Recording material transport device and image formation system

Abstract

To provide a recording material transport device that can prevent the productivity from declining when detecting the characteristics of the recording material.SOLUTION: The recording material transport device includes: a first transport section constituting a transport route for recording material; a second transport section branching from the first transport section and constituting a transport route for recording material different from the transport route of the first transport section; and a detection section for detecting recording material characteristics of the recording material located in the second transport section downstream of the branching section where the first and second transport sections diverge in the transport direction of the recording material.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a recording material conveying device and an image forming system having the recording material conveying device. [Background technology]

[0002] In some image forming apparatuses, multiple types of recording materials are used. In such cases, the quality of the formed image can be improved by appropriately setting the image formation conditions, such as the toner transfer voltage and fixing temperature, during image formation according to the type and physical properties of the recording material. Furthermore, by transporting the recording material under more appropriate transport conditions according to the type and physical properties of the recording material, it is possible to prevent problems such as jams, image misalignment, and uneven recording material transport.

[0003] As an image forming apparatus that optimizes image formation conditions according to the type and physical properties of such recording materials, a configuration has been proposed in which a detection unit for detecting characteristics such as the type and physical properties of the recording material (hereinafter referred to as recording material characteristics) is arranged in the recording material transport path (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2020-128269 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in an image forming apparatus in which a detector is disposed in the recording material transport path as described above, when detecting recording material characteristics, the transport of the recording material is stopped or transported at a low speed to improve detection accuracy and prevent erroneous detection. Therefore, in an image forming job, the detection of recording material characteristics is performed before image formation is performed, and the start of image formation must be delayed and the recording material must be put on standby for the period during which the recording material characteristics of the recording material are measured. As a result, productivity in the image forming apparatus decreases.

[0006] In order to solve the above-mentioned problems, the present invention provides a recording material conveying device and an image forming system that can suppress a decrease in productivity when detecting the characteristics of the recording material. [Means for solving the problem]

[0007] The recording material conveying device of the present invention comprises a first conveying section that forms a conveying path for the recording material, a second conveying section that branches off from the first conveying section and forms a conveying path for the recording material that is different from the conveying path of the first conveying section, and a detection section that is arranged in the second conveying section and detects values ​​corresponding to the recording material characteristics of the recording material. The image forming system of the present invention includes an image forming unit that forms an image on a recording material, a first conveying unit that forms a recording material conveying path, a second conveying unit that branches off from the first conveying unit and forms a recording material conveying path different from the conveying path of the first conveying unit, and a detection unit that is disposed in the second conveying unit and detects a value corresponding to the recording material characteristics of the recording material. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a recording material conveying device and an image forming system that are capable of suppressing a decrease in productivity when detecting the characteristics of a recording material. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an image forming system according to a first embodiment. [Figure 2] FIG. 1 is a system block diagram of an image forming system according to a first embodiment. [Figure 3] FIG. 2 is a functional block diagram of a control unit of the image forming system according to the first embodiment. [Figure 4] 4 is a flowchart of a method for detecting recording material characteristics in the image forming system according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] <Embodiments of Recording Material Conveying Device and Image Forming System> Hereinafter, examples of embodiments for carrying out the present invention will be described, but the present invention is not limited to the following examples. FIG. 1 shows a schematic configuration diagram of an image forming system equipped with a recording material conveying device according to this embodiment. The image forming system 10 shown in FIG. 1 includes a recording material supplying device 100, a recording material conveying device 400, an image forming device 200, and a post-processing device 300. In the image forming system 10, recording materials S loaded in a recording material supply device 100 are supplied to an image forming device 200 via a recording material conveying device 400. Then, after an image is formed on the recording material S in the image forming device 200, the recording material S is conveyed from the image forming device 200 to a post-processing device 300. Then, after a predetermined post-processing is performed on the recording material S after the image formation process in the post-processing device 300, the recording material S is discharged from the post-processing device 300.

[0011] [Recording material supply device] In the image forming system 10, the recording material supplying device 100 stores recording materials for image formation and supplies recording materials S to the image forming device 200 in accordance with an image formation job. As shown in Fig. 1, the recording material supplying device 100 includes a conveying section 50 and a recording material supplying section 70 as a recording material storage section.

[0012] The recording material supply unit 70 is configured, for example, by a plurality of paper feed trays arranged inside the recording material supply device 100. The recording material supply unit 70 is capable of loading a plurality of sheets of recording material S in a stacked state. Figure 1 shows an example of a configuration including four recording material supply units 70 arranged one above the other. Each recording material supply unit 70 individually stores recording materials of different types and sizes.

[0013] The conveying section 50 includes take-out rollers (not shown) that take out the recording material from each recording material supplying section 70, and a plurality of conveying rollers 53 that are provided along a predetermined recording material conveying path for conveying the recording material. Therefore, the conveying path of the conveying section 50 merges the plurality of recording material supplying sections 70 into one path and is connected to the recording material conveying device 400. As a result, the conveying section 50 drives the conveying rollers 53 to convey the recording material S fed from the recording material supplying section 70 to the recording material conveying device 400.

[0014] [Recording material transport device] The recording material conveying device 400 includes an inlet 54 through which the recording material S is conveyed into the recording material conveying device 400, a first conveying section 51 and a second conveying section 52 that convey the recording material S, an outlet 55 through which the recording material S is conveyed out, and a media sensor 71 as a detection section that detects the characteristics of the recording material S.

[0015] The first conveying section 51 constitutes a conveying path along which the recording material S is conveyed from the carry-in entrance 54 until it is conveyed out from the discharge exit 55. The second conveying section 52 branches off from the first conveying section 51 at a branching section 58 downstream of the carry-in entrance 54. Furthermore, the second conveying section 52 merges with the first conveying section 51 again at a junction 59 upstream of the discharge exit 55. The first conveying section 51 and the second conveying section 52 are provided with a plurality of conveying rollers 53 and the like for conveying the recording material S, which are arranged along the first conveying section 51 and the second conveying section 52.

[0016] A media sensor 71 is disposed on the second conveying section 52 as a detection section that detects the recording material characteristics of the recording material S. A plurality of media sensors 71 are provided on the second conveying section 52. The second transport section 52 branches off from the first transport section 51 upstream of the media sensor 71 disposed on the second transport section 52 at the most upstream side. The second conveying section 52 merges with the first conveying section 51 again downstream of the most downstream media sensor 71 arranged on the second conveying section 52 to form a single path. Then, downstream of the joining position of the second conveying section 52, the first conveying section 51 is connected to an outlet 55 through which the recording material S is discharged from the recording material conveying device 400 to the image forming apparatus 200.

[0017] The first conveying section 51 is configured so that the conveying distance of the recording material S is shorter than that of the second conveying section 52. In particular, the first conveying section 51 is configured so that the conveying distance of the recording material S from the branching section 58 of the second conveying section 52 to the junction 59 is shorter than that of the second conveying section 52. It is preferable that the first conveying section 51 is configured so that the conveying distance of the recording material is the shortest between the carry-in entrance 54 and the carry-out exit 55 of the recording material conveying device 400.

[0018] Furthermore, the second conveying section 52 is configured to convey the recording material S over a longer distance than the first conveying section 51. The second conveying section 52 is preferably configured to convey the recording material S over a distance that is equal to or greater than the length of the long side of the recording material S that can be accommodated in the recording material supplying device 100 and that can be conveyed by the recording material conveying device 400. For example, the second conveying section 52 is preferably configured to have a length equal to or greater than the long side of the maximum standard size of recording material S, excluding long paper such as roll paper.

[0019] The recording material S is conveyed to the second conveying section 52, and the recording material characteristics are detected by the media sensor 71. The recording material S conveyed to the second conveying section 52 has its characteristics detected by the media sensor 71 arranged in the path. In the second conveying section 52, the recording material characteristics are detected by the media sensor 71 while the conveyance of the recording material S is stopped or while the recording material S is being conveyed at a speed slower than the normal conveying speed during image formation. On the other hand, the recording material S whose characteristics cannot be detected by the media sensor 71 is conveyed to the first conveying section 51. In the first conveying section 51, the recording material S is conveyed at a normal conveying speed during image formation.

[0020] (Media Sensor) The media sensor 71 detects the recording material characteristics of the recording material S conveyed to the second conveying section 52 under the control of the control section 90 (FIG. 2). The second conveying section 52 is provided with the media sensor 71, which detects the recording material characteristics when the conveyance of the recording material S is stopped or when the conveyance speed is reduced, thereby enabling an improvement in the detection accuracy of the recording material characteristics.

[0021] The media sensor 71 detects the type (for example, plain paper, high-quality paper, glossy paper, etc.) and size of the recording material S, as well as the physical properties of the recording material S. Examples of the physical properties of the recording material S that are detected include thickness, basis weight, surface condition such as smoothness, stiffness, charge amount, moisture content, and grain (angle of the fiber direction of the recording material).

[0022] The media sensor 71 also includes various sensors for detecting recording material characteristics. For example, the media sensor 71 includes an imaging sensor for detecting the type of recording material S. The imaging sensor includes a light source that irradiates the front surface of the recording material S with light, a light source that irradiates the back surface of the recording material S with light, and an imaging element that images the front surface of the recording material S. An image of the reflective state when the front surface of the recording material S is irradiated with light, and an image of the transmissive state when the back surface of the recording material S is irradiated with light are obtained. It is possible to identify the type of recording material S to which the image belongs based on the characteristics and properties of these acquired images.

[0023] The media sensor 71 also includes an optical sensor and a weight sensor for detecting the size, weight, and basis weight of the recording material S. The optical sensor has a light-receiving element that detects the edge of the recording material S on an inspection table over which the conveyed recording material S passes. The weight sensor detects the weight per unit area of ​​the recording material S from changes in the weight of the inspection table as the recording material S passes. The size and area of ​​the recording material S are detected from the output of the optical sensor, and the basis weight can be obtained from the weight per unit area of ​​the recording material S detected by the weight sensor.

[0024] [Image forming device] The image forming apparatus 200 shown in FIG. 1 includes an operation display unit 220, a scanner 230, an image forming unit 240, a conveying unit 250, and the like.

[0025] The operation display unit 220 is composed of an operation unit and a display unit. The display unit is configured by a display device such as an LCD (Liquid Crystal Display), and displays various screens in accordance with instructions of a display signal input from the control unit 90 (FIG. 2). The operation unit includes a touch panel formed to cover the display screen of the display unit, and various operation buttons such as numeric buttons and a start button, and outputs operation signals based on user operations to the control unit 90, which will be described later. The operation unit accepts operation instructions from the user.

[0026] The scanner 230 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 from the light source that is illuminated 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 generates image data.

[0027] Image forming unit 240 forms an image on recording material S based on image data. Image forming unit 240 includes photosensitive drums 241Y, 241M, 241C, and 241K corresponding to the colors yellow (Y), magenta (M), cyan (C), and black (K), charging units 242Y, 242M, 242C, and 242K, exposure units 243Y, 243M, 243C, and 243K, developing units 244Y, 244M, 244C, and 244K, and primary transfer rollers 245Y, 245M, 245C, and 245K. Image forming unit 240 also includes an intermediate transfer belt 246, a secondary transfer roller 247, and a fixing unit 248.

[0028] The charging sections 242Y, 242M, 242C, and 242K uniformly charge the photosensitive drums 241Y, 241M, 241C, and 241K. The exposure units 243Y, 243M, 243C, and 243K are composed of a laser light source, a polygon mirror, a lens, and the like, and scan and expose the surfaces of the photosensitive drums 241Y, 241M, 241C, and 241K with a laser beam based on image data of each color to form an electrostatic latent image. The developing units 244Y, 244M, 244C, and 244K develop the electrostatic latent images on the photosensitive drums 241Y, 241M, 241C, and 241K by attaching toner of each color to the electrostatic latent images.

[0029] The primary transfer rollers 245Y, 245M, 245C, and 245K sequentially transfer (primary transfer) the toner images of each color formed on the photosensitive drums 241Y, 241M, 241C, and 241K onto the intermediate transfer belt 246. That is, a color toner image is formed on the intermediate transfer belt 246, in which the toner images of four colors are superimposed. The secondary transfer roller 247 transfers the color toner images on the intermediate transfer belt 246 all at once onto one side of the recording material S supplied from the supply tray (secondary transfer). The fixing unit 248 fixes the toner image onto the recording material S by applying heat and pressure to the recording material S by passing the recording material S through a nip formed by a fixing roller and a pressure roller.

[0030] The conveying section 250 includes a plurality of conveying rollers 53 and the like, which are provided along a predetermined conveying path and are used to convey the recording material S. The conveying section 250 drives the conveying rollers 53 to convey the recording material along the predetermined conveying path within the image forming apparatus 200. Then, the recording material S after image formation is conveyed to the post-processing device 300.

[0031] [Post-processing device] The post-processing device 300 receives the recording material S on which an image has been formed in the image forming device 200. The post-processing device 300 includes, for example, a plurality of post-processing units, and predetermined post-processing is performed in the post-processing unit designated by the job. For example, the post-processing device 300 includes post-processing units that perform processes such as perforation, folding, foil stamping, binding, cutting, stapling, gluing, and binding. In the post-processing device 300, the recording material S that has been conveyed from the image forming device 200 and has undergone image formation processing is conveyed by a conveying section 350 to a post-processing unit (not shown), where predetermined post-processing is performed on the recording material S. The conveying section 350 conveys the recording material S by conveying rollers 351 and the like provided along the conveying path, and discharges the recording material S onto a discharge tray 352.

[0032] [System block diagram] FIG. 2 shows a system block diagram of each device constituting the image forming system shown in FIG.

[0033] The control unit 90 includes, for example, a CPU (Central Processing Unit) 91, a ROM (Read Only Memory), and The image forming system 10 is configured with a ROM (Read Only Memory) 92, a RAM (Random Access Memory) 93, etc. The CPU 91 reads out various processing programs stored in the ROM 92, loads them into the RAM 93, and performs centralized control of the operations of each part of the image forming system 10 in accordance with the loaded programs. The ROM 92 stores various processing programs for controlling each part of the image forming system 10, parameters and table data required for executing the programs, various files, and the like. The RAM 93 is made up of a volatile semiconductor memory, and forms a work area for temporarily storing various processing programs read from the ROM 92, input or output data, parameters, etc., during various processes executed and controlled by the CPU 91.

[0034] The storage unit 98 stores, for example, image data received from an external device. The storage unit 98 also stores various processing programs executed by the CPU 91, information related to the processing functions of the device itself that are necessary for executing the programs, image data read by the scanner 230, image data input from a client device (not shown) or the like, and characteristic values ​​of the recording material S detected by the media sensor 71. The storage unit 98 may be configured, for example, by a non-volatile memory such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a flash memory.

[0035] The communication unit 99 is composed of a NIC (Network Interface Card), a modem, etc., and connects the recording material supply device 100, the recording material conveying device 400, the image forming device 200, and the post-processing device 300 to a communication network such as a LAN (Local Area Network) or a WAN (Wide Area Network), and transmits and receives various data to and from external information devices (e.g., client devices).

[0036] The operation display unit 220 is configured with a touch panel or the like on which an operation unit (touch sensor) such as a pressure-sensitive or capacitance type with transparent electrodes arranged in a grid pattern is provided on a display unit such as an LCD (Liquid Crystal Display) or an organic EL (Electro Luminescence) display, and functions as both a display unit and an operation unit. The display unit displays various operation screens in accordance with display control signals input from the control unit 90. The operation unit accepts various input operations by the user and outputs operation signals to the control unit 90.

[0037] The scanner 230 optically scans an original placed on a contact glass and reads the original image by forming an image of the light reflected from the original on the light receiving surface of a CCD (Charge Coupled Device) sensor. The image (analog image signal) read by the scanner 230 is subjected to predetermined image processing in the image processing unit 80.

[0038] The image processing unit 80 is composed of a circuit that performs analog-to-digital (A / D) conversion processing and a circuit that performs digital image processing. The image processing unit 80 generates digital image data by performing A / D conversion processing on the analog image signal from the scanner 230. The image processing unit 80 also analyzes a print job acquired from an external information device (e.g., a client device) and rasterizes each page of the document to generate digital image data. The image processing unit 80 then performs image processing such as color conversion processing, correction processing (shading correction, etc.) according to initial settings or user settings, and compression processing on the image data as necessary, and outputs the image data after image processing to the image forming unit 240.

[0039] [Controller function configuration] Next, we will explain the functional configuration of the control unit 90. Fig. 3 shows a functional block diagram of the control unit 90. As shown in Fig. 3, the control unit 90 has a paper feed control unit 94, a conveyance control unit 95, a media detection control unit 96, and an image formation control unit 97.

[0040] The paper feed control unit 94 controls the supply of the recording material S from the recording material supply unit 70 to the conveying unit 50 in the recording material supply device 100. The paper feed control unit 94 supplies the recording material S to the conveying unit 50 in accordance with the conveying control of the recording material S by the conveying control unit 95.

[0041] The conveyance control unit 95 controls the operation of the conveyance mechanisms for the recording material S between and within the recording material supplying device 100, recording material conveying device 400, image forming apparatus 200, and post-processing device 300 that make up the image forming system 10. Specifically, the conveyance control unit 95 controls the driving of the conveyance unit 50 of the recording material supplying device 100, the first conveyance unit 51 and the second conveyance unit 52 of the recording material conveying device 400, the conveyance unit 250 of the image forming apparatus 200, and the conveyance unit 350 of the post-processing device 300. The conveyance control unit 95 controls the driving of each drive unit, such as stopping and starting the driving of each drive unit, adjusting the driving speed, etc., according to the conveyance conditions that are tailored to the characteristics of the recording material S, thereby linking the drive units between the devices to control the conveyance of the recording material S.

[0042] The conveyance control unit 95 sets the conveyance conditions for the recording material S according to the recording material characteristics acquired by the media detection control unit 96. For example, the conveyance control unit 95 acquires the conveyance conditions according to the recording material characteristics from data stored in the memory unit 98 or the like. Then, the conveyance control unit 95 sets the conveyance conditions for each of the components of the conveyance unit 50, the first conveyance unit 51, the second conveyance unit 52, the conveyance unit 250, and the conveyance unit 350 based on the data acquired from the memory unit 98 or the like.

[0043] Furthermore, the conveyance control unit 95 selects the conveyance path of the recording material S to either the first conveyance unit 51 or the second conveyance unit 52 in the recording material conveying device 400, and switches the conveyance path of the recording material S at the branching unit 58. Then, the conveyance control unit 95 controls the driving of the first conveyance unit 51 or the second conveyance unit 52 selected as the conveyance path to convey the recording material S. When conveying multiple recording materials S in a print job, the conveyance control unit 95 conveys at least one sheet of recording material S to the second conveyance unit 52.

[0044] The conveyance control unit 95 drives the first conveying unit 51 to convey the recording material S at a normal speed during image formation. Then, the conveyance control unit 95 conveys the recording material S by the first conveying unit 51, thereby conveying the recording material S from the recording material conveying device 400 to the image forming device 200.

[0045] Furthermore, the conveyance control unit 95 reduces the conveyance speed in the second conveying unit 52 after the entire recording material S has been conveyed to the second conveying unit 52, that is, after the trailing edge of the recording material S has passed the branching unit 58. Then, after the recording material S reaches the media sensor 71 that detects the characteristics of the recording material, the conveyance control unit 95 reduces the conveyance speed to a speed that allows for highly accurate detection by the media sensor 71. Furthermore, after conveying the recording material S to a position where the media sensor 71 can detect the characteristics of the recording material, the conveyance control unit 95 may stop conveying the recording material S until detection of the characteristics of the recording material by the media sensor 71 is completed.

[0046] Furthermore, the conveyance control unit 95 conveys the recording material S after the recording material characteristics have been detected in the second conveying unit 52, and conveys the recording material S from the second conveying unit 52 to the first conveying unit 51 at the junction 59. The conveyance control unit 95 conveys the recording material S conveyed to the first conveying unit 51 from the recording material conveying device 400 to the image forming apparatus 200.

[0047] The media detection control unit 96 controls the detection of the recording material characteristics of the recording material S by the media sensor 71. For example, when the recording material S is conveyed to a conveyance path on which the media sensor 71 is provided, the media detection control unit 96 instructs the media sensor 71 to detect the recording material characteristics. Based on this instruction, the media sensor 71 starts detecting the recording material characteristics of the recording material S.

[0048] Furthermore, the media detection control unit 96 receives various data detected by each sensor of the media sensor 71, and calculates the recording material characteristics of the recording material S based on this data. For example, in a configuration in which the image forming system 10 is equipped with multiple media sensors 71, the media detection control unit 96 combines the data acquired from the multiple media sensors 71 and calculates the recording material characteristics of the recording material S.

[0049] The image formation control unit 97 controls the image formation operation in the image forming unit 240 of the image forming apparatus 200. The image formation control unit 97 also sets image formation conditions according to the recording material characteristics acquired by the media detection control unit 96. For example, the image formation control unit 97 acquires the image formation conditions according to the recording material characteristics from data stored in the storage unit 98 or the like. Then, the image formation control unit 97 sets operating conditions for each component of the image forming unit 240 based on the data acquired from the storage unit 98 or the like. Then, in accordance with the set operating conditions, the image formation control unit 97 controls the operation of each component of the image forming unit 240 to form an image on the recording material S based on the image data.

[0050] [Detection of recording material characteristics] Next, we will explain a method for detecting recording material characteristics in the image forming system 10. A flowchart of the method for detecting recording material characteristics is shown in Fig. 4. Note that the flowchart shown in Fig. 4 mainly explains the conveyance of the recording material in the recording material conveying device 500 and the detection of recording material characteristics.

[0051] First, in the image forming system 10, the control unit 90 determines whether or not a measurement mode for measuring the recording material characteristics of the recording material S has been set in response to an instruction from a user or the like (step S10). If the measurement mode is not set (No in step S10), the conveying control unit 95 passes the recording material S (first sheet or first recording material S) conveyed from the recording material supply device 100 to the first conveying section 51 of the recording material conveying device 500 through the branching section 58 as is, and continues conveying in the first conveying section 51 (step S11).

[0052] If the measurement mode is set (Yes in step S10), the conveying control unit 95 switches the conveying path of the first recording material S conveyed from the recording material supply device 100 to the first conveying section 51 of the recording material conveying device 500 at the branching section 58 and conveys the first recording material S to the second conveying section 52 (step S12).

[0053] Next, the media detection control unit 96 activates the media sensor 71 and detects the recording material characteristics of the first recording material S transported to the second transport unit 52 (step S13). At this time, the transport control unit 95 stops the transport of the first recording material S in the second transport unit 52, or transports the first recording material S at a speed slower than the normal transport speed during image formation. The media detection control unit 96 detects the recording material characteristics of the first recording material S that is stopped or transported at a low speed using the media sensor 71.

[0054] Next, the conveyance control unit 95 determines whether the trailing edge of the first recording material S has passed through the branching unit 58 (step S14). Whether the first recording material S has passed through the branching unit 58 is determined, for example, from detection of the trailing edge of the first recording material S by the media sensor 71 disposed on the most upstream side of the second conveyance unit 52, or from the conveyance speed and conveyance time of the first recording material S after being conveyed into the recording material conveyance device 500. If the trailing edge of the first recording material S has not passed the branching portion 58 (No in step S14), the process of step S13 is continued until the trailing edge of the first recording material S passes the branching portion 58.

[0055] When the trailing edge of the first recording material S has passed the branching section 58 (Yes in step S14), the conveyance control section 95 conveys the next recording material S (the second sheet or second recording material S) conveyed from the recording material supply device 100 to the recording material conveying device 500 to the first conveying section 51 (step S15). Here, the conveyance control section 95 does not cause the recording material S to be conveyed to the second conveying section 52 at the branching section 58, but continues conveying the second recording material S at the first conveying section 51. It is preferable that the second recording material S be conveyed by the first conveying section 51 to a position where the second recording material S is conveyed from the recording material conveying device 500 to the image forming apparatus 200 by the conveying section 250 of the image forming apparatus 200. For example, the second recording material S is conveyed to a registration roller immediately before the secondary transfer roller 247 of the image forming unit 240 .

[0056] Next, the conveyance control unit 95 determines whether or not detection of all recording material characteristics has been completed for the first recording material S (step S16). If detection of all recording material characteristics has not been completed (No in step S16), the conveyance control unit 95 continues the detection process of the recording material characteristics for the first recording material S.

[0057] When detection of all recording material characteristics for the first recording material S has been completed (Yes in step S16), the conveyance control unit 95 conveys the first recording material S, whose recording material characteristics have been detected, from the second conveyance unit 52 to the first conveyance unit 51 (step S17). The first recording material S is conveyed downstream of the second conveyance unit 52, thereby conveying the first recording material S from the junction 59 to the first conveyance unit 51. The first recording material S, whose recording material characteristics have been detected, merges with the first conveyance unit 51 behind (upstream in the conveyance direction) the second recording material S conveyed to the first conveyance unit 51 in step S15. The junction position of the first recording material S does not have to be limited to immediately after the second recording material S, and can be changed depending on the number of recording materials S that can be retained up to the position of the registration rollers and the conveyance interval of the recording materials S. If there is no margin in the conveyance interval of the recording material S, it is also possible to merge the first recording material S as the recording material S on which an image is formed last in the job.

[0058] After the first recording material S is conveyed from the second conveying section 52 to the first conveying section 51, the process according to this flowchart ends. After this process, the recording material S (first recording material S and second recording material S) conveyed by the first conveying section 51 in the image forming system 10 is conveyed from the recording material conveying device 500 to the registration roller of the image forming apparatus 200. In the image forming apparatus 200 to which the recording material S is conveyed, the image formation control section 97 sets image formation conditions according to the detected recording material characteristics, and image formation is performed in the image forming section 240.

[0059] In the process according to the flowchart described above, the recording material S (first sheet or first recording material S) first conveyed to the recording material conveying device 400 is conveyed to the second conveying section 52, and the recording material characteristics are detected while the recording material is stopped or conveyed at a low speed. Then, during the period when the recording material characteristics of the first recording material S are being detected, the next recording material S (second sheet or second recording material S) and subsequent recording materials S are conveyed from the recording material conveying device 400 to the image forming device 200 by the first conveying section 51. In this way, by providing the second conveying section 52 and arranging the media sensor 71 in the second conveying section 52, while the recording material characteristics of the first recording material S conveyed to the second conveying section 52 are being detected, the next second recording material S can be conveyed to the image forming device 200 by the first conveying section 51. Therefore, after the detection of the recording material characteristics of the first recording material S is completed in the second conveying section 52, and before the first recording material S is conveyed from the second conveying section 52 to the image forming device 200, image formation can be performed on the second recording material S conveyed in advance to the image forming device 200 under conditions that reflect the recording material characteristics. Therefore, it is possible to reduce the time loss that occurs when detecting recording material characteristics, thereby improving the accuracy of image formation through the detection of recording material characteristics and reducing the decrease in productivity of image formation.

[0060] The present invention is not limited to the configurations described in the above-described embodiments, and various modifications and changes are possible without departing from the scope of the present invention. [Explanation of symbols]

[0061] 10 Image forming system, 50, 250, 350 Conveying section, 51 First conveying section, 52 Second conveying section, 53, 351 Conveying roller, 54 Inlet, 55 Outlet, 58 Branching section, 59 Merging section, 70 Recording material supplying section, 71 Media sensor, 80 Image processing section, 90 Control section, 91 CPU, 92 ROM, 93 RAM, 94 Paper feed control section, 95 Conveying control section, 96 Media detection control section, 97 Image forming control section, 98 Memory section, 99 Communication section, 100 Recording material supplying device, 200 Image forming apparatus, 220 Operation display section, 230 Scanner, 240 Image forming section, 241 Photosensitive drum, 242 Charging section, 243 Exposure section, 244 Development section, 245 Primary transfer roller, 246 Intermediate transfer belt, 247 Secondary transfer roller, 248 Fixing unit, 300 post-processing device, 352 discharge tray, 400, 500 recording material conveying device

Claims

1. A recording material conveying device disposed upstream of an image forming unit in a recording material conveying direction, a first conveying section that constitutes a conveying path for the recording material; a second conveying section that branches off from the first conveying section at a branching section and forms a conveying path for the recording material that is different from the conveying path of the first conveying section; a detection unit disposed in the second conveying unit and configured to detect a value corresponding to a recording material characteristic of the recording material, a first recording material is conveyed to the second conveying section, and after the trailing edge of the first recording material passes through the branching section, a second recording material that is conveyed next to the first recording material is conveyed to the first conveying section without being conveyed to the second conveying section at the branching section; Recording material transport device.

2. The second transport section rejoins the first transport section after branching. The recording material transport device according to claim 1 .

3. The recording material conveying device according to claim 1 or 2, wherein in a job for conveying a plurality of recording materials, the detection unit in the second conveying section detects values ​​corresponding to the recording material characteristics for some of the plurality of recording materials.

4. a control unit that controls conveyance of the recording material in the first conveying unit and the second conveying unit, The control unit causes the first conveying unit to convey the second recording material while the detection unit detects a value corresponding to the recording material characteristic of the first recording material in the second conveying unit. The recording material transport device according to claim 3 .

5. The control unit stops conveying the recording material in the second conveying unit or reduces the conveying speed while the detection unit detects the value corresponding to the recording material characteristic.

5. The recording material conveying device according to claim 1.

6. The second conveying section conveys the recording material over a longer distance than the first conveying section.

6. The recording material conveying device according to claim 1.

7. The conveying distance of the recording material of the second conveying section is equal to or greater than the long side of the maximum size of the standard form that can be conveyed.

7. The recording material conveying device according to claim 1.

8. An image forming system having an image forming unit that forms an image on a recording material, a first conveying section that is disposed upstream of the image forming section in a conveying direction of the recording material and that constitutes a conveying path of the recording material; a second conveying section that branches off from the first conveying section at a branching section and forms a conveying path for the recording material that is different from the conveying path of the first conveying section; a detection unit disposed in the second conveying unit and configured to detect a value corresponding to a recording material characteristic of the recording material, a first recording material is conveyed to the second conveying section, and after the trailing edge of the first recording material passes through the branching section, a second recording material that is conveyed next to the first recording material is conveyed to the first conveying section without being conveyed to the second conveying section at the branching section; Imaging system.

9. a control unit that controls conveyance of the recording material in the first conveying unit and the second conveying unit, The control unit causes the first conveying unit to convey the second recording material while the detection unit detects a value corresponding to the recording material characteristic of the first recording material in the second conveying unit. The image forming system according to claim 8 .

10. The control unit stops conveying the recording material in the second conveying unit or reduces the conveying speed while the detection unit detects the value corresponding to the recording material characteristic. The image forming system according to claim 9 .

11. The image forming unit is disposed downstream of the second conveying unit in the conveying direction of the recording material.

11. The image forming system according to claim 8.

12. the second transport section rejoins the first transport section after branching, In the conveyance direction of the recording material, the image forming unit is disposed downstream of a joining point between the first conveyance unit and the second conveyance unit. The image forming system according to claim 11 .

13. an image forming apparatus including the image forming unit; a recording material conveying device including the first conveying section and the second conveying section, wherein the recording material conveying device is disposed upstream of the image forming device in a conveying direction of the recording material. The image forming system according to claim 11 .

Images