Paper property detection device, image forming system, and recording medium

Abstract

The invention relates to a paper characteristic detection device, an image forming system and a recording medium, which can prevent problems generated according to characteristics of paper when the characteristics of the paper are measured. A paper sheet characteristic detection device (2) is provided with: a first characteristic detection unit which is disposed on a conveyance path of a paper sheet and detects first characteristic information corresponding to a first characteristic of the paper sheet; and a second characteristic detection unit which is disposed on the conveyance path of the sheet, detects second characteristic information corresponding to a second characteristic of the sheet, and controls the other characteristic detection unit on the basis of the detection result of one of the first characteristic detection unit and the second characteristic detection unit.

Description

Technical Field

[0001] The present invention relates to a paper property detection device, an image forming system, and a recording medium. Background Art

[0002] In image forming devices that form and output images on paper, various conditions related to the image forming process and the recording medium transport process (image forming conditions) are appropriately adjusted based on the characteristics of the paper being formed, thereby enabling stable recording medium transport and the formation of high-quality images. Since various types of paper are used, there is a technique in which an image forming device is equipped with a sensor that measures the physical properties of the paper. The physical properties of the paper being transported are determined based on the sensor's measurement results and used to set conditions (for example, Patent Document 1). The physical properties of the paper include, for example, moisture content, electrical resistance, and stiffness.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2023-084232

[0004] However, various problems may arise when using these sensors for measurement, depending on paper characteristics such as its physical properties. For example, if a high voltage is applied to paper with a high moisture content to measure its resistance, the following problems may arise. Specifically, leakage voltage may be applied to electrical equipment within the device through the paper, exceeding its withstand voltage and causing damage. Summary of the Invention

[0005] An object of the present invention is to provide a paper property detection device, an image forming system, and a recording medium that can prevent problems caused by paper properties when measuring paper properties.

[0006] In order to achieve the above-mentioned purpose, the paper property detection device described in Technical Solution 1 comprises:

[0007] a first characteristic detecting unit, disposed on a paper conveying path, for detecting first characteristic information corresponding to a first characteristic of the paper; and

[0008] The second characteristic detecting unit is arranged on the conveying path and is used to detect second characteristic information corresponding to the second characteristic of the paper.

[0009] The paper property detection device controls the first property detection section and the second property detection section based on a detection result of one of the property detection sections.

[0010] The invention described in claim 2 is a paper property detection device described in claim 1.

[0011] The paper property detection device is arranged upstream or downstream of an image forming section that forms an image on the paper.

[0012] The invention described in claim 3 is a paper property detection device described in claim 2.

[0013] The paper property detection device is arranged on the upstream side of the image forming unit.

[0014] The image forming condition in the image forming section is determined based on at least one of the first characteristic information and the second characteristic information.

[0015] The invention described in claim 4 is a paper property detection device described in claim 1.

[0016] The second characteristic detection unit is arranged on the downstream side of the first characteristic detection unit.

[0017] The paper property detecting device controls the second property detecting section based on a detection result of the first property detecting section.

[0018] The invention described in claim 5 is a paper property detection device described in claim 4.

[0019] The detection conditions of the second characteristic detection section are changed based on the detection result of the first characteristic detection section.

[0020] The invention described in claim 6 is a paper property detection device described in claim 4.

[0021] Based on the detection result of the first characteristic detection section, control is performed so as not to perform detection by the second characteristic detection section.

[0022] The invention described in claim 7 is a paper property detection device described in claim 6.

[0023] When the second characteristic detecting section does not perform detection, the paper is discharged without stopping the paper by the second characteristic detecting section.

[0024] The invention described in claim 8 is a paper property detection device described in claim 1.

[0025] The first characteristic and the second characteristic are different from each other.

[0026] The invention described in claim 9 is a paper property detection device described in claim 1.

[0027] The first characteristic information is information corresponding to the moisture content of the paper.

[0028] The second characteristic information is information corresponding to the electrical resistance of the paper.

[0029] The invention described in technical solution 10 is a paper property detection device described in technical solution 9.

[0030] The larger the moisture content, the lower the voltage applied to the paper when the second characteristic detecting section detects information corresponding to the resistance.

[0031] The invention described in technical solution 11 is in the paper property detection device described in technical solution 9,

[0032] The larger the moisture content, the smaller the number of times the second characteristic detection unit detects information corresponding to the resistance.

[0033] The invention described in technical solution 12 is a paper property detection device described in technical solution 1.

[0034] The second characteristic detection unit is arranged on the downstream side of the first characteristic detection unit.

[0035] The first characteristic information is information corresponding to the moisture content of the paper.

[0036] The second characteristic information is information corresponding to the stiffness of the paper.

[0037] The invention described in technical solution 13 is a paper property detection device described in technical solution 12.

[0038] The detection operation when the second characteristic detection unit detects information corresponding to the stiffness is changed according to the moisture content.

[0039] The invention described in claim 14 is a paper property detection device described in claim 1.

[0040] The second characteristic detection unit is arranged on the downstream side of the first characteristic detection unit.

[0041] The first characteristic information is information corresponding to the thickness of the paper.

[0042] The second characteristic information is information corresponding to the moisture content of the paper.

[0043] The invention described in technical solution 15 is in the paper property detection device described in technical solution 14,

[0044] The detection conditions when the second characteristic detecting unit detects information corresponding to the moisture content are changed according to the paper thickness.

[0045] The invention described in claim 16 is a paper property detection device described in claim 1.

[0046] A control unit is provided for controlling the first characteristic detection unit and the second characteristic detection unit based on a detection result of one of the first characteristic detection unit and the second characteristic detection unit.

[0047] The image forming system according to claim 17 comprises:

[0048] The paper property detection device according to any one of technical solutions 1 to 16; and

[0049] The image forming unit forms an image on the paper.

[0050] The computer-readable recording medium according to claim 18 stores a program for causing a computer of the paper property detection device to function as a control unit, wherein:

[0051] The paper characteristics detection device has:

[0052] a first characteristic detecting unit, disposed on a paper conveying path, for detecting first characteristic information corresponding to a first characteristic of the paper; and

[0053] The second characteristic detecting unit is arranged on the conveying path and is used to detect second characteristic information corresponding to the second characteristic of the paper.

[0054] The control section controls the first characteristic detection section and the second characteristic detection section based on a detection result of one of the characteristic detection sections.

[0055] The invention described in claim 19 is that in the recording medium described in claim 18,

[0056] The paper property detection device is arranged upstream or downstream of an image forming section that forms an image on the paper.

[0057] The invention described in claim 20 is a recording medium described in claim 19,

[0058] The paper property detection device is arranged on the upstream side of the image forming unit.

[0059] The image forming condition in the image forming section is determined based on at least one of the first characteristic information and the second characteristic information.

[0060] The invention described in claim 21 is a recording medium described in claim 18,

[0061] The second characteristic detection unit is arranged on the downstream side of the first characteristic detection unit.

[0062] The control unit controls the second characteristic detection unit based on a detection result of the first characteristic detection unit.

[0063] The invention described in technical solution 22 is that in the recording medium described in technical solution 21,

[0064] The control unit changes a detection condition in the second characteristic detection unit based on a detection result of the first characteristic detection unit.

