Sheet characteristic detection device, image forming system and program

Abstract

To provide a sheet characteristic detection device that can prevent a decrease in the detection accuracy of paper thickness of a recording medium, an image forming system and a program.SOLUTION: A paper characteristic detection device includes a clamping part that clamps a recording medium, a paper thickness detection sensor, and a control part. The paper thickness detection sensor detects the displacement in a thickness direction of the recording medium in the clamping part. The control part calculates the thickness of the recording medium based on a detection value detected by the paper thickness detection sensor. In addition, the control part corrects the detection value or thickness detected by the paper thickness detection sensor according to a length in a width direction perpendicular to a conveyance direction in the recording medium or ta length in a width direction of a point that comes into contact with the clamping part in the recording medium, and acquires the thickness of the recording medium.SELECTED DRAWING: Figure 14

Description

[Technical Field]

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

[0002] The image forming system includes an image forming device that forms an image on paper and a paper supply device that supplies paper to the image forming device. The image forming device forms an image on paper based on output job information. The image forming system also includes a paper characteristic detection device that detects the size and type of paper before forming the image on the paper.

[0003] A conventional paper characteristic detection device of this type is described, for example, in Patent Document 1. Patent Document 1 describes a technology including a first roller and a second roller that sandwich and transport a recording medium, a roller shaft that rotatably supports the second roller, a shaft support unit, and a displacement detection unit. The shaft support unit supports the roller shaft so that it can move in the thickness direction of the recording medium. The displacement detection unit detects the displacement of the second roller in the thickness direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-42049 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the technology described in Patent Document 1, it was found that if the width of the recording medium or the length of contact with the clamping portion of the recording medium is shorter than the member that clamps the recording medium, there may be variations depending on the size of the recording medium even if the recording medium has the same thickness.As a result, the technology described in Patent Document 1 had the problem of reduced accuracy in detecting the paper thickness of the recording medium.

[0006] In view of the above-mentioned problems of the related art, an object of the present invention is to provide a paper characteristic detection device, an image forming system, and a program that can prevent a decrease in the detection accuracy of the paper thickness of a recording medium. [Means for solving the problem]

[0007] To solve the above problems and achieve the object of the present invention, a paper characteristic detection device of the present invention includes a clamping unit that clamps a recording medium, a paper thickness detection sensor, and a control unit. The paper thickness detection sensor detects displacement of the recording medium in the clamping unit in the thickness direction. The control unit calculates the thickness of the recording medium based on the detection value detected by the paper thickness detection sensor. The control unit also corrects the detection value or thickness detected by the paper thickness detection sensor in accordance with the length of the recording medium in the width direction perpendicular to the transport direction or the length of the recording medium in the width direction at the point of contact with the clamping unit, thereby obtaining the thickness of the recording medium.

[0008] The image forming system of the present invention includes an image forming device that forms an image on a recording medium, and a paper characteristic detection device that is disposed upstream of the image forming device in the recording medium transport direction and detects the characteristics of the recording medium. The paper characteristic detection device is the paper characteristic detection device described above.

[0009] The program of the present invention is a program that causes a paper characteristic detection device to execute the following procedures (1) to (3). (1) a procedure for detecting a displacement in the thickness direction of the recording medium in a clamping portion that clamps the recording medium; (2) A procedure for acquiring the width of the recording medium in a direction perpendicular to the conveyance direction, or the width of the recording medium at the point where the recording medium comes into contact with the clamping unit. (3) A procedure for correcting the detected value or thickness according to the width of the recording medium or the width of the portion of the recording medium that comes into contact with the clamping unit, and obtaining the thickness of the recording medium. [Effects of the Invention]

[0010] According to the paper characteristic detection device, image forming system, and program having the above configuration, it is possible to prevent a decrease in the accuracy of detecting the paper thickness of the recording medium. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram showing the overall configuration of an image forming system according to an embodiment of the present invention; [Figure 2] 1 is a block diagram showing a hardware configuration of a paper characteristic detection device according to an embodiment of the present invention; [Figure 3] FIG. 2 is a schematic diagram illustrating the configuration of a paper physical property detection unit according to an embodiment of the present invention. [Figure 4] 3 is a cross-sectional view showing a clamping unit of a paper physical property detection unit according to an embodiment of the present invention. FIG. [Figure 5] FIG. 2 is a schematic diagram of a paper physical property detection unit according to an embodiment of the present invention, showing a state in which paper is clamped; [Figure 6] 1 is a cross-sectional view showing a clamping unit of a paper physical property detection unit according to an embodiment of the present invention, showing a state in which paper is clamped. FIG. [Figure 7] FIG. 2 is a schematic diagram illustrating a paper size detection unit according to an embodiment of the present invention. [Figure 8] An explanatory diagram showing the difference in the displacement amount of the driven roller shaft of the paper property detection unit due to differences in paper size (widthwise length), where Figure 8A shows an example where the paper width is shorter than the roller width, and Figure 8B shows an example where the paper width is longer than the roller width. [Figure 9] 9B is a table showing the amount and rate of change between the detected value of the paper thickness detection sensor and the actual paper thickness due to differences in paper width (CD length). And FIG. 9B is a graph showing the detected value of the paper thickness detection sensor due to differences in paper width. [Figure 10] 10 is a graph showing an outline for obtaining a correction coefficient. [Figure 11] 10 is a flowchart showing an operation of acquiring a correction coefficient in the image forming system according to the embodiment of the present invention. [Figure 12]5 is a flowchart showing a calibration operation in the image forming system according to the embodiment of the present invention. [Figure 13] 5 is a flowchart showing a paper thickness calculation operation in the image forming system according to the embodiment of the present invention. [Figure 14] 5 is a flowchart showing an example of a paper thickness detection operation in the image forming system according to the embodiment of the present invention. [Figure 15] 10A and 10B are explanatory diagrams showing a modified example of the paper thickness detection operation in the image forming system according to the embodiment of the present invention. [Figure 16] 1 shows an example of a correction table in the image forming system according to the embodiment of the present invention. [Figure 17] 10A and 10B are explanatory diagrams showing a modified example of the paper thickness detection operation in the image forming system according to the embodiment of the present invention. [Figure 18] 10 shows another example of the correction table in the image forming system according to the embodiment of the present invention. [Figure 19] 10 is a flowchart showing a modified example of the paper thickness detection operation in the image forming system according to the embodiment of the present invention. [Figure 20] 10 shows another example of the correction table in the image forming system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the image forming system of the present invention will be described with reference to Figures 1 to 20. Note that common members in each figure are given the same reference numerals. Furthermore, the present invention is not limited to the following embodiments.

