Image forming system

Abstract

To provide an image forming system that has a configuration to detect the characteristics of a recording material with a media sensor, and can achieve both the accuracy in detecting the characteristics of the recording material and productivity.SOLUTION: An image forming system comprises: a conveying unit that conveys a recording material; a recording material characteristic detection unit that is arranged on a conveyance path of the recording material and detects the recording characteristics of the recording material; a fixing unit that fixes a toner image formed on the recording material; and a control unit that, while the fixing unit executes warm-up for an image forming job, causes the recording material characteristic detection unit to detect the recording material characteristics, and sets an image forming condition in the image forming job based on the detected recording material characteristics.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an image forming system.

Background Art

[0002] An image forming apparatus forms an electrostatic latent image by irradiating a photosensitive member with a laser beam, and forms a toner image by developing the electrostatic latent image with toner. The image forming apparatus transfers the formed toner image onto a recording material and performs image formation on the recording material by thermally fixing it. The image forming apparatus sets optimum image forming conditions such as an optimum fixing temperature and a conveyance speed of the recording material according to the recording material characteristics such as the thickness of the recording material, the state of the surface, and the type of the recording material.

[0003] The recording material characteristics were set by the user's operation from an operation unit provided in the image forming apparatus or a print setting screen of a printer driver. Recently, an image forming apparatus has been proposed that detects recording material characteristics using a built-in sensor (hereinafter referred to as a "media sensor") and automatically sets image forming conditions according to the detection results (see, for example, Patent Document 1).

[0004] In the image forming apparatus described in Patent Document 1 above, a media sensor is provided in a conveyance path from a paper feeding unit of the recording material to a position where the toner image is transferred. The recording material is conveyed to the position of the media sensor, and the recording material characteristics are detected. By detecting the recording material characteristics using the media sensor and setting the conditions of each part according to the detected recording material characteristics to perform image formation, it becomes unnecessary for the user to set the recording material characteristics, and the convenience is improved. In order to accurately detect the characteristics of the recording material by the media sensor, it takes a predetermined time, so the conveyance of the recording material is stopped or the conveyance speed of the recording material is reduced, and the characteristics of the recording material are detected in a state where the behavior of the recording material is stable.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a normal image forming apparatus, since a fixing target temperature according to the characteristics of a recording material is required, after detecting the characteristics of the recording material by a media sensor, the fixing target temperature is determined according to the detection result. For this reason, a waiting time occurs until the conveyance of the recording material is stopped and the detection of the recording material characteristics is completed, the start of printing including fixing is delayed, and productivity decreases. Also, as in the image forming apparatus described in Patent Document 1 above, it is conceivable to start fixing warm-up before detecting the characteristics of the recording material by a media sensor using the recording material characteristics detected in the previous job and the corresponding fixing target temperature to reduce the waiting time. However, in this method, since the recording material used in the document job does not always have the same characteristics as the previous job, it cannot be applied when the recording material is replaced or replenished, and a decrease in productivity cannot be suppressed.

[0007] In order to solve the above-described problems, in the present invention, there is provided an image forming system and an image forming apparatus capable of achieving both the accuracy of detecting the characteristics of a recording material and productivity in a configuration in which the characteristics of the recording material are detected by a media sensor.

Means for Solving the Problems

[0008] The image forming system of the present invention includes a conveyance unit that conveys a recording material, a recording material characteristic detection unit that is disposed in a conveyance path of the recording material and detects the recording material characteristics of the recording material, a fixing unit that fixes a toner image formed on the recording material, and a control unit that causes the recording material characteristic detection unit to detect the recording material characteristics while the fixing unit is performing warm-up for an image forming job, and sets image forming conditions in the image forming job based on the detected recording material characteristics.

Effects of the Invention

[0009] According to the present invention, in a configuration for detecting the characteristics of a recording material by a media sensor, an image forming system and an image forming apparatus capable of achieving both the accuracy of detecting the characteristics of the recording material and productivity can be provided.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 10

Embodiments for Carrying Out the Invention

[0011] 〈Embodiment of 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 of an image forming system. The image forming system 1 shown in FIG. 1 uses a roll-shaped recording material S, which is continuous paper, as a recording medium, and forms an image on this recording material S. The image forming system 1 includes, from the upstream side in the conveyance direction of the recording material S, a paper feeding device 10, a media detection device 30, an image forming device 40, and a recovery device 60. In the image forming system 1 shown in FIG. 1, the media detection device 30 is disposed inside the housing of the paper feeding device 10. Further, the image forming system 1 includes a supply adjustment unit 20 between the paper feeding device 10 and the image forming device 40, and a recovery adjustment unit 50 between the image forming device 40 and the recovery device 60.