[0065] The invention described in claim 23 is that in the recording medium described in claim 21,

[0066] The control unit controls the second characteristic detection unit so as not to perform detection based on a detection result of the first characteristic detection unit.

[0067] The invention described in claim 24 is that in the recording medium described in claim 23,

[0068] When the second characteristic detecting section does not perform detection, the control section discharges the paper without stopping the paper by the second characteristic detecting section.

[0069] The invention described in claim 25 is that in the recording medium described in claim 18,

[0070] The first characteristic and the second characteristic are different from each other.

[0071] The invention described in claim 26 is that in the recording medium described in claim 18,

[0072] The first characteristic information is information corresponding to the moisture content of the paper.

[0073] The second characteristic information is information corresponding to the electrical resistance of the paper.

[0074] The invention described in claim 27 is that in the recording medium described in claim 26,

[0075] The control unit reduces the voltage applied to the paper when the second characteristic detection unit detects information corresponding to the resistance, as the moisture content increases.

[0076] The invention described in claim 28 is that in the recording medium described in claim 26,

[0077] The control unit reduces the number of times the second characteristic detection unit detects information corresponding to the resistance as the moisture content increases.

[0078] The invention described in claim 29 is that in the recording medium described in claim 18,

[0079] The second characteristic detection unit is arranged on the downstream side of the first characteristic detection unit.

[0080] The first characteristic information is information corresponding to the moisture content of the paper.

[0081] The second characteristic information is information corresponding to the stiffness of the paper.

[0082] The invention described in claim 30 is a recording medium described in claim 29.

[0083] The control unit changes a detection operation performed when the second characteristic detection unit detects information corresponding to the stiffness, based on the moisture content.

[0084] The invention described in claim 31 is that in the recording medium described in claim 18,

[0085] The second characteristic detection unit is arranged on the downstream side of the first characteristic detection unit.

[0086] The first characteristic information is information corresponding to the thickness of the paper.

[0087] The second characteristic information is information corresponding to the moisture content of the paper.

[0088] The invention described in claim 32 is that in the recording medium described in claim 31,

[0089] The control unit changes a detection condition when the second characteristic detection unit detects information corresponding to the moisture content, according to the paper thickness.

[0090] According to the present invention, it is possible to prevent problems caused by the characteristics of paper when measuring the characteristics of paper. BRIEF DESCRIPTION OF THE DRAWINGS

[0091] Figure 1 1 is a diagram showing the overall configuration of the image forming system according to this embodiment.

[0092] Figure 2 This is a diagram illustrating the detailed structure of the paper property detection device.

[0093] Figure 3 This is a diagram showing an example of a schematic configuration of a moisture content sensor.

[0094] Figure 4A This is a perspective view showing an example of a schematic structure of a stiffness sensor.

[0095] Figure 4B This is a side view showing an example of a schematic structure of a stiffness sensor.

[0096] Figure 5 1 is a diagram showing an example of a schematic structure of a resistance sensor.

[0097] Figure 6 This is a flowchart showing the control steps of the detection control process.

[0098] Figure 7 This is a flowchart showing the control procedure of the detection control process according to the first modification.

[0099] Figure 8 This is a flowchart showing the control steps of the detection control process of Modification Example 2.

[0100] Figure 9 This is a diagram showing the correspondence between the moisture content of paper and the applied voltage in Modification 2.

[0101] Figure 10 This is a diagram showing the correspondence between the moisture content of paper and the number of measurements by the resistance sensor in Modification 2.

[0102] Figure 11 This is a flowchart showing the control steps of the detection control process of Modification Example 3.

[0103] Figure 12A A schematic diagram showing the paper and the stiffness sensor before the first movement of the pressing member.

[0104] Figure 12B A schematic diagram showing the paper and the stiffness sensor after the first movement of the pressing member.

[0105] Figure 13A A schematic diagram showing the paper and the stiffness sensor before the second movement of the pressing member.

[0106] Figure 13B A schematic diagram showing the paper and the stiffness sensor after the second movement of the pressing member.

[0107] Figure 14 This is a flowchart showing the control steps of the detection control process according to the fourth modification.

[0108] Explanation of reference numerals: 1…paper feeding device; 11…paper feeding tray; 2…paper property detecting device; 21…control unit; 22…storage unit; 23…paper thickness sensor; 24…moisture content sensor; 25…rigidity sensor; 26…resistance sensor; 27…conveying unit; 271…clearing tray; 27M…first conveying path; 27S…second conveying path; 28…communication unit; 3…image forming device; 31…writing unit; 31a…light scanning unit; 31b…photosensitive body; 31c…developing unit; 31d…charging unit; 31e…cleaning unit; 31f…primary transfer roller; 32…intermediate transfer belt; 33…secondary transfer roller; 34…fixing unit; 36…reversing path; 4…post-processing device; 301…control unit; 302…document reading unit; 303…operation receiving unit; 304…display unit; 305…image forming unit; E…ejection tray; U…image forming system. DETAILED DESCRIPTION

[0109] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the scope of the invention is not limited to the examples shown in the drawings.

[0110] <1. Image Forming System Structure>

[0111] Figure 1 1 is a diagram showing the overall configuration of the image forming system U according to the present embodiment.

[0112] The image forming system U includes a paper feeding device 1 , a paper property detecting device 2 , an image forming device 3 , and a post-processing device 4 .

[0113] (Paper feeding device)

[0114] The paper feeding device 1 includes a plurality of paper feeding trays 11. The paper feeding device 1 feeds out media (paper) on which images are to be recorded, one by one, from any selected and set paper feeding tray 11.

[0115] (Paper characteristics detection device)

[0116] The paper property detection device 2 includes multiple sensors for measuring the physical properties of the paper. The paper property detection device 2 uses the multiple sensors to measure the paper fed from the paper feed device 1 along its path. Based on the measurement results, the paper property detection device 2 can determine the physical properties of the paper (characteristic information). The paper property information can be the characteristic value of the paper itself or a value indicating the characteristic, such as the current or voltage, of the sensor corresponding to the characteristic value. The paper property detection device 2 can also output the physical property values obtained through measurement as is to an external device, such as the image forming device 3.

[0117] Figure 2This is a block diagram of the paper property detection device 2. The paper property detection device 2 includes a control unit 21, a storage unit 22, a paper thickness sensor 23, a moisture sensor 24, a stiffness sensor 25, a resistance sensor 26, a conveying unit 27, and a communication unit 28.

[0118] The control unit 21 centrally controls the operation of the paper property detection device 2. The control unit 21 includes a CPU (Central Processing Unit), RAM (Random Access Memory), and other components. The CPU controls the measurement operations of the sensors (paper thickness sensor 23, moisture sensor 24, stiffness sensor 25, and resistance sensor 26) and the paper conveyance operation of the conveyance unit 27. The RAM temporarily stores the measurement results of the sensors.

[0119] The storage unit 22 stores control programs for measurement operations of each sensor, measurement setting data, etc. The storage unit 22 includes a nonvolatile memory such as an HDD or a flash memory.

[0120] The conveying unit 27 is Figure 1 The right side receives the paper fed from the paper feeding device 1 and conveys it along the first conveying path 27M. Figure 1 The left side of the first conveying path 27M is sent to the image forming apparatus 3. A second conveying path 27S branches off from the middle of the horizontally extending first conveying path 27M. The front end of the second conveying path 27S is connected to a clearing tray 271.

