Y direction is also referred to as the width direction or the rotation axis direction, and the X direction is also referred to as the conveyance direction or the paper feeding direction.

[0024] Figure 1 is a diagram showing the schematic configuration of an image forming system 1 according to one embodiment of the present invention.

[0025] As shown in Figure 1, the image forming system 1 includes an image forming apparatus 10, a paper feeder 20, and a paper characteristics detection device 30. The devices are connected in the order of paper feeder 20, paper characteristics detection device 30, and image forming apparatus 10 along the transport direction of the paper 90.

[0026] <Image forming apparatus 10> The image forming apparatus 10 comprises a control unit 11, a storage unit 12, a communication unit 13, an operation display unit 14, a main paper feeding unit 15, a transport unit 16, an image forming unit 17, and a fixing unit 18. Each of these units is interconnected via a bus for exchanging signals.

[0027] The control unit 11 is a CPU (Central Processing Unit) and performs control of the above-mentioned parts and various calculation processes according to the program.

[0028] The memory unit 12 consists of a ROM (Read Only Memory) for pre-storing various programs and data, a RAM (Random Access Memory) for temporarily storing programs and data as a working area, and a hard disk for storing various programs and data.

[0029] The communication unit 13 is an interface for communicating with other devices. For example, the communication unit 13 transmits and receives various data and signals with the paper feed device 20 and the paper characteristics detection device 30.

[0030] The operation display unit 14 is equipped with a touch panel, a numeric keypad, a start button, a stop button, etc., and is used for displaying various information and inputting various instructions.

[0031] The main paper feed unit 15 accommodates a stack of multiple sheets of paper 90 and feeds the paper 90 from the stack one sheet at a time.

[0032] The transport unit 16 includes a transport path 161, a plurality of transport roller pairs 162, and a drive motor (not shown) that drives the transport roller pairs 162, and transports the paper 90 fed from the main paper feeding unit 15 or the paper feeding device 20 along the transport path 161.

[0033] The image forming unit 17 forms an image on the paper 90 fed from the main paper feeding unit 15 or on the paper 90 fed from the paper feeding device 20. The image forming unit 17 forms an image on the paper 90 using, for example, a well-known electrophotographic image formation process that includes the steps of charging, exposure, development, and transfer.

[0034] The fixing unit 18 includes a heating roller and a pressure roller that are heated by a heater, and heats and pressurizes the paper 90 on which the image has been formed by the image forming unit 17 to fix the image to the paper 90.

[0035] <Paper feeder 20> The paper feeder 20 comprises a control unit 21, a storage unit 22, a communication unit 23, a paper feeding unit 24, and a transport unit 25. These units are interconnected via a bus for exchanging signals. Note that the parts of the paper feeder 20 that have the same functions as those of the image forming apparatus 10 will not be described.

[0036] The paper feed unit 24 accommodates a stack of multiple sheets of paper 90 and feeds the paper 90 one sheet at a time. The paper feed unit 24 employs an air-assist system that blows air onto the stack of paper to lift the multiple sheets of paper 90 at the top of the stack, separating the top sheet of paper 90 from the sheets below and feeding it. A detailed explanation of the paper feed unit 24 will be given later.

[0037] The storage unit 22 of the paper feeder 20 stores a conversion table that shows the relationship between the type of paper (plain paper, coated paper, glossy paper, etc.), the size of the paper, the moisture content of the paper, and the airflow rate blown onto the paper. The control unit 21 of the paper feeder 20 adjusts the airflow rate when the paper is fed by the paper feeder 24 by referring to the conversion table stored in the storage unit 22.

[0038] <Paper characteristics detection device 30> The paper characteristic detection device 30 comprises a control unit 31, a storage unit 32, a communication unit 33, a moisture sensor (detection unit) 34, and a transport unit 35. These units are interconnected via a bus for exchanging signals. The parts of the paper characteristic detection device 30 that have the same functions as those of the image forming apparatus 10 will not be described.