[0012] The paper feeding device 10 includes a paper feeding unit including a support shaft 11 that rotatably holds the recording material S wound in a roll shape, and a conveyance unit 14 that conveys the recording material S wound around the support shaft 11 to the supply adjustment unit 20 at a constant speed by a plurality of rollers. Note that the shape of the recording material S is not limited to roll-shaped continuous paper. The recording material S may have a shape that is longer than the length from the media detection device 30 to the fixing unit 47 of the image forming device 40. For example, a foldable shape or a shape of long paper can be applied as the recording material S. Further, the paper feeding device 10 is an example of a recording material supply device that supplies the recording material to the image forming device 40.

[0013] The supply adjustment unit 20 conveys the recording material S conveyed from the paper feeding device 10 to the image forming unit 46 of the image forming device 40. The supply adjustment unit 20 slackens and holds the recording material S in order to absorb the speed difference between the paper feeding and conveyance speed of the recording material S from the paper feeding device 10 and the conveyance speed of the recording material S in the image forming unit 46, and adjusts the paper feeding of the recording material S to the image forming unit 46.

[0014] The media detection device 30 is arranged in the paper feeding device 10 on the conveyance path of the recording material S. The media detection device 30 has a media detection unit 33 (see FIG. 2) that detects the recording material characteristics of the recording material S conveyed from the paper feeding device 10. The media detection unit 33 detects the recording material characteristics of the recording material S when setting the conditions of the recording material S during the execution of an image forming job. Then, the media detection device 30 outputs the detected detection information to the image forming device 40. Note that the media detection device 30 only needs to be arranged not only inside the paper feeding device 10 but also on the upstream side of the image forming unit 46 of the image forming device 40. For example, it may be installed on the conveyance path of the recording material S in any of the housing of the supply adjustment unit 20, between the supply adjustment unit 20 and the image forming device 40, and inside the housing of the image forming device 40. Further, the media detection device 30 is an example of a recording material characteristic detection device that detects the characteristics of the recording material S. As the media detection device 30, a conventionally known media sensor capable of detecting the recording material characteristics of the recording material S can be applied. The media detection device 30 detects, as the recording material characteristics, for example, the thickness of the recording material S, the state of the surface (smoothness), the type of the recording material (paper type), stiffness, charge amount, moisture content, and grain direction (angle of the fiber direction of the recording material), etc.

[0015] The image forming device 40 includes a control unit 41, an operation display unit 42, a scanner unit 43, a conveyance unit 44, an image processing unit 45, an image forming unit 46, a fixing unit 47, and the like. Note that the image forming device 40 may include the above-described paper feeding device 10 as a recording material supply unit inside the device of the image forming device 40. Further, the image forming device 40 may include the above-described media detection device 30 as a recording material characteristic detection unit inside the device of the image forming device 40. In a configuration where the image forming device 40 includes a recording material characteristic detection unit inside the device, the recording material characteristic detection unit is preferably arranged on the recording material conveyance path between the paper feeding device 10 (recording material supply unit) and the image forming unit 46.

[0016] The scanner unit 43 exposes and scans the manuscript surface placed on the manuscript table with a light source, receives the reflected light from the manuscript surface, photoelectrically converts the received reflected light by a CCD (Charge Coupled Device) to generate image data, and outputs the image data to the image processing unit 45.

[0017] The control unit 41 comprehensively controls each component of the image forming system 1 and the image forming apparatus 40. The image processing unit 45 performs image processing on the image data input from the scanner unit 43 and the control unit 41 and outputs the processed data to the image forming unit 46. The details of the configurations of the control unit 41 and the image processing unit 45 will be described later.

[0018] The operation display unit 42 is composed of an LCD (Liquid Crystal Display) or the like, and performs display of various operation buttons, the status display of the apparatus, the operation status of each function, etc. on the display screen according to the instruction of the display signal input from the control unit 41. The display screen of the LCD is covered with a pressure-sensitive (resistive film pressure type) touch panel configured by arranging transparent electrodes in a grid pattern. The XY coordinates of the force point pressed by a finger or a touch pen are detected as voltage values, and the detected position signal is output to the control unit 41 as an operation signal. In addition, the operation display unit 42 is provided with various operation buttons such as numeric buttons and a start button, and outputs an operation signal generated by a button operation to the control unit 41.

[0019] The image forming unit 46 forms an image on the recording material S conveyed from the supply adjustment unit 20 by an electrophotographic method based on the image data of each page input from the image processing unit 45. The image forming unit 46 is provided with a recording material conveyance path in which conveyance rollers such as a conveyance belt and a registration roller, and a motor (not shown) for driving them are arranged. According to the control from the control unit 41, an image is formed on the recording material S while the recording material S is being conveyed.

[0020] The image forming unit 46 includes four sets of exposure units 461, photoreceptors 462, developing units 463, primary transfer rollers 464 corresponding to the respective color components of Y, M, C, and K, an intermediate transfer belt 465, and a secondary transfer roller 466. The four sets of exposure units 461, photoