Paper characteristic detection system, paper characteristic detection control device, paper characteristic detection control program, and image forming system

Abstract

To make it possible to detect only a paper sheet property required for a system.SOLUTION: An image forming system 100 according to one aspect of the present invention comprises a paper sheet property detection device 2 including a plurality of media sensors corresponding to a plurality of different paper sheet properties, and a control part 30 (or 20) capable of changing types of the paper sheet properties detected by the plurality of media sensors.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a paper characteristic detection system, a paper characteristic detection control device, a paper characteristic detection control program, and an image forming system. [Background technology]

[0002] Conventionally, in order to optimize paper processing such as transport, processing, and printing in response to a wide variety of paper, paper characteristics are detected using a media sensor, and processing is performed under conditions suitable for the detected paper characteristics. For example, Patent Document 1 discloses a technology that uses a paper characteristic detection device (media sensor unit) that combines multiple media sensors capable of measuring multiple paper characteristics such as surface properties, basis weight, moisture content, stiffness, and resistance into a single unit. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-89499 A Summary of the Invention [Problem to be solved by the invention]

[0004] The media sensor unit described in Patent Document 1 etc. can be used in various systems such as a system including an image forming apparatus, a system that processes paper, etc. However, if one tries to uniformly measure various paper characteristics using the media sensor unit described in Patent Document 1, there is an issue that the measurement takes a long time, lowering the productivity of the entire system.

[0005] For example, a paper characteristic detection device used in a system including an image forming apparatus needs to detect many types of paper characteristics or needs to detect paper characteristics with high accuracy in order to optimize process conditions, etc. On the other hand, a paper characteristic detection device used in a system that only performs paper processing does not need to detect paper characteristics required for image formation.

[0006] Among the sensors that detect paper characteristics, there are, for example, sensors such as a basis weight detection sensor that can measure while the paper is being transported, and sensors such as a resistance detection sensor or stiffness detection sensor that are difficult to measure accurately unless the paper transport is stopped. Also, depending on the contents of the system to which the paper characteristic detection device is applied, there are sensors that require high accuracy in detecting the paper characteristics to be detected, and sensors that do not require high detection accuracy.

[0007] Therefore, if a paper characteristic detection device detects all paper characteristics uniformly, for example in a system that only performs paper processing, unnecessary paper characteristics will also be detected. In this case, the time that paper transport is stopped or waiting time increases, and productivity decreases. Similarly, the required paper characteristics may differ depending on the type of paper processing or the type of device, and similar problems will arise if a paper characteristic detection device tries to detect all paper characteristics uniformly.

[0008] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it possible to detect paper characteristics required for a system. [Means for solving the problem]

[0009] A paper characteristic detection system according to one aspect of the present invention includes: Paper size, stiffness, resistance, moisture content, surface properties, and thickness multiple For Paper characteristics Can detect A paper characteristic detection device; A paper characteristic detection device for detecting a plurality of different paper characteristics The type of paper characteristics to be detected setting and a control unit capable of controlling the Effect of the Invention

[0010] The present invention allows the system to sense the required paper characteristics. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of an image forming system according to a first embodiment of the present invention; [Diagram 2] 2 is a block diagram showing an example of the configuration of each control system of a paper characteristic detection device and an image forming apparatus according to an embodiment of the present invention; [Diagram 3] FIG. 11 is a diagram illustrating an example of the configuration of an image forming system according to Example 2 of the first embodiment of the present invention. [Figure 4] 2 is a block diagram showing an example of the configuration of a control system of the image forming apparatus according to the embodiment of the present invention; [Diagram 5] 5 is a flowchart showing an example of a procedure of a paper characteristic detection control process by the paper characteristic detection system according to the first embodiment of the present invention. [Figure 6] 5 is a flowchart showing an example of a procedure for setting control parameters based on a detection result by a paper property detection device according to the first embodiment of the present invention. [Figure 7] FIG. 11 is a diagram illustrating an example of the configuration of an image forming system according to a second embodiment of the present invention. [Figure 8] 13 is a flowchart showing an example of a procedure of an image formation control process according to Example 3 of the second embodiment of the present invention. [Figure 9] 13 is a flowchart showing an example of a procedure of an image formation control process according to Example 4 of the second embodiment of the present invention. [Figure 10] FIG. 13 is a diagram illustrating an example of the configuration of an image forming system according to a first embodiment of a third embodiment of the present invention. [Figure 11] FIG. 13 is a diagram illustrating an example of the configuration of an image forming system according to Example 2 of the third embodiment of the present invention. [Figure 12] 13 is a flowchart showing an example of a procedure for a paper characteristic detection setting process performed by an image forming system according to a third embodiment of the present invention. [Figure 13] 13 is a flowchart showing an example of a procedure for a paper characteristic detection setting process performed by an image forming system according to a third embodiment of the present invention. [Figure 14] 13 is a flowchart showing an example of a procedure for a paper characteristic detection setting process performed by an image forming system according to a third embodiment of the present invention. [Figure 15]13 is a flowchart showing an example of a procedure for a paper characteristic detection setting process performed by an image forming system according to a third embodiment of the present invention. [Figure 16] 13 is a flowchart showing an example of a procedure for a paper characteristic detection setting process performed by an image forming system according to a third embodiment of the present invention. [Figure 17] FIG. 13 is a diagram showing an example of the configuration of an image forming system including a paper feeder incorporating a paper property detection unit according to a modified example of the present invention. [Figure 18] FIG. 13 is a diagram showing an example of the configuration of an image forming system including a paper cutter with a built-in paper property detection unit according to a modified example of the present invention. [Figure 19] 13 is a diagram illustrating an example of the configuration of a paper characteristic detection device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are denoted by the same reference numerals, and duplicated explanations will be omitted.

[0013] The paper property detection device of the present invention is capable of detecting multiple types of paper properties, and changes the type of paper property to be detected depending on the connection (arrangement) position of the paper property detection device in the paper property detection system, the type of device connected to the paper property detection device, the type of post-processing set for the job, etc.

[0014] <First embodiment> In the first embodiment, an example is given in which an image forming system to which a paper characteristic detection system is applied includes one paper characteristic detection device. Fig. 1 is a diagram showing an example of the configuration of an image forming system 100 according to a first embodiment of the first embodiment.

[0015] [Example 1] 1, an image forming system 100 includes a paper feeder 1, a paper characteristic detection device 2, an image forming device 3, and a paper discharge unit 4. In the image forming system 100, the paper characteristic detection device 2 is connected to a position subsequent to the paper feeder 1 and preceding the image forming device 3.

[0016] (Paper Feeding Device) The paper feeder 1 has paper feed trays 11-13, and conveys paper fed from each of the paper feed trays 11-13 to the paper characteristic detection device 2. Note that, although an example in which the paper feeder 1 has three paper feed trays is shown in FIG. 1, the present invention is not limited to this. The number of paper feed trays that the paper feeder 1 has is not limited to three. Also, the paper characteristic detection device 2 of the present invention may be applied to an image forming apparatus that does not have the paper feeder 1.

[0017] (Paper characteristic detection device) The paper characteristic detection device 2 includes media sensors, namely, a paper size detection sensor 23, a paper thickness detection sensor 24, a moisture content detection sensor 25, a basis weight detection sensor 26, a stiffness detection sensor 27, a surface property detection sensor 28 and a paper resistance detection sensor 29.

[0018] The paper size detection sensor 23 is configured by a line sensor such as a CIS (Contact Image Sensor), and detects the size of the paper based on the size of each pixel read by the line sensor.

[0019] The paper thickness detection sensor 24 detects the thickness of the paper based on the distance between two members of a paper thickness detection unit (not shown) when the paper is sandwiched between the two members.

[0020] The moisture content sensor 25 is, for example, a moisture content sensor that detects the moisture content of the paper by optically detecting the amount of light absorbed by OH groups using a near-infrared method based on the light transmitted through the paper. Note that the moisture content sensor may be a sensor that measures the change in the amount of light reflected from inside the paper using reflected light separated by a polarizing filter.

[0021] The basis weight detection sensor 26 is configured, for example, by a transmission type optical sensor having a light emitting portion and a light receiving portion, and detects the basis weight of the paper based on the attenuation rate (transmittance) of light transmitted through the paper.

[0022] The stiffness detection sensor 27 includes, for example, a push-up member that pushes up the paper and a pressure detection unit that detects the pressure (both not shown), and obtains the pressure detected by the pressure detection unit when the paper is bent by the push-up member as the stiffness of the paper. The stiffness detection sensor 27 detects the stiffness of the paper when the paper transport is temporarily stopped.

[0023] The surface property detection sensor 28 includes, for example, a housing, a light emitting unit, a collimating lens, and multiple light receiving units (all not shown). The surface property detection sensor 28 detects the surface properties of the paper, such as the smoothness, glossiness, and unevenness, based on the specular reflected light and diffuse reflected light from the paper surface received by the multiple light receiving units. The detection of the surface property of the paper by the surface property detection sensor 28 is performed while the transport of the paper is temporarily stopped.

[0024] The paper resistance detection sensor 29 detects physical properties corresponding to the electrical resistance inside or on the surface of the paper. For example, the paper resistance detection sensor 29 applies a high voltage to the paper and electrically measures the paper resistance based on the voltage and the current that flows at that time. The detection of the paper resistance by the paper resistance detection sensor 29 is performed while the transport of the paper is temporarily stopped.

[0025] The detection results by the detection sensors of the paper characteristic detection device 2 are transmitted to the subsequent image forming device 3. Then, the control unit 30 (see FIG. 2) of the image forming device 3 controls the paper feeding operation in the paper feeding device 1 or the image forming operation in the image forming device 3 based on the various detection results transmitted from the paper characteristic detection device 2.