[0121] The paper thickness sensor 23 is located on the upstream side of the first conveyance path 27M, and the moisture content sensor 24 is located on the downstream side.

[0122] The stiffness sensor 25 is located on the upstream side of the second transport path 27S, and the resistance sensor 26 is located on the downstream side.

[0123] The paper thickness sensor 23 measures the paper thickness of the paper as characteristic information of the paper and outputs the measurement result.

[0124] The paper thickness sensor 23 includes a pair of conveyor rollers, at least one of which moves according to the thickness of the paper passing through the roller nip, and a measuring unit that measures the distance between the axes of the conveyor roller pair. The measuring unit includes, for example, an actuator, an encoder, a light emitting unit, and a light receiving unit. The axis of the movable driven roller shifts according to the thickness of the paper sandwiched between the conveyor roller pair. The paper thickness sensor 23 measures the paper thickness by measuring the height of this shifted axis.

[0125] The moisture content sensor 24 measures characteristic information corresponding to the moisture content of the paper and outputs the measurement result. In this embodiment, a moisture content sensor that measures the moisture content of the paper as characteristic information of the paper is used as an example. However, a moisture content sensor that measures the amount of water contained in the paper as characteristic information of the paper can also be used.

[0126] Figure 3 Schematic diagram showing the structure of the moisture content sensor 24 .

[0127] like Figure 3 As shown, the moisture content sensor 24 includes a first light emitting unit 241 , a second light emitting unit 242 , a light receiving unit 243 , lenses 244 and 245 , and the like.

[0128] The first light emitting unit 241 emits first near-infrared light (reference light) in a specific wavelength band toward the paper P. A specific example of the first light emitting unit 241 is an LED (Light Emitting Diode). The absorption rate of this first near-infrared light in the paper P when reflected by the paper P is independent of the moisture content of the paper P.

[0129] The light receiving unit 243 receives the first near-infrared light emitted from the first light emitting unit 241 and reflected by the paper P via the lens 244 through the lens 245 .

[0130] Specific examples of the light receiving unit 243 include a CCD (Charge-Coupled Device) or a CMOS image sensor (Complementary metal-oxide-semiconductor).

[0131] The second light emitting unit 242 emits second near-infrared light of a specific wavelength band toward the paper P. A specific example of the second light emitting unit 242 is an LED. The absorption rate of the second near-infrared light in the paper P when reflected by the paper P varies depending on the moisture content of the paper P.

[0132] The light receiving unit 243 receives the second near-infrared light emitted from the second light emitting unit 242 and reflected by the paper P via the lens 244 through the lens 245 .

[0133] The moisture content sensor 24 outputs the amount of first near-infrared light and the amount of second near-infrared light received by the light receiving unit 243 (characteristic information corresponding to the moisture content of the paper) to the control unit 21 .

[0134] The control unit 21 calculates the moisture content of the paper P based on the ratio between the amount of received first near-infrared light and the amount of received second near-infrared light.

[0135] The structure of the moisture content sensor 24 is not limited to Figure 3 The moisture content sensor 24 may have other configurations as long as it can measure characteristic information corresponding to the moisture content of the paper P.

[0136] The paper thickness sensor 23 and the moisture content sensor 24 can measure the above-mentioned characteristic information while each paper being conveyed is moved at a conveyance speed.

[0137] The stiffness sensor 25 measures characteristic information corresponding to the stiffness of the paper and outputs the measurement result. The stiffness of the paper is an index indicating the resistance of the paper when it is bent.

[0138] Figure 4A It is a perspective view showing the structure of the stiffness sensor 25 . Figure 4B It is a side view showing the structure of the stiffness sensor 25 .

[0139] The stiffness sensor 25 includes a paper holding roller 251 that holds one end portion of the paper P and a pressing portion 252. Figure 4A 、 Figure 4B In the illustrated example, the paper holding roller 251 is also included in the conveying portion 27 and has a function of conveying the paper P, but a separate independent member may also be employed.

[0140] The pressing portion 252 includes a pressing member 252 a , a pressing force detection portion 252 b , a support mechanism 252 c , and a motor M1 .

[0141] The pressing member 252a is formed into a strip shape long in the paper width direction (Y-axis direction) so as to be able to contact the entire width of the paper P conveyed in the paper conveying direction (Z-axis direction).

[0142] The pressing force detection unit 252 b includes, for example, a pressure sensor, and detects the pressing force from the paper P when the pressing member 252 a presses the paper P.

[0143] The support mechanism 252c supports the pressing member 252a and the pressing force detection unit 252b so as to be movable in the X-axis direction.

[0144] The motor M1 is a driving source for moving the pressing member 252a and the pressing force detection unit 252b in the X-axis direction via the support mechanism 252c. The motor M1 includes, for example, a stepping motor.

[0145] A method of obtaining the stiffness of the paper P will be described below.

[0146] like Figure 4A 、 Figure 4BAs shown, the conveying unit 27, under the control of the control unit 21, stops the motor M2 driving the paper holding roller 251, thereby stopping the conveyance of the paper P at a predetermined position on the second conveying path 27S. At this time, the paper P is nipped and held between the paper holding rollers 251. The paper holding rollers 251 hold the paper P at a predetermined distance from the end Pa of the paper P.

[0147] Next, the pressing portion 252 is driven by the motor M1 to move the pressing member 252a in the positive direction of the X axis. Figure 4B As shown, the end Pa (free end) of the paper P is pressed by the pressing member 252a and bent. At this time, the pressing member 252a starts to contact the paper surface ( Figure 4B The position where the pressing member 252a contacts the paper P (the right side in the figure) is defined as the starting position of the pressing member 252a in the X-axis direction. The pressing force detection unit 252b detects the pressing force applied to the paper P when the pressing member 252a bends the paper P by a predetermined amount (e.g., 3 mm) from the starting position.

[0148] The pressing portion 252 pushes a pressing member 252a against the paper P at a position closer to the end Pa of the paper P than the position where the paper P is held by the paper holding roller 251, thereby pressing the paper P. The amount of pressure and bending of the paper P by the pressing member 252a can be determined by the number of pulse signals input to the driver of the motor M1.

[0149] The stiffness sensor 25 outputs the pressing force detected by the pressing force detection unit 252b (characteristic information corresponding to the stiffness of the paper) to the control unit 21. The control unit 21 calculates the stiffness of the paper based on the pressure value of the pressing force.

[0150] exist Figure 4A 、 Figure 4B In the embodiment, the pressing member 252a presses the paper P from right to left, but the present invention is not limited thereto. The pressing member 252a may press the paper P from left to right.

[0151] The resistance sensor 26 measures characteristic information corresponding to the resistance (volume resistance) of paper and outputs the measurement result.

[0152] Figure 5 Schematic diagram showing the structure of the resistance sensor 26 .

[0153] like Figure 5 As shown in FIG. 1 , the resistance sensor 26 includes a paper holding roller 261 that sandwiches the paper P with a pair of rollers, and an HV (high voltage) unit 262. Figure 5 In the illustrated example, the paper holding roller 261 is also included in the conveying portion 27 and has a function of conveying the paper P, but a separate independent member may also be employed.

[0154] The paper holding roller 261 includes a detection roller 261 a located on the left side of the paper surface and an opposing roller 261 b located on the right side of the paper surface and in contact with the paper surface.

[0155] A method of obtaining the resistance of the paper P will be described below.

[0156] like Figure 5 As shown, under the control of the control unit 21, the conveying unit 27 stops the motor M3 that drives the paper holding roller 261, and temporarily stops the paper P at a specified position on the second conveying path 27S. At this time, the paper P is clamped and held between the paper holding rollers 261. In this state, the resistance sensor 26 applies a high voltage to the detection roller 261a through the HV unit 262, and measures the current value flowing through the paper P to the opposing roller 261b. The resistance sensor 26 outputs the measured current value (characteristic information corresponding to the resistance of the paper) to the control unit 21. The control unit 21 calculates the resistance of the paper by dividing the voltage applied to the detection roller 261a by the HV unit 262 by the current value measured by the resistance sensor 26.

[0157] Alternatively, the resistance sensor 26 may measure characteristic information corresponding to the resistance of a sheet of paper a plurality of times to calculate the resistance of the paper.

[0158] In this case, as described above, the resistance sensor 26 applies a high voltage to the detection roller 261a via the HV unit 262, thereby first measuring the current value flowing to the opposing roller 261b via the paper P held by the paper holding roller 261. The resistance sensor 26 then outputs the first measured current value to the control unit 21.

[0159] Next, under the control of the control unit 21, the conveying unit 27 conveys the paper P and temporarily stops so that the paper P is held by the paper holding roller 261 at a position other than the position where it was held by the paper holding roller 261 during the first current value measurement. In this state, the resistance sensor 26 applies a high voltage to the detection roller 261a via the HV unit 262, and performs a second measurement of the current value flowing through the paper P held by the paper holding roller 261 to the opposing roller 261b. The resistance sensor 26 then outputs the current value measured for the second time to the control unit 21. The resistance sensor 26 similarly measures the current value flowing through the paper P to the opposing roller 261b multiple times.

[0160] Next, the control unit 21 calculates the resistance of the paper by dividing the voltage applied to the detection roller 261 a by the HV unit 262 by the average value of the current values measured a plurality of times.

[0161] The stiffness sensor 25 and the resistance sensor 26 measure the above-mentioned characteristic information in a state where the conveyance of the paper is temporarily stopped.

[0162] Under the control of the control unit 21 , the conveying unit 27 discharges the paper sheet, which has been measured by each sensor, to the clear tray 271 without conveying it to the image forming apparatus 3 .

[0163] In the image forming system U, the communication unit 28 controls communication between the paper characteristics detection device 2 and the paper feeding device 1 , the image forming device 3 , and the post-processing device 4 .

[0164] The control unit 21 outputs at least one of the paper thickness, moisture content, stiffness, and electrical resistance of the paper as the paper characteristics to the image forming apparatus 3 via the communication unit 28 .

[0165] (Image Forming Apparatus)

[0166] The image forming device 3 forms an image of image data read from a document onto paper and outputs the image. Based on image data received from an external device (not shown), the image forming device 3 electrophotographically forms the image onto paper and outputs the image. Specifically, the image forming device 3 is a multifunction peripheral. The image forming device 3 can connect to external devices, such as a PC, via a LAN (Local Area Network).

[0167] The image forming apparatus 3 includes a control unit 301 , a document reading unit 302 , an operation accepting unit 303 , a display unit 304 , an image forming unit 305 , a storage unit (not shown), a communication unit (not shown), and the like.

[0168] The control unit 301 comprehensively controls the operation of the image forming apparatus 3. The control unit 301 includes a CPU, RAM, etc. The CPU performs various settings and operations related to image formation based on an operation signal input from the operation receiving unit 303 or an instruction signal received from the communication unit.

[0169] The document reading unit 302 reads an image of a document placed on a document table or on an automatic document feeder (ADF). The document reading unit 302 scans and exposes the document using the optical system of a scanning exposure device, and then reads the reflected light with a line image sensor to obtain an image signal. The document reading unit 302 then performs processing such as A / D conversion, shading correction, and compression on this image signal to generate image data.

[0170] The operation receiving unit 303 receives external input operations from the user or the like. The operation receiving unit 303 includes a touch panel provided on the screen of the display unit 304 and various hard keys arranged around the screen of the display unit 304. The operation receiving unit 303 converts the content of the received operation into an operation signal corresponding to the content and outputs it to the control unit 301. The touch panel may be any of pressure-sensitive, electrostatic, optical, and other types.

[0171] The display unit 304 includes, for example, a color liquid crystal display, and displays various information based on the control of the control unit 301 .

[0172] The image forming unit 305 applies colorant to paper based on image data to be formed and fixes the color.

[0173] The control unit 301 determines image forming conditions in the image forming unit 305 based on at least one of the paper thickness, moisture content, stiffness, and electrical resistance received from the paper property detection device 2. The image forming unit 305 forms an image on the paper based on the image forming conditions.

[0174] The image forming section 305 includes four writing sections 31 , an intermediate transfer belt 32 , a secondary transfer roller 33 , a fixing section 34 , and the like.

[0175] Four writing units 31 are arranged in tandem along the surface of the intermediate transfer belt 32 to form images in the colors C (cyan), M (magenta), Y (yellow), and K (black). The structure of each writing unit 31 can be the same for each color. For example, the writing unit 31 includes a light scanning unit 31a, a photoreceptor 31b, a developing unit 31c, a charging unit 31d, a cleaning unit 31e, and a primary transfer roller 31f.

[0176] In each writing unit 31, the charging unit 31d uniformly charges the photoreceptor 31b. The optical scanning unit 31a emits a light beam based on the original image data to scan and expose the charged photoreceptor 31b, forming an electrostatic latent image. The developing unit 31c supplies colorant such as toner to the electrostatic latent image and develops it, forming an image on the photoreceptor 31b.

[0177] The four writing units 31 sequentially transfer the images formed on the photoreceptors 31b onto the intermediate transfer belt 32 via their respective primary transfer rollers 31f, overlapping each other. Through this transfer (primary transfer), the writing units 31 form images composed of various colors on the intermediate transfer belt 32. The intermediate transfer belt 32 is wound around multiple rollers and rotates. After the primary transfer, the cleaning unit 31e removes any residual colorant from the photoreceptors 31b.

[0178] The image forming device 3 passes a sheet of paper over the secondary transfer roller 33, based on the timing when the image on the rotating intermediate transfer belt 32 reaches the position of the secondary transfer roller 33. The secondary transfer roller 33 comprises a pair of rollers. One of the rollers is in pressure contact with the intermediate transfer belt 32, and the other roller forms one of the multiple rollers around which the intermediate transfer belt 32 is wound. The image is transferred (secondary transfer) from the intermediate transfer belt 32 to the sheet of paper by the pressure contact of the secondary transfer roller 33.

[0179] The paper to which the image has been secondary transferred is conveyed to the fixing section 34 for fixing. The fixing section 34 includes a pair of fixing rollers in pressure contact with each other, at least one of which is heated. The fixing rollers heat and pressurize the paper passing between the rollers, fixing the image on the paper.

[0180] When images are formed on both sides of the paper, the paper, on which an image has been formed and fixed on one side, is fed to the reversing path 36 and reversed. The paper then returns to a position upstream of the secondary transfer roller 33. When image formation is only on one side, or when image formation on both sides is complete, the paper is discharged from the fixing unit 34 to the post-processing device 4.

[0181] (Post-processing device)

[0182] The post-processing device 4 performs post-processing on the paper sheets with images formed thereon. Post-processing includes, for example, sorting, cutting, stapling, folding, etc. The post-processing device 4 discharges the post-processed paper sheets to a discharge tray E or the like.

[0183] <2. Image Forming System Operation>

[0184] Next, the operation of the image forming system U will be described.

[0185] Figure 6 1 is a flowchart showing a control procedure of a detection control process executed by the control unit 21 of the paper characteristics detection device 2. The control unit 21 executes the detection control process before starting the image forming operation.

[0186] In this embodiment, the first characteristic of the paper is its moisture content, and the moisture content sensor 24 functions as a first characteristic detection unit. The second characteristic of the paper is its electrical resistance, and the resistance sensor 26 functions as a second characteristic detection unit.

[0187] In the detection control process, the control unit 21 controls the second characteristic detection unit based on the detection result of the first characteristic detection unit.

[0188] (Detection control processing)

[0189] The control unit 21 causes the paper feeding device 1 to feed the first sheet of paper from the tray for feeding paper to be image-formed and to convey the first sheet of paper along the first conveyance path 27M (step A1 ).

[0190] Next, the control unit 21 obtains characteristic information (first characteristic information) corresponding to the moisture content of the paper from the moisture content sensor 24 of the paper property detection device 2. Next, the control unit 21 calculates the moisture content of the paper based on the characteristic information to obtain the moisture content of the paper (step A2).

[0191] Next, the control unit 21 conveys the paper to the second conveyance path 27S (step A3 ).

[0192] Next, the control unit 21 acquires characteristic information corresponding to the stiffness of the paper from the stiffness sensor 25. The control unit 21 calculates the stiffness of the paper based on the characteristic information, thereby acquiring the stiffness of the paper (step A4).

[0193] Next, the control unit 21 determines whether the moisture content of the paper acquired in step A2 is equal to or greater than a predetermined first threshold value (for example, 30%) (step A5). The first threshold value is set in advance.

[0194] If the moisture content of the paper is less than the first threshold value (step A5: No), the control unit 21 obtains characteristic information (second characteristic information) corresponding to the resistance of the paper through the resistance sensor 26. The control unit 21 calculates the resistance of the paper based on this characteristic information to obtain the resistance of the paper (step A6).

[0195] Next, the control unit 21 conveys the paper along the second conveyance path 27S and discharges the paper onto the clearing tray 271 (step A7 ), and ends the detection control process.

[0196] On the other hand, when the moisture content of the paper is equal to or greater than the first threshold value (step A5 : Yes), the control unit 21 moves the detection control process to step A7 .

[0197] Specifically, if the moisture content of the paper is above the first threshold, the control unit 21 ejects the paper without performing measurement by the resistance sensor 26. In other words, based on the detection result of the moisture content sensor 24 (the first characteristic detection unit), the control unit 21 controls the paper so that the resistance sensor 26 (the second characteristic detection unit) does not perform detection. In this case, the control unit 21 ejects the paper without performing the action of stopping the paper by the resistance sensor 26 (the second characteristic detection unit).

[0198] This can prevent a situation where, when the moisture content of the paper is equal to or greater than the first threshold, a high voltage is applied to the paper by the resistance sensor 26 , and a leakage voltage is applied to the electrical equipment in the paper property detection device 2 through the paper, thereby preventing the electrical equipment from being damaged.

[0199] <3. Modifications>

[0200] While the present embodiment has been described above, the specific structure is not limited to the above-described embodiment and can be modified without departing from the scope of the invention. Below, variations of the present embodiment are described. In the variations, the same reference numerals are used for the same structures as in the above-described embodiment, and the description thereof is omitted.

[0201] (Variation 1)

[0202] Figure 7 A flowchart showing the detection control process according to Modification 1.

[0203] In Modification 1, the first characteristic of the paper is its moisture content, and the moisture content sensor 24 functions as a first characteristic detection unit. The second characteristic of the paper is its electrical resistance, and the resistance sensor 26 functions as a second characteristic detection unit.

[0204] In the detection control process of Modification 1, the control unit 21 controls the second characteristic detection unit based on the detection result of the first characteristic detection unit.

[0205] (Detection Control Processing of Modification 1)

[0206] The control unit 21 executes steps B1 to B7 which are the same as steps A1 to A7 of the above-described embodiment.

[0207] If the moisture content of the paper is above the first threshold (step B5: Yes), the control unit 21 changes the measurement conditions for the characteristic information (second characteristic information) corresponding to the paper's electrical resistance by the resistance sensor 26. Specifically, the control unit 21 changes the detection conditions of the resistance sensor 26 (second characteristic information) based on the detection results of the moisture content sensor 24 (first characteristic detection unit). Next, the control unit 21 obtains the characteristic information corresponding to the paper's electrical resistance measured under the changed measurement conditions from the resistance sensor 26. The control unit 21 then calculates the paper's electrical resistance based on this characteristic information to obtain the paper's electrical resistance (step B8), and then moves the detection control process to step B7.

[0208] In step B8 , the control unit 21 reduces the voltage applied to the detection roller 261 a by the HV unit 262 from 2000 V to 1000 V, for example, as a change in the measurement conditions.

[0209] (Variation 2)

[0210] Figure 8 A flowchart showing the detection control process of Modification 2.

[0211] In Modification 2, the first characteristic of the paper is its moisture content, and the moisture content sensor 24 functions as a first characteristic detection unit. The second characteristic of the paper is its electrical resistance, and the resistance sensor 26 functions as a second characteristic detection unit.

[0212] In the detection control process of the second modification, the control unit 21 controls the second characteristic detection unit based on the detection result of the first characteristic detection unit.

[0213] (Detection Control Processing of Modification Example 2)

[0214] The control unit 21 executes steps C1 to C4 which are the same as steps A1 to A4 of the above-described embodiment.

[0215] Next, the control unit 21 determines whether the moisture content of the paper acquired in step C2 is equal to or greater than a predetermined second threshold value (eg, 50%) (step C5 ). The second threshold value is set in advance.

[0216] If the moisture content of the paper is less than the second threshold value (step C5: No), the control unit 21 changes the measurement conditions for the characteristic information (second characteristic information) corresponding to the paper's electrical resistance in the resistance sensor 26 based on the paper's moisture content acquired in step C2. Next, the control unit 21 acquires the characteristic information corresponding to the paper's electrical resistance measured under the changed measurement conditions from the resistance sensor 26. Next, the control unit 21 calculates the paper's electrical resistance based on this characteristic information to acquire the paper's electrical resistance (step C6).

[0217] In step C6, as a change to the measurement conditions, the control unit 21 reduces the voltage applied to the detection roller 261a by the HV unit 262 as the moisture content of the paper increases. In other words, the control unit 21 reduces the voltage applied to the paper when the resistance sensor 26 (second characteristic detection unit) detects characteristic information corresponding to the resistance as the moisture content (water content) of the paper increases.

[0218] Figure 9 The correspondence between the moisture content of the paper and the voltage (applied voltage) applied to the detection roller 261 a by the HV unit 262 is shown.

[0219] Alternatively, in step C6, resistance sensor 26 may measure characteristic information corresponding to the resistance of a single sheet of paper multiple times. In this case, as a change in measurement conditions, control unit 21 reduces the number of measurements performed by resistance sensor 26 on a single sheet of paper as the moisture content of the paper increases. In other words, as the moisture content (water content) of the paper increases, control unit 21 reduces the number of times resistance sensor 26 (second characteristic detection unit) detects characteristic information corresponding to the resistance.

[0220] Figure 10The correspondence between the moisture content of the paper and the number of measurements performed by the resistance sensor 26 on one sheet of paper is shown.

[0221] Next, the control unit 21 conveys the paper along the second conveyance path 27S and discharges the paper onto the clearing tray 271 (step C7 ), and ends the detection control process.

[0222] On the other hand, when the moisture content of the paper is equal to or greater than the second threshold value (step C5 : Yes), the control unit 21 shifts the detection control process to step C7 .

[0223] That is, when the moisture content of the paper is equal to or greater than the second threshold value, the control unit 21 discharges the paper without performing measurement by the resistance sensor 26 .

[0224] (Variation 3)

[0225] Figure 11 A flowchart showing the detection control process of Modification 3.

[0226] In Modification 3, the first characteristic of the paper is its moisture content, and the moisture content sensor 24 functions as a first characteristic detection unit. The second characteristic of the paper is its stiffness, and the stiffness sensor 25 functions as a second characteristic detection unit.

[0227] In the detection control process of Modification 3, the control unit 21 controls the second characteristic detection unit based on the detection result of the first characteristic detection unit.

[0228] (Detection Control Processing of Modification 3)

[0229] The control unit 21 executes steps D1 to D3 which are the same as steps A1 to A3 of the above-described embodiment.

[0230] Next, the control unit 21 determines whether the moisture content of the paper acquired in step D2 is equal to or less than a predetermined third threshold value (for example, 3%) (step D4). The third threshold value is set in advance.

[0231] If the moisture content of the paper is greater than the third threshold value (step D4: No), the control unit 21 obtains characteristic information (second characteristic information) corresponding to the stiffness of the paper from the stiffness sensor 25. The control unit 21 calculates the stiffness of the paper based on this characteristic information, thereby obtaining the stiffness of the paper (step D5).

[0232] In step D5 , the pressing unit 252 drives the motor M1 to move the pressing member 252 a only once in the positive direction of the X axis. The pressing force detector 252 b detects the pressing force received from the paper P at this time.

[0233] Next, the control unit 21 executes steps D6 and D7 which are the same as steps A6 and A7 of the above-described embodiment.

[0234] On the other hand, if the moisture content of the paper is below the third threshold (step D4: Yes), the control unit 21 changes the measurement conditions for the characteristic information corresponding to the paper's stiffness by the stiffness sensor 25. The control unit 21 then acquires the characteristic information corresponding to the paper's stiffness, measured under the changed measurement conditions, from the stiffness sensor 25. The control unit 21 then calculates the stiffness of the paper based on this characteristic information to obtain the stiffness of the paper (step D8), and then moves the detection control process to step D6.

[0235] In step D8 , as a change in the measurement conditions, the control unit 21 moves the pressing member 252 a twice in the positive direction of the X axis, and measures the pressing force received from the paper P after the second movement by the pressing force detection unit 252 b .

[0236] Figures 12A to 13B The following shows an example in which characteristic information corresponding to the stiffness of the paper is measured by the stiffness sensor 25 when the moisture content of the paper is equal to or less than the third threshold value.

[0237] Figure 12A A schematic diagram showing the paper P and the stiffness sensor 25 before the pressing member 252 a moves in the positive direction of the X axis for the first time.

[0238] When the moisture content of the paper is less than the third threshold value, the paper P is charged due to friction between the paper P and the conveying roller while the paper P is conveyed to the stiffness sensor 25. Figure 12A As shown, when the paper P is held by the paper holding roller 251 , a predetermined portion Pb of the paper P is attached to the second transport path 27S.

[0239] Figure 12B In this state, the pressing member 252 a is moved in the positive direction of the X axis, and the paper P is pressed by the pressing member 252 a.

[0240] In this case, the end Pa of the paper P is Figure 12B The pressing force detecting portion 252 b cannot accurately measure the pressing force received from the paper P due to movement in the direction of the arrow shown.

[0241] Then, the stiffness sensor 25 returns the pressing member 252a to the original position.

[0242] like Figure 12B As shown in FIG. 1 , the charge of the paper P is removed by the pressing member 252a touching the paper P. Figure 13A As shown in FIG. 2 , before the second movement of the pressing member 252 a in the positive direction of the X axis, the paper P is not attached to the second transport path 27S.

[0243] Therefore, if Figure 13B As shown, after the second movement of the pressing member 252 a , the pressing force detection unit 252 b can accurately measure the pressing force received from the paper P.

[0244] As described above, in step D8 , the control unit 21 changes the detection operation when the stiffness sensor 25 (second characteristic detection unit) detects characteristic information corresponding to stiffness, according to the moisture content (water content) of the paper.

[0245] (Variation 4)

[0246] Figure 14 A flowchart showing the detection control process of Modification 4.

[0247] In Modification 4, the first characteristic of the paper is the paper thickness, and the paper thickness sensor 23 functions as the first characteristic detection unit. The second characteristic of the paper is the paper moisture content, and the moisture content sensor 24 functions as the second characteristic detection unit.

[0248] In the detection control process of Modification 4, the control unit 21 controls the second characteristic detection unit based on the detection result of the first characteristic detection unit.

[0249] (Detection Control Processing of Modification 4)

[0250] The control unit 21 executes step E1 which is the same as step A1 of the above embodiment.

[0251] Next, the control unit 21 acquires the paper thickness (first characteristic information) of the paper from the paper thickness sensor 23 (step E2 ).

[0252] Next, the control unit 21 determines whether the paper thickness acquired in step E2 is equal to or less than a predetermined fourth threshold value (step E3). The fourth threshold value is set in advance.

[0253] If the paper thickness is greater than the fourth threshold (step E3: No), the control unit 21 executes steps E4 to E6, which are similar to steps A2, A3, and A7 in the above embodiment, and ends the detection control process. In this case, the control unit 21 may also execute the same processes as steps A5 and A6 in the above embodiment after step E5.

[0254] On the other hand, if the paper thickness is less than the fourth threshold value (step E3: Yes), the control unit 21 changes the measurement conditions for the characteristic information (second characteristic information) corresponding to the moisture content of the paper by the moisture content sensor 24. Next, the control unit 21 obtains the characteristic information corresponding to the moisture content of the paper measured under the changed measurement conditions from the moisture content sensor 24. Next, the control unit 21 calculates the moisture content of the paper based on this characteristic information to obtain the moisture content of the paper (step E7), and then moves the detection control process to step E5.

