JP2020116752A - Image formation device, sheet property detection method and sheet property detection program - Google Patents

Abstract

To provide an image formation device that can accurately detect property of a sheet even when special paper, such as additional printing paper and label paper, is used, and to provide a sheet property detection method and a sheet property detection program.SOLUTION: An image formation device includes: a transportation unit for transporting a sheet; a sheet property detection unit for detecting property of a sheet; an image formation unit for forming an image on a sheet; and an image diagnosis unit for diagnosing an image on a sheet. The image formation device is provided with a detection position changing unit for changing a detection position so that the sheet property detection unit detects property of a sheet at a non-image part on a sheet on the basis of a diagnostic result by the image diagnosis unit.SELECTED DRAWING: Figure 4

Description

The present invention relates to an image forming apparatus, a sheet characteristic detecting method, and a sheet characteristic detecting program, and more particularly, to an image forming apparatus that forms an image based on the characteristic of a medium (sheet), a sheet characteristic detecting method in the image forming apparatus, and the image. The present invention relates to a sheet characteristic detection program that operates in a forming apparatus.

When an image is formed on a medium (paper) using an image forming apparatus such as an MFP (Multi-Functional Peripherals), a paper having water content, basis weight, rigidity, surface smoothness, glossiness, density, whiteness, etc. The image forming conditions (for example, the speed of the conveying roller, the nip pressure, the transfer voltage, the fixing temperature, the fixing speed, etc.) vary depending on the characteristics of (1). Therefore, various sensors are arranged in a sheet conveyance path that conveys a sheet from the sheet feeding section to the image forming section, the characteristics of the sheet are detected, and the image forming condition is adjusted according to the detected characteristic of the sheet.

Regarding a sensor for detecting the characteristics of such a sheet, for example, in Patent Document 1 below, a light emitting unit that emits light to the surface of the recording sheet and a regular reflection light reflected by the surface of the recording sheet are received. Detection results obtained from first light receiving means, second light receiving means for receiving irregularly reflected light reflected on the surface of the recording paper, and output of the first light receiving means and output of the second light receiving means. And a predetermined threshold value to determine the type of the recording paper, and the control means determines the type of the recording paper based on the relative difference between the detection result and the threshold value. A recording material discriminating apparatus is disclosed.

Japanese Patent Laid-Open No. 2007-013993

When detecting the characteristics of the paper using an optical sensor, the paper is irradiated with light to detect reflected light, diffused light, and transmitted light, but the characteristics of special paper such as additional printing paper and label paper are detected. In this case, the amount of reflected light, the amount of diffused light, and the amount of transmitted light are different between the image portion where the image has already been formed and the non-image portion where the image has not been formed.

Therefore, in order to accurately detect the characteristics of the paper, it is necessary to distinguish between the image part and the non-image part on the paper, but with the conventional method, the image forming position of the reprinted paper or the label paper is unknown. Since there is no light, the irradiation position of light is not always an effective position, and there is a problem that the characteristics of the paper cannot be accurately detected.

The present invention has been made in view of the above problems, and its main purpose is to be able to accurately detect the characteristics of paper even when using special paper such as reprint paper or label paper. An object is to provide an image forming apparatus, a sheet characteristic detection method, and a sheet characteristic detection program.

One aspect of the present invention is a conveyance unit that conveys paper, a paper characteristic detection unit that detects characteristics of the paper, an image forming unit that forms an image on the paper, and an image diagnosis unit that diagnoses the image of the paper. And a detection position for changing the detection position so that the paper characteristic detection unit detects the characteristics of the paper in a non-image portion of the paper based on the diagnosis result of the image diagnosis unit. It is characterized by including a changing unit.

One aspect of the present invention is a conveyance unit that conveys a sheet, a sheet characteristic detection unit that detects the characteristic of the sheet, an image forming unit that forms an image on the sheet, and an image diagnosis unit that diagnoses the image of the sheet. A sheet characteristic detection method in an image forming system having:, based on a diagnosis result of the image diagnosis section, the sheet characteristic detection section detects the characteristic of the sheet in a non-image portion of the sheet, It is characterized in that the detection position is changed.

One aspect of the present invention is a conveyance unit that conveys a sheet, a sheet characteristic detection unit that detects the characteristic of the sheet, an image forming unit that forms an image on the sheet, and an image diagnosis unit that diagnoses the image of the sheet. And a controller, the sheet characteristic detecting program operating in an image forming system, wherein the controller determines the non-image portion of the sheet based on the diagnosis result of the image diagnosis unit. The detection position is changed so as to detect the characteristics of the sheet.

According to the image forming apparatus, the sheet characteristic detecting method, and the sheet characteristic detecting program of the present invention, the characteristic of the sheet can be accurately detected even when the special sheet such as the reprint sheet or the label sheet is used.

The reason is that an image forming unit includes a conveying unit that conveys a sheet, a sheet characteristic detecting unit that detects the characteristic of the sheet, an image forming unit that forms an image on the sheet, and an image diagnosing unit that diagnoses the image of the sheet. This is because the system is provided with a detection position changing unit that changes the detection position so that the sheet characteristic detection unit detects the sheet characteristic in the non-image portion of the sheet based on the diagnosis result of the image diagnosis unit.