[0026] The media sensor included in the paper characteristic detection device 2 and the types of paper characteristics detected by the media sensor are not limited to the example shown in FIG.

[0027] (Image forming device) The image forming apparatus 3 is a monochrome image forming apparatus of a direct transfer type that utilizes electrophotographic process technology. That is, the image forming apparatus 3 forms an image by directly transferring a toner image of a K component (black) formed on a photoconductor drum 341 onto a sheet of paper. The image forming apparatus 3 forms an image onto a sheet of paper based on a job transmitted from a terminal device (not shown). Note that, in this embodiment, an example is given in which the image forming apparatus 3 is a monochrome image forming apparatus, but the present invention is not limited to this. The image forming apparatus according to the present invention may be applied to a color image forming apparatus.

[0028] As shown in FIG. 1, the image forming apparatus 3 includes a paper feed tray 32, an image forming section 34, a fixing section 35, and an operation display section 36.

[0029] The paper feed tray 32 is composed of three paper feed trays, paper feed tray 321 to paper feed tray 323. Paper stored in each paper feed tray is fed by a transport control unit 33 (see FIG. 2) and transported to the image forming unit 34. The number of paper feed trays included in the paper feed tray 32 is not limited to three, and may be two or less or four or more.

[0030] The image forming unit 34 includes a photoconductor drum 341, a developing device 342, and a transfer unit 343. The developing device 342 visualizes the electrostatic latent image and forms a toner image by adhering K component toner to the surface of the photoconductor drum 341. The transfer unit 343 transfers the toner image formed on the photoconductor drum 341 to paper.

[0031] The fixing unit 35 performs a fixing process of fixing the image onto the paper by applying heat and pressure to the paper onto which the toner image has been transferred by the transfer unit 343 .

[0032] The operation display unit 36 ​​is composed of a display unit 361 made of a liquid crystal panel or the like, and an operation input unit 362 made of buttons or the like. The display unit 361 and the operation input unit 361 may be integrally formed as a touch panel. The operation display unit 36 ​​generates an operation signal representing the content of an operation from the user inputted to the operation input unit, and supplies the operation signal to the control unit 30 (see FIG. 2).

[0033] (Paper ejection unit) The paper discharge unit 4 has a paper discharge tray 41 and a purge tray 42. The paper discharge tray 41 is a tray onto which paper on which an image is formed by the image forming device 3 is discharged. The purge tray 42 is a tray onto which printed matter for which an abnormality has been detected and paper remaining inside the image forming device 3 when the abnormality was detected are discharged.

[0034] (Configuration of the control system of the paper characteristic detection device and the image forming device) Next, the configuration of each control system of the paper characteristic detection device 2 and the image forming device 3 included in the image forming system 100 according to this embodiment will be described with reference to Fig. 2. Fig. 2 is a block diagram showing an example of the configuration of each control system of the paper characteristic detection device 2 and the image forming device 3.

[0035] As shown in FIG. 2, the image forming apparatus 3 of the image forming system 100 includes a control unit 30, a storage unit 31, a conveyance control unit 33, an image forming unit 34, a fixing unit 35, an operation display unit 36, and a communication I / F (Interface) unit 37.

[0036] The control unit 30 includes a central processing unit (CPU) 301, a random access memory (RAM) 302, and a read only memory (ROM) 303.

[0037] CPU 301 is a central processing unit, and controls the operation of each unit constituting image forming apparatus 3. For example, CPU 301 detects the connection state with other devices such as paper characteristic detection device 2 connected to its own device, and information on the connection position of each device. In the configuration of embodiment 1, that is, in the configuration in which paper characteristic detection device 2 is connected between paper feeder 1 and image forming apparatus 3, CPU 301 controls paper characteristic detection device 2 to detect all paper characteristics. In other words, CPU 301 causes all media sensors included in paper characteristic detection device 2 to detect the respective paper characteristics.

[0038] Then, based on the detected connection information of the other device, the CPU 301 performs control to change the type of paper characteristics detected by the paper characteristic detection device 2. That is, in this embodiment, the image forming device 3 also functions as a paper characteristic detection control device.

[0039] The paper characteristic detection control process by the CPU 301 may be performed on the paper characteristic detection device 2 side. In this case, the paper characteristic detection device 2 functions as a paper characteristic detection control device. The paper characteristic detection device is not limited to being applied to a device provided in the image forming system 100, and may be applied to other devices connected to the image forming system 100 via a network.

[0040] Furthermore, CPU 301 controls the paper feeding operation in paper feeding device 1 and the image forming operation in image forming unit 34 based on various paper characteristics transmitted from paper characteristic detection device 2. Specifically, CPU 301 controls the amount of air suction in the air suction of paper feeding device 1 and the amount of air for paper handling, adjusts the intake and exhaust ports of a fan (not shown), and optimizes the paper feeding operation, transport operation, etc., based on information such as the size, basis weight, moisture content, thickness, and stiffness of the paper detected by paper characteristic detection device 2.

[0041] Furthermore, CPU 301 controls the transfer current in image forming unit 34 and the fixing temperature in fixing unit 35 (an example of a fixing condition) based on information on the basis weight, moisture content, thickness, stiffness, and surface properties of the paper. CPU 301 also controls the transfer current (an example of a transfer condition) based on the resistance value of the paper. Furthermore, CPU 301 controls the formation position of the image on the paper based on the paper size.

[0042] Furthermore, the CPU 301 sets each control parameter used for each control described above based on the various paper characteristics detected by the paper characteristic detection device 2, and stores the control parameters in the RAM 302, the storage unit 31, etc. Then, when a job is executed, the CPU 301 reads the control parameters from the RAM 302, the storage unit 31, etc., and performs control based on the control parameters. Note that the CPU 301 may read the control parameters stored in advance in the ROM 303.

[0043] The RAM 302 is used as a work area when the CPU 301 executes a program. The ROM 303 stores a system program for operating the image forming apparatus 3, a program for executing the paper characteristic detection control process according to the present embodiment, control parameters set based on the paper characteristics, and the like.

[0044] The storage unit 31 is configured with, for example, a hard disk drive (HDD), a solid state drive (SSD), etc. The storage unit 31 stores image data included in a job, control parameters set based on paper characteristics, etc. The storage unit 31 may also store a program for executing the paper characteristic detection control process according to this embodiment.

[0045] The programs (or applications) stored in the ROM 303 or the storage unit 31 are stored in the form of computer-readable program codes. In other words, the ROM 303 or the storage unit 31 is used as an example of a computer-readable non-transitory recording medium that stores a program executed by a computer.

[0046] The conveyance control unit 33 controls the conveyance of the paper fed from the paper feeder 1 (see FIG. 1) on a conveyance path (not shown) in the image forming apparatus 3.

[0047] The image forming unit 34, the fixing unit 35, and the operation display unit 36 ​​have already been described with reference to FIG. 1, and therefore a description thereof will be omitted.

[0048] The communication I / F unit 37 controls the transmission and reception of various signals and data between the device and other devices, such as the paper characteristic detection device 2, that are connected to the device itself.

[0049] (Paper characteristic detection device) Next, again with reference to Fig. 2, the configuration of the control system of the paper characteristic detection device 2 will be described. As shown in Fig. 2, the paper characteristic detection device 2 includes a control unit 20, a memory unit 21, a communication I / F unit 22, a paper size detection sensor 23, a paper thickness detection sensor 24, a moisture content detection sensor 25, a basis weight detection sensor 26, a stiffness detection sensor 27, a surface property detection sensor 28, and a paper resistance detection sensor 29.

[0050] The control unit 20 includes a CPU 201 , a RAM 202 , and a ROM 203 . The CPU 201 is a central processing unit, and controls the operation of each unit constituting the paper characteristic detection device 2. For example, the CPU 201 controls the detection of the type of paper characteristic set by the image forming device 3 by a corresponding media sensor among various media sensors that the paper characteristic detection device 2 has.

[0051] The RAM 202 is used as a work area when the CPU 201 executes a program. The ROM 203 stores a system program for operating the paper characteristic detection device 2 and the like.

[0052] The storage unit 21 is configured with, for example, an HDD, an SSD, etc., and stores setting information on the type of paper characteristics transmitted from the image forming device 3. Note that the storage unit 21 may also store a system program that operates the paper characteristic detection device 2.

[0053] The programs (or applications) stored in the ROM 203 or the storage unit 21 are stored in the form of computer-readable program codes. In other words, the ROM 203 or the storage unit 21 is used as an example of a computer-readable non-transitory recording medium that stores a program executed by a computer.

[0054] The communication I / F unit 22 controls the transmission and reception of various signals and data between the image forming apparatus 3 and other apparatuses connected to the local apparatus.

[0055] The paper size detection sensor 23, paper thickness detection sensor 24, moisture content detection sensor 25, basis weight detection sensor 26, stiffness detection sensor 27, surface property detection sensor 28 and paper resistance detection sensor 29 have already been explained with reference to Figure 1, so explanation of these will be omitted.

[0056] [Example 2] Next, an image forming system 100 according to Example 2 of the first embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a diagram showing an example of the configuration of an image forming system 100A according to Example 2 of the first embodiment.

[0057] 3, the image forming system 100A includes an image forming apparatus 3, a paper characteristic detection apparatus 2, a paper cutter 5, and a folding processing apparatus 6. The paper cutter 5 is a device that cuts the paper on which an image has been formed by the image forming apparatus 3. The folding processing apparatus 6 is a device that binds the paper together to form a booklet, and performs processes such as folding the paper, stapling, and bookbinding.

