Image forming apparatus and control method
Patent Information
- Application Number
- JP2025108211
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2026-02-16
AI Technical Summary
Existing image forming devices face challenges in accurately recognizing the correspondence between the intended paper type and the actual paper used, especially when there is a time lag between instruction and execution or multiple instructions are issued simultaneously, leading to operational errors and wasted output due to incorrect paper types.
An image forming apparatus with a detection unit to identify paper properties, a reception unit for user input, and judgment units to compare detected properties with user specifications, controlling operations based on these judgments to ensure correct paper usage.
Reduces loss of output material by accurately matching user-specified paper types with detected properties, minimizing errors through dual judgment mechanisms.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present invention relates to an image forming apparatus. [Background technology]
[0002] Conventionally, image forming devices such as printers and multifunction devices use various types of paper, such as fine paper, coated paper, straw paper, etc. To check whether the correct type of paper is being used, various image forming devices have been developed that are equipped with paper detection means that detect the physical properties of the paper.
[0003] For example, in an image forming device that can sequentially transport multiple sheets of paper to form and output multiple pages of images, a technology has been proposed that stops image formation and output based on the difference between the characteristics of the paper that has already been output and the characteristics of the newly detected paper (see Patent Document 1).
[0004] In addition, an image forming device has been proposed that interrupts image formation and conveyance of the recording material when the first media characteristics of the recording material being conveyed, detected by a media detection means, differ from the second media characteristics of the recording material on which an image has already been formed, and when the image formation conditions according to the first media characteristics differ from the image formation conditions according to the second media characteristics (see Patent Document 2).
[0005] Also proposed is an image forming device that includes a paper type detection means for detecting the type of paper being transported from a paper feed cassette, and when the paper type changes during printing, searches for whether there is another paper feed cassette that contains paper of the same paper type as the paper before the paper type change, and if there is another paper feed cassette, resumes transporting paper from the other paper feed cassette (see Patent Document 3). [Prior art documents] [Patent documents]
[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-211062 [Patent Document 2] Japanese Patent Application Publication No. 2018-106112 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-160737 Summary of the Invention [Problem to be solved by the invention]
[0007] However, even with the above-mentioned conventional technology, there was a problem in that it was difficult to recognize the correspondence between the type of paper to be used for each job when there was a time lag between the execution instruction to the image forming device and the actual execution of image formation, or when multiple execution instructions were issued simultaneously. This raised the risk of operational errors, such as loading the wrong paper into the image forming device or stacking different types of paper. In such cases, image formation would be performed on paper different from the paper intended by the user, resulting in wasted output.
[0008] The present invention has been made in consideration of the above-mentioned problems in the prior art, and an object of the present invention is to reduce the loss of output material due to incorrect paper types. [Means for solving the problem]
[0009] In order to solve the above problem, the invention described in claim 1 is an image forming apparatus comprising an image forming unit that forms an image on paper, a detection unit that detects the physical properties of the paper, a reception unit that receives paper identification information for identifying paper specified by a user, a first judgment unit that determines whether the paper identification information received by the reception unit corresponds to the detection result by the detection unit, a second judgment unit that determines whether the detection result by the detection unit for a first paper being transported corresponds to the detection result by the detection unit for a second paper being transported, and an operation control unit that controls the operation of the image forming unit based on the judgment result by the first judgment unit and the judgment result by the second judgment unit. [Effects of the Invention]
[0010] According to the present invention, it is possible to reduce the loss of output material due to incorrect paper types. [Brief explanation of the drawings]
[0011] [Figure 1] 1 is a schematic cross-sectional view showing the overall configuration of an image forming apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing a functional configuration of the image forming apparatus. [Figure 3] FIG. 10 is a diagram for explaining a method for determining the paper type using two types of physical property values. [Figure 4] 6 is a flowchart showing a first paper inspection process executed by the image forming apparatus according to the first embodiment. [Figure 5] 10 is a flowchart showing a second paper inspection process executed by the image forming apparatus according to the second embodiment. [Figure 6] 10 is a flowchart showing a third paper inspection process executed by the image forming apparatus according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the illustrated examples.
[0013] [First embodiment] FIG. 1 is a schematic cross-sectional view showing the overall configuration of an image forming apparatus 100 according to a first embodiment of the present invention. The image forming apparatus 100 is a tandem type image forming apparatus that forms a color image by electrophotography based on image data obtained by reading an image from an original or image data received from an external device.