[0255] When the paper thickness is less than the fourth threshold value, the paper is easily deformed in the vertical direction ( Figure 1 In order to accurately measure characteristic information corresponding to the moisture content of the paper, it is necessary to perform measurement at the timing when the vibration stops.

[0256] Therefore, in step E7, as a change in measurement conditions, the control unit 21 controls the moisture content sensor 24 so that the timing for measuring characteristic information corresponding to the moisture content of the paper is later than when the paper thickness is greater than the fourth threshold value. In other words, the control unit 21 changes the detection conditions for the moisture content sensor 24 (second characteristic detection unit) detecting characteristic information corresponding to the moisture content (moisture content) of the paper, based on the paper thickness.

[0257] (other)

[0258] In the image forming system U of the above embodiment and the modified example, the paper property detection device 2 is arranged upstream of the image forming device 3 , but the present invention is not limited thereto. The paper property detection device 2 may be arranged downstream of the image forming device 3 .

[0259] In this case, the control unit 301 of the image forming apparatus 3 also determines the image forming conditions based on at least one of the paper thickness, moisture content, stiffness, and electrical resistance received from the paper property detection apparatus 2 .

[0260] In the detection control process of the above embodiment and the modified example, the control unit 21 controls the second characteristic detection unit based on the detection result of the first characteristic detection unit, but the present invention is not limited to this. The control unit 21 may also control the first characteristic detection unit based on the detection result of the second characteristic detection unit.

[0261] <4. Effect>

[0262] As described above, the paper property detection device 2 of this embodiment includes a first property detection unit that is disposed on the paper conveyance path and detects first property information corresponding to the first property of the paper.

[0263] The paper property detection device 2 of this embodiment includes a second property detection unit that is disposed on a paper conveyance path and detects second property information corresponding to a second property of the paper.

[0264] In the paper property detection device 2 of this embodiment, based on the detection result of one of the first property detection section and the second property detection section, the other property detection section is controlled.

[0265] Therefore, if the moisture content of the paper is above a specified value, measurement by resistance sensor 26 can be omitted, or the voltage applied to the paper can be reduced in resistance sensor 26. This prevents device malfunctions caused by leakage voltage generated when detecting the resistance of the paper. In other words, problems caused by the paper's characteristics when measuring the paper's properties can be avoided.

[0266] The paper property detection device 2 of this embodiment is arranged upstream or downstream of the image forming unit 305 that forms an image on paper.

[0267] Therefore, in either the configuration in which the paper property detection device 2 is arranged upstream or downstream of the image forming device 3 , it is possible to prevent device malfunction caused by leakage voltage generated when detecting paper resistance.

[0268] The paper property detection device 2 of this embodiment is arranged upstream of the image forming unit 305 .

[0269] The image forming conditions in the image forming unit 305 are determined based on at least one of the first characteristic information and the second characteristic information.

[0270] Therefore, it is possible to form a high-quality image while stably conveying the paper under image forming conditions that match the characteristics of the paper.

[0271] In the paper property detection device 2 of this embodiment, the second property detection section is arranged downstream of the first property detection section.

[0272] In the paper property detection device 2 of this embodiment, the second property detection section is controlled based on the detection result of the first property detection section.

[0273] In the paper property detection device 2 of this embodiment, the detection conditions in the second property detection section are changed based on the detection result of the first property detection section.

[0274] Therefore, when the moisture content of the paper is equal to or greater than a predetermined value, the voltage applied to the paper can be reduced in the resistance sensor 26. This prevents device failure caused by leakage voltage generated when detecting the resistance of the paper.

[0275] In the paper property detection device 2 of this embodiment, control is performed so as not to perform detection by the second property detection section (resistance sensor 26 ) based on the detection result by the first property detection section.

[0276] Therefore, when the moisture content of the paper is equal to or greater than a predetermined value, control can be performed so as not to perform measurement by the resistance sensor 26. This prevents malfunction of the device due to leakage voltage generated when detecting the resistance of the paper.

[0277] In the paper property detection device 2 of this embodiment, when the second property detection section does not perform detection, the paper is discharged without performing the operation of stopping the paper by the second property detection section.

[0278] In the paper property detection device 2 of this embodiment, the first property and the second property are different from each other.

[0279] In the paper property detection device 2 of this embodiment, the first property information is information corresponding to the moisture content of the paper, and the second property information is information corresponding to the electrical resistance of the paper.

[0280] In the paper property detection device 2 of this embodiment, the voltage applied to the paper when the second property detection unit (resistance sensor 26 ) detects information corresponding to resistance is reduced as the moisture content (moisture content) of the paper increases.

[0281] Therefore, it is possible to prevent a malfunction of the device caused by a leakage voltage generated when detecting the resistance of the paper.

[0282] In the paper property detection device 2 of this embodiment, the greater the moisture content (moisture content) of the paper, the smaller the number of times the second property detection section detects information corresponding to the resistance.

[0283] Therefore, it is possible to prevent a malfunction of the device caused by a leakage voltage generated when detecting the resistance of the paper.

[0284] In the paper property detection device 2 of this embodiment, the second property detection section is arranged downstream of the first property detection section.

[0285] In the paper property detection device 2 of this embodiment, the first property information is information corresponding to the moisture content of the paper, and the second property information is information corresponding to the stiffness of the paper.

[0286] In the paper property detection device 2 of this embodiment, the detection operation when the second property detection unit (stiffness sensor 25 ) detects information corresponding to stiffness is changed according to the moisture content (moisture content) of the paper.

[0287] Therefore, even when the moisture content of the paper is equal to or less than a predetermined value and the paper is charged and adheres to the second transport path 27S, the stiffness of the paper can be accurately detected.

[0288] In the paper property detection device 2 of this embodiment, the second property detection section is arranged downstream of the first property detection section.

[0289] In the paper property detection device 2 of this embodiment, the first property information is information corresponding to the paper thickness, and the second property information is information corresponding to the moisture content (moisture content) of the paper.

[0290] In the paper property detection device 2 of this embodiment, the detection conditions when the second property detection unit (moisture content sensor 24 ) detects information corresponding to the moisture content of the paper are changed according to the paper thickness.

[0291] Therefore, even when the paper thickness is less than a predetermined value and the paper easily vibrates, the moisture content of the paper can be accurately detected.

[0292] The paper property detection device 2 of this embodiment includes a control unit 21 that controls the first property detection unit and the second property detection unit based on the detection result of one of the first property detection unit and the second property detection unit.

[0293] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0294] For example, in the above embodiment, the control unit 21 of the paper characteristic detection device 2 controls the first characteristic detection unit or the second characteristic detection unit based on the detection results of the other characteristic detection unit. However, the present invention is not limited to this. Alternatively, the control unit 301 of the image forming apparatus 3 may control the first characteristic detection unit or the second characteristic detection unit based on the detection results of the other characteristic detection unit.

[0295] In the above embodiment, the control unit 301 of the image forming apparatus 3 determines the image forming conditions of the image forming unit 305 by obtaining at least one of the paper thickness, moisture content, stiffness, and electrical resistance of the paper from the paper characteristics detection device 2. However, the present invention is not limited to this. Alternatively, the control unit 21 of the paper characteristics detection device 2 may determine the image forming conditions of the image forming unit 305. Alternatively, a control unit for determining the image forming conditions of the image forming unit 305 may be provided separately from the control unit 301 of the image forming apparatus 3.