[0058] In image forming system 100A, paper characteristic detection device 2 is connected between image forming apparatus 3 and paper cutter 5. In this embodiment as well, the paper characteristic detection control device of the present invention is applied to image forming apparatus 3. In other words, the type of paper characteristic detected by paper characteristic detection device 2 is set by control unit 30 of image forming apparatus 3 (see FIG. 2).

[0059] In this embodiment, the control unit 30 of the image forming apparatus 3 controls the paper characteristic detection device 2 to detect the thickness, stiffness, and size of the paper. Then, based on the information on the paper size detected by the paper characteristic detection device 2, the control unit 30 optimizes control parameters such as the cutting position of the paper by the paper cutter 5 and the folding position of the paper by the folding device 6.

[0060] Furthermore, the control unit 30 adjusts the cutting settings for the paper cutter 5 and the number of folds for the folding device 6 based on the information on the stiffness and thickness of the paper detected by the paper property detection device 2. The cutting settings include, for example, the movement speed during the cutting process of a cutter (not shown) that cuts the paper.

[0061] Fixing process is performed by the fixing unit 35 of the image forming device 3, and heat is applied to the paper, which changes the moisture content of the paper, the paper size, etc. In particular, the moisture content of the paper is reduced more significantly as the paper becomes thinner. Therefore, the control unit 30 controls the cutting position based on the thickness, stiffness, and size of the paper after the fixing process, thereby improving cutting accuracy.

[0062] Furthermore, when the paper is thick and / or the paper is stiff, the load on the motor (not shown) that drives the cutter of the paper cutter 5 also increases. Therefore, when the thickness of the paper detected by the paper characteristic detection device 2 is thick and / or the paper is stiff, the control unit 30 controls the cutter to move slower, thereby reducing the load on the motor.

[0063] In other words, according to the second embodiment, various control parameters are optimized or set based on the characteristics of the paper that has been affected by the fixing process by the image forming device 3, thereby making it possible to further improve the cutting accuracy by the paper cutter 5 and the folding accuracy by the folding device 6.

[0064] In addition, according to the second embodiment, only the paper characteristics required during the cutting process by the paper cutter 5 are detected by the paper characteristic detection device 2, so the time required for detection can be reduced compared to when all of the media sensors possessed by the paper characteristic detection device 2 detect each paper characteristic.

[0065] In the second embodiment, the control unit 30 of the image forming device 3 controls the paper characteristic detection device 2 to detect the thickness, stiffness, and size of the paper in a configuration in which the paper characteristic detection device 2 is connected to the rear of the image forming device 3 and the front of the paper cutter 5, but the present invention is not limited to this. The control unit 30 may detect any one or a combination of the thickness, stiffness, and size of the paper.

[0066] [Example 3] Next, a bookbinding system 200 according to Example 3 of the first embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is a diagram showing an example of the configuration of the bookbinding system 200 according to Example 3 of the first embodiment. The bookbinding system 200 (an example of a paper characteristic detection system) shown in Fig. 4 is a so-called offline bookbinding system, and is an apparatus that performs bookbinding processing on paper on which an image has already been formed by an image forming apparatus 3 or the like.

[0067] In the third embodiment, the paper characteristic detection device 2 is included in a bookbinding system 200 , and the bookbinding system 200 includes a printed matter paper feeder 7 , the paper characteristic detection device 2 , a cutter 5 and a folding device 6 .

[0068] The printed matter feeding device 7 is a device that feeds paper on which an image has been formed by the image forming device 3 or the like to a subsequent device, which is the paper cutter 5 in this embodiment.

[0069] In the bookbinding system 200, the paper characteristic detection device 2 is connected to a position subsequent to the printed matter paper feeder 7 and preceding the paper cutter 5.

[0070] In the third embodiment, the paper characteristic detection control device according to the present invention is applicable to, for example, the paper characteristic detection device 2. That is, the control unit 20 (see FIG. 2) in the paper characteristic detection device 2 performs paper characteristic detection control processing.

[0071] In this embodiment, the control unit 20 in the paper characteristic detection device 2 controls the paper characteristic detection device 2 to detect the thickness, stiffness, and size of the paper. Then, the control unit 30 adjusts the cutting position and the like based on the information on the thickness, stiffness, and size of the paper detected by the paper characteristic detection device 2.

[0072] The device connected downstream of the paper property detection device 2 may be another post-processing device, such as a binding device that performs a binding process on the paper or a punching device that performs a punching process. When the paper property detection system of the present invention is applied to a system including a post-processing device, a control unit of the image forming device 3 or the like that functions as a paper property detection control device controls changing the type of paper property detected by the paper property detection device 2 according to the type of function provided in the post-processing device.

[0073] [Paper characteristic detection control process] Next, a paper characteristic detection control process by the paper characteristic detection system (image forming systems 100, 100A, bookbinding system 200, etc.) according to the first embodiment of the present invention will be described with reference to Fig. 5. Fig. 5 is a flowchart showing an example of the procedure of the paper characteristic detection control process by the paper characteristic detection system according to the first embodiment of the present invention. In the example shown in Fig. 5, the paper characteristic detection control process is performed by the control unit 20 of the paper characteristic detection device 2.

[0074] First, a job is set based on a user's operation on a terminal device (not shown) (step S1). Next, the control unit 20 of the paper characteristic detection device 2 judges whether or not the device is connected to the paper characteristic detection system (step S2). If it is judged in step S2 that the device is not connected to the paper characteristic detection system (if step S2 is judged as NO), the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0075] On the other hand, if it is determined in step S2 that the device is connected to the paper characteristic detection system (if the determination in step S2 is YES), the control unit 20 determines whether or not the device connected to the device itself is the image forming device 3 (step S3). If it is determined in step S3 that the device connected is the image forming device 3 (if the determination in step S3 is YES), the control unit 20 determines whether or not the paper for which the paper characteristics are to be detected is the first sheet of paper fed from each paper feed tray (paper feed trays 11 to 13: see FIG. 1) in which the paper used in the job is stored (step S4).

[0076] If it is determined in step S4 that the paper is the first sheet fed from the paper feed tray (YES in step S4), the control unit 20 sets the types of paper characteristics detected by the paper characteristic detection device 2 to all types (step S5), i.e., the size, thickness, moisture content, basis weight, stiffness, surface properties, and paper resistance of the paper.

[0077] On the other hand, if it is determined in step S4 that the paper is the second or subsequent sheet of paper fed from the paper feed tray (if step S4 is judged as NO), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to only the paper thickness, basis weight, moisture content, and paper size (step S6).

[0078] In step S6, the paper characteristics detected by the paper characteristic detection device 2 are limited to only those characteristics that change due to the image fixing process. This makes it possible to maintain print quality while further improving the effect of preventing a decrease in productivity of the image forming system 100. After the process of step S5 or step S6, the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0079] If it is determined in step S3 that the image forming device 3 is not connected to the own device (if step S3 is judged as NO), the control unit 20 determines whether the device is connected to the paper cutter 5 (step S7). If it is determined in step S7 that the device is connected to the paper cutter 5 (if step S7 is judged as YES), the control unit 20 determines whether the paper whose paper characteristics are to be detected is the first sheet of paper fed to the paper characteristic detection device 2 (step S8).

[0080] If it is determined in step S8 that the paper is the first sheet of paper (if step S8 is a YES judgement), the control unit 20 sets the types of paper characteristics to be detected by the paper characteristic detection device 2 to only the paper thickness, stiffness, and paper size (step S9). On the other hand, if it is determined in step S8 that the paper is the second or subsequent sheet of paper fed to the paper characteristic detection device 2 (if step S8 is a NO judgement), the control unit 20 sets the paper characteristics to be detected by the paper characteristic detection device 2 to only the paper thickness and paper size (step S10). After the processing of step S9 or step S10, the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0081] If it is determined in step S7 that the device connected to the control unit 20 is not the paper cutter 5 (if step S7 is a NO judgment), the control unit 20 determines whether the device connected to the control unit 20 is a binding process or punching process device (not shown) (step S11). If it is determined in step S11 that the device connected to the control unit 20 is a binding process or punching process device (if step S11 is a YES judgment), the control unit 20 determines whether the paper for which the paper characteristics are to be detected is the first sheet of paper fed to the paper characteristic detection device 2 (step S12).

[0082] If it is determined in step S12 that the paper is the first sheet (if step S12 is a YES judgement), the control unit 20 sets the types of paper characteristics to be detected by the paper characteristic detection device 2 to only the paper thickness, paper stiffness, paper size, and moisture content (step S13). On the other hand, if it is determined in step S12 that the paper is the second or subsequent sheet fed to the paper characteristic detection device 2 (if step S12 is a NO judgement), the control unit 20 limits the paper characteristics to be detected by the paper characteristic detection device 2 to only the paper thickness, paper size, and moisture content (step S14).

[0083] After the process of step S13 or step S14, the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0084] If it is determined in step S11 that the device connected to the own device is not a binding device or a punching device (if step S11 is a NO judgment), the control unit 20 determines whether or not the device connected to the own device is a folding device (not shown) (step S15).If it is determined in step S15 that the device connected to the own device is a folding device (if step S15 is a YES judgment), the control unit 20 determines whether or not the paper for which the paper characteristics are to be detected is the first sheet of paper fed to the paper characteristic detection device 2 (step S16).