[0014] As shown in FIG. 1, the image forming apparatus 100 includes an operation unit 10, a display unit 11, a scanner 12, an image forming unit 20, a paper feed unit 30, a conveyance unit 40, a paper detection unit 50, and the like.
[0015] The operation unit 10 includes a touch panel formed to cover the display screen of the display unit 11, and various operation buttons such as numeric buttons and a start button, and outputs operation signals based on user operations to the control unit 60 (see FIG. 2). The operation unit 10 accepts operation instructions from the user.
[0016] The display unit 11 is configured with an LCD (Liquid Crystal Display) or the like, and displays various screens in accordance with instructions of a display signal input from the control unit 60.
[0017] The scanner 12 optically scans an original document transported from an ADF (Auto Document Feeder) onto a contact glass or an original document placed on the contact glass, forms an image of the reflected light of the light emitted from the light source and scanned onto the original document on the light receiving surface of a CCD (Charge Coupled Device) sensor, reads the original document image, A / D converts the read image, and outputs the obtained image data to the control unit 60.
[0018] Image forming unit 20 forms an image on a sheet of paper. Image forming unit 20 includes photosensitive drums 21Y, 21M, 21C, and 21K corresponding to the colors yellow (Y), magenta (M), cyan (C), and black (K), charging units 22Y, 22M, 22C, and 22K, exposure units 23Y, 23M, 23C, and 23K, developing units 24Y, 24M, 24C, and 24K, primary transfer rollers 25Y, 25M, 25C, and 25K, an intermediate transfer belt 26, a secondary transfer roller 27, and a fixing unit 28.
[0019] The charging sections 22Y, 22M, 22C, and 22K uniformly charge the photosensitive drums 21Y, 21M, 21C, and 21K. The exposure units 23Y, 23M, 23C, and 23K are composed of a laser light source, a polygon mirror, a lens, etc., and scan and expose the surfaces of the photosensitive drums 21Y, 21M, 21C, and 21K with a laser beam based on image data of each color to form an electrostatic latent image. The developing units 24Y, 24M, 24C, and 24K develop the electrostatic latent images on the photosensitive drums 21Y, 21M, 21C, and 21K by attaching toner of each color to the electrostatic latent images.
[0020] The primary transfer rollers 25Y, 25M, 25C, and 25K sequentially transfer (primary transfer) the toner images of each color formed on the photosensitive drums 21Y, 21M, 21C, and 21K onto the intermediate transfer belt 26. That is, a color toner image is formed on the intermediate transfer belt 26 in which the toner images of four colors are superimposed. The secondary transfer roller 27 transfers the color toner images on the intermediate transfer belt 26 all at once onto a sheet of paper supplied from the paper feed unit 30 (secondary transfer).
[0021] The fixing unit 28 fixes the toner image onto the paper by applying heat and pressure by passing the paper through a nip formed by a heating roller and a pressure roller.
[0022] The paper feed unit 30 includes a plurality of paper feed trays 31, 32, and 33 for feeding paper, and supplies the paper stored in each of the paper feed trays 31, 32, and 33 to the image forming unit 20. The paper feed trays 31, 32, and 33 store paper of a paper type and size predetermined for each paper feed tray.
[0023] The conveying section 40 is equipped with conveying rollers and the like for conveying paper, and conveys paper within the image forming device 100 from the time the paper stored in the paper feed trays 31, 32, and 33 is supplied to the image forming section 20 until the paper is discharged outside the machine after fixing.
[0024] The paper detection unit 50 detects the physical properties of paper and is provided on the transport path from the paper feed unit 30 to the image forming unit 20. The paper detection unit 50 detects values related to the physical properties of multiple types of paper, including the paper's basis weight, surface properties, and thickness (hereinafter referred to as physical property values). The physical property values may be information that can be converted (transformed) into physical properties. The paper detection unit 50 may also detect physical properties such as the gloss, stiffness, and grain direction of the paper. The paper detection unit 50 may be composed of a single sensing element or multiple sensing elements.
[0025] FIG. 2 is a block diagram showing the functional configuration of the image forming apparatus 100. As shown in FIG. 2, the image forming apparatus 100 is configured to include an operation unit 10, a display unit 11, a scanner 12, a communication unit 13, a storage unit 14, an image forming unit 20, a paper feed unit 30, a conveyance unit 40, a paper detection unit 50, and a control unit 60. Note that a description of the functional units that have already been described will be omitted.
[0026] The communication unit 13 transmits and receives data to and from external devices connected to a communication network such as a LAN (Local Area Network).