[0039] The moisture sensor 34 is installed in the transport path for the paper 90 and detects the moisture content (moisture ratio) of the paper 90 as it is transported from the paper feed device 20 to the image forming apparatus 10. The moisture sensor 34 irradiates the paper 90 with two types of near-infrared light with different wavelengths and detects the moisture content of the paper 90 based on the ratio of the amount of reflected light received from the paper 90. Note that the technology of detecting the moisture content of paper using two types of near-infrared light is a known technology, so a detailed explanation will be given later.

[0040] The moisture sensor 34 of the paper characteristics detection device 30 detects the moisture content at multiple locations along the transport direction of a single sheet of paper 90 as it is being transported along the transport path. The control unit 31 of the paper characteristics detection device 30 assigns the maximum weight to the moisture content at the leading edge (downstream side in the transport direction) of the paper 90, and calculates the total moisture content of the paper 90 by weighting the moisture content at the multiple locations.

[0041] Furthermore, the image forming apparatus 10, the paper feeding device 20, and the paper characteristic detection device 30 may include components other than those described above, and may not include some of the components described above.

[0042] Next, the paper feeding section 24 of the paper feed device 20 will be described in detail with reference to Figures 2 to 4.

[0043] <Configuration of the paper feeding unit 24> Figure 2 is a cross-sectional view showing the configuration of the paper feeding section 24 of the paper feeding device 20, and Figure 3 is a perspective view showing the configuration of the paper feeding section 24.

[0044] As shown in Figure 2, the paper feeding section 24 of the paper feeder 20 includes a paper storage section 40, an air supply section 50, and a paper suction section 60.

[0045] (Paper storage section 40) The paper storage section 40 includes a mounting section 41, a front end regulating plate 42, a rear end regulating plate 43, and side regulating plates 44.

[0046] The mounting section 41 is a plate-shaped member and can support a stack of paper 100 consisting of multiple sheets of paper 90. The stack of paper 100 placed on the mounting section 41 is restricted on all four sides by a front-end restricting plate 42, a rear-end restricting plate 43, and a pair of side restricting plates 44.

[0047] The front regulating plate 42 is fixed to the housing of the paper feeding unit 24 and is a member that restricts the front end of the paper 90 in the paper feeding direction (X direction). The rear regulating plate 43 is a member that restricts the rear end of the paper 90 in the paper feeding direction and is configured to be movable according to the size of the paper 90 placed on the mounting unit 41. The side regulating plates 44 are members that restrict both sides in the width direction (Y direction) and are configured to be movable according to the size of the paper 90 placed on the mounting unit 41. The side regulating plates 44 are integrally formed with the duct 522, which will be described later.

[0048] The mounting section 41 is configured to be able to move up and down in the vertical direction (Z direction) by a lifting drive motor (not shown). The mounting section 41 is controlled by the control unit 21 of the paper feed device 20 so that the top surface of the paper stack 100 is at a predetermined height position according to the output of a photosensor (not shown).

[0049] (Air supply unit 50) The air supply unit 50 has a front air supply unit 51 and a pair of side air supply units 52.

[0050] The tip air supply unit 51 blows air onto the leading edge of the paper 90. The tip air supply unit 51 has a tip fan 511 and a duct 512. The tip fan 511 is installed at the bottom of the tip air supply unit 51 and generates an airflow directed towards the top of the tip air supply unit 51. The duct 512 sends the air from the tip fan 511 towards the paper 90. The air from the tip fan 511 is discharged from an exhaust port 512H located at the top of the duct 512 in a nearly horizontal or diagonally upward direction.

[0051] The side air supply unit 52 blows air onto the side of the paper 90. The side air supply unit 52 has a side fan 521 and a duct 522. The side fan 521 is installed at the bottom of the side air supply unit 52 and generates an airflow directed towards the top of the side air supply unit 52. The duct 522 sends the air from the side fan 521 towards the paper 90. The air from the side fan 521 is discharged almost horizontally from an exhaust port 522H located at the top of the duct 522.