FIG. 1 is a schematic diagram showing a configuration of an image forming system according to an exemplary embodiment of the present invention. It is a schematic diagram which shows the other structure of the image forming system which concerns on one Example of this invention. It is a schematic diagram which shows the other structure of the image forming system which concerns on one Example of this invention. FIG. 1 is a block diagram showing a configuration of an image forming system according to an exemplary embodiment of the present invention. FIG. 3 is a schematic diagram showing a structure of an image forming unit in the image forming system according to the embodiment of the present invention. It is a schematic diagram which shows the structure of the paper characteristic detection part (optical basis weight sensor) which concerns on one Example of this invention. It is a flowchart figure which shows operation|movement of the image forming system which concerns on one Example of this invention. It is a flowchart figure which shows operation|movement (paper characteristic detection processing) of the image forming system which concerns on one Example of this invention. It is a flowchart figure which shows the other example of operation|movement of the image forming system which concerns on one Example of this invention. It is a schematic diagram which shows the paper characteristic detection mode setting screen which concerns on one Example of this invention. It is a schematic diagram which shows the paper type setting screen which concerns on one Example of this invention. It is a schematic diagram which shows the paper characteristic detection result screen which concerns on one Example of this invention. It is a schematic diagram which shows the profile registration screen which concerns on one Example of this invention. It is a schematic diagram which shows the profile data screen which concerns on one Example of this invention. It is a schematic diagram which shows the profile detailed data screen which concerns on one Example of this invention. FIG. 6 is a schematic diagram illustrating a timing of reading sheet characteristics according to an embodiment of the present invention. It is a schematic diagram explaining the detection point of the paper characteristic which concerns on one Example of this invention. FIG. 9 is a schematic diagram illustrating another example of the sheet characteristic detection points according to the embodiment of the present invention. FIG. 9 is a schematic diagram illustrating another example of the sheet characteristic detection points according to the embodiment of the present invention.

As described in the background art, in image forming apparatuses such as MFPs, various sensors are arranged in a sheet conveyance path that conveys a sheet from a sheet feeding section to an image forming section, and moisture content, basis weight, rigidity, and surface smoothness are set. The characteristics of the paper such as glossiness, density and whiteness are detected, and the image forming condition is adjusted according to the detected characteristics of the paper. For example, when an optical sensor is used, the characteristics of the paper are detected by irradiating the paper with light and detecting reflected light, diffused light, and transmitted light, but the image portion where the image is formed and the image is not formed. Since the amount of reflected light, the amount of diffused light, and the amount of transmitted light are different from the non-image portion, there is a problem that the characteristics of the paper cannot be accurately detected.

Therefore, in one embodiment of the present invention, a conveyance unit that conveys a sheet, a sheet characteristic detection unit that detects the characteristic of the sheet, an image forming unit that forms an image on the sheet, and an image diagnosis that diagnoses the image of the sheet. And a detection position changing unit for changing the detection position based on the diagnosis result of the image diagnosis unit so that the paper characteristic detection unit detects the characteristics of the paper in the non-image portion of the paper. Set up.

Specifically, when the paper characteristic detecting unit is arranged on the upstream side of the image forming unit and the image diagnosing unit is arranged on the downstream side of the image forming unit, the paper characteristic detecting unit is configured to detect a plurality of predetermined detections. When the characteristic of the paper is detected at the position, and the variation in the detection data at the plurality of detection positions is equal to or more than a predetermined value, the image diagnosis unit diagnoses the image previously formed on the paper, and the detection position changing unit determines the image diagnosis. The detection position is changed based on the diagnosis result of the unit, the sheet characteristic detection unit detects the characteristic of the sheet again at the changed detection position, and the image forming unit forms an image on the sheet based on the characteristic of the sheet. The image diagnosis unit diagnoses an image formed on a sheet.

Further, the paper characteristic detection unit is arranged upstream of the image forming unit, the image diagnosis unit is arranged downstream of the image forming unit, and the first image diagnosis unit arranged upstream of the paper characteristic detection unit. In the case of having two image diagnostic units, the first image diagnostic unit diagnoses an image previously formed on a sheet, and the detection position changing unit detects the image based on the diagnostic result of the first image diagnostic unit. The position is changed, the sheet characteristic detection unit detects the characteristic of the sheet at the changed detection position, the image forming unit forms an image on the sheet based on the characteristic of the sheet, and the second image diagnosis unit determines the sheet. The image formed on the eye is diagnosed.

By performing such control, the characteristics of the paper can be accurately detected even when special paper such as reprint paper or label paper is used.

In order to describe the above-described embodiment of the present invention in more detail, an image forming apparatus, a sheet characteristic detection method, and a sheet characteristic detection program according to an example of the present invention will be described with reference to FIGS. 1 to 19. To do. 1 to 3 are schematic diagrams showing the configuration of the image forming system of this embodiment, and FIG. 4 is a block diagram showing the configuration of the image forming system. 5 is a schematic diagram showing the structure of the image forming unit in the image forming system of the present embodiment, and FIG. 6 is a schematic diagram showing the structure of the paper characteristic detecting unit (optical basis weight sensor). 7 to 9 are flowcharts showing the operation of the image forming system of this embodiment, and FIGS. 10 to 15 are examples of screens displayed on the image forming system of this embodiment. Further, FIG. 16 is a schematic diagram for explaining the reading timing of the paper characteristic of the present embodiment, and FIGS. 17 to 19 are schematic diagrams for explaining the detection points of the paper characteristic.

As illustrated in FIG. 1, the image forming system 1 according to the present exemplary embodiment includes a sheet feeding unit 70 that feeds a sheet, an image forming unit 80 that forms an image on the sheet, and an image diagnosis that diagnoses an image formed on the sheet. A unit 100, a paper discharge unit 110 that discharges paper according to the image diagnosis result, and a conveyance unit 120 that conveys paper along a paper conveyance path from the paper feed unit 70 to the paper discharge unit 110. A paper characteristic detection unit 90 is arranged in a paper transportation path from the paper feeding unit 70 to the image forming unit 80. The image forming unit 80 includes, for example, photoconductor drums 83Y, 83M, 83C, and 83K as photoconductors corresponding to four colors of yellow (Y), magenta (M), cyan (C), and black (K). It is a tandem type image forming apparatus that is arranged in series in the running direction of a transfer target (intermediate transfer belt).