[0013] 1. Example of implementation 1-1. Image formation system configuration First, the overall configuration of an image forming system according to an embodiment of the present invention (hereinafter referred to as "this example") will be described. Fig. 1 is a schematic diagram of an image forming system 1 according to this example.

[0014] 1, the image forming system 1 includes a paper feed unit 10 that feeds paper S, an image forming device 20, and a paper characteristic detection device 30. The paper feed unit 10, the image forming device 20, and the paper characteristic detection device 30 are each connected to a network such as a LAN, and are interconnected via the network. In the image forming system 1, the paper feed unit 10, the paper characteristic detection device 30, and the image forming device 20 are arranged in this order from the upstream side of the transport path of the paper S, and are connected in series.

[0015] The paper feed unit 10 is disposed at the most upstream position of the image forming system 1. It is equipped with multiple paper feed cassettes and is configured to be able to store a large amount of paper. The paper feed unit 10 feeds paper S stored in the paper feed cassettes to the paper characteristic detection device 30 via a paper transport section.

[0016] Although the image forming system 1 has been described as being provided with the paper feed unit 10, the present invention is not limited to this, and the image forming system 1 does not necessarily have to be provided with the paper feed unit 10.

[0017] The paper characteristic detection device 30 detects the paper type of the transported paper S, as well as characteristics such as the basis weight, thickness, surface properties, base and color of the paper S. The paper characteristic detection device 30 also has a paper size detection unit 50 that detects the size of the paper S, and a paper physical property detection unit 60 that detects the thickness of the paper S. The paper characteristic detection device 30 also has a transport unit 31 that transports the paper S, and a paper discharge unit 32 that branches off from the transport unit 31 and discharges the paper S to a paper discharge tray.

[0018] The paper size detection unit 50 and the paper physical property detection unit 60 are disposed on the conveying unit 31. The paper size detection unit 50 is disposed upstream of the paper physical property detection unit 60 in the conveying direction. A branching unit to the paper discharge unit 32 is disposed downstream of the paper physical property detection unit 60 in the conveying direction in the conveying unit 31. The paper S conveyed from the conveying unit 31 is then conveyed to the image forming device 20.

[0019] The image forming apparatus 20 forms an image on the fed paper S based on the output job information and image data. The image forming apparatus 20 is an apparatus that forms an image on the paper S by, for example, an electrophotographic method. The image forming apparatus 20 includes a paper conveying section 230, an operation display panel 240, an image forming section 270, a fixing section 280, and a reverse conveying section 290.

[0020] An operation display panel 240 representing a notification unit is installed on the upper part of the housing of the image forming apparatus 20. The operation display panel 240 has a configuration in which a display panel and a touch panel (operation unit) are superimposed, and allows the user to perform operations and display information. The operation display panel 240 is a touch panel made up of a display such as a liquid crystal display (LCD) or an organic ELD (Electro Luminescence Display).

[0021] The operation display panel 240 is an example of a display unit and an input unit, and displays an instruction menu for the user, information about the acquired image data, etc. Furthermore, the operation display panel 240 has a plurality of keys, and accepts input of various instructions, characters, numbers, and other data by the user operating the keys, and outputs the input signal to the control units of the image forming device 20 and the paper characteristic detection device 30.

[0022] In this example, an example in which the input section and the display section are configured as an integrated unit has been described as the operation display panel 240, but this is not limited to this, and the operation section and the display section may be configured separately.

[0023] The paper transport section 230 transports the paper S fed from the paper feed unit 10 to the image forming section 270, the fixing section 280, the reverse transport section 290, and the paper discharge tray.

[0024] Image forming section 270 includes image forming units of multiple colors (cyan, magenta, yellow, black, etc.), and can form color toner images on paper. Downstream of image forming section 270 in the paper transport direction, there is arranged fixing section 280, to which paper on which a toner image has been formed is transported.

[0025] The fixing unit 280 applies pressure and heat to the transported paper S, thereby fixing the toner image transferred to the paper S to the paper S. After the fixing process is performed by the fixing unit 280, the paper transport unit 230 transports the paper S to the reverse transport unit 290 or the paper output tray.

[0026] The reverse conveyance section 290 is provided with a reversing section that reverses the sheet S. The sheet S that has been reversed by the reversing section is conveyed through the reverse conveyance section 290 to the upstream side of the image forming section 270 or the downstream side of the fixing section 280.