[0052] The front fan 511 and the side fan 521 are configured to allow airflow adjustment within a range of 0 to 100% using a PWM value (0 to 100%). Furthermore, the two side fans 521 are variably controlled to produce the same output when controlling airflow. The front fan 511 and the side fan 521 are controlled by the control unit 21 of the paper feed device 20.

[0053] The exhaust port 512H of the duct 512 of the tip air supply unit 51 is provided with a wind direction switching gate 53 that switches between a lower exhaust port and an upper exhaust port. When the wind direction switching gate 53 is in the first position, the lower exhaust port is opened and air is discharged through the lower exhaust port in a nearly horizontal direction. On the other hand, when the wind direction switching gate 53 is in the second position, the upper exhaust port is opened and air is discharged through the upper exhaust port in an oblique upward direction. The wind direction switching gate 53 is composed of, for example, a shutter and a solenoid and is controlled by the control unit 21 of the paper feed device 20.

[0054] (Paper adsorption section 60) The paper suction unit 60 picks up the paper 90 that has been lifted from the paper stack 100 by the air blown by the air supply unit 50, and feeds them out one sheet at a time along the paper feeding direction. The paper suction unit 60 is positioned above the leading edge of the paper 90 stored in the paper storage unit 40 in the paper feeding direction, and has a suction belt 61 and an air suction unit 62.

[0055] The suction belt 61 includes three endless belts arranged in parallel in the width direction and is rotatably supported by a large-diameter roller connected to a drive motor (not shown) and two smaller-diameter rollers. The endless belts are provided with numerous small-diameter through holes.

[0056] The air suction unit 62 is located inside the suction belt 61 and includes a suction fan 621 and a duct 622. The suction fan 621 is positioned inside the duct 622 and sucks in and discharges air from within the duct 622. A suction port 622H is provided at the lower part of the duct 622, facing the suction belt 61.

[0057] When the suction fan 621 is activated, the air in the duct 622 is discharged, creating negative pressure inside the duct 622, and generating an airflow (hereinafter referred to as "suction air") from the paper storage section 40 to the paper adsorption section 60. The suction air causes the paper 90 to adhere to the surface of the adsorption belt 61.

[0058] Furthermore, the paper suction unit 60 is provided with a suction photosensor 63. The suction photosensor 63 outputs a signal when the paper 90 is attracted to the surface of the suction belt 61. The suction photosensor 63 has, for example, an actuator (not shown) that is configured to rotate around a predetermined axis of rotation, and when the actuator rotates due to the paper 90 being attracted, the suction photosensor 63 outputs a signal.

[0059] Furthermore, an exit roller pair 64 is provided in front of the paper suction unit 60. The exit roller pair 64 feeds the paper 90, which has been held by the paper suction unit 60, downstream. The paper handling photosensor 65 detects that the paper 90 has been successfully transported to a predetermined position on the transport path.

[0060] <Paper feeding operation of paper feed unit 24> Next, the paper feeding operation of the paper feeding unit 24 will be described with reference to Figures 4A to 4D. The paper feeding operation of the paper feeding unit 24 includes four operations: paper lifting operation, paper suction operation, paper handling operation, and paper feeding start operation.

[0061] (1) Paper floating operation As shown in Figure 4A, during the paper levitation operation, the air direction switching gate 53, which switches the direction of the air discharged from the front air supply unit 51, is in the first position. Then, the front air supply unit 51 and the side air supply unit 52 blow air onto the paper stack 100 from the front and sides, respectively, in a nearly horizontal direction. As a result, multiple sheets of paper 90 on top of the paper stack 100 are lifted off the paper stack 100.