Note that, in FIG. 1, a configuration is provided in which the paper feed unit 70 (paper feed tray) is provided in the housing that stores the image forming unit 80, and the characteristics of the paper fed from the paper feed unit 70 are detected. As shown in FIG. 2, a sheet feeding unit 71 may be provided separately from the housing that stores the image forming unit 80, and the characteristic of the sheet fed from the sheet feeding unit 71 may be detected.

Further, in FIG. 2, the image diagnostic unit 100 is provided on the downstream side of the image forming unit 80, the image diagnostic unit 100 diagnoses the image formed on the sheet by the image forming unit 80, and the sheet characteristic is based on the image diagnostic result. However, as shown in FIG. 3, an image diagnosis unit 101 different from the image diagnosis unit 100 is arranged upstream of the image forming unit 80 (sheet characteristic detection unit 90), and the image is detected. The detection position of the sheet characteristic may be changed based on the image diagnosis result of the diagnosis unit 101, and the sheet characteristic detection unit 90 may detect the sheet characteristic at the detection position.

As shown in FIG. 4A, the image forming system 1 of FIG. 1 includes a control unit 10, a storage unit 20, a network I/F unit 30, a display operation unit 40, an image reading unit 50, an image processing unit 60, and a paper supply unit. The paper unit 70, the image forming unit 80, the paper characteristic detection unit 90, the image diagnosis unit 100, the paper discharge unit 110, the transport unit 120, and the like.

The control unit 10 includes a CPU (Central Processing Unit) 11 and memories such as a ROM (Read Only Memory) 12 and a RAM (Random Access Memory) 13. The CPU 11 centrally controls the operation of each block of the image forming system 1 by reading a program according to the processing content from the ROM 12 or the storage unit 20, expanding the program in the RAM 13, and executing the program.

The storage unit 20 is configured by an HDD (Hard Disk Drive), an SSD (Solid State Drive), or the like, and is a program for the CPU 11 to control each unit, information regarding the processing function of the device, and image data read by the image reading unit 50. Image data input from a client device (not shown), paper profile data, and the like are stored.

The network I/F unit 30 is configured by a NIC (Network Interface Card), a modem, or the like, connects the image forming system 1 to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network), and provides external information. Various data is transmitted/received to/from a device (for example, a client device).

The display operation unit 40 is a pressure-sensitive or capacitance-type operation unit (touch sensor) in which transparent electrodes are arranged in a grid on a display unit such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display. ) Is provided on the touch panel or the like, and functions as a display unit and an operation unit. The display unit displays various operation screens (for example, a paper characteristic detection mode setting screen, a paper type setting screen, a paper characteristic detection result screen, a profile registration screen, a profile data screen, which will be described later) according to a display control signal input from the control unit 10. A profile detail data screen, a screen for notifying the user of a message that the paper characteristics could not be effectively detected, etc. are displayed. The operation unit receives various input operations by the user (for example, a setting operation of the sheet characteristic detection mode on the screen, a setting operation of the sheet type, a registration operation of the sheet profile, etc.), and outputs an operation signal to the control unit 10.

The image reading unit 50 optically scans a document placed on the contact glass, forms reflected light from the document on the light receiving surface of a CCD (Charge Coupled Device) sensor, and reads the document image. The image (analog image signal) read by the image reading unit 50 is subjected to predetermined image processing in the image processing unit 60.

The image processing unit 60 includes a circuit that performs analog-digital (A/D) conversion processing, a circuit that performs digital image processing, and the like. The image processing unit 60 generates digital image data by subjecting the analog image signal from the image reading unit 50 to A/D conversion processing. Further, the image processing unit 60 analyzes a print job acquired from an external information device (for example, a client device), rasterizes each page of a document, and generates digital image data. Then, the image processing unit 60 performs image processing such as color conversion processing, correction processing (shading correction or the like) according to initial setting or user setting, and compression processing on the image data as necessary, The processed image data is output to the image forming unit 80.

The paper feed unit 70 is composed of a plurality of paper feed trays for accommodating various papers, and standard papers and special papers identified based on the basis weight, size, etc. of the papers are preset in each paper feed tray. It is accommodated for each type. The sheets accommodated in the sheet feeding tray are sent out one by one from the uppermost part, and are conveyed to the image forming section 80 by the conveying section 120 including a plurality of conveying rollers such as registration rollers. In the present embodiment, a sheet characteristic detection unit 90 described later is arranged in the sheet conveyance path from the sheet feeding unit 70 (sheet feeding unit 71 in the case of the image forming system 1 of FIG. 2 or FIG. 3) to the image forming unit 80. It

As shown in FIGS. 4B and 5, the image forming unit 80 includes an exposure device 81 (81Y, 81M, 81C, 81K) provided corresponding to different color components Y, M, C, K. Developing device 82 (82Y, 82M, 82C, 82K), photoconductor drum 83 (83Y, 83M, 83C, 83K), charging device 84 (84Y, 84M, 84C, 84K), cleaning device 85 (85Y, 85M, 85C, 85K), a primary transfer roller 86 (86Y, 86M, 86C, 86K), an intermediate transfer unit 87, a fixing device 88, and the like. In the following description, reference numerals excluding Y, M, C, and K will be used as necessary.

The photoconductor drums 83 of the respective color components Y, M, C, and K have an organic photoconductor layer (OPC) in which an overcoat layer as a protective layer is provided on the outer peripheral surface of a cylindrical metal base made of an aluminum material. Image bearing member. The photoconductor drum 83 is rotated in the counterclockwise direction in FIG. 5 while being grounded and driven by an intermediate transfer belt described later.

The charging device 84 for each color component Y, M, C, K is of a scorotron type, and is arranged close to the corresponding photoconductor drum 83 with its longitudinal direction aligned with the rotation axis direction of the photoconductor drum 83. By the corona discharge having the same polarity as that of the toner, a uniform electric potential is applied to the surface of the photoconductor drum 83.