[0027] 1-2. Hardware configuration Next, the hardware configuration of the paper characteristic detection device 30 will be described with reference to FIG. FIG. 2 is a block diagram showing the hardware configuration of the paper characteristic detection device 30. As shown in FIG.

[0028] 2, the paper characteristic detection device 30 has a control unit 101, a paper size detection unit 50, a paper physical property detection unit 60, and a paper conveyance roller drive source 121 that drives the conveyance unit 31. The paper size detection unit 50 has a linear CIS (Contact Image Sensor) 151 that detects the size of the paper S. The paper physical property detection unit 60 has a paper thickness detection sensor 161 and a paper leading edge detection sensor 162. The paper thickness detection sensor 161 detects the thickness of the paper S. The paper leading edge detection sensor 162 detects the upper end, i.e., the leading edge, of the paper S conveyed to the paper physical property detection unit 60. The control unit 101 is also connected to the operation display panel of the image forming apparatus 20 via a serial communication (UART) circuit 106.

[0029] The control unit 101 includes, for example, a CPU (Central Processing Unit) 102, an EEPROM (Electrically Erasable Programmable Read-Only Memory) 103 which is an example of a storage unit, an LED drive circuit 104, a motor drive circuit 105, and a serial communication circuit 106. The EEPROM 103, the LED drive circuit 104, the motor drive circuit 105, and the serial communication circuit 106 are connected to the CPU 102.

[0030] The EEPROM 103 stores programs executed by the CPU 102 and is used as a work area for the CPU 102. The EEPROM 103 also stores a correction coefficient K and a correction table used when calculating the thickness of the paper S.

[0031] The LED drive circuit 104 is connected to the paper size detection unit 50. The LED drive circuit 104 outputs a drive signal to an LED, which is an example of a light source provided in the paper size detection unit 50.

[0032] The motor drive circuit 105 is connected to the paper conveying roller drive source 121. The motor drive circuit 105 controls the drive of the paper conveying roller drive source 121 based on a control signal from the CPU 102. This controls the conveyance of the paper S passing through the paper characteristic detection device 30.

[0033] CPU 102 has paper thickness calculation unit 111, paper size calculation unit 112, physical property detection control unit 113, and paper size detection control unit 114. Paper thickness calculation unit 111 is connected to paper thickness detection sensor 161 and paper leading edge detection sensor 162. Paper thickness calculation unit 111 receives a pulse signal from paper thickness detection sensor 161 and a paper detection signal from paper leading edge detection sensor 162. Paper thickness calculation unit 111 calculates the thickness of paper S based on these signals, size information of paper S, and correction coefficient K and correction table stored in EEPROM 103.

[0034] Furthermore, paper thickness calculation unit 111 is connected to physical property detection control unit 113. Physical property detection control unit 113 controls paper physical property detection unit 60 via paper thickness calculation unit 111. Furthermore, physical property detection control unit 113 acquires paper size information input by the user to operation display panel 240 via serial communication circuit 106. If the user does not input paper size information to operation display panel 240, physical property detection control unit 113 acquires paper size information calculated by paper size calculation unit 112 via paper size detection control unit 114, which will be described later.

[0035] The paper size calculation unit 112 calculates the size of the paper S based on an output signal from the CIS 151 provided in the paper size detection unit 50. The paper size calculation unit 112 is also connected to the paper size detection control unit 114. The paper size detection control unit 114 controls the paper size detection unit 50 via the paper size calculation unit 112. The paper size detection control unit 114 also transmits the paper size information calculated by the paper size calculation unit 112 to the physical property detection control unit 113.

[0036] 1-3. Example of the configuration of the paper property detection unit Next, the configuration of the paper property detection unit 60 will be described with reference to FIGS. 3 and 5 are schematic diagrams showing the paper physical property detection unit 60, and Fig. 4 and Fig. 6 are cross-sectional views showing the paper physical property detection unit 60. Fig. 3 and Fig. 4 show a state where no paper S is present, and Fig. 5 and Fig. 6 show a state where paper S is present.

[0037] As shown in Figure 3, the paper property detection unit 60 has a drive roller shaft 61, a driven roller shaft 62, a first roller 63 representing the first clamping unit, a second roller 64 representing the second clamping unit, a biasing member 65, a support unit 67, and a paper thickness detection sensor 161.

[0038] The drive roller shaft 61 is connected to a paper transport roller drive source 121. The drive roller shaft 61 is rotated by the paper transport roller drive source 121. The drive roller shaft 61 is disposed so that its axial direction is perpendicular to the transport direction and parallel to the width direction of the paper S.

[0039] In this example, two first rollers 63 are provided on the drive roller shaft 61. The two first rollers 63 are arranged at an interval in the axial direction of the drive roller shaft 61. The two first rollers 63 rotate together with the rotation of the drive roller shaft 61.

[0040] The driven roller shaft 62 is disposed so that its axial direction is parallel to the axial direction of the drive roller shaft 61. The driven roller shaft 62 is disposed opposite the drive roller shaft 61. The driven roller shaft 62 is rotatably supported. The driven roller shaft 62 is supported so that it can move toward and away from the drive roller shaft 61. Although the drive roller shaft 61 is rotatably supported, its movement toward and away from the driven roller shaft 62 is restricted.

[0041] Two second rollers 64 are provided on the driven roller shaft 62. The two second rollers 64 are arranged with a gap between them in the direction of the driven roller shaft 62. The two second rollers 64 face the first rollers 63 provided on the drive roller shaft 61. As shown in FIGS. 5 and 6, the first roller 63 and the second roller 64 sandwich the paper S.