[0085] If it is determined in step S16 that the paper is the first sheet (if step S16 is a YES judgement), the control unit 20 sets the types of paper characteristics to be detected by the paper characteristic detection device 2 to only thickness, stiffness, paper size, and moisture content (step S17). On the other hand, if it is determined in step S16 that the paper is the second or subsequent sheet fed to the paper characteristic detection device 2 (if step S16 is a NO judgement), the control unit 20 sets the paper characteristics to be detected by the paper characteristic detection device 2 to only paper thickness, paper size, and moisture content (step S18). After the processing of step S17 or step S18, the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0086] If it is determined in step S15 that the device connected to the paper characteristic detection device 2 is not the folding processing device (if step S15 is a NO determination), the device connected to the paper characteristic detection device 2 is a device other than the image forming device 3, the paper cutter 5, the binding processing device, the punching device, and the folding processing device. In this case, the control unit 20 sets the types of paper characteristics detected by the paper characteristic detection device 2 to all types (step S19). Then, after the process of step S19, the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0087] [Control parameter setting process based on detection results] Next, a process for setting control parameters based on the detection result by the paper characteristic detection device 2 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the procedure for setting control parameters based on the detection result by the paper characteristic detection device 2.

[0088] First, a job is started in a device such as the image forming device 3 connected to the paper characteristic detection device 2 (step S20). Next, the control unit of the device that plays a role in the paper characteristic detection control process acquires the detection result of the paper characteristics by the paper characteristic detection device 2 (step S21). Next, the control unit sets control parameters according to the detection result (step S22). After the process of step S22, the process of setting the control parameters based on the detection result by the paper characteristic detection device 2 ends.

[0089] According to each example of the first embodiment described above, the type of paper characteristics detected by the paper characteristic detection device 2 is set according to the type of device connected to the paper characteristic detection device 2. Therefore, compared to the case where the paper characteristic detection device 2 detects all detectable paper characteristics, it is possible to reduce waiting time and the like during paper characteristic detection, thereby improving the productivity of the paper characteristic detection system.

[0090] <Second embodiment> Next, a second embodiment of the present invention will be described. In the second embodiment, an example is given in which an image forming system to which the paper characteristic detection system of the present invention is applied includes a plurality of paper characteristic detection devices. Fig. 7 is a diagram showing an example of the configuration of an image forming system 100B according to the second embodiment.

[0091] 7, image forming system 100B includes paper feeder 1, paper characteristic detection device 2a (an example of a first paper characteristic detection device), image forming device 3, paper inverting device 8, paper characteristic detection device 2b (an example of a second paper characteristic detection device), and paper discharge unit 4. Paper characteristic detection devices 2a and 2b have the same functions as paper characteristic detection device 2 in the first embodiment. Paper inverting device 8 is a device that inverts paper on which an image has been formed by image forming device 3, and outputs the paper.

[0092] In image forming system 100B, the first paper characteristic detection device 2a located on the upstream side is connected to a position subsequent to the paper feeder 1 and preceding the image forming device 3. The second paper characteristic detection device 2b located downstream is connected to a position subsequent to the paper inversion device 8 and preceding the paper discharge unit 4. In this embodiment as well, the paper characteristic detection control device of the present invention is applied to the image forming device 3. In other words, the type of paper characteristic detected by the paper characteristic detection devices 2a and 2b is set by the control unit 30 (see FIG. 2) of the image forming device 3.

[0093] In this embodiment, the control unit 30 of the image forming apparatus 3 causes the first paper characteristic detection device 2a installed upstream to detect all paper characteristics as in Example 1 of the first embodiment. Then, the control unit 30 generates control parameters for the paper feeding operation by the paper feeder 1 and each control parameter for the paper transport operation and image forming operation by the image forming apparatus 3 based on all the paper characteristics detected by the paper characteristic detection device 2a.

[0094] The second paper characteristic detection device 2b installed downstream detects the characteristics of the back side of the paper in a back side characteristic detection mode executed during double-sided printing. The back side characteristic detection mode is a mode executed in a test stage before a print job is executed, and during double-sided printing, the paper on which an image has been formed by the image forming device 3 is inverted by the paper inverting device 8 to become the back side. Then, the paper with the back side facing up is supplied to the paper characteristic detection device 2b. After the paper characteristic detection by the paper characteristic detection device 2b, the paper is discharged to the purge tray 42 of the paper discharge unit.

[0095] In the back surface characteristic detection mode, the control unit 30 causes the paper characteristic detection device 2b to detect only some of the paper characteristics that can be detected by the paper characteristic detection device 2b and that are affected by the fixing process of the image forming device 3, such as the moisture content of the paper, paper resistance, paper size, and surface properties.

[0096] Then, based on the paper size information detected by the paper characteristic detection device 2b, the control unit 30 generates control parameters for controlling the size of the image formed on the back side of the paper by the image forming device 3, the writing position of the image, etc. Also, based on each piece of information on the moisture content, paper resistance, and surface properties of the paper detected by the paper characteristic detection device 2b, the control unit 30 generates control parameters for controlling the transfer current, fixing temperature, etc. when the image forming device 3 forms an image on the back side.

[0097] [Paper characteristic detection control process] Next, a paper characteristic detection control process by the image forming system 100B according to the second embodiment will be described with reference to Fig. 8. Fig. 8 is a flowchart showing an example of the procedure of a paper characteristic detection setting process by the control unit 30 of the image forming apparatus 3.

[0098] First, a job is set based on a user's operation on a terminal device (not shown) (step S31). Next, the control unit 30 judges whether or not the paper characteristic detection device 2 is connected to the image forming apparatus 3 (step S32). If it is judged in step S32 that the paper characteristic detection device 2 is not connected (if the judgment in step S32 is NO), the paper characteristic detection setting process by the control unit 30 of the image forming apparatus 3 ends.

[0099] On the other hand, if it is determined in step S32 that the paper characteristic detection device 2 is connected (if step S32 is a YES judgment), the control unit 30 determines whether or not multiple paper characteristic detection devices 2 are connected (step S33). If it is determined in step S33 that multiple paper characteristic detection devices 2 are not connected (if step S33 is a NO judgment), the paper characteristic detection setting process by the control unit 30 of the image forming apparatus 3 ends. In other words, if the paper characteristic detection system includes one paper characteristic detection device 2, the process in the first embodiment described above is performed.

[0100] On the other hand, if it is determined in step S33 that multiple paper characteristic detection devices 2 are connected (YES in step S33), the control unit 30 assigns numbers (IM1, IM2, ...) to each of the multiple paper characteristic detection devices 2 (step S34). The numbers are assigned consecutively, for example, starting from the paper characteristic detection device 2 arranged upstream.

[0101] Next, the control unit 30 assigns the number "IMx" to the paper property detection device 2 for which the type of paper property to be detected is to be set (step S35). The "x" in "IMx" is set to "1". Next, the control unit 30 determines whether the location of the paper property detection device 2 numbered IMx is upstream of the image forming device 3 (step S36).

[0102] If it is determined in step S36 that the paper is located upstream of the image forming device 3 (if step S36 is determined to be YES), the control unit 30 determines whether the paper whose paper characteristics are to be detected is the first sheet of paper fed from each paper feed tray (paper feed trays 11 to 13: see Figure 1) in which the paper to be used in the job is stored (step S37).

[0103] If it is determined in step S37 that the paper is the first sheet fed from the paper feed tray (if step S37 is a YES judgement), the control unit 30 sets the types of paper characteristics detected by the paper characteristic detection device 2 to all types (step S38). On the other hand, if it is determined in step S37 that the paper is the second or subsequent sheet fed from the paper feed tray (if step S37 is a NO judgement), the control unit 30 sets the paper characteristics detected by the paper characteristic detection device 2 to only the paper moisture content and paper size (step S39).

[0104] If it is determined in step S36 that the image forming device 3 is disposed downstream of the image forming device 3 (if step S36 is a NO judgment), the control unit 30 determines whether or not double-sided printing is set in the job (step S40). If it is determined in step S40 that double-sided printing is set (if step S40 is a YES judgment), the control unit 30 sets the paper characteristics detected by the paper characteristic detection device 2 to only the paper moisture content, paper resistance, paper size, and surface properties (step S41).

[0105] On the other hand, if it is determined in step S40 that double-sided printing is not set (if step S40 is a NO determination), the control unit 30 turns off the paper characteristic detection execution setting by the paper characteristic detection device 2. In other words, the control unit 30 does not cause the paper characteristic detection device 2 to execute the paper characteristic detection process (step S42).

[0106] After the processing of step S38, S39, S41, or S42, the control unit 30 judges whether or not the setting of all the paper characteristic detection devices 2 assigned with the number IMx is completed (step S43). If it is judged in step S43 that the setting of all the paper characteristic detection devices 2 is not completed (if the judgment in step S43 is NO), the control unit 30 adds 1 to the value of "x" (step S44). Next, the control unit 30 returns to step S36 and makes another judgment.

[0107] On the other hand, if it is determined in step S43 that the settings of all the paper characteristic detection devices 2 have been completed (YES in step S43), the paper characteristic detection setting process by the control unit 30 of the image forming apparatus 3 ends.

[0108] [Paper characteristic detection control process during double-sided printing] Next, a paper characteristic detection control process during double-sided printing by the image forming system 100B (see FIG. 7) according to the second embodiment will be described with reference to Fig. 9. Fig. 9 is a flowchart showing an example of the procedure of the paper characteristic detection control process during double-sided printing by the control unit 30 of the image forming apparatus 3 of the image forming system 100B according to the second embodiment.

[0109] First, the image forming apparatus 3 starts a job (step S51). Next, it is determined whether or not double-sided printing is set in the job (step S52). If it is determined in step S52 that double-sided printing is not set (if step S52 returns NO), the paper characteristic detection control process during double-sided printing by the control unit 30 ends.

[0110] On the other hand, if it is determined in step S52 that double-sided printing is set (YES in step S52), the control unit 30 determines whether the first paper characteristic detection device 2a (see FIG. 7) assigned the number IM1 is installed upstream of the image forming device 3 (step S53). In step S53, it is determined whether the paper characteristic detection device 2a for which the detection type of the paper characteristic is to be set is installed upstream of the image forming device 3 as expected.