The exposure device 81 for each color component Y, M, C, K scans in parallel with the rotation axis of the photoconductor drum 83 by, for example, a polygon mirror or the like, so that the surface of the corresponding photoconductor drum 83 is uniformly charged. An electrostatic latent image is formed by performing image exposure based on the image data.

The developing device 82 for each of the color components Y, M, C, and K contains a two-component developer composed of a toner having a small particle diameter of the corresponding color component and a magnetic material, and the toner is deposited on the surface of the photosensitive drum 83. The electrostatic latent image carried on the photosensitive drum 83 is conveyed and visualized by toner.

The primary transfer rollers 86 of the respective color components Y, M, C, and K press the intermediate transfer belt against the photosensitive drum 83, and the toner images of the respective colors formed on the corresponding photosensitive drums 83 are sequentially superposed so as to be primary on the intermediate transfer belt. Transcribe.

The cleaning device 85 for each of the color components Y, M, C, and K collects the residual toner remaining on the corresponding photosensitive drum 83 after the primary transfer. Further, a lubricant applying mechanism (not shown) is provided in the adjoining state on the downstream side of the cleaning device 85 in the rotation direction of the photosensitive drum 83, and the lubricant is applied to the photosensitive surface of the corresponding photosensitive drum 83. There is.

The intermediate transfer unit 87 includes an endless intermediate transfer belt serving as a transfer target, a support roller, a secondary transfer roller, and an intermediate transfer cleaning unit. The intermediate transfer belt is stretched around a plurality of support rollers. .. When the intermediate transfer belt to which the toner images of respective colors are primarily transferred by the primary transfer rollers 86Y, 86M, 86C, and 86K is pressed against the paper by the secondary transfer roller, the toner images are secondarily transferred to the paper, and the fixing device 88 is reached. Sent. The intermediate transfer cleaning unit has a belt cleaning blade that is in sliding contact with the surface of the intermediate transfer belt. Transfer residual toner remaining on the surface of the intermediate transfer belt after the secondary transfer is scraped off and removed by the belt cleaning blade.

In the present exemplary embodiment, the sheet after the sheet characteristic detection unit 90 detects the sheet characteristic is conveyed to the intermediate transfer unit 87, and the image is transferred to the sheet according to the sheet characteristic. When there is variation and the sheet characteristics are to be detected again, the secondary transfer roller is separated from the intermediate transfer belt, and the image is conveyed to the image diagnostic unit 100 without transferring the image to the sheet.

The fixing device 88 includes a heating roller that serves as a heat source, a fixing roller, a fixing belt and a pressure roller that are wound around the heating roller, and the pressure roller is pressed against the fixing roller via the fixing belt. Constitutes the nip part. Then, the sheet passing through the nip portion is heated and pressed by the fixing belt heated by the heating roller and each roller to fix the unfixed toner image formed on the sheet.

In this embodiment, the sheet after the sheet characteristic detection by the sheet characteristic detection unit 90 is conveyed to the fixing device 88, and the toner image is fixed according to the sheet characteristic, but the detection data of the sheet characteristic varies. If the sheet characteristics are to be detected again, the pressure roller is separated from the fixing belt, and the toner image is conveyed to the image diagnostic unit 100 without being fixed.

Then, the paper on which the image is formed by the image forming unit 80 and the paper on which the image is not formed by the image forming unit 80 because the paper characteristic detecting unit 90 detects the paper characteristic again are subjected to the image diagnosis by the conveying unit 120. It is conveyed to the section 100.

As described above, the sheet characteristic detection unit 90 is arranged in the sheet conveyance path from the sheet feeding unit 70 or the sheet feeding unit 71 to the image forming unit 80, and has a water content (or water content), a basis weight (or weight), Detect paper characteristics such as stiffness (or rigidity), surface smoothness, glossiness, density, and whiteness. For example, as shown in FIG. 6, a sheet characteristic detection unit (optical basis weight sensor) 90 that optically detects the basis weight, as shown in FIG. 6, a reflection light source 91 (here, a green light source) that emits light from the front side of the sheet. A reflection light source reference plate 92 (here, a green reference plate), a transmission light source 93a (here, a blue light source) and a transmission light source 93b (here, a near infrared light source) that emit light from the back side of the paper. ) And a photodiode 94 for detecting the light reflected by the paper and the light transmitted through the paper, and processing the reflected light, the diffused light, and the transmitted light detected by the photodiode 94. Amount).

FIG. 6 shows a configuration in which the grammage is detected as a sheet characteristic, but surface smoothness, glossiness, whiteness and the like can be detected by measuring the intensity distribution and wavelength of light reflected on the surface of the sheet. You can Further, the water content of the paper can be detected by measuring the electrostatic capacity of the paper with electrodes arranged on the front and back of the paper. Further, the rigidity of the paper can be detected by bending the paper conveyance path and installing a piezoelectric sensor in the bent portion to measure the pressure. Further, the thickness of the paper can be detected by installing an encoder on the conveying roller and measuring the displacement, and the density of the paper can also be detected from the basis weight and the thickness of the paper. Note that the above is an example of the sheet characteristic detection unit 90, and the structure and principle thereof are not particularly limited as long as the sheet characteristic used for image formation or the like can be detected.

The image diagnostic unit 100 is provided with a sensor that can read an image formed on one surface of the paper or the front and back surfaces of the paper (for example, provided in a paper conveyance path between the image forming unit 80 and the paper discharge unit 110). The image formed on the paper is read to diagnose whether the position, density, and color of the image are appropriate, whether there is stain, or the like. Further, the image diagnosis unit 100 (the image diagnosis unit 101 in the case of the image forming system 1 in FIG. 3) specifies the image portion on which the image is formed and the non-image portion on which the image is not formed. This in-line sensor has, for example, a structure in which CCDs (Charge Coupled Devices) and CMOSs (Complementary Metal Oxide Semiconductors) are arranged in a line. When light is emitted from a light source, reflected light from the paper is received via a light receiving lens. An image is formed on the measuring device, converted into an electric signal corresponding to the amount of reflected light by the light receiving device, and the measurement data of the read image is output.