[0042] Moreover, a biasing member 65 is disposed on each of both axial ends of the driven roller shaft 62. One end of the biasing member 65 abuts against the driven roller shaft 62. The other end of the biasing member 65 is disposed on a support portion 67 facing the driven roller shaft 62. The biasing member 65 biases the driven roller shaft 62 toward the drive roller shaft 61.

[0043] As the driven roller shaft 62 is urged toward the drive roller shaft 61, the second roller 64 supported by the driven roller shaft 62 is urged toward the first roller 63, as shown in Fig. 4. When the first roller 63 is driven to rotate, the second roller 64 also rotates together with the first roller 63. As the first roller 63 and the second roller 64 rotate, the first roller 63 and the second roller 64 convey the paper S sandwiched between them, as shown in Figs. 5 and 6.

[0044] For example, a compression coil spring is used as the biasing member 65. Note that the biasing member 65 is not limited to a compression coil spring, and various other elastic members such as a leaf spring or rubber may be used.

[0045] Furthermore, a lever piece of a paper thickness detection sensor 161 abuts between the two second rollers 64 on the driven roller shaft 62. The paper thickness detection sensor 161 is disposed on the side of the driven roller shaft 62 opposite to the side facing the drive roller shaft 61.

[0046] 5 and 6, when paper S enters between the first roller 63 and the second roller 64, the driven roller shaft 62 displaces in a direction away from the drive roller shaft 61 against the biasing force of the biasing member 65. Also, the lever piece of the paper thickness detection sensor 161 that abuts against the driven roller shaft 62 also rotates in a direction away from the drive roller shaft 61. Then, the paper thickness detection sensor 161 detects the thickness of the paper S from the rotation angle of the lever piece. Also, the paper thickness calculation unit 111 calculates the thickness of the paper S based on the detection value of the paper thickness detection sensor 161 when there is no paper S between the first roller 63 and the second roller 64 and the detection value of the paper thickness detection sensor 161 when there is paper S between the first roller 63 and the second roller 64.

[0047] 6, a paper leading edge detection sensor 162 is disposed downstream in the conveyance direction of the first roller 63 and the second roller 64. The paper leading edge detection sensor 162 detects the leading edge of the paper S. Then, the control unit 101 determines whether or not the paper S is present between the first roller 63 and the second roller 64 based on the paper detection information from the paper leading edge detection sensor 162.

[0048] Furthermore, for example, a roller made of resin is used as the first roller 63. And, for example, a roller made of elastic rubber is used as the second roller 64. Note that the materials of the first roller 63 and the second roller 64 are not limited to those mentioned above. For example, the first roller 63 may be formed of a roller made of metal or rubber, and the second roller 64 may be formed of a roller made of metal or resin.

[0049] Furthermore, although an example has been described in which rollers, which are rotating bodies, are used as the first clamping portion and the second clamping portion, this is not limited to this, and a flat or approximately semicircular guide plate or the like may also be used.

[0050] 1-4. Paper size detection unit configuration example Next, the configuration of the paper size detection unit 50 will be described with reference to FIG. FIG. 7 is a schematic diagram showing the configuration of the paper size detection unit 50. As shown in FIG.

[0051] 7, the paper size detection unit 50 has a CIS 151 that is longer than the width T of the paper S being transported. The CIS 151 is a sensor that integrates multiple light receiving units, multiple LEDs that indicate light sources, a lens for focusing the light, and the like.

[0052] The multiple LEDs emit light toward the paper S. The multiple light receiving units receive the light reflected from the paper S. The light receiving units of the CIS 151 detect the boundary lines between the leading and trailing ends of the paper S and the boundary lines at both ends of the paper S in the width direction while transporting the paper S. The paper size calculation unit 112 then calculates the length T of the paper S in the width direction and the length L of the paper S in the direction parallel to the transport direction based on the output signal from the CIS.

[0053] 2. Differences in displacement of the driven roller shaft due to differences in paper size Next, differences in the amount of displacement of driven roller shaft 62 of paper property detection unit 60 due to differences in the width direction length of paper (hereinafter referred to as paper width) will be described with reference to FIGS. 8 and 9. FIG. 8A and 8B are explanatory diagrams showing differences in the amount of displacement of driven roller shaft 62 of paper property detection unit 60 due to differences in paper size (width direction length). Note that Fig. 8A and Fig. 8B explain an example in which the length from one end to the other end in the axial direction of two first rollers 63 and two second rollers 64 (hereinafter referred to as roller width) is 130 mm.

[0054] 9A is a table showing the amount and rate of change between the detected value of the paper thickness detection sensor 161 and the actual paper thickness due to differences in paper width (CD length). FIG. 9B is a graph showing the detected value of the paper thickness detection sensor 161 due to differences in paper width. The horizontal axis of FIG. 9B represents the paper width, and the vertical axis of FIG. 9A represents the detected value. In FIGS. 9A and 9B, when the basis weight is 68 g / m 2 and 128g / m 2 The data for the paper is shown.

[0055] As shown in FIG. 8B, when the width of the sheet S2 to be detected is sufficiently longer than the roller width, i.e., when the sheet width is 130 mm or more, the sheet S2 comes into contact with the entire surfaces of the first roller 63 and the second roller 64. Therefore, the second roller 64 is not crushed. As a result, as shown in FIGS. 9A and 9B, the detection value of the sheet thickness detection sensor 161 does not differ from the actual sheet thickness, and the amount of change and rate of change are almost zero. In other words, when the sheet width of the sheet S2 is sufficiently longer than the roller width, the sheet thickness of the sheet S2 can be detected with high accuracy.