[0062] (2)Paper suction operation As shown in Figure 4B, during the paper suction operation, one or more sheets of paper 91-94 from the multiple sheets of paper 90 that have been lifted from the paper stack 100 by the paper levitation operation are adsorbed onto the surface of the suction belt 61 by the suction air from the air suction unit 62. When the suction photosensor 63 detects that the paper 90 has been adsorbed onto the suction belt 61, the side fan 521 of the side air supply unit 52 is stopped. At the same time, the air direction switching gate 53 is switched from the first position to the second position, and air is discharged from the front air supply unit 51 diagonally upward.

[0063] (3) Paper handling operation As shown in Figure 4C, during the paper handling operation, the air discharged diagonally upward from the tip air supply unit 51 separates the paper sheets 90 from the top sheet 91 from the one or more sheets 90 that are attached to the suction belt 61. For example, if three sheets of paper 92-94 in addition to the top sheet 91 are attached to the suction belt 61, the air blown onto the tips of the sheets 91-94 separates the sheets 92-94 from the sheet 91, causing them to fall and return to the paper stack 100.

[0064] In the paper feeder 20 of this embodiment, in order to reliably separate the remaining sheets 92-94 from the top sheet 91, the amount of air blown onto the leading edge of the sheet 90 is adjusted based on the moisture content of the sheet 90. Generally, the higher the moisture content of the paper, the more the sheets adhere to each other, making it more difficult to separate them. Therefore, in the paper feeder 20 of this embodiment, the leading edge air supply unit 51 is controlled so that the higher the moisture content of the paper, the greater the amount of air blown onto the leading edge of the paper.

[0065] (4) Paper feed priority operation As shown in Figure 4D, during the paper feeding start operation, the suction belt 61 is driven, and the uppermost sheet of paper 91 is transported downstream. The paper 91 transported by the suction belt 61 is then fed downstream by the exit roller pair 64.

[0066] <Paper feed condition control> Next, with reference to Figure 5, the control of paper feeding conditions by the paper feeding unit 24 during paper feeding will be explained. As described above, in the paper feeding device 20 of this embodiment, the amount of air blown onto the leading edge of the paper 90 is adjusted based on the moisture content of the paper 90.

[0067] Figure 5 is a flowchart showing the procedure for paper feed control processing by the paper feed device 20. Paper feed control processing is performed, for example, when the paper feed device 20 receives a signal from the image forming apparatus 10 instructing it to execute a job (feed a predetermined number of sheets of paper).

[0068] (Step S101) First, the paper feeder 20 feeds the paper 90. More specifically, the paper feeder 20 performs the above-described paper feeding operation and feeds one sheet of paper 90 to the image forming apparatus 10. The paper 90 fed from the paper feeder 20 passes through the paper characteristics detection device 30 and is transported to the image forming apparatus 10. At this time, the paper characteristics detection device 30 detects the moisture content of the paper 90 during transport and transmits the moisture content information of the paper 90 to the paper feeder 20. As described above, the moisture content information is calculated by giving maximum weight to the moisture content of the leading edge of the paper 90.

[0069] (Step S102) Next, the paper feeder 20 acquires information on the moisture content of the paper 90. More specifically, the paper feeder 20 receives information on the moisture content of the paper 90 fed in step S101 from the paper characteristics detection device 30.

[0070] (Step S103) Next, the paper feeder 20 determines the amount of air to be blown onto the leading edge of the next sheet of paper 90 when feeding the next sheet 90. More specifically, the paper feeder 20 determines the amount of air from the leading edge fan 511 of the leading edge air supply unit 51 when feeding the next sheet of paper 90, based on the moisture content information obtained in step S102. In this embodiment, the control unit 21 of the paper feeder 20 refers to the conversion table stored in the storage unit 22 and determines the amount of air from the leading edge fan 511 when feeding the next sheet of paper 90, based on the moisture content information obtained in step S102. As a result, during the paper handling operation (see Figure 4C) when feeding the next sheet of paper 90, the control unit 21 controls the leading edge fan 511, and the amount of air blown onto the leading edge of one or more sheets of paper 90 that are held in place by the suction belt 61 is adjusted.