[0027] The storage unit 14 is configured with a non-volatile storage device such as a hard disk or flash memory, and stores various data. For example, the storage unit 14 stores a brand physical property table 141, paper type physical property variation information 142, and a paper feed tray management table 143.
[0028] The brand physical property table 141 stores the range of physical property values (basis weight, surface properties, thickness, etc.) corresponding to each brand of paper. The range of physical property values includes, for example, an upper limit and a lower limit. Paper brands may be represented by product names, such as fine paper, coated paper, and straw paper.
[0029] The paper type physical property variation information 142 is information in which, for each paper type, physical property values (basis weight, surface properties, thickness, etc.) detected from multiple sheets of paper belonging to that paper type are associated with each other. Paper types that are used include fine paper, coated paper, and straw paper. The paper type physical property variation information 142 includes a combination of physical property values obtained for each sheet of paper.
[0030] In the paper feed tray management table 143, the paper type, size, etc. of the paper stored in each paper feed tray are associated with each other.
[0031] The paper detection unit 50 includes a basis weight sensor 51, a surface property sensor 52, a thickness sensor 53, and the like. Basis weight sensor 51 detects the basis weight of the paper. The basis weight of the paper is measured based on some or all of the physical properties of the paper, such as its density, air permeability, stiffness, and electrical resistance. The basis weight may also be detected using the results of a weight sensor that directly measures the weight of the paper. The surface property sensor 52 detects the surface property (smoothness, smoothness) of the paper. The surface property of the paper is measured, for example, using a reflection sensor that outputs the intensity and / or intensity ratio of specularly reflected light and diffusely reflected light of light irradiated onto the paper, based on the intensity ratio. The thickness sensor 53 detects the thickness of the paper. The thickness of the paper is measured, for example, by a displacement sensor that detects the distance between the axes of two rollers that can move in the thickness direction according to the thickness of the paper.
[0032] The control unit 60 is composed of a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. The CPU reads various processing programs stored in the ROM, loads them into the RAM, and performs centralized control of the operations of each unit of the image forming apparatus 100 according to the loaded programs.
[0033] The control unit 60 has functions such as a printing condition input unit 61, a first determination unit 62, a second determination unit 63, and an operation control unit 64. These functions are realized by cooperation between the CPU of the control unit 60 and a program stored in the ROM.
[0034] The printing condition input unit 61 accepts printing conditions specified by the user. The printing conditions include paper identification information for identifying the paper. In other words, the printing condition input unit 61 functions as a reception unit that accepts paper identification information for identifying the paper specified by the user. The paper identification information is information that indicates the paper type or brand.
[0035] The first determination unit 62 determines whether the paper identification information received by the printing condition input unit 61 corresponds to the detection result by the paper detection unit 50. Here, "the paper identification information corresponds to the detection result by the paper detection unit 50" means that the physical properties of the paper specified by the paper identification information match the detection result by the paper detection unit 50 (the physical properties of the paper).
[0036] Specifically, the first determination unit 62 determines whether the information indicating the paper type or brand of the paper received by the printing condition input unit 61 and the detection result by the paper detection unit 50 correspond to each other. For example, the first judgment unit 62 obtains the range of physical property values (basis weight, surface properties, thickness, etc.) corresponding to the brand specified by the user from the brand physical property table 141 in the memory unit 14, and determines whether each of the physical property values obtained by the paper detection unit 50 is within the range of physical property values corresponding to this brand.
[0037] The first determination section 62 makes a determination when the image forming section 20 starts an image forming job.
[0038] The second determination unit 63 determines whether or not the detection result of the first sheet of paper being transported by the paper detection unit 50 corresponds to the detection result of the second sheet of paper being transported by the paper detection unit 50. Here, "the detection result of the first sheet of paper by the paper detection unit 50 corresponds to the detection result of the second sheet of paper by the paper detection unit 50" means that the detection result of the first sheet of paper (physical properties of the paper) and the detection result of the second sheet of paper (physical properties of the paper) match.
[0039] For example, the second determination unit 63 compares a statistically processed value of the detection result of the first sheet with a statistically processed value of the detection result of the second sheet. The statistically processed value is a value (information) obtained by statistical processing. The second determination unit 63 calculates the average value of physical property values (basis weight, surface properties, thickness, etc.) for each paper type based on the paper type physical property variation information 142 in the memory unit 14. The second determination unit 63 calculates the square root of the sum of squares of the differences between the average value for each paper type and the physical property values (basis weight, surface properties, thickness, etc.) detected by the paper detection unit 50 of the first paper, and determines the paper type for which this value is smallest as the paper type of the first paper. Similarly, the second determination unit 63 determines the paper type of the second paper. Then, the second determination unit 63 compares the paper type of the first paper with the paper type of the second paper and determines whether the two match. Here, the paper type of the first paper corresponds to a "statistically processed value of the detection result of the first paper," and the paper type of the second paper corresponds to a "statistically processed value of the detection result of the second paper."