[0296] In the above-described image forming system U, the paper property detection device 2 is independently located between the paper feed device 1 and the image forming device 3, but the present invention is not limited thereto. Alternatively, the paper feed device 1 or the image forming device 3 may include a paper thickness sensor 23, a moisture content sensor 24, a stiffness sensor 25, and a resistance sensor 26.

[0297] In the above description, the computer-readable medium storing the program related to the configuration control of the present invention is described using the storage unit 22 composed of non-volatile memory such as an HDD or flash memory as an example, but the present invention is not limited to these. Other computer-readable media can be non-volatile memories such as MRAM, or portable recording media such as CD-ROMs and DVDs. A carrier wave is also used in the present invention as a medium for providing the data of the program related to the present invention via a communication line.

[0298] The specific configurations, processing operations, and steps described in the above embodiments may be modified as appropriate without departing from the spirit of the present invention. The scope of the present invention encompasses the scope of the invention described in the claims and their equivalents.

Claims

1. A paper property detection device, wherein: have: a first characteristic detecting unit, disposed on a paper conveying path, for detecting first characteristic information corresponding to a first characteristic of the paper; and The second characteristic detecting unit is arranged on the conveying path and is used to detect second characteristic information corresponding to the second characteristic of the paper. The paper characteristic detection device controls the first characteristic detection section and the second characteristic detection section based on a detection result of one of the first characteristic detection section and the second characteristic detection section.

2. The paper property detection device according to claim 1, wherein: The paper property detection device is arranged on the upstream side or the downstream side of an image forming section that forms an image on the paper.

3. The paper property detection device according to claim 2, wherein: The paper property detection device is arranged on the upstream side of the image forming section. Image forming conditions in the image forming section are determined based on at least one of the first characteristic information and the second characteristic information.

4. The paper property detection device according to claim 1, wherein: The second characteristic detection section is arranged on the downstream side of the first characteristic detection section, The paper property detecting device controls the second property detecting section based on a detection result of the first property detecting section.

5. The paper property detection device according to claim 4, wherein: The detection conditions of the second characteristic detection section are changed based on the detection result of the first characteristic detection section.

6. The paper property detection device according to claim 4, wherein: Based on the detection result of the first characteristic detection section, control is performed so as not to perform detection by the second characteristic detection section.

7. The paper property detection device according to claim 6, wherein: When the second characteristic detecting section does not perform detection, the paper is discharged without stopping the paper by the second characteristic detecting section.

8. The paper property detection device according to claim 1, wherein: The first characteristic and the second characteristic are different from each other.

9. The paper property detection device according to claim 1, wherein: The first characteristic information is information corresponding to the moisture content of the paper, The second characteristic information is information corresponding to the electrical resistance of the paper.

10. The paper property detection device according to claim 9, wherein: The larger the moisture content, the lower the voltage applied to the paper when the second characteristic detecting section detects information corresponding to the resistance.

11. The paper property detection device according to claim 9, wherein: The larger the moisture content, the smaller the number of times the second characteristic detection unit detects information corresponding to the resistance.

12. The paper property detection device according to claim 1, wherein: The second characteristic detection portion is arranged on the downstream side of the first characteristic detection portion, The first characteristic information is information corresponding to the moisture content of the paper, The second characteristic information is information corresponding to the stiffness of the paper.

13. The paper property detection device according to claim 12, wherein: The detection operation when the second characteristic detection unit detects information corresponding to the stiffness is changed according to the moisture content.

14. The paper property detection device according to claim 1, wherein: The second characteristic detection portion is arranged on the downstream side of the first characteristic detection portion, The first characteristic information is information corresponding to the paper thickness of the paper, The second characteristic information is information corresponding to the moisture content of the paper.

15. The paper property detection device according to claim 14, wherein: The detection conditions when the second characteristic detection unit detects information corresponding to the moisture content are changed according to the paper thickness.

16. The paper property detection device according to claim 1, wherein: A control unit is provided for controlling the first characteristic detection unit and the second characteristic detection unit based on a detection result of one of the first characteristic detection unit and the second characteristic detection unit.

17. An image forming system, wherein: have: The paper property detection device according to any one of claims 1 to 16; and The image forming unit forms an image on the paper.

18. A computer-readable recording medium storing a program for causing a computer of a paper property detection device to function as a control unit, wherein: The paper property detection device comprises: a first characteristic detecting unit, disposed on a paper conveying path, for detecting first characteristic information corresponding to a first characteristic of the paper; and The second characteristic detecting unit is arranged on the conveying path and is used to detect second characteristic information corresponding to the second characteristic of the paper. The control section controls the first characteristic detection section and the second characteristic detection section based on a detection result of one of the first characteristic detection section and the second characteristic detection section.

19. The recording medium according to claim 18, wherein The paper property detection device is arranged on the upstream side or the downstream side of an image forming section that forms an image on the paper.

20. The recording medium according to claim 19, wherein The paper property detection device is arranged on the upstream side of the image forming section. Image forming conditions in the image forming section are determined based on at least one of the first characteristic information and the second characteristic information.

21. The recording medium according to claim 18, wherein The second characteristic detection portion is arranged on the downstream side of the first characteristic detection portion, The control section controls the second characteristic detection section based on a detection result of the first characteristic detection section.

22. The recording medium according to claim 21, wherein The control unit changes a detection condition in the second characteristic detection unit based on a detection result of the first characteristic detection unit.

23. The recording medium according to claim 21, wherein The control unit controls the second characteristic detection unit not to perform detection based on the detection result of the first characteristic detection unit.

24. The recording medium according to claim 23, wherein When the second characteristic detecting section does not perform detection, the control section causes the paper to be discharged without stopping the paper by the second characteristic detecting section.

25. The recording medium according to claim 18, wherein The first characteristic and the second characteristic are different from each other.

26. The recording medium according to claim 18, wherein The first characteristic information is information corresponding to the moisture content of the paper, The second characteristic information is information corresponding to the electrical resistance of the paper.

27. The recording medium according to claim 26, wherein The control unit reduces the voltage applied to the paper when the second characteristic detection unit detects information corresponding to the resistance, as the moisture content increases.

28. The recording medium according to claim 26, wherein The control unit reduces the number of times the second characteristic detection unit detects information corresponding to the resistance as the moisture content increases.

29. The recording medium according to claim 18, wherein The second characteristic detection portion is arranged on the downstream side of the first characteristic detection portion, The first characteristic information is information corresponding to the moisture content of the paper, The second characteristic information is information corresponding to the stiffness of the paper.

30. The recording medium according to claim 29, wherein The control unit changes a detection operation when the second characteristic detection unit detects information corresponding to the stiffness, based on the moisture content.

31. The recording medium according to claim 18, wherein The second characteristic detection portion is arranged on the downstream side of the first characteristic detection portion, The first characteristic information is information corresponding to the paper thickness of the paper, The second characteristic information is information corresponding to the moisture content of the paper.

32. The recording medium according to claim 31, wherein The control unit changes a detection condition when the second characteristic detection unit detects information corresponding to the moisture content, based on the paper thickness.

Images