[0071] (Step S104) Next, the paper feeder 20 determines whether the job has been completed. More specifically, the paper feeder 20 determines whether the job (feeding a predetermined number of sheets) that was instructed to be executed by the image forming apparatus 10 has been completed.

[0072] If it is determined that the job is not finished (step S104: NO), the paper feeder 20 returns to the process in step S101. Then, the processes in steps S101 to S104 are repeated until it is determined that the job is finished. On the other hand, if it is determined that the job is finished (step S104: YES), the paper feeder 20 terminates the process.

[0073] As described above, according to the flowchart shown in Figure 5, each time a sheet of paper 90 is fed from the paper feeder 20 to the image forming apparatus 10, the paper characteristic detection device 30 detects the moisture content of the paper 90. Based on the moisture content of the paper 90, the amount of air blown onto the leading edge of the paper 90 during the next paper feeding operation (paper handling operation) is adjusted. Specifically, the airflow of the leading edge fan 511 is adjusted so that the more moisture content the paper 90 has, the greater the airflow blown onto the paper 90. In this embodiment, the airflow of the leading edge fan 511 is adjusted steplessly (0 to 100%) according to the moisture content (moisture ratio) of the paper 90.

[0074] As described above, according to the image forming system 1 of this embodiment, the airflow of the tip fan 511 is adjusted so that the amount of air blown onto the paper increases as the moisture content of the paper increases. With this configuration, even when the moisture content of the paper 90 is high and the degree of adhesion between the sheets of paper 90 is high, the paper is reliably separated by blowing a large amount of air onto the paper 90, enabling sufficiently stable paper feeding.

[0075] Furthermore, according to the image forming system 1 of this embodiment, when detecting the moisture content of the paper 90, weighting is given to the moisture content of the leading edge of the paper 90. With this configuration, the airflow is adjusted based on the moisture content of the area to which air is blown, so the paper 90 can be separated more reliably. Note that the moisture content may differ depending on the in-plane position of the paper 90.

[0076] The present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the claims.

[0077] For example, in the embodiment described above, the airflow of the tip fan 511 was adjusted steplessly (0 to 100%) according to the moisture content of the paper 90. However, unlike the embodiment described above, the airflow of the tip fan 511 may be adjusted in two or three stages according to the moisture content of the paper 90.

[0078] Furthermore, in the embodiment described above, the amount of air blown onto the paper 90 from the front fan 511 was adjusted according to the moisture content of the paper 90. However, the method for adjusting the amount of air is not limited to the embodiment described above, and may be adjusted, for example, by controlling the number of fans to be driven. Specifically, if the moisture content of the paper 90 is low, for example, only the front fan 511 is driven, and if the moisture content of the paper 90 is high, for example, in addition to the front fan 511, the side fan 521 is also driven.

[0079] Furthermore, in the embodiment described above, the amount of air blown onto the paper 90 was adjusted according to the moisture content of the paper 90. However, the paper feeding conditions of the paper feeding unit 24, which are adjusted according to the moisture content of the paper 90, are not limited to the amount of air blown onto the paper; the air blowing time may also be adjusted. For example, by delaying the start time of the suction belt 61 as the moisture content of the paper increases, air from the tip air supply unit 51 is blown onto the paper 90 for a longer period of time. As a result, even if the moisture content of the paper 90 is high, the paper is reliably separated, and sufficiently stable paper feeding becomes possible.

[0080] Furthermore, in the above-described embodiment, the moisture content at multiple locations on the paper 90 was detected, and the weighted average of the moisture content at multiple locations was used as the moisture content of the paper. However, unlike the above-described embodiment, the moisture content at only the leading edge of the paper 90 may be selectively detected.

[0081] In the embodiment described above, the moisture sensor 34 for detecting the moisture content of the paper 90 is mounted on the paper characteristic detection device 30. However, the moisture sensor 34 may be mounted on the paper feed device 20, or on the image forming apparatus 10.