[0040] A method for determining the paper type using two types of physical property values A and B will be described with reference to Figure 3. In Figure 3, the horizontal axis represents physical property value A (e.g., basis weight) and the vertical axis represents physical property value B (e.g., thickness). The physical property values A and B of paper belonging to paper type 1 included in paper type physical property variation information 142 vary within the range of ellipse 71, and the average value of physical property value A of paper type 1 is set to a1, and the average value of physical property value B of paper type 1 is set to b1. The physical property values A and B of paper belonging to paper type 2 included in paper type physical property variation information 142 vary within the range of ellipse 72, and the average value of physical property value A of paper type 2 is set to a2, and the average value of physical property value B of paper type 2 is set to b2. Although not shown in the figure, similarly, the average value of physical property value A of paper type i is set to a i , the average value of the physical property B of paper type i is b i When the detection results of the physical property values A and B of the newly fed paper by the paper detection unit 50 are (a, b), (a i -a)^2+(b i -b) The paper type i (paper type 2 in Figure 3) for which the square root of ^2 is smallest is the correct paper type.
[0041] In the second determination section 63, the first sheet and the second sheet are assumed to be sheets that are transported consecutively.
[0042] The judgment criteria in the first judgment unit 62 are different from the judgment criteria in the second judgment unit 63. Specifically, the first judgment unit 62 makes a judgment by comparing the paper identification information specified by the user with the detection results by the paper detection unit 50, whereas the second judgment unit 63 makes a judgment by comparing the detection results by the paper detection unit 50 for different papers.
[0043] The operation control unit 64 controls the operation of the image forming unit 20 based on the determination result by the first determination unit 62 and the determination result by the second determination unit 63. For example, the operation control unit 64 stops image formation by the image forming unit 20 when the first judgment unit 62 judges that the paper identification information specified by the user does not correspond to the detection result by the paper detection unit 50, or when the second judgment unit 63 judges that the detection result by the paper detection unit 50 for the first paper does not correspond to the detection result by the paper detection unit 50 for the second paper.
[0044] In addition, if the first judgment unit 62 determines that the paper identification information specified by the user does not correspond to the detection result by the paper detection unit 50, or if the second judgment unit 63 determines that the detection result by the paper detection unit 50 for the first paper does not correspond to the detection result by the paper detection unit 50 for the second paper, the operation control unit 64 causes the display unit 11 to display the judgment result by the first judgment unit 62 or the second judgment unit 63 or information regarding the detection result by the paper detection unit 50.
[0045] Next, the operation of the first embodiment will be described. FIG. 4 is a flowchart showing the first paper inspection process executed by the image forming apparatus 100. As shown in FIG.
[0046] First, the printing condition input unit 61 acquires printing conditions, including the paper brand, for the image formation job to be executed (step S1). Specifically, the printing condition input unit 61 acquires printing conditions for the job received from an external device such as a PC (Personal Computer) via the communication unit 13. The printing conditions include paper conditions such as the paper brand, the number of copies to be printed, post-processing (finishing conditions), etc. The printing conditions are specified by the user when an instruction to execute the job is given in the external device. Alternatively, the printing condition input unit 61 may acquire printing conditions (including the paper brand) specified from the operation unit 10. The printing condition input unit 61 stores the printing conditions, including the paper brand, in the storage unit 14.
[0047] Here, the operation control unit 64 sets N to 1 (step S2), and controls the paper feed unit 30 to feed the Nth sheet of paper in the job (step S3). The paper detection unit 50 detects the physical properties (basis weight, surface properties, thickness, etc.) of the Nth sheet of paper being transported by the transport unit 40 (step S4), and the operation control unit 64 acquires the detection results from the paper detection unit 50. The operation control unit 64 stores the detection results of the physical properties of the Nth sheet of paper in the memory unit 14 in association with the value of N.