The paper discharge unit 110 includes a plurality of paper discharge trays, and discharges the paper diagnosed by the image diagnosis unit 100 to the paper discharge tray. At that time, the paper for which the image is diagnosed as abnormal is discharged to a paper discharge tray different from the paper for which the image is diagnosed as normal. If the variation in the detection data is less than the predetermined value, it is discharged as normal paper to the normal output tray, and if the variation in the detection data is more than the predetermined value, it is output to a destination different from the normal output tray. By ejecting the paper, the user is notified that the paper characteristics could not be effectively detected.

The transport unit 120 includes a plurality of transport rollers provided along the paper transport path, and is provided in each of the paper feed unit 70, the paper characteristic detection unit 90, the image forming unit 80, the image diagnosis unit 100, and the paper discharge unit 110. Transport the paper.

Further, as shown in FIG. 4C, the control unit 10 functions as a detection data determination unit 14, a detection position changing unit 15, a sheet characteristic registration unit 16 and the like.

The detection data determination unit 14 acquires a plurality of detection data read by the sheet characteristic detection unit 90 from a plurality of detection positions of the sheet, and determines whether the variation of the plurality of detection data is less than a predetermined value.

In the detection position changing unit 15, the sheet characteristic detecting unit 90 determines the sheet characteristic in the non-image portion of the sheet based on the diagnosis result of the image diagnosing unit 100 (the image diagnosing unit 101 in the case of the image forming system 1 in FIG. 3). Change the detection position to detect. For example, the detection position changing unit 15 changes the detection position in the sheet conveyance direction by shifting the detection timing of the sheet characteristic detection unit 90, or moves the sheet characteristic detection unit 90 in a direction orthogonal to the sheet conveyance direction. By doing so, the detection position may be changed in a direction orthogonal to the sheet conveyance direction. For example, in the case of the image forming system 1 of FIGS. 1 and 2, in the first detection, the detection positions are set so as to detect a plurality of places (for example, 5 places) at a constant interval (for example, 20 mm intervals). .. When the detection data determination unit 14 determines that the variation of the plurality of detection data is greater than or equal to a predetermined value and performs detection again, the detection data determination unit 14 does not overlap the image portion based on the image diagnosis result of the image diagnosis unit 100. Change the detection position (so that the paper characteristic is detected in the non-image part). At that time, only the detection position where the detection data is determined to be abnormal may be changed, or the interval between the detection positions is set to be equal to or smaller than the predetermined minimum interval by changing the detection position where the detection data is determined to be abnormal. If it occurs, the detection data may be changed including the detection position determined to be normal.

When the detection data determination unit 14 determines that the variation of the plurality of detection data is less than a predetermined value, the sheet characteristic registration unit 16 determines the sheet characteristic based on the detection data and registers it in the sheet profile. At that time, when the number of pieces of detection data determined to be normal in one sheet is less than a predetermined number, the pieces of detection data of the next sheet can be added together to determine the characteristics of the sheet. Further, the paper characteristic registration unit 16 can register the detection position changed by the detection position changing unit 15 as paper profile data.

The detection data determination unit 14, the detection position changing unit 15, and the sheet characteristic registration unit 16 may be configured as hardware, or the control unit 10 may be used as the detection data determination unit 14, the detection position changing unit 15, and the sheet characteristic registration. It may be configured as software (paper characteristic detection program) that functions as the unit 16 (particularly, the detection position changing unit 15) and the CPU 11 may execute the sheet characteristic detection program.

1 to 6 are examples of the image forming system 1 of the present embodiment, and the configuration and control thereof can be changed as appropriate.

Next, a paper characteristic detection method using the image forming system 1 will be described. The CPU 11 expands the sheet characteristic detection program stored in the ROM 12 or the storage unit 20 into the RAM 13 and executes the program to execute the processing of each step shown in the flowcharts of FIGS. 7 to 9. 7 and 8 show the operation of the image forming system 10 having the configuration shown in FIG. 1 or 2, and FIG. 9 shows the operation of the image forming system 10 having the configuration shown in FIG.

First, when detecting the paper characteristics, the user sets the operation mode of the image forming system 1 to the paper characteristics detection mode. For example, the control unit 10 causes the display operation unit 40 to display the paper characteristic detection mode setting screen 130 as shown in FIG. 10, and when the user presses the “paper characteristic detection” button, the display operation unit 40 is displayed as shown in FIG. 11. Such a paper type setting screen 131 is displayed. Then, when the user selects the plain paper or the special paper on the paper type setting screen 131, the paper characteristic detection mode according to the selected paper type is set.

Thereafter, as shown in FIG. 7, the control unit 10 determines whether the operation mode of the image forming system 1 is the sheet characteristic detection mode (S100), and when the operation mode is not the sheet characteristic detection mode (No in S100). ), a series of processing ends.

On the other hand, when the operation mode is the paper characteristic detection mode (Yes in S100), the transport unit 120 feeds and transports the paper from the paper feeding unit 70 (or the paper feeding unit 71) (S110). Then, when the sheet reaches the sheet characteristic detection unit 90, the sheet characteristic detection unit 90 detects the sheet characteristic (S120). FIG. 8 shows the details of this step. First, it is judged whether or not the paper image was previously read (that is, whether it is re-detection after the image diagnosis of the image diagnosis unit 100) (S121), and the paper is detected. If the image is being read (Yes in S121), the sheet characteristics are detected by shifting the reading timing, as described later (S122). On the other hand, when the sheet image is not read (No in S121), the sheet characteristic is detected at a predetermined position (for example, 5 times at 20 mm intervals from the leading edge of the sheet) (S123).