[0056] On the other hand, if the width of the paper S1 to be detected is shorter than the roller width, the paper S1 only comes into contact with parts of the first roller 63 and the second roller 64. Pressure is then applied locally to the part of the second roller 64 that comes into contact with the paper S1, causing the second roller 64 to partially collapse. As a result, the displacement of the driven roller shaft 62 that supports the second roller 64 decreases.

[0057] 9A and 9B, the difference between the detection value of the paper thickness detection sensor 161 and the actual paper thickness increases, and the detection accuracy of the paper thickness of the paper S1 decreases. Similar results are seen for paper of different basis weights.

[0058] Furthermore, the shorter the paper width, the greater the amount of crushing of the second roller 64. Therefore, as shown in Figures 9A and 9B, it can be seen that the detection accuracy decreases proportionally as the paper width becomes shorter.

[0059] The control unit 101 of the image forming system 1 of this embodiment performs correction control on the detection value of the paper physical property detection unit 60 in accordance with the paper width, thereby improving the detection accuracy of the paper thickness.

[0060] 3.Operation 3-1. Correction coefficient acquisition operation First, the operation of acquiring the correction coefficient K for performing correction control will be described with reference to FIGS. Fig. 10 is a graph showing an overview of how to obtain a correction coefficient. The horizontal axis of Fig. 10 indicates general paper sizes, and the vertical axis of Fig. 10 indicates detected paper thickness values. Fig. 11 is a flowchart showing the operation of obtaining the correction coefficient K, Fig. 12 is a flowchart showing the calibration operation, and Fig. 13 is a flowchart showing the operation of calculating paper thickness.

[0061] 10 to 13, an example will be described in which A6 size paper (width 105 mm) which is shorter than the roller width and A4 size paper (width 210 mm) which is longer than the roller width, which are common paper sizes, are passed through the paper characteristic detection device 30 to obtain the correction coefficient K. The following operations are performed as an adjustment work in the production process of the image forming system 1.

[0062] 11, the control unit 101 gives the following instructions to the operator via the operation display panel 240: an instruction to load A4 size paper in the first paper feed cassette of the paper feed unit 10, and an instruction to load A6 size paper in the second paper feed cassette of the paper feed unit 10. The control unit 101 also sets the A6 size paper width X1 (105 mm) in the EEPROM 103, and sets the A4 size paper width X2 (210 mm) in the EEPROM 103 (step S11).

[0063] Then, the operator loads one sheet of A4 size paper into the first paper feed cassette and one sheet of A6 size paper into the second paper feed cassette. Next, the control unit 101 determines whether the paper loading is complete (step S12). If the control unit 101 determines that the paper loading is complete in the process of step S12 (YES in step S12), it determines whether there is paper in the first paper feed cassette (step S13).

[0064] If the control unit 101 determines in step S13 that there is paper in the first paper cassette (YES in step S13), it executes an operation to calculate the thickness of A4 size paper (step S14).

[0065] In the process of step S14, calibration is first performed, and then the paper is passed through the paper characteristic detection device 30, and the paper is detected by the paper physical property detection unit 60. Then, the paper thickness calculation unit 111 calculates the paper thickness.

[0066] The calibration operation will now be described with reference to FIG. 12, the paper thickness calculation unit 111 waits for an initialization instruction from the physical property detection control unit 113 (step S31). When the initialization instruction is issued, the paper thickness calculation unit 111 clears all the detected values ​​and calculated values ​​from the paper thickness detection sensor 161 (step S32).

[0067] Next, paper thickness calculation unit 111 waits for a detection start instruction from physical property detection control unit 113 (step S33). Then, paper thickness calculation unit 111 waits for a measurement start instruction from control unit 101 (step S34). Next, paper thickness calculation unit 111 acquires a sensor count value (detection value) from paper thickness detection sensor 161 (step S35). Then, paper thickness calculation unit 111 records the detection value (no-paper value) when no paper is passing through paper physical property detection unit 60 in EEPROM 103, which is an example of a memory unit (step S36). This completes the calibration operation.

[0068] Next, with reference to FIG. 13, the operation of detecting paper by the paper physical property detection unit 60 and the operation of calculating paper thickness by the paper thickness calculation unit 111 will be described. 13, the paper thickness calculation unit 111 waits for a detection start instruction from the physical property detection control unit 113 (step S41). Then, the paper thickness calculation unit 111 waits for a measurement start instruction from the control unit 101 (step S42).

[0069] Next, paper thickness calculation unit 111 determines whether paper leading edge detection sensor 162 has detected paper, i.e., whether paper is present in paper physical property detection unit 60 (step S43). If it is determined in the processing of step S43 that paper is present in paper physical property detection unit 60 (YES determination in step S43), paper thickness calculation unit 111 acquires a sensor count value (detection value) from paper thickness detection sensor 161 (step S44). Then, paper thickness calculation unit 111 records the detection value (paper presence value) in the state where paper is passing through paper physical property detection unit 60 in EEPROM 103, which is an example of a storage unit (step S45).

[0070] Next, the paper thickness calculation unit 111 calculates the paper thickness measurement value (step S46). In the processing of step S46, the paper thickness calculation unit 111 calculates the paper thickness measurement value by subtracting the paper-absence value acquired in the calibration operation from the paper-presence value acquired in the processing of step S45. Then, the paper thickness calculation unit 111 records the calculated paper thickness measurement value in the EEPROM 103 (step S47). This completes the paper detection operation by the paper physical property detection unit 60 and the paper thickness calculation operation by the paper thickness calculation unit 111.