[0048] Next, first determination unit 62 determines whether the physical properties of the brand match the physical properties of the Nth sheet of paper detected in step S4 (step S5). Specifically, first determination unit 62 references brand physical property table 141 in memory unit 14, acquires the range of physical property values (basis weight, surface properties, thickness, etc.) corresponding to the brand specified by the user, and determines whether the physical property values of the Nth sheet of paper fall within this acquired range. When multiple physical property values are used in the determination by first determination unit 62, it is determined that the physical properties of the brand and the physical properties of the Nth sheet of paper match when all of the physical property values of the Nth sheet of paper fall within the range of physical property values corresponding to the brand.
[0049] If the first judgment unit 62 determines that the physical properties of the brand and the physical properties of the Nth sheet of paper match (step S5; YES), the operation control unit 64 causes the image forming unit 20 to start image formation (step S6).
[0050] Next, the operation control unit 64 determines whether the job is completed (step S7). Specifically, the operation control unit 64 determines whether image formation for the number of sheets specified in the job is completed. If the job is not completed (step S7; NO), the operation control unit 64 adds 1 to N (step S8) and controls the paper feed unit 30 to feed the Nth sheet of paper in the job (step S9). The paper detection unit 50 detects the physical properties (basis weight, surface properties, thickness, etc.) of the Nth sheet of paper being transported by the transport unit 40 (step S10), and the operation control unit 64 acquires the detection results from the paper detection unit 50. The operation control unit 64 stores the detection results of the physical properties of the Nth sheet of paper in the memory unit 14 in association with the value of N.
[0051] Next, the second determination unit 63 reads out from the memory unit 14 the detection results of the physical properties of the N-1th sheet of paper and the detection results of the physical properties of the N-th sheet of paper detected in step S10, and determines whether the physical properties of the N-1th sheet of paper match the physical properties of the N-th sheet of paper (step S11). Specifically, the second determination unit 63 calculates the square root of the sum of squares of the differences between the physical property values of the N-1th sheet of paper and the average value of the physical property values for each paper type obtained from the paper type physical property variation information 142 in the memory unit 14, and determines the paper type for which this value is smallest as the paper type of the N-1th sheet of paper (see FIG. 3). Similarly, the second determination unit 63 determines the paper type of the N-th sheet of paper. Then, the second determination unit 63 determines whether the paper type of the N-1th sheet of paper matches the paper type of the N-th sheet of paper. Here, by storing the paper type of the Nth sheet in the storage unit 14, it is possible to omit determining the paper type of the (N-1)th sheet in step S11 the next time.
[0052] Note that the second determination unit 63 may determine that the physical properties of the N-1th sheet of paper match the physical properties of the Nth sheet of paper simply when the difference between the physical property values detected from the N-1th sheet of paper and the Nth sheet of paper is equal to or less than a predetermined value, rather than comparing the paper types of the N-1th sheet of paper and the Nth sheet of paper. Here, when a plurality of physical property values are used in the determination by the second determination unit 63, the physical properties of the N-1th sheet of paper are determined to match the physical properties of the Nth sheet of paper when the difference between the physical property values detected from the N-1th sheet of paper and the Nth sheet of paper is equal to or less than a predetermined value (which differs for each physical property value) for all physical property values.
[0053] If the second determination unit 63 determines that the physical properties of the (N-1)th sheet match those of the Nth sheet (step S11; YES), the operation control unit 64 continues image formation by the image forming unit 20 (step S12). Then, the process returns to step S7, and the process is repeated.
[0054] If the first determination unit 62 determines in step S5 that the physical properties of the brand do not match the physical properties of the Nth sheet of paper (step S5; NO), or if the second determination unit 63 determines in step S11 that the physical properties of the (N-1)th sheet of paper do not match the physical properties of the Nth sheet of paper (step S11; NO), the operation control unit 64 stops image formation by the image forming unit 20 and displays a warning message on the display unit 11 (step S13). The warning message includes information about the determination result of the first determination unit 62 or the second determination unit 63 that the two sheets do not match and the detection result by the paper detection unit 50. For example, a warning message such as "The paper being used is not the specified brand" or "The paper type is incorrect" is displayed on the display unit 11.
[0055] In step S7, if the job is completed (step S7; YES), the first paper inspection process is completed.
[0056] As described above, according to the first embodiment, first determination unit 62 determines whether the paper identification information specified by the user corresponds to the detection result by paper detection unit 50, and second determination unit 63 determines whether the detection result by paper detection unit 50 for the first paper sheet corresponds to the detection result by paper detection unit 50 for the second paper sheet. Then, based on the determination results by first determination unit 62 and second determination unit 63, the operation of image forming unit 20 is controlled, thereby making it possible to reduce loss of output material due to incorrect paper type.