Returning to FIG. 7, the control unit 10 (detection data determination unit 14) determines whether the variation of the plurality of detection data detected by the sheet characteristic detection unit 90 at the plurality of detection positions is equal to or more than a predetermined value (S130). When the variation in the detection data is equal to or more than the predetermined value (Yes in S130), the transport unit 120 transports the sheet to the image diagnosis unit 100, the image diagnosis unit 100 reads the sheet image, and the non-image of the sheet is detected. The part is specified (S140). At that time, the sheet is conveyed to the image diagnostic section 100 via the image forming section 80. However, since the effective sheet characteristic is not obtained at this stage, the image forming section 80 does not form an image on the sheet. It is preferable to convey the image to the image diagnostic unit 100 (without transferring or fixing the toner image). Next, the control unit 10 (detection position changing unit 15) changes the detection position so as to detect the sheet characteristic in the non-image portion of the sheet (S150), and the sheet ejection unit 110 ejects the sheet once ( S160). At this time, the user can be informed that the sheet characteristics could not be effectively detected by discharging the sheet to a discharge destination different from the normal discharge tray. After that, the process returns to S110, and the sheet feeding and conveyance is started.

On the other hand, when the variation of the detection data is less than the predetermined value (No in S130), the control unit 10 (sheet characteristic registration unit 16) determines the sheet characteristic based on the detection data and sets the determined sheet characteristic to the sheet profile. (S170). For example, when the paper characteristic can be detected (the variation in the detected data is less than the predetermined value), the control unit 10 causes the display operation unit 40 to display the paper characteristic detection result screen 132 as shown in FIG. When registering the characteristics (paper type and basis weight in this case), when the user presses the “register in profile” button, the control unit 10 displays the profile registration screen 133 as shown in FIG. 13 on the display operation unit 40. Let When confirming the paper profile, the registered data profile can be confirmed by displaying the profile data screen 134 as shown in FIG. 14 on the display operation unit 40 and selecting the tab of the paper profile. Further, the detection position changed by the detection position changing unit 15 can be registered in the paper profile. In that case, the display operation unit 40 displays the profile detailed data screen 135 as shown in FIG. The detection position (here, the detection start position and the detection interval) can be registered by pressing the "call" button.

Next, the image forming unit 80 forms an image under the image forming condition according to the sheet characteristic (S180), the image diagnosis unit 100 diagnoses the image formed on the sheet (S190), and the sheet discharge unit 110. Discharges the sheet according to the image diagnosis result (S200). For example, the paper for which the image is diagnosed as abnormal is discharged to a paper discharge tray different from the paper for which the image is diagnosed as normal.

The above flow is the operation in the case of the image forming system 1 of FIG. 1 or FIG. 2, but when the image diagnosis unit 101 is on the upstream side of the sheet characteristic detection unit 90, the procedure is as shown in FIG.

First, the control unit 10 determines whether the operation mode of the image forming system 1 is the sheet characteristic detection mode (S300). If the operation mode is not the sheet characteristic detection mode (No in S300), the series of processes is ended. To do.

On the other hand, when the operation mode is the sheet characteristic detection mode (Yes in S300), the transport unit 120 feeds and transports a sheet from the sheet feeding unit 70 (or the sheet feeding unit 71) (S310). When the sheet reaches the image diagnostic section 101, the image diagnostic section 101 reads the sheet image and identifies the non-image portion of the sheet (S320). Then, the control unit 10 (detection position changing unit 15) changes the detection position so as to detect the paper characteristic in the non-image portion of the paper (S330), and the paper characteristic detecting unit 90 causes the paper to be detected at the changed detection position. The characteristics are detected (S340).

Then, the control unit 10 (sheet characteristic registration unit 16) determines the sheet characteristic based on the detection data, and registers the determined sheet characteristic in the sheet profile (S350). Next, the image forming unit 80 forms an image under the image forming condition according to the sheet characteristics (S360), the image diagnosis unit 100 diagnoses the image formed on the sheet (S370), and the sheet discharge unit 110. Discharges the sheet according to the image diagnosis result (S380). For example, the paper for which the image is diagnosed as abnormal is discharged to a paper discharge tray different from the paper for which the image is diagnosed as normal.

Next, a method of changing the detection position will be described with reference to the schematic diagrams of FIGS. 16 to 19. 16 to 19 are examples in which the paper characteristics are detected for 9-imposition additional printing paper (paper in which an image of 3×3 pages is imprinted on paper). The hatched portion of the dots in the figure is the image portion where the image is formed. The broken line indicates the sensor position of the sheet characteristic detecting unit 90 in the direction orthogonal to the sheet conveying direction, the diamond in the figure indicates the position where the sensor detects the sheet characteristic, and the number in the vicinity thereof indicates the detection number.

As shown in FIG. 16A, in the first detection, the sensor of the sheet characteristic detection unit 90 detects the sheet characteristic at a predetermined position (for example, 5 times at 20 mm intervals from the leading edge of the sheet). At this time, the sensor is arranged substantially at the center in the direction (main scanning direction) orthogonal to the sheet conveying direction, and in 9-sided mounting, pages 4 to 6 are arranged at the central portion of the sheet in the main scanning direction. Therefore, a part of the detection position overlaps the image part. As a result, the detection data has a large transmitted light intensity in the non-image portion and a small transmitted light intensity in the image portion, and the variation of the plurality of detection data exceeds a predetermined value.