[0071] 11, the paper thickness calculation unit 111 stores the paper thickness measurement value calculated in step S14 as the detected paper thickness value Y2 of A4 size paper in the EEPROM 103 (step S15). Next, the control unit 101 determines whether the paper whose thickness has been measured has been discharged to the paper discharge tray of the image forming device 20 or the paper characteristic detection device 30 (step S16).

[0072] In the process of step S16, if it is determined that the paper has been discharged to the paper output tray (YES in step S16), it is determined whether or not there is paper in the second paper feed cassette (step S17). If control unit 101 determines that there is paper in the second paper feed cassette in step S17 (YES in step S17), it executes an operation to calculate the paper thickness of A6 size paper (step S18). Note that the calculation operation in step S18 is the same as the calculation operation in step S14, and therefore a description thereof will be omitted.

[0073] The paper thickness calculation unit 111 stores the paper thickness measurement value calculated in step S18 as the detected paper thickness value Y1 of A6 size paper in the EEPROM 103 (step S19). As a result, linear data such as that shown in FIG. 10 can be obtained.

[0074] Next, the control unit 101 determines whether the paper whose thickness has been measured has been discharged to the paper output tray of the image forming device 20 or the paper characteristic detection device 30 (step S20). If it is determined in the processing of step S20 that the paper has been discharged to the paper output tray (YES determination in step S20), the paper thickness calculation unit 111 calculates the correction coefficient K (step S21).

[0075] The correction coefficient K can be obtained from the slope of the linear data shown in Fig. 10. In other words, if the width of A6 size paper is X1, the width of A4 size paper is X2, the detected value of A6 size paper is Y1, and the detected value of A4 size paper is Y2, the correction coefficient K can be calculated from the following formula 1. [Formula 1] K = (Y2 - Y1) / (X2 - X2)

[0076] Next, the control unit 101 determines whether the calculated correction coefficient K>0 (step S22). If the control unit 101 determines in the process of step S22 that the correction coefficient K>0 (YES determination in step S22), the control unit 101 stores the calculated correction coefficient K in the EEPROM 103 (step S23). This completes the calculation operation of the correction coefficient K.

[0077] Furthermore, if the control unit 101 determines in the process of step S22 that the correction coefficient K is equal to or less than 0 (NO in step S22), the control unit 101 determines that the adjustment work has failed (step S24). Then, the control unit 101 returns to the process of step S11 and performs the operation of acquiring the correction coefficient K again. This allows the correction coefficient K to be reliably acquired in the adjustment work in the production process of the image forming system 1.

[0078] 3-2. Example of paper thickness detection operation Next, an example of the paper thickness detection operation using the above-mentioned correction coefficient K will be described with reference to FIG. FIG. 14 is a flowchart showing the paper thickness detection operation.

[0079] As shown in FIG. 14, first, the control unit 101 determines whether a job has been started by the image forming system 1 (step S51). If it is determined in the processing of step S51 that a job has been started, the operation of calculating the paper thickness of the paper conveyed to the paper characteristic detection device 30 is performed (step S52). In the processing of step S52, calibration is first performed, and then the paper is passed through the paper characteristic detection device 30, and the paper physical property detection unit 60 performs a paper detection operation. Then, the paper thickness calculation unit 111 performs a paper thickness calculation operation. Note that the processing of step S52 is similar to the processing of steps S14 and S18 described above, and therefore a description thereof will be omitted.

[0080] Next, the control unit 101 stores the paper thickness measurement value calculated in the process of step S52 as Z1 in the EEPROM 103 (step S53). Next, the control unit 101 determines whether there is information on the paper width and paper size of the paper measured from the operation display panel 240 (step S54).

[0081] In the process of step S54, if it is determined that paper width size information is available from the operation display panel 240 (YES in step S54), the control unit 101 acquires the paper width size information from the operation display panel 240 (step S55). In addition, in the process of step S54, if it is determined that paper width size information is not available from the operation display panel 240 (NO in step S54), the control unit 101 acquires the paper width size information from the paper size detection unit 50 (step S56).

[0082] When the control unit 101 acquires the paper width size information, it stores the paper width size information as paper width X3 in the EEPROM 103 (step S57). Next, it determines whether the stored paper width X3 is equal to or greater than the roller width (e.g., 130 mm) (step S58). If the control unit 101 determines in the processing of step S58 that the paper width X3 is equal to or greater than the roller width (e.g., 130 mm), the paper thickness calculation unit 111 does not perform calculation processing for correction, and sets the measurement detection value Z1 calculated in step S52 as the corrected detection value Z2 (step S59). Then, the control unit 101 outputs the corrected detection value Z2 as the paper thickness.

[0083] Furthermore, if the control unit 101 determines in the processing of step S58 that the paper width X3 is less than the roller width (for example, 130 mm), the control unit 101 reads the correction coefficient K from the EEPROM 103 (step S60). Next, the paper thickness calculation unit 111 corrects the measurement detection value Z1 calculated in step S52 using the correction coefficient K to calculate the corrected detection value Z2 (step S61). For example, if the roller width is 130 mm, the corrected detection value Z2 is calculated from the following formula 2. [Formula 2] Z2 = (130 - X3) x K + Z1

[0084] Then, the control unit 101 outputs the corrected detection value Z2 as the paper thickness, thereby completing the operation of detecting the paper thickness by the image forming system 1.