[0057] In this way, checking paper using two different criteria improves the accuracy of paper inspection. Specifically, the first judgment unit 62 can judge whether the paper being used is the paper intended by the user. Meanwhile, the second judgment unit 63 can judge whether the physical properties of two sheets of paper fed at different times match.
[0058] The first determination section 62 can also determine whether or not the information indicating the paper type or brand of paper specified by the user corresponds to the detection result by the paper detection section 50. Furthermore, since the first determination section 62 makes a determination at the start of an image forming job by the image forming section 20, it is possible to minimize loss of output material due to incorrect paper type.
[0059] Furthermore, the second determination section 63 can determine whether or not the detection result of the first sheet and the detection result of the second sheet correspond to each other using statistically processed values.
[0060] Furthermore, if the first determination unit 62 or the second determination unit 63 determines that the printing is not compatible, image formation by the image forming unit 20 is stopped, thereby reducing loss of output material. Furthermore, if the first judgment unit 62 or the second judgment unit 63 judges that there is no correspondence, the user can be alerted by displaying information on the judgment result or the detection result of the physical property on the display unit 11.
[0061] [Second embodiment] Next, a second embodiment to which the present invention is applied will be described. The image forming apparatus in the second embodiment has the same configuration as the image forming apparatus 100 shown in the first embodiment, and therefore, illustration and description of the configuration will be omitted, and Figures 1 and 2 will be used. The configuration and processing characteristic of the second embodiment will be described below.
[0062] The second determination unit 63 determines whether or not the detection result of the paper detection unit 50 for the first paper being transported corresponds to the detection result of the paper detection unit 50 for the second paper being transported. The second determination unit 63 makes a determination before and after paper is replenished in the paper feed trays 31, 32, and 33 used for paper feeding in the paper feed unit 30.
[0063] Each of the paper feed trays 31, 32, and 33 is provided with an open / close detection unit (not shown), and each open / close detection unit detects whether the paper feed tray in which the open / close detection unit is provided is open (open state) or closed (closed state). When the open / close detection unit detects that the paper feed tray is open once and then detects that the paper feed tray is closed, the operation control unit 64 determines that paper has been replenished in the paper feed tray. It should be noted that the method of detecting that paper has been replenished in the paper feed tray is not limited to the above example.
[0064] Next, the operation of the second embodiment will be described. FIG. 5 is a flowchart showing a second paper inspection process executed by the image forming apparatus according to the second embodiment. The processing of steps S21 to S30 is the same as the processing of steps S1 to S10 in the first paper inspection processing (see FIG. 4), and therefore a description thereof will be omitted.
[0065] After step S30, the operation control unit 64 determines whether or not paper has been replenished in the paper feed tray in use (step S31). Specifically, the operation control unit 64 determines whether or not the Nth sheet of paper is the first sheet of paper fed immediately after the paper feed tray in use was replenished with paper. More specifically, after the N-1th sheet of paper has been fed, the operation control unit 64 determines whether or not the open / close detection unit provided in the paper feed tray that stored the N-1th sheet and the Nth sheet of paper detected an open state of the paper feed tray and then detected a closed state before the Nth sheet was fed.
[0066] When paper is replenished into the paper feed tray in use (step S31; YES), that is, when the Nth sheet of paper is the first sheet of paper fed immediately after paper is replenished into the paper feed tray in use, the second judgment unit 63 reads the detection results of the physical properties of the N-1th sheet of paper and the detection results of the physical properties of the Nth sheet of paper detected in step S30 from the memory unit 14, and judges whether the physical properties of the N-1th sheet of paper match the physical properties of the Nth sheet of paper (step S32).
[0067] In step S31, if the paper feed tray in use has not been replenished with paper just before feeding the Nth sheet (step S31; NO), or if in step S32 the second determination unit 63 determines that the physical properties of the (N-1)th sheet match the physical properties of the Nth sheet (step S32; YES), the operation control unit 64 causes the image forming unit 20 to continue image formation (step S33). Then, the process returns to step S27 and is repeated.
[0068] If, in step S25, the first judgment unit 62 determines that the physical properties of the brand do not match the physical properties of the Nth sheet of paper (step S25; NO), or if, in step S32, the second judgment unit 63 determines that the physical properties of the N-1th sheet of paper do not match the physical properties of the Nth sheet of paper (step S32; NO), the operation control unit 64 stops image formation by the image forming unit 20 and displays a warning message on the display unit 11 (step S34).
[0069] In step S27, if the job is completed (step S27; YES), the second paper inspection process is completed.