[0111] If it is determined in step S53 that the first paper characteristic detection device 2a numbered IM1 is not installed upstream of the image forming device 3 (if step S53 is determined to be NO), the paper characteristic detection control process by the control unit 30 during double-sided printing is terminated.

[0112] On the other hand, if it is determined in step S53 that the first paper characteristic detection device 2a assigned the number IM1 is installed upstream of the image forming device 3 (YES in step S53), the control unit 30 determines whether the second paper characteristic detection device 2b assigned the number IM2 (see FIG. 7) is installed downstream of the image forming device 3 (step S54). In step S54, it is determined whether the paper characteristic detection device 2b for which the detection type of the paper characteristic is set is installed downstream of the image forming device 3 as expected.

[0113] If it is determined in step S54 that the second paper characteristic detection device 2b numbered IM2 is not installed downstream of the image forming device 3 (if step S54 is determined to be NO), the paper characteristic detection control process by the control unit 30 during double-sided printing is terminated.

[0114] On the other hand, if it is determined in step S54 that the second paper characteristic detection device 2b numbered IM2 is installed downstream of the image forming device 3 (YES in step S54), the control unit 30 determines whether or not execution of the back-side characteristic detection mode has been instructed (step S55). If it is determined in step S55 that execution of the back-side characteristic detection mode has not been instructed (NO in step S55), the paper characteristic detection control process during double-sided printing by the control unit 30 ends.

[0115] On the other hand, if it is determined in step S55 that the execution of the back surface characteristic detection mode has been instructed (if step S55 is determined to be YES), the control unit 30 controls the transport of paper one sheet at a time from each paper feed tray (paper feed trays 11 to 13, see Figure 7) in which the paper to be used in the job is stored to the paper characteristic detection device 2a (step S56).

[0116] Next, the control unit 30 sets the types of paper characteristics detected by the upstream paper characteristic detection device 2a to all types (step S57). Next, the control unit 30 sets the types of paper characteristics detected by the downstream paper characteristic detection device 2b to paper size, moisture content, surface properties, and paper resistance (step S58).

[0117] Next, the control unit 30 controls the upstream paper characteristic detection device 2a to detect all types of paper characteristics (step S59). Next, the control unit 30 optimizes or sets control parameters for front-side printing based on the detection results of the paper characteristics by the upstream paper characteristic detection device 2a (step S60). After the process of step S60, the image forming device 3 prints on the front side of the paper, and the paper with the image formed on the front side is transported to the paper reversing device 8.

[0118] Next, the control unit 30 causes the paper inverting device 8 to invert the paper and transport the paper, whose back side has become the upper side as a result of inversion, to the downstream paper characteristic detection device 2b (step S61). Next, the control unit 30 causes the downstream paper characteristic detection device 2b to detect the paper characteristics of the type set in step S58 (step S62).

[0119] Next, the control unit 30 optimizes or sets the control parameters for back side printing based on the detection result of the paper characteristics by the downstream paper characteristic detection device 2b (step S63). Next, the control unit 30 stores the control parameters for front side printing and the control parameters for back side printing in the storage unit 31 (see FIG. 2) or the like, and ejects the paper whose paper characteristics have been detected by the paper characteristic detection device 2b from the purge tray 42 of the paper ejection unit 4 (step S64). After the process of step S64, the paper characteristic detection control process by the control unit 30 during double-sided printing ends.

[0120] According to the second embodiment described above, the types of paper characteristics detected by the paper characteristic detection device 2b that detects the paper characteristics of the back side are limited to the types required for image formation on the back side of the paper. Therefore, compared to the case where the paper characteristic detection device 2b detects all the paper characteristics that it can detect as the paper characteristics of the back side of the paper, it is possible to reduce the waiting time when detecting the paper characteristics.

[0121] <Third embodiment> In the third embodiment, an example is given in which an image forming system to which the paper characteristic detection system of the present invention is applied includes a plurality of image forming apparatuses and a plurality of paper characteristic detection devices. Fig. 10 is a diagram showing a configuration example of an image forming system 100C according to Example 1 of the third embodiment.

[0122] [Example 1] 10, image forming system 100C includes a paper feeder 1, a paper characteristic detection device 2a, an image forming device 3a (an example of a first image forming device), a paper reversing device 8, a paper characteristic detection device 2b, an image forming device 3b (an example of a second image forming device), and a paper discharge unit 4. In other words, image forming system 100C is a tandem type image forming system in which two image forming devices 3a and 3b are connected in series. Each of these devices included in image forming system 100C has been described in each of the above-mentioned embodiments, so description thereof will be omitted here.

[0123] In addition, a purge unit or the like for adjusting the height of the paper discharge outlet of the upstream image forming device 3a and the height of the paper feed outlet of the downstream image forming device 3b may be provided between the paper inversion device 8 and the paper characteristic detection device 2b in the image forming system 100C.

[0124] In the image forming system 100C, the detection type of paper characteristics in the paper characteristic detection devices 2a and 2b is set by the control unit of the image forming device 3a. That is, in this embodiment, the paper characteristic detection control device of the present invention is applied to the image forming device 3a. The types of paper characteristics detected by the paper characteristic detection devices 2a and 2b may be set by different control units. For example, the control unit 30a of the image forming device 3a may set the detection type of paper characteristics in the paper characteristic detection device 2b, and the control unit of the image forming device 3a may set the detection type of paper characteristics.

[0125] The control unit 30a of the image forming apparatus 3a performs the same setting as in the first embodiment described above for the type of paper characteristics to be detected by the paper characteristic detection device 2a arranged upstream. That is, when the first sheet of paper fed from the paper feed tray is to be detected, the control unit 30a sets the type of paper characteristics to be detected by the paper characteristic detection device 2a to all types. On the other hand, when the second and subsequent sheets of paper fed from the paper feed tray are to be detected, the control unit 30a sets the paper characteristics to be detected by the paper characteristic detection device 2a to only moisture content and paper size.

[0126] The control unit 30a of the image forming apparatus 3a sets the moisture content, paper resistance, paper size, and surface properties of the paper as the types of paper properties to be detected by the paper property detection device 2b installed downstream. In other words, the control unit 30a causes the downstream paper property detection device 2b to detect the paper properties that change due to the influence of the fixing process by the upstream image forming apparatus 3a.

[0127] Then, the control unit 30a generates control parameters for optimizing the transfer current and fixing temperature in the upstream image forming device 3a based on the information on the moisture content, surface properties, and paper resistance of the paper detected by the upstream paper characteristic detection device 2a, and transmits the control parameters to the image forming device 3a.

[0128] Furthermore, the control unit 30a generates control parameters for optimizing the transfer current and fixing temperature in the downstream image forming apparatus 3b based on the information on the moisture content, surface properties, and paper resistance of the paper detected by the downstream paper property detection device 2b, and transmits the control parameters to the image forming apparatus 3b. Therefore, according to this embodiment, even when the paper property detection system of the present invention is applied to a serial tandem type image forming system including two image forming apparatuses 3a and 3b, an appropriate image formation process is executed based on the paper properties detected by each of the paper property detection devices 2a and 2b.

[0129] Furthermore, the control unit 30a corrects the magnification and writing position of the image formed on the paper by the downstream image forming device 3b based on information on the difference between the paper size detected by the paper characteristic detection device 2b and the paper size detected by the upstream paper characteristic detection device 2a, i.e., the paper size of the paper before image formation. This makes it possible to prevent the magnification or writing position of the image formed on the front and back of the paper from being different.

[0130] Furthermore, according to this embodiment, it is possible to obtain the same effect as that obtained by each of the above-mentioned embodiments. That is, it is possible to reduce the waiting time when detecting paper characteristics, compared with the case where the paper characteristic detection device 2b detects all detectable paper characteristics.

[0131] [Example 2] Fig. 11 is a diagram showing a configuration example of an image forming system 100D according to Example 2 of the third embodiment. The image forming system 100D shown in Fig. 11 differs from the image forming system 100C shown in Fig. 10 in that a sheet feeding device 1b is provided in front of the image forming device 3b arranged on the downstream side.

[0132] 11, the image forming system 100D includes a paper feeder 1a, a paper characteristic detection device 2a, an image forming device 3a, a paper reversing device 8, a paper feeder 1b, a paper characteristic detection device 2b, an image forming device 3b, and a paper discharge unit 4. Each of these devices included in the image forming system 100D has been described in the above-mentioned embodiments, so description thereof will be omitted here.

[0133] In this embodiment, since the paper feeder 1b is disposed in front of the downstream image forming device 3b, the downstream image forming device 3b may perform single-sided printing on the paper fed from the paper feeder 1b. When the downstream image forming device 3b performs single-sided printing, the control unit 30a of the image forming device 3a performs the same setting as in the first embodiment as the setting of the type of paper characteristics detected by the paper characteristic detection device 2b.

[0134] That is, when the first sheet fed from the feed tray of the feeder 1b is the detection target, the controller 30a sets the types of sheet characteristics to be detected by the sheet characteristic detector 2b to all types. On the other hand, when the second or subsequent sheet fed from the feed tray is the detection target, the controller 30a sets the sheet characteristics to be detected by the sheet characteristic detector 2b to only the moisture content and the sheet size.

[0135] In addition, when double-sided printing is performed by the upstream image forming device 3a and the downstream image forming device 3b, the control unit 30a performs settings for each of the upstream paper characteristic detection device 2a and the downstream paper characteristic detection device 2b in the same manner as in Example 1 of the third embodiment described with reference to Figure 10.