Therefore, in the present embodiment, after the first detection, the image diagnosis unit 100 acquires the image of the sheet, specifies the image portion and the non-image portion on the sheet, and detects so that the detection position does not overlap the image portion. Change the position. As a result, as shown in FIG. 16(b), in the second detection, No. The detection positions of Nos. 2 and 5 are No. of the non-image part. Since the detection positions of 6 and 7 are changed, the detection positions of all the detection data are non-image portions, and the variation of the detection data is less than a predetermined value. Therefore, the sheet characteristics are accurately determined based on the detection data. be able to.

In addition, at the time of the second detection, No. Since the detection positions 1, 3, and 4 (white-filled diamonds) are originally non-image portions, by omitting the detection at these detection positions, it is possible to reduce the paper characteristic detection time. Further, in FIG. 16B, only the detection position where the detection data is determined to be abnormal is changed, but when the detection position is changed, the interval between the detection positions becomes equal to or smaller than a predetermined minimum interval. For example, the detection position where the detection data is determined to be normal may be changed.

Further, in the case of the image forming system 1 having the configuration of FIG. 1 or FIG. 2, the detection position is changed based on the image diagnosis result after the first detection, but in the case of the image forming system 1 of the configuration of FIG. Since the image diagnosis unit 101 first acquires the image, as shown in FIG. 17, the sheet characteristic can be detected at the detection position avoiding the image portion from the beginning.

16 and 17, the detection position (detection timing) is changed in the paper conveyance direction so that the detection position does not overlap the image portion. However, the sensor of the paper characteristic detection unit 90 is orthogonal to the paper conveyance direction. When it is possible to move in the direction (main scanning direction), the detection position (detection timing) may be changed in the direction orthogonal to the sheet conveyance direction as shown in FIG. , It is possible to detect the paper characteristics at regular intervals.

Further, when determining the paper characteristics from the detection data, a certain number of pieces of data are required, but in this embodiment, the paper characteristics are detected at the same intervals, so if the paper types do not change, a plurality of papers can be detected. The data can be added together. For example, as shown in FIG. 17A, two of the five data (No. 2, 5) are invalidated by the first detection, and the number of data is 3. When the accurate sheet characteristic cannot be determined by these three detection data, the sheet characteristic can be determined by adding the second sheet detection data (three effective detection data) shown in FIG. 17B.

It should be noted that the present invention is not limited to the above embodiment, and the configuration and control thereof can be appropriately changed without departing from the spirit of the present invention.

The present invention relates to an image forming apparatus that forms an image based on sheet characteristics, a sheet characteristic detecting method in the image forming apparatus, a sheet characteristic detecting program that operates in the image forming apparatus, and a recording medium that records the sheet characteristic detecting program. Is available for.

1 Image Forming System 10 Control Unit 11 CPU
12 ROM
13 RAM
14 detection data determination unit 15 detection position changing unit 16 paper characteristic registration unit 20 storage unit 30 network I/F unit 40 display operation unit 50 image reading unit 60 image processing unit 70 paper feeding unit 71 paper feeding unit 80 image forming unit 81, 81Y, 81M, 81C, 81K Exposure device 82, 82Y, 82M, 82C, 82K Developing device 83, 83Y, 83M, 83C, 83K Photoreceptor drum 84, 84Y, 84M, 84C, 84K Charging device 85, 85Y, 85M, 85C , 85K Cleaning device 86, 86Y, 86M, 86C, 86K Primary transfer roller 87 Intermediate transfer unit 88 Fixing device 90 Paper characteristic detection unit 91 Reflection light source 92 Reflection light source reference plate 93a Transmission light source (blue)
93b Transmission light source (near infrared)
94 Photodiode 100, 101 Image diagnosis unit 110 Paper ejection unit 120 Conveyance unit 130 Paper characteristic detection mode setting screen 131 Paper type setting screen 132 Paper characteristic detection result screen 133 Profile registration screen 134 Profile data screen 135 Profile detailed data screen

Claims (23)