[0070] As described above, according to the second embodiment, the operation of the image forming unit 20 is controlled based on the judgment results by the first judgment unit 62 and the judgment results by the second judgment unit 63, thereby reducing the loss of output material due to incorrect paper type. Furthermore, the second judgment unit 63 makes a judgment before and after paper is replenished in the paper feed tray in use, so it is possible to check the paper at a time when mistakes in the paper type are likely to occur, and to detect operational errors made by the user when replenishing paper at an early stage.
[0071] [Third embodiment] Next, a third embodiment to which the present invention is applied will be described. The image forming apparatus in the third embodiment has the same configuration as the image forming apparatus 100 shown in the first embodiment, and therefore, illustration and description of the configuration will be omitted, and Figures 1 and 2 will be used. The configuration and processing characteristic of the third embodiment will be described below.
[0072] The second determination unit 63 determines whether the detection result of the paper detection unit 50 for the first paper being transported corresponds to the detection result of the paper detection unit 50 for the second paper being transported. The second determination unit 63 makes a determination before and after the paper feed tray used for paper feeding is switched from one of the multiple paper feed trays 31, 32, and 33 to another paper feed tray.
[0073] Each of the paper feed trays 31, 32, and 33 is provided with a paper out detection unit (not shown), and each paper out detection unit detects whether or not there is paper in the paper feed tray in which the paper out detection unit is provided. When the paper out detection unit provided in the paper feed tray in use detects that there is no paper in the paper feed tray, the operation control unit 64 refers to the paper feed tray management table 143 in the memory unit 14, identifies the paper feed tray that stores paper of the same paper type and size as the paper in the paper feed tray in use, and switches to paper feeding from the identified paper feed tray.
[0074] Next, the operation of the third embodiment will be described. FIG. 6 is a flowchart showing a third paper inspection process executed by the image forming apparatus according to the third embodiment. The processing of steps S41 to S50 is the same as the processing of steps S1 to S10 in the first paper inspection processing (see FIG. 4), and therefore a description thereof will be omitted.
[0075] After step S50, the operation control unit 64 determines whether the paper feed tray in use has been switched (step S51). Specifically, the operation control unit 64 determines whether the Nth sheet is the first sheet fed immediately after the paper feed tray has been switched. More specifically, after the N-1th sheet has been fed, the operation control unit 64 determines whether the paper out detector provided in the paper feed tray that stored the N-1th sheet detected that there was no paper in that paper feed tray before the Nth sheet was fed.
[0076] If the paper feed tray in use is switched (step S51; YES), that is, if the Nth sheet of paper is the first sheet of paper fed immediately after the paper feed tray is switched, the second judgment unit 63 judges whether the physical properties of the N-1th sheet of paper match the physical properties of the Nth sheet of paper detected in step S50 (step S52).
[0077] In step S51, if the paper feed tray in use has not been switched immediately before feeding the Nth sheet (step S51; NO), or if in step S52 the second determination unit 63 determines that the physical properties of the (N-1)th sheet match the physical properties of the Nth sheet (step S52; YES), the operation control unit 64 causes the image forming unit 20 to continue image formation (step S53). Then, the process returns to step S47 and is repeated.
[0078] If, in step S45, the first judgment unit 62 determines that the physical properties of the brand do not match the physical properties of the Nth sheet of paper (step S45; NO), or if, in step S52, the second judgment unit 63 determines that the physical properties of the N-1th sheet of paper do not match the physical properties of the Nth sheet of paper (step S52; NO), the operation control unit 64 stops image formation by the image forming unit 20 and displays a warning message on the display unit 11 (step S54).
[0079] In step S47, if the job is completed (step S47; YES), the third paper inspection process is completed.
[0080] As described above, according to the third embodiment, the operation of the image forming unit 20 is controlled based on the judgment results by the first judgment unit 62 and the judgment results by the second judgment unit 63, thereby reducing the loss of output material due to incorrect paper type. In addition, the second judgment unit 63 makes a judgment before and after the paper feed tray used for paper feeding is switched, so it is possible to check the paper at a time when mistakes in the paper type are likely to occur, and it is possible to quickly detect operating errors when setting paper in the paper feed tray and setting errors in the paper feed tray management table 143.
[0081] The above-described embodiments are merely examples of the image forming apparatus according to the present invention, and the present invention is not limited to these. The detailed configuration and operation of each part constituting the apparatus can be appropriately changed without departing from the spirit of the present invention. For example, the characteristic configurations of the above-described embodiments may be combined.