[0136] According to the above-mentioned example 2 of the third embodiment, even when a paper feeder 1b is provided in front of a downstream image forming device 3b in a serial tandem type image forming system, an appropriate image forming process is executed based on the paper characteristics detected by each of the paper characteristic detection devices 2a and 2b. Also, this example can obtain the same effect as that obtained by each of the above-mentioned embodiments. In other words, it is possible to reduce the waiting time when detecting paper characteristics, compared to the case where the downstream paper characteristic detection device 2b detects all the paper characteristics that it can detect.

[0137] In the third embodiment, a post-processing device such as a paper cutter 5 and a folding device 6 may be connected to the rear stage of the image forming device 3a and / or 3b. Also, the number of paper characteristic detection devices 2 and the number of image forming devices 3 may be three or more.

[0138] [Paper characteristic detection control process] Next, a paper characteristic detection control process by the image forming system according to the third embodiment will be described with reference to Fig. 12 to Fig. 16. Fig. 12 to Fig. 16 are flowcharts showing an example of the procedure of the paper characteristic detection setting process by the image forming system according to the third embodiment. In the image forming system that performs the processes shown in Fig. 12 to Fig. 16, the paper characteristic detection control process is performed by the control unit 20 (20a or 20b) of the paper characteristic detection device 2 (2a or 2b).

[0139] The image forming system performing the processes shown in Figures 12 to 16 is not limited to the forms shown in Examples 1 and 2 of the third embodiment, but can also be applied to a serial tandem type image forming system equipped with a post-processing device, etc.

[0140] First, a job is set based on a user's operation on a terminal device (not shown) (step S71). Next, the control unit 20 of the paper characteristic detection device 2 judges whether or not the device is connected to the paper characteristic detection system (step S72). If it is judged in step S72 that the device is not connected to the paper characteristic detection system (if step S72 is judged as NO), the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0141] On the other hand, if it is determined in step S72 that the paper characteristic detection system is connected (if step S72 is judged as YES), the control unit 20 determines whether or not multiple paper characteristic detection devices 2 are connected (step S73). If it is determined in step S73 that multiple paper characteristic detection devices 2 are connected (if step S73 is judged as YES), the control unit 20 assigns numbers (IM1, IM2...) to each of the multiple paper characteristic detection devices 2 (step S74).

[0142] Next, the control unit 20 judges whether or not a plurality of image forming apparatuses 3 are connected in the image forming system (step S75). If it is judged in step S75 that a plurality of image forming apparatuses 3 are connected (if the judgement in step S75 is YES), the control unit 20 assigns the number "IMx" to the paper characteristic detection device 2 for which the type of paper characteristic to be detected is to be set (step S76). "x" in "IMx" is set to "1". Next, the control unit 30 judges whether or not the arrangement position of the paper characteristic detection device 2 numbered IMx (x=1) is upstream of the image forming apparatus 3 (step S77 in FIG. 13).

[0143] If it is determined in step S77 that the paper characteristic detection device 2 is located upstream of the image forming device 3 (if step S77 is determined to be YES), the control unit 20 determines whether the paper whose paper characteristics are to be detected is the first sheet of paper fed from each paper feed tray in which the paper used in the job is stored (step S78).

[0144] If it is determined in step S78 that the paper is the first sheet fed from the paper feed tray (if step S78 is a YES judgement), the control unit 20 sets the types of paper characteristics detected by the paper characteristic detection device 2 to all types (step S79). On the other hand, if it is determined in step S78 that the paper is the second or subsequent sheet fed from the paper feed tray (if step S78 is a NO judgement), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to only the moisture content and paper size (step S80).

[0145] On the other hand, if it is determined in step S77 that the paper characteristic detection device 2 is not located upstream of the image forming device 3, i.e., that it is located downstream of the image forming device 3 (if step S77 is determined to be NO), the control unit 20 determines whether the paper characteristic detection device 2 assigned the number IMx is installed between the upstream image forming device 3 and the downstream image forming device 3 (step S81).

[0146] If it is determined in step S81 that the paper characteristic detection device 2 is installed between the upstream image forming device 3 and the downstream image forming device 3 (if step S81 is a YES judgment), the control unit 20 determines whether or not the paper feeder 1 is disposed between the upstream image forming device 3 and the downstream image forming device 3 (step S82). If it is determined in step S82 that the paper feeder 1 is not disposed (if step S82 is a NO judgment), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to only the moisture content, paper resistance, paper size, and surface properties (step S83).

[0147] On the other hand, if it is determined in step S82 that the paper feeder 1 is disposed between the upstream image forming device 3 and the downstream image forming device 3 (if step S82 is determined as YES), the control unit 20 determines whether or not double-sided printing is set in the job (step S84). If it is determined in step S84 that double-sided printing is set (if step S84 is determined as YES), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to only the moisture content, paper resistance, paper size, and surface properties (step S85).

[0148] On the other hand, if it is determined in step S84 that double-sided printing is not set (if step S84 is determined to be NO), the control unit 20 causes the paper feeding device 1, which is arranged between the upstream image forming device 3 and the downstream image forming device 3, to feed paper to the downstream image forming device 3 (step S86).

[0149] Next, the control unit 20 judges whether the paper for which the paper characteristics are to be detected is the first sheet fed from each paper feed tray in which the paper used in the job is stored (step S87). If it is judged in step S87 that the paper is the first sheet fed from the paper feed tray (YES in step S87), the control unit 20 sets the types of paper characteristics to be detected by the paper characteristic detection device 2 to all types (step S88). On the other hand, if it is judged in step S87 that the paper is the second or subsequent sheet fed from the paper feed tray (NO in step S87), the control unit 20 sets the paper characteristics to be detected by the paper characteristic detection device 2 to only the moisture content and paper size (step S89).

[0150] If it is determined in step S81 that the paper characteristic detection device 2 is not installed between the upstream image forming device 3 and the downstream image forming device 3 (if step S81 is a NO judgment), the control unit 20 determines whether or not a post-processing device is connected to the paper characteristic detection device 2 to which the number IMx is assigned (step S90). If it is determined in step S90 that the paper characteristic detection device 2 is not connected to a post-processing device (if step S90 is a NO judgment), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to all types (step S91).

[0151] If it is determined in step S90 that a post-processing device is connected to the paper property detection device 2 to which the number IMx is assigned (if the determination in step S90 is YES), the control unit 20 performs the processes in steps S92 to S104 in Fig. 14. The processes in steps S92 to S104 in Fig. 14 are the same as the processes in steps S7 to S19 in Fig. 5, and therefore a description thereof will be omitted here.

[0152] If it is determined in step S75 of FIG. 12 that multiple image forming apparatuses 3 are not connected (if step S75 is a NO determination), the control unit 20 assigns a number (IM1, IM2, ...) to each of the multiple paper characteristic detection devices 2 (step S105 of FIG. 15). Next, the control unit 20 assigns a number "IMx" to the paper characteristic detection device 2 for which the type of paper characteristic to be detected is to be set (step S106). "x" in "IMx" is set to "1". Next, the control unit 30 determines whether the arrangement position of the paper characteristic detection device 2 numbered IMx is upstream of the image forming apparatus 3 or not (step S107).

[0153] If it is determined in step S107 that the paper characteristic detection device 2 is located upstream of the image forming device 3 (if step S107 is determined to be YES), the control unit 20 sets the types of paper characteristics detected by the paper characteristic detection device 2 to all types (step S108).

[0154] On the other hand, if it is determined in step S107 that the paper characteristic detection device 2 is not disposed upstream of the image forming device 3, i.e., that it is disposed downstream (if step S107 is determined as NO), the control unit 20 determines whether or not double-sided printing is set in the job (step S109). If it is determined in step S109 that double-sided printing is set (if step S109 is determined as YES), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to only the moisture content, paper resistance, paper size, and surface properties (step S110).

[0155] On the other hand, if it is determined in step S109 that double-sided printing is not set (if step S109 is a NO determination), the control unit 20 turns off the execution setting of the paper characteristic detection process by the paper characteristic detection device 2. In other words, the paper characteristic detection process is not executed (step S111).

[0156] After the process of step S108, S110, or S111, the control unit 20 judges whether or not the setting of all the paper characteristic detection devices 2 has been completed (step S112). If it is judged in step S112 that the setting of all the paper characteristic detection devices 2 has not been completed (if the judgment in step S112 is NO), the control unit 20 adds 1 to the value of "x" of the number Imx (step S113). After the process of step S113, the control unit 20 returns to step S107 and makes another judgment.

[0157] On the other hand, if it is determined in step S112 that the settings of all paper characteristic detection devices 2 have been completed (YES in step S112), the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0158] If it is determined in step S73 of FIG. 12 that multiple paper characteristic detection devices 2 are not connected (if step S73 is a NO determination), the control unit 20 determines whether the location of the paper characteristic detection device 2 numbered IMx is upstream of the image forming device 3 (step S114).

[0159] If it is determined in step S114 that the paper characteristic detection device 2 is disposed upstream of the image forming device 3 (if YES is determined in step S114), the control unit 20 sets the types of paper characteristics to be detected by the paper characteristic detection device 2 to all types (step S115). On the other hand, if it is determined in step S114 that the paper characteristic detection device 2 is disposed downstream of the image forming device 3 (if NO is determined in step S114), the control unit 20 determines whether a post-processing device is connected to the paper characteristic detection device 2 numbered IMx (step S116).

[0160] If it is determined in step S116 that the post-processing device is connected (YES in step S116), the control unit 20 determines whether the paper for which the paper characteristics are to be detected is the first sheet fed from each paper feed tray in which the paper used in the job is stored (step S117). If it is determined in step S117 that the paper is the first sheet fed from the paper feed tray (YES in step S117), the control unit 20 sets the types of paper characteristics to be detected by the paper characteristic detection device 2 to the thickness, stiffness, and paper size (step S118).