An image forming system including a conveying unit that conveys a sheet, a sheet characteristic detecting unit that detects a characteristic of the sheet, an image forming unit that forms an image on the sheet, and an image diagnosing unit that diagnoses an image of the sheet. At
A detection position changing unit that changes a detection position so that the paper characteristic detection unit detects the characteristics of the paper in a non-image portion of the paper based on the diagnosis result of the image diagnosis unit,
An image forming system characterized by the above. The paper characteristic detection unit is arranged on the upstream side of the image forming unit, the image diagnosis unit is arranged on the downstream side of the image forming unit,
The sheet characteristic detection unit detects the characteristic of the sheet at a plurality of predetermined detection positions,
When the variation of the detection data of the plurality of detection positions is a predetermined value or more,
The image diagnosis unit diagnoses an image previously formed on the sheet,
The detection position changing unit changes the detection position based on the diagnosis result of the image diagnosis unit,
The paper characteristic detection unit re-detects the characteristics of the paper at the changed detection position,
The image forming unit forms an image on the sheet based on the characteristics of the sheet,
The image diagnosis unit diagnoses an image formed on the sheet,
The image forming system according to claim 1, wherein: A sheet discharging unit for discharging the sheet after the image diagnosis,
When the variation of the detection data is less than the predetermined value, the sheet discharge unit discharges the normal sheet to a normal sheet discharge tray, and when the variation of the detection data is the predetermined value or more, the normal sheet is discharged. Paper is ejected to a destination different from the paper ejection tray,
The image forming system according to claim 2, wherein. The paper characteristic detection unit is arranged on the upstream side of the image forming unit, and the image diagnosis unit is arranged on the first image diagnosis unit arranged on the upstream side of the paper characteristic detection unit and on the downstream side of the image forming unit. And a second image diagnostic unit
The first image diagnosis unit diagnoses an image previously formed on the sheet,
The detection position changing unit changes the detection position based on the diagnosis result of the first image diagnosis unit,
The paper characteristic detection unit detects the characteristics of the paper at the changed detection position,
The image forming unit forms an image on the sheet based on the characteristics of the sheet,
The second image diagnosis unit diagnoses an image formed on the sheet,
The image forming system according to claim 1, wherein: The detection position changing unit changes the detection position in the conveyance direction of the paper by shifting the detection timing of the paper characteristic detection unit.
The image forming system according to any one of claims 1 to 4, characterized in that: The detection position changing unit changes the detection position at which the detection data is determined to be abnormal,
The image forming system according to claim 5, wherein. The detection position changing unit also changes the detection position at which the detection data is determined to be normal,
The image forming system according to claim 6, wherein. The detection position changing unit changes the detection position in a direction orthogonal to the sheet conveyance direction by moving the sheet characteristic detection unit in a direction orthogonal to the sheet conveyance direction,
The image forming system according to any one of claims 1 to 7, characterized in that. A sheet characteristic registration unit that determines and registers the characteristic of the sheet based on the detection data,
If the number of pieces of detection data determined to be normal in one sheet is less than a predetermined number, the sheet characteristic registration unit sums the detection data of the next sheet to determine the characteristic of the sheet.
The image forming system according to claim 1, wherein: The paper characteristic registration unit registers the detection position changed by the detection position changing unit as profile data of the paper,
The image forming system according to claim 9, wherein. The characteristics of the paper include one selected from water content, basis weight, rigidity, surface smoothness, glossiness, density, and whiteness.
The image forming system according to any one of claims 1 to 10, characterized in that. An image forming system including a conveying unit that conveys a sheet, a sheet characteristic detecting unit that detects a characteristic of the sheet, an image forming unit that forms an image on the sheet, and an image diagnosing unit that diagnoses an image of the sheet. A method for detecting paper characteristics in
Based on the diagnosis result of the image diagnosis unit, the detection position is changed so that the paper property detection unit detects the property of the paper in the non-image portion of the paper,
A paper characteristic detection method characterized by the above. The paper characteristic detection unit is arranged on the upstream side of the image forming unit, the image diagnosis unit is arranged on the downstream side of the image forming unit,
A first detection process in which the paper characteristic detection unit detects the characteristics of the paper at a plurality of predetermined detection positions;
When the variation of the detection data detected at the plurality of detection positions is a predetermined value or more, the image diagnosis unit, a first image diagnosis process for diagnosing an image previously formed on the paper,
The detection position changing unit, a detection position changing process for changing the detection position based on the diagnosis result of the image diagnosis unit,
A second detection process in which the paper characteristic detection unit again detects the characteristics of the paper at the changed detection position;
An image forming process in which the image forming unit forms an image on the paper based on the characteristics of the paper;
The image diagnostic unit executes a second image diagnostic process for diagnosing an image formed on the sheet.
13. The method for detecting paper characteristics according to claim 12, wherein: When the paper for which the image is diagnosed in the second image diagnosis process is discharged, if the variation in the detection data is less than the predetermined value, the paper is discharged as a normal paper to a normal paper discharge tray and the detection is performed. When the data variation is equal to or more than the predetermined value, the paper is discharged to a discharge destination different from the normal discharge tray,
14. The paper characteristic detecting method according to claim 13, wherein: The paper characteristic detection unit is arranged on the upstream side of the image forming unit, and the image diagnosis unit is arranged on the first image diagnosis unit arranged on the upstream side of the paper characteristic detection unit and on the downstream side of the image forming unit. And a second image diagnostic unit
A first image diagnostic process in which the first image diagnostic unit diagnoses an image previously formed on the sheet;
A detection position changing process for changing the detection position based on the diagnosis result of the first image diagnosis unit,
A detection process in which the paper characteristic detection unit detects the characteristic of the paper at the changed detection position;
An image forming process in which the image forming unit forms an image on the sheet based on the characteristics of the sheet;
The second image diagnostic unit executes a second image diagnostic process for diagnosing an image formed on the sheet.
The paper characteristic detecting method according to claim 12, wherein In the detection position changing process, the detection position is changed in the sheet conveyance direction by shifting the detection timing of the paper characteristic detection unit.
The sheet characteristic detecting method according to any one of claims 12 to 15, wherein In the detection position changing process, the detection position at which the detection data is determined to be abnormal is changed,
The sheet characteristic detecting method according to claim 16, wherein In the detection position changing process, the detection position at which the detection data is determined to be normal is also changed,
18. The paper characteristic detecting method according to claim 17, wherein: In the detection position changing process, the detection position is changed in a direction orthogonal to the sheet conveyance direction by moving the sheet characteristic detection unit in a direction orthogonal to the sheet conveyance direction,
19. The sheet characteristic detecting method according to claim 12, wherein Performing a paper characteristic registration process of determining and registering the characteristics of the paper based on the detection data,
In the paper characteristic registration processing, when the number of the detected data which is determined to be normal in one sheet is less than a predetermined number, the detected data of the next sheet is added to determine the characteristic of the sheet.
20. The sheet characteristic detecting method according to claim 12, wherein In the paper characteristic registration processing, the detection position changed in the detection position changing processing is registered as profile data of the paper,
21. The paper characteristic detecting method according to claim 20, wherein The characteristics of the paper include one selected from water content, basis weight, rigidity, surface smoothness, glossiness, density, and whiteness.
22. The sheet characteristic detection method according to claim 12, wherein A conveyance unit configured to convey a sheet, a sheet characteristic detection unit configured to detect a characteristic of the sheet, an image forming unit configured to form an image on the sheet, an image diagnosis unit configured to diagnose an image of the sheet, and a control unit. A sheet characteristic detection program that operates in an image forming system that the
In the control unit,
Changing the detection position based on the diagnosis result of the image diagnosis section so that the sheet characteristic detection section detects the characteristic of the sheet in the non-image portion of the sheet;
A sheet characteristic detection program characterized in that

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