[0082] In the above-described embodiments, the second determination unit 63 determines whether the detection results by the paper detection unit 50 for two sheets of paper that are transported consecutively correspond to each other, but the sheets of paper that are the subject of determination by the second determination unit 63 do not have to be consecutive. For example, it may be determined whether the detection results by the paper detection unit 50 for two sheets of paper that are transported with one or more sheets of paper sandwiched between them correspond to each other. The second determination unit 63 may also detect the physical properties of a plurality of sheets of first paper and second paper using the paper detection unit 50 and compare the average values. In addition, the second judgment unit 63 may determine whether the detection result of the Nth sheet of paper by the paper detection unit 50 corresponds to the average value obtained by averaging the physical property values of all sheets of paper up to the N-1th sheet of paper.
[0083] Furthermore, in the above embodiments, the first determination unit 62 determines whether the paper identification information received by the printing condition input unit 61 corresponds to the detection result of the first paper by the paper detection unit 50, but the paper detected by the paper detection unit 50 does not have to be the first paper of the job. However, in order to detect paper errors early, it is desirable to use the detection result of a paper that is fed early after the job is started.
[0084] Also, the first determination unit 62 may use a method using statistically processed values as shown in Fig. 3. Specifically, for each brand of paper, information is prepared in advance in which physical property values (basis weight, surface properties, thickness, etc.) detected from multiple sheets of paper belonging to that brand are associated with each other, and the square root of the sum of squares of the differences between the physical property values detected by the paper detection unit 50 of the first sheet of paper and the average value for each brand is calculated, and the brand for which this value is smallest is determined to be the brand of the first sheet of paper, and it is determined whether or not it matches the brand specified by the user.
[0085] Furthermore, in each of the above embodiments, the paper detection unit 50 detects physical properties of the paper such as basis weight, surface properties, and thickness, but the paper detection unit 50 may also be configured to detect one type of physical property of the paper. In addition, in each of the above embodiments, the physical properties of the paper are detected by a paper detection unit 50 provided on the paper transport path within the image forming device 100, but some of the physical properties of the paper may also be detected outside the image forming device 100 (offline).
[0086] In the above description, an example has been disclosed in which a ROM is used as a computer-readable medium storing a program for executing each process, but this is not limiting. Other computer-readable media may also be used, such as non-volatile memory such as flash memory, or portable recording media such as CD-ROM. Furthermore, a carrier wave may also be used as a medium for providing program data via a communication line. [Explanation of symbols]
[0087] 10 Control section 11 Display section 13 Communications Department 14 Storage section 20 Image forming unit 30 Paper feed section 31, 32, 33 Paper tray 40 Conveying section 50 Paper detection unit 51 Basis weight sensor 52 Surface Sensor 53 Thickness Sensor 60 Control Unit 61 Printing condition input section 62 1st judgment part 63 Second Judgment Section 64 Operation control section 100 Image forming device
Claims
1. an image forming unit that forms an image on a sheet; a detection unit that detects the physical properties of the paper; an acquisition unit that acquires a statistically processed value based on the physical property; a control unit that controls the formation of an image on the second sheet by the image forming unit based on a comparison result between the statistically processed value of the first sheet and the statistically processed value of the second sheet, the physical properties of which are detected later than those of the first sheet; An image forming apparatus comprising:
2. An image forming device as described in Claim 1, wherein the detection unit detects the physical properties of multiple types of paper.
3. An image forming device as described in claim 1 or 2, wherein the detection unit detects at least one of the basis weight of the paper, the surface properties of the paper, and the thickness of the paper.
4. An image forming device described in any one of claims 1 to 3, wherein the acquisition unit identifies the type of paper based on the statistical processing value.
5. A control method for an image forming apparatus including an image forming unit that forms an image on a sheet of paper and a detection unit that detects physical properties of the sheet of paper, comprising: an acquisition step of acquiring a statistically processed value based on the physical property; a control step of controlling image formation by the image forming unit on the second sheet of paper based on a comparison result between the statistically processed value of the first sheet of paper and the statistically processed value of the second sheet of paper, the physical properties of which are detected later than those of the first sheet of paper; A control method comprising:
6. A control method as described in Claim 5, wherein the detection unit detects the physical properties of multiple types of paper.
7. A control method as described in claim 5 or 6, wherein the detection unit detects at least one of the basis weight of the paper, the surface properties of the paper, and the thickness of the paper.
8. A control method described in any one of claims 5 to 7, wherein in the acquisition process, the type of paper is identified based on the statistical processing value.