[0085] Thus, according to the image forming system 1 of this example, when the paper width is smaller than the roller width, the paper thickness is corrected in the processes of steps S60 and S61. This makes it possible to accurately detect the paper thickness even when the paper width is smaller than the roller width and the second roller 64 is crushed, reducing detection accuracy. As a result, it is possible to prevent a reduction in the detection accuracy of the paper thickness detection value.

[0086] 3-3. Modified example of paper thickness detection operation Next, a modified example of the paper thickness detection operation will be described with reference to FIGS. 15 and 17 are explanatory diagrams showing modified examples of the paper thickness detection operation, and FIGS. 16 and 18 show correction tables used in the modified examples of the paper thickness detection operation.

[0087] 15, in the paper property detection unit 60 described above, a paper thickness detection sensor 161 is disposed between two second rollers 64. Here, the distance between the two second rollers 64 is set to, for example, 30 mm. Therefore, the actual length X4 of contact between the second roller 64 and the paper S2 (hereinafter referred to as contact width) is the value obtained by subtracting the distance between the two second rollers 64 from the paper width.

[0088] In the paper thickness detection operation according to the modified example, the correction table shown in Fig. 16 is created in advance and stored in the EEPROM 103. When creating the correction table shown in Fig. 16, the contact width X4 is calculated by subtracting the distance between the two second rollers 64 from the paper width X3. Then, correction values ​​H corresponding to a plurality of paper widths X3 and contact widths X4 are measured and stored in the EEPROM 103 as the correction table shown in Fig. 16.

[0089] 17 is a diagram showing a modified example of a paper property detection unit. In paper property detection unit 60B shown in FIG. 17, paper thickness detection sensor 161 is located at one axial end of driven roller shaft 62. Therefore, second roller 64 is not divided into multiple parts. In paper property detection unit 60B shown in FIG. 17, the actual length X4 of contact between second roller 64 and paper S2 (hereinafter referred to as contact width) is the same as paper width X3.

[0090] In the paper property detection unit 60B shown in Fig. 17, similarly to the correction table shown in Fig. 16, the correction value H corresponding to each of a plurality of paper widths X3 and contact widths X4 can be measured to create the correction table shown in Fig. 18. The correction table shown in Fig. 18 is then stored in the EEPROM 103.

[0091] Next, a modified example of the paper thickness detection operation will be described with reference to FIG. FIG. 19 is a flowchart showing a modified example of the paper thickness detection operation.

[0092] 19, the processes from step S71 to step S77 are the same as the processes from step S51 to step S57 shown in FIG. 14, and therefore a description thereof will be omitted. When the process of storing the paper width size information in step S77 is completed, the control unit 101 calculates the paper contact width X4 from the paper width X3 (step S78). In the process of step S78, in the case of the paper physical property detection unit 60 shown in FIG. 15, the contact width X4 is the value obtained by subtracting the spacing between the two second rollers 64 (for example, 30 mm) from the paper width X3 (X4 = X3 - 30). Also, in the case of the paper physical property detection unit 60B shown in FIG. 17, the paper width X3 becomes the contact width X4 (X4 = X3). In other words, the effective contact width with the paper is obtained from information about the arrangement of the rollers themselves (such as the width of the rollers themselves and the positions of the rollers themselves in the conveyance path, including the spacing).

[0093] Next, the control unit 101 reads out the correction amount H corresponding to the contact width X4 calculated from the correction table stored in advance in the EEPROM 103 (step S79). Then, the paper thickness calculation unit 111 corrects the measurement detection value Z1 calculated in step S72 using the read correction amount H to calculate a corrected detection value Z2 (step S80). In the processing of step S80, the corrected detection value Z2 is calculated using the following formula 3. [Formula 3] Z2 = Z1 + H

[0094] Then, the control unit 101 outputs the corrected detection value Z2 as the paper thickness, thereby completing the operation of detecting the paper thickness by the image forming system 1.

[0095] Even in paper thickness detection operations using such a correction table, even if the paper contact width is smaller than the roller width, the detection value can be corrected based on the correction value, thereby preventing a decrease in the detection accuracy of the paper thickness detection value.

[0096] Furthermore, the amount of compression of the second roller 64 varies depending on the material of the second roller 64. Fig. 20 shows a correction table for the second roller 64 made of a material different from that shown in Fig. 16. If the second roller 64 is replaced with a roller made of a different material due to maintenance work or the like, the operator changes the correction table stored in the EEPROM 103 from the correction table shown in Fig. 16 to the correction table shown in Fig. 20. As a result, during paper thickness detection, an optimal correction value can be obtained using a correction table suited to the material of the second roller 64, thereby improving the detection accuracy of the paper thickness detection value.

[0097] The correction table stored in the EEPROM 103 is changed as appropriate depending on the roller material and the configuration of the paper physical property detection unit. Alternatively, multiple correction tables may be stored in the EEPROM 103 depending on the roller material and the configuration of the paper physical property detection unit, and the optimal correction table may be selected from the multiple correction tables when performing the paper thickness detection operation.

[0098] The above describes the embodiments, including their effects. However, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the invention as defined in the claims.

[0099] In the above-described embodiment, the above-described operations are performed by the control unit 101 of the paper characteristic detection device 30, but the present invention is not limited to this. For example, the operations may be performed by a control unit that controls the image forming device 20 or a control unit that controls the entire image forming system 1. Furthermore, the paper characteristic detection device 30 may be provided within the image forming device 20.

[0100] Furthermore, although an example in which paper is used as the recording medium has been described, the present invention is not limited to this, and various other materials such as film and fabric can also be used as the recording medium.