[0082] The means and methods for performing various processing in the image forming system 1 according to the above embodiment can be implemented by either a dedicated hardware circuit or a programmed computer. The program may be provided, for example, on a computer-readable recording medium such as a USB (Universal Serial Bus) memory or a DVD (Digital Versatile Disc)-ROM, or it may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. Furthermore, the program may be provided as a standalone application software, or it may be incorporated into the software of the image forming system 1 as a function of the device.

[0083] While embodiments of the present invention have been described and illustrated in detail, the disclosed embodiments are for illustrative purposes only and are not limiting. The scope of the present invention should be interpreted in accordance with the language of the appended claims. [Explanation of Symbols]

[0084] 1. Image forming system, 10 Image forming apparatus, 11,21,31 Control Unit, 12,22,32 storage section, 13, 23, 33 Communications Department, 14 Operation display section, 15 Main paper feed section, 16, 25, 35 Conveyor section, 17 Image forming unit, 18 Fixing section, 20 Paper feed device, 24 Paper feed section, 30. Paper characteristics detection device, 34 Moisture sensor, Papers 90, 91, 92, 93, 94 100 paper stacks.

Claims

1. An image forming unit that forms an image on paper, A paper feeding unit that feeds one sheet of paper at a time from a stack of multiple sheets of paper to the image forming unit, A detection unit for detecting the moisture content of paper fed by the aforementioned paper feeding unit, A control unit adjusts the paper feeding conditions when the paper feeding unit feeds paper based on the amount of moisture detected by the detection unit, An image forming system having the following features.

2. The paper feeding unit is configured to separate the top sheet of paper from the stack by blowing air onto the paper. The image forming system according to claim 1, wherein the control unit adjusts the airflow rate or the air blowing time as the paper feeding conditions.

3. The aforementioned paper feeding unit has an air supply unit that blows air onto the paper, The image forming system according to claim 1 or 2, wherein the control unit controls the operation of the air supply unit so that the airflow rate increases as the amount of moisture increases.

4. The aforementioned paper feeding unit has an air supply unit that blows air onto the paper, The image forming system according to claim 1 or 2, wherein the control unit controls the operation of the paper feeding unit such that the air blowing time increases as the amount of moisture increases.

5. The paper feeding unit includes a plurality of air supply units that blow air onto the paper, The image forming system according to claim 1 or 2, wherein the control unit controls the operation of the plurality of air supply units such that the number of air supply units that blow air onto the paper increases as the amount of moisture increases.

6. The paper feeding unit is configured to separate the top sheet of paper from the stack by blowing air onto the paper. The image forming system according to claim 1 or 2, wherein the control unit adjusts the paper feeding conditions based on the amount of moisture in the portion of the paper to which the air is blown.

7. The detection unit detects the moisture content at multiple locations on the paper, The image forming system according to claim 6, wherein the control unit calculates the moisture content of the paper by giving maximum weight to the moisture content of the portion of the paper to which the air is blown, and adjusts the paper feeding conditions.

8. The detection unit detects the amount of moisture in the portion of the paper to which the air is blown, The image forming system according to claim 6, wherein the control unit adjusts the paper feeding conditions based on the moisture content of the portion of the paper.

9. The image forming system according to claim 1 or 2, wherein the control unit adjusts the paper feeding conditions each time a sheet of paper is fed from the paper feeding unit to the image forming unit.

10. The image forming system according to claim 1 or 2, wherein the detection unit is disposed between the image forming unit and the paper feeding unit.

11. The image forming system according to claim 1 or 2, wherein the detection unit detects the amount of moisture in the paper being transported within the image forming system.

12. A control method for an image forming system having an image forming unit that forms an image on paper, and a paper feeding unit that feeds one sheet of paper at a time to the image forming unit from a stack of multiple sheets of paper, Step (a) of detecting the moisture content of the paper fed by the paper feeding unit, Step (b) adjusts the paper feeding conditions when the paper feeding unit feeds paper based on the amount of moisture detected in step (a), A control method for an image forming system, comprising the following:

Images