[0161] On the other hand, if it is determined in step S117 that the paper is the second or subsequent sheet fed from the paper feed tray (if step S117 is a NO judgment), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to only the paper thickness and paper size (step S119). On the other hand, if it is determined in step S116 that no post-processing device is connected to the paper characteristic detection device 2 (if step S116 is a NO judgment), the control unit 20 sets the paper characteristics detected by the paper characteristic detection device 2 to all types (step S120). After the processing of steps S115, S118, S119, or S120, the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0162] After the processing of steps S80, S83, S85, S88, and S89 in FIG. 13 and steps S94, S95, S98, S99, S102, S103, or S104 in FIG. 14, the control unit 20 judges whether or not the setting of all the paper characteristic detection devices 2 has been completed (step S121 in FIG. 16). If it is judged in step S121 that the setting of all the paper characteristic detection devices 2 has not been completed (if the judgment in step S121 is NO), the control unit 20 adds 1 to the value of "x" of the number Imx (step S122). After the processing of step S122, the control unit 20 returns to step S77 in FIG. 13 and makes a judgment.

[0163] On the other hand, if it is determined in step S121 that the settings of all the paper characteristic detection devices 2 have been completed (YES in step S121), the paper characteristic detection setting process by the control unit 20 of the paper characteristic detection device 2 ends.

[0164] In the above-described embodiments, various media sensors for detecting paper characteristics are provided in the paper characteristic detection device 2, but the present invention is not limited to this. A paper characteristic detection unit including various media sensors may be provided in another device included in the paper characteristic detection system.

[0165] Fig. 17 is a diagram showing an example of the configuration of an image forming system 100E including a paper feeder 1A with a built-in paper characteristic detection unit 2A. The paper characteristic detection unit 2A in the paper feeder 1A shown in Fig. 17 has each of the media sensors, namely, the paper size detection sensor 23, the paper thickness detection sensor 24, the moisture content detection sensor 25, the basis weight detection sensor 26, the stiffness detection sensor 27, the surface property detection sensor 28, and the paper resistance detection sensor 29, which have been described with reference to Fig. 2.

[0166] A control unit (not shown) in the paper characteristic detection unit 2A causes a media sensor that detects paper characteristics required for a device connected in a downstream stage to detect the paper characteristics. In the image forming system 100E shown in Fig. 17, since an image forming device 3 is disposed in the downstream stage of the paper feeder 1A including the paper characteristic detection unit 2A, the control unit causes all of the media sensors to detect the respective paper characteristics as in the first embodiment.

[0167] Fig. 18 is a diagram showing an example of the configuration of an image forming system 100F including a paper cutter 5A with a built-in paper characteristic detection unit 2A. The paper characteristic detection unit 2A in the paper cutter 5A shown in Fig. 18 also has a paper size detection sensor 23, a paper thickness detection sensor 24, a moisture content detection sensor 25, a basis weight detection sensor 26, a stiffness detection sensor 27, a surface property detection sensor 28, and a paper resistance detection sensor 29, all of which are not shown.

[0168] A control unit (not shown) in the paper characteristic detection unit 2A of the image forming system 100F causes a media sensor, which detects paper characteristics required for a device connected in a downstream stage, to detect the paper characteristics. In the image forming system 100F shown in Fig. 18, the paper cutter 5A including the paper characteristic detection unit 2A is disposed in the downstream stage of the image forming device 3, so that the control unit performs control to detect the thickness, stiffness, and size of the paper, similarly to Example 2 of the first embodiment.

[0169] In the above-described embodiment, an example was given in which a control unit within a device functioning as a paper characteristic detection control device detects the connection status of each device in the system and changes the type of paper characteristic to be detected based on the type of connected device and its positional relationship to the device, but the present invention is not limited to this.

[0170] For example, the control unit may perform control to change the type of paper characteristics to be detected according to the settings set for the job. The settings referred to by the control unit include, for example, single-sided or double-sided printing settings, settings for post-processing functions such as cutting and folding, etc. Alternatively, these various settings may be set directly as parameters for the device that functions as the paper characteristic detection control device.

[0171] In addition, in each of the above-described embodiments, examples have been given in which each media sensor included in the paper characteristic detection device 2 or the paper characteristic detection unit 2A detects a different paper characteristic, but the present invention is not limited to this, and one media sensor may detect a plurality of different paper characteristics. Alternatively, one media sensor may detect different types of information about one paper characteristic by varying the detection range or detection process on the paper.

[0172] For example, the detection position (detection count) on the same sheet of paper can be changed as the detection range of the paper characteristics. Also, a process with a high or low computational load can be selected as the detection process. For example, in a specific detection range or detection process, the paper characteristics can be detected with a specific accuracy, and in other detection ranges or detection processes, the detection accuracy of the paper characteristics can be made lower or coarser than that of the specific detection range or detection process, thereby giving priority to productivity.

[0173] In the above-described embodiment, an example was given in which the paper whose paper characteristics have been detected by the paper characteristic detection device 2 (see FIG. 1, etc.) is transported to the image forming device 3, but the present invention is not limited to this. For example, the paper characteristic detection device 2 may be configured to eject the paper from the paper characteristic detection device 2 after the detection of specific paper characteristics, without transporting it to the image forming device 3.

[0174] Fig. 19 is a diagram showing an example of the configuration of a paper characteristic detection device 2' according to a modified example. The paper characteristic detection device 2' shown in Fig. 19 has a first transport path and a second transport path. The first transport path connects a first paper feed port 210, through which paper transported from a paper feeder 1 (not shown in Fig. 19) is fed, to a paper discharge section 220, which discharges paper from the paper characteristic detection device 2'.

[0175] The second transport path is a path formed horizontally within the device, connecting the first paper feed port 210 and the second paper feed port 230 that transports paper to the image forming device 3 (not shown in FIG. 19). The first transport path and the second transport path branch off at a branching section 240.

[0176] 19, the paper size detection sensor 23, the paper thickness detection sensor 24, the moisture content detection sensor 25, and the basis weight detection sensor 26 are arranged side by side in a position up to the branching section 240 on the first transport path. Meanwhile, the stiffness detection sensor 27, the surface property detection sensor 28, and the paper resistance detection sensor 29 are arranged side by side in a vertical direction in a position from the branching section 240 to the paper discharge section 220.

[0177] By configuring the paper characteristic detection device 2' in this way, the types of paper characteristics detected for the paper conveyed to the image forming device 3, i.e., the paper on which an image is formed, can be limited to one or more of the paper size, paper thickness, moisture content, and basis weight. Therefore, according to the modified example, the time until printing is completed by the image forming device 3 during execution of a normal job can be shortened, and productivity can be improved.

[0178] Also, by forming the first transport path along which the paper is transported to the image forming device 3 as substantially straight in the horizontal direction as shown in Fig. 19, it becomes possible to stably transport paper such as thick paper. Furthermore, compared to a configuration in which the transport path is curved, the transport time of the paper when detecting the paper characteristics can be shortened, and productivity can be improved.

[0179] In this specification, "making it possible to change the type of paper characteristics detected by a plurality of media sensors" includes, for example, the following aspects (A) and (B). (A) Under one condition α, all of the multiple media sensors detect the respective paper characteristics, whereas under another condition β, some of the multiple media sensors detect the paper characteristics and the other media sensors do not detect the paper characteristics. (B) Under certain condition α, paper characteristics are detected using some of the multiple media sensors or a single media sensor A, and under another condition β, paper characteristics are detected using other of the multiple media sensors (including both cases where some of the media sensors overlap with condition α and cases where no media sensors overlap with condition α) or another single media sensor B.

[0180] Note that "not detecting paper characteristics with the media sensor" includes both of the following modes (1) and (2). (1) The media sensor does not detect the paper characteristics. (2) The paper characteristics are detected, but the detected data is not used.

[0181] Specific examples of the above aspect (A) include the following (A-1) and (A-2). (A-1) When this is the first sheet of paper in a print job, all of the media sensors detect the paper characteristics, but when this is the second or subsequent sheet of paper, only some of the media sensors detect the paper characteristics. (A-2) In the condition that the paper is changed to the first sheet, the paper characteristics are detected by all of the media sensors, but in the condition that the paper is the second or subsequent sheet, the paper characteristics are detected by only some of the media sensors. The change of paper may be performed by the user inputting information on the change of paper, or may be detected based on the detection results of the opening and closing of the paper tray, etc.

[0182] As a specific example of another aspect of the above aspect (A), it is preferable that the media sensor that does not detect paper characteristics under condition β is at least one of the stiffness detection sensor 27, the surface property detection sensor 28, and the paper resistance detection sensor 29. It is also preferable that the media sensor that detects paper characteristics under condition β is at least one of the paper size detection sensor 23, the paper thickness detection sensor 24, the moisture detection sensor 25, and the basis weight detection sensor 26.

[0183] Furthermore, each of the above-described embodiments and variants provides a detailed and specific description of the configuration of the device and system in order to clearly explain the present invention, and is not necessarily limited to having all of the configurations described.

[0184] In addition, the control lines and information lines shown in solid lines in Figure 2 are those considered necessary for explanation, and do not necessarily show all control lines and information lines in the product. In reality, it can be considered that almost all components are connected to each other.

[0185] In addition, in this specification, the processing steps describing chronological processing include not only processing that is performed chronologically in the order described, but also processing that is not necessarily performed chronologically but is performed in parallel or individually (for example, parallel processing or processing by objects). [Explanation of symbols]

[0186] 1, 1a, 1A, 1b...paper feeder, 2, 2a, 2b...paper characteristic detection device, 2A...paper characteristic detection unit, 3, 3a, 3b...image forming device, 5, 5A...cutter, 6...folding device, 7...printed material feeder, 8...paper inversion device, 20...control unit, 23...paper size detection sensor, 24...paper thickness detection sensor, 25...moisture content detection sensor, 26...basis weight detection sensor, 27...stiffness detection sensor, 28...surface property detection sensor, 29...paper resistance detection sensor, 30, 30a, 30b...control unit, 34...image forming unit, 35...fixing unit, 100, 100A, 100B, 100C, 100D, 100E, 100F...image forming system, 200...bookbinding system

Claims

1. A paper characteristic detection system for detecting paper characteristics, comprising: a paper characteristic detection device capable of detecting a plurality of paper characteristics including paper size, stiffness, resistance, moisture content, surface property, and thickness; a control unit capable of setting a type of the paper characteristic to be detected by the paper characteristic detection device among the plurality of different paper characteristics. Paper characteristic detection system.

2. The control unit is capable of changing the combination of the paper characteristics detected by the paper characteristic detection device. The paper characteristic sensing system of claim 1 .

3. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, The control unit changes the type of paper characteristic to be detected depending on the type of post-processing function set in the job. Paper characteristic detection system.

4. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, The control unit changes the type of the paper characteristic detected by the paper characteristic detection device according to at least one of a type of device connected to the paper characteristic detection device in the paper characteristic detection system and a connection position of the paper characteristic detection device in the paper characteristic detection system. Paper characteristic detection system.

5. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, The control unit changes the type of the paper characteristic detected by the paper characteristic detection device according to the type of the post-processing device connected to the paper characteristic detection device. Paper characteristic detection system.

6. The control unit causes the paper characteristic detection device to detect at least one of a size, a stiffness, and a thickness of the paper when the paper characteristic detection device is connected to a paper cutter that cuts the paper. The paper characteristic detection system according to claim 5 .

7. The control unit adjusts at least one of a cutting position and a cutting time of the paper in the paper cutter based on a detection result of the paper characteristic detection device. The paper characteristic detection system according to claim 6.

8. The control unit causes the paper characteristic detection device to detect at least one of stiffness, thickness, and moisture content of the paper when the paper characteristic detection device is connected to a device capable of binding or punching. The paper characteristic detection system according to claim 5 .

9. The control unit causes the paper characteristic detection device to detect at least one of stiffness, thickness, and moisture content of the paper when the paper characteristic detection device is connected to the folding processing device. The paper characteristic detection system according to claim 5 .

10. When the paper characteristic detection device is connected to an image forming apparatus, the control unit causes the paper characteristic detection device to detect information corresponding to at least two or more paper characteristics of the paper size, stiffness, resistance, moisture content, surface property, and thickness. The paper characteristic sensing system of claim 1 .

11. When the paper characteristic detection device is connected to an image forming apparatus, the control unit causes the paper characteristic detection device to detect information corresponding to a moisture content of the paper and information corresponding to at least one of a size, stiffness, resistance, surface property, and thickness of the paper. The paper characteristic sensing system of claim 1 .

12. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, The control unit changes the type of the paper characteristic detected by the paper characteristic detection device depending on whether the paper characteristic detection device is connected to the upstream side of the image forming device or the downstream side of the image forming device in a paper characteristic detection system including the image forming device. Paper characteristic detection system.

13. When the paper characteristic detection device is connected upstream of the image forming device in a paper characteristic detection system including the image forming device, the control unit causes the paper characteristic detection device to detect at least one of the size, stiffness, resistance, moisture content, surface property, and thickness of the paper. The paper characteristic sensing system of claim 12.

14. When the paper characteristic detection device is connected downstream of the image forming device in a paper characteristic detection system including the image forming device, the control unit causes the paper characteristic detection device to detect at least one of the size, stiffness, and moisture content of the paper. The paper characteristic sensing system of claim 12.

15. When the paper characteristic detection device is connected between a first image forming device arranged upstream in a paper transport direction and a second image forming device arranged downstream in the paper transport direction, the control unit causes the paper characteristic detection device to detect at least one of a size, a resistance, a moisture content, and a surface property of the paper. The paper characteristic sensing system of claim 12.

16. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, When a first paper characteristic detection device is disposed upstream of a first image forming device disposed upstream in the paper characteristic detection system, and a second paper characteristic detection device is disposed between the first image forming device and a second image forming device disposed downstream of the first image forming device, the control unit changes the types of paper characteristics detected by the first paper characteristic detection device and the second paper characteristic detection device. Paper characteristic detection system.

17. The control unit determines an image forming position or an image magnification by the second image forming device based on each paper size detected by the first paper characteristic detection device and the second paper characteristic detection device, and determines a transfer condition or a fixing condition of the second image forming device based on at least one of resistance, moisture content, and surface property of the paper detected by the second paper characteristic detection device. The paper characteristic sensing system of claim 16.

18. an image is formed on a first side of the paper by the first image forming device, and an image is formed on a second side of the paper, which is different from the first side, by the second image forming device, thereby forming images on both sides of the paper. The paper characteristic sensing system of claim 16.

19. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, When the paper characteristic detection device is connected between a first image forming device disposed upstream in a paper transport direction and a second image forming device disposed downstream in the paper transport direction, the control unit changes the type of paper characteristic to be detected depending on whether a paper feeder that stores paper is connected between the first image forming device and the second image forming device. Paper characteristic detection system.

20. A paper characteristic detection system for detecting paper characteristics, comprising: A paper characteristic detection device capable of detecting a plurality of different paper characteristics of paper; a control unit capable of setting the type of the paper characteristic detected by the paper characteristic detection device, When the paper characteristic detection device is disposed in a paper characteristic detection system including a first image forming device and a second image forming device, the control unit changes the type of paper characteristic to be detected based on information on whether an image is formed on only one side of the paper or on both sides of the paper. Paper characteristic detection system.

21. the control unit changes the type of paper characteristic to be detected depending on whether the paper fed from the paper feed device is the first paper or the second or subsequent paper fed in a job. The paper characteristic sensing system of claim 1 .

22. the control unit detects all types of paper characteristics detectable by the paper characteristic detection device when the paper being fed is the first sheet, and detects only some types of paper characteristics among all types of paper characteristics detectable by the paper characteristic detection device when the paper being fed is the second or subsequent sheet.

22. The paper characteristic sensing system of claim 21.

23. A paper characteristic detection system for detecting paper characteristics, comprising: a paper characteristic detection device capable of detecting information corresponding to the paper characteristics; a control unit that determines detection contents of the paper characteristics to be detected by the paper characteristic detection device in accordance with at least one of a type of device connected to the paper characteristic detection device in the paper characteristic detection system, a connection position of the paper characteristic detection device in the paper characteristic detection system, and a selected function. Paper characteristic detection system.

24. The control unit can determine, as the detection contents of the paper characteristics, the type of the paper characteristics to be detected, the detection range of the paper characteristics to be detected, or a detection process.

24. The paper characteristic sensing system of claim 23.

25. the paper characteristic detection device includes a plurality of media sensors corresponding to a plurality of different paper characteristics; The control unit is capable of changing the type of the paper characteristic to be detected.

24. The paper characteristic sensing system of claim 23.

26. The control unit is capable of changing a combination of the paper characteristics detected by the plurality of media sensors.

26. The paper characteristic sensing system of claim 25.

27. The device connected to the paper characteristic detection device is a device in which the media sensor of the paper characteristic detection device can be disposed.

24. The paper characteristic sensing system of claim 23.

28. A paper characteristic detection control device for detecting paper characteristics by a paper characteristic detection device having a media sensor, The paper characteristic detection device includes a plurality of media sensors corresponding to a plurality of paper characteristics among paper size, stiffness, resistance, moisture content, surface property, and thickness; a control unit capable of changing the type of the paper characteristic detected by the paper characteristic detection device among the plurality of paper characteristics; Paper characteristic detection and control device.

29. A paper characteristic detection control device for detecting paper characteristics by a paper characteristic detection device having a media sensor, and a control unit that determines the detection contents of the paper characteristics to be detected by the paper characteristic detection device in accordance with at least one of a device connected to the paper characteristic detection device, a connection position of the paper characteristic detection device in the system, and a type of post-processing function set in a print job for the paper to be detected. Paper characteristic detection and control device.

30. A paper characteristic detection control program for detecting a plurality of paper characteristics including a size, stiffness, resistance, moisture content, surface property, and thickness of a paper by a paper characteristic detection device having a media sensor, comprising: determining a type of the paper characteristic detected by the paper characteristic detection device from among the plurality of paper characteristics; The type of the paper characteristic determined in the determining step can be changed. Paper characteristic detection control program.

31. A paper characteristic detection control program for detecting paper characteristics by a paper characteristic detection device having a media sensor, A paper characteristic detection control program that enables a computer to execute a determination step of determining the detection contents of the paper characteristics to be detected by the paper characteristic detection device depending on at least one of the device connected to the paper characteristic detection device, the connection position of the paper characteristic detection device within the system, and the type of post-processing function set in the print job for the paper to be detected.

32. 1. An image forming system, comprising: an image forming apparatus for forming an image on a sheet; A paper characteristic detection system for detecting paper characteristics, The paper characteristic detection system includes: a paper characteristic detection device capable of detecting a plurality of paper characteristics including paper size, stiffness, resistance, moisture content, surface property, and thickness; a control unit capable of changing the type of the paper characteristic detected by the paper characteristic detection device among the plurality of paper characteristics. Image forming system.

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