[0101] Furthermore, some or all of the above-described components, functions, processing units, etc. may be implemented in hardware, for example, by designing an integrated circuit. Furthermore, the above-described components, functions, etc. may be implemented in software by a processor interpreting and executing a program that implements each function. Information such as the programs, tables, and files that implement each function can be stored in a storage device such as a memory, a hard disk, or an SSD (Solid State Drive), or in a storage medium such as an IC card, SD card, or DVD.

[0102] In this specification, the words "parallel" and "orthogonal" are used, but these do not mean only "parallel" and "orthogonal" in the strict sense, but also include "parallel" and "orthogonal" and may also mean a "substantially parallel" or "substantially orthogonal" state within a range in which the functions can be exerted. [Explanation of symbols]

[0103] 1...image forming system, 10...paper feeding unit, 20...image forming apparatus, 30...paper characteristic detection device, 31...conveying section, 32...paper discharge section, 50...paper size detection section, 60, 60B...paper physical property detection section, 61...drive roller shaft, 62...driven roller shaft, 63...first roller (first clamping section), 64...second roller (second clamping section), 65...urging member, 67...support section, 101...control section, 102...CPU, 103...EEPROM (storage section), 104...LED drive circuit, 105...motor drive circuit, 106...serial communication circuit, 111...paper thickness calculation section, 112...paper size calculation section, 113...physical property detection control section, 114...paper size detection control section, 121...paper transport roller drive source, 161... Paper thickness detection sensor, 162... Paper leading edge detection sensor, 230... Paper transport section, 240... Operation display panel (input section), 270... Image forming section, 280... Fixing section, 290... Reversing transport section

Claims

1. a clamping unit that clamps the recording medium; a paper thickness detection sensor that detects a displacement of the recording medium in the clamping section in a thickness direction; a control unit that calculates the thickness of the recording medium based on the detection value detected by the paper thickness detection sensor, The control unit corrects the detection value or the thickness detected by the paper thickness detection sensor according to the length of the recording medium in a width direction perpendicular to the conveyance direction or the length of the recording medium in the width direction at a position where the recording medium comes into contact with the clamping unit, and acquires the thickness of the recording medium. Paper characteristic detection device.

2. The clamping unit is a roller. The paper characteristic detecting device according to claim 1 .

3. The clamping unit is A first roller; a second roller disposed opposite the first roller, a roller shaft that rotatably supports the second roller, The paper thickness detection sensor detects the displacement of the roller shaft in the thickness direction. The paper characteristic detecting device according to claim 2 .

4. The clamping portion is formed of an elastic member. The paper characteristic detecting device according to claim 1 .

5. At least one of the first roller and the second roller is formed of an elastic member. The paper characteristic detecting device according to claim 3 .

6. an input unit for inputting the size of the recording medium; The control unit obtains the width of the recording medium from the size information input to the input unit. The paper characteristic detecting device according to claim 1 .

7. a size detection unit for detecting the width of the recording medium; The control unit obtains the width of the recording medium from the information detected by the size detection unit. The paper characteristic detecting device according to claim 1 .

8. The size detection unit is a linear sensor arranged on the paper transport path. The paper characteristic detecting device according to claim 7.

9. The widthwise length of the portion of the recording medium that comes into contact with the clamping unit is acquired based on information about the arrangement of the clamping unit and the widthwise length of the recording medium that is perpendicular to the conveyance direction. The paper characteristic detecting device according to claim 1 .

10. The control unit does not correct the detected value or the thickness when the length of the recording medium in the width direction is greater than the length of the clamping unit in the width direction. The paper characteristic detecting device according to claim 1 .

11. The control unit changes the correction of the detected value or the thickness depending on the material of the clamping unit. The paper characteristic detecting device according to claim 1 .

12. a storage unit that stores a correction coefficient for correcting the detection value in accordance with the width of the recording medium or the width of the portion of the recording medium that comes into contact with the clamping unit; The control unit acquires the correction coefficient from the storage unit and corrects the detection value. The paper characteristic detecting device according to claim 1 .

13. a storage unit that stores a correction table having a plurality of correction values ​​that correct the detection value in accordance with the width direction length of the recording medium or the width direction length of the portion of the recording medium that comes into contact with the clamping unit, The control unit acquires the correction table from the storage unit, and corrects the detection value based on a corresponding correction value from among the plurality of correction values ​​included in the correction table. The paper characteristic detecting device according to claim 1 .

14. an image forming apparatus for forming an image on a recording medium; a paper characteristic detection device that is disposed upstream of the image forming device in a conveyance direction of the recording medium and detects characteristics of the recording medium; the paper characteristic detection device, a clamping unit that clamps the recording medium; a paper thickness detection sensor that detects a displacement of the recording medium in the clamping section in a thickness direction; a control unit that calculates the thickness of the recording medium based on the detection value detected by the paper thickness detection sensor, The control unit corrects the detection value or the thickness detected by the paper thickness detection sensor according to the length of the recording medium in a width direction perpendicular to the conveyance direction or the length of the recording medium in the width direction at a position where the recording medium comes into contact with the clamping unit, and acquires the thickness of the recording medium. Imaging system.

15. a step of detecting a displacement of the recording medium in a thickness direction of the clamping portion that clamps the recording medium; a step of acquiring a width of the recording medium in a direction perpendicular to the conveyance direction, or a width of a portion of the recording medium that comes into contact with the clamping unit; a step of correcting the detected value or the thickness according to the width direction length of the recording medium or the width direction length of the portion of the recording medium that contacts the clamping unit, and acquiring the thickness of the recording medium; A program that causes a paper characteristic detection device to execute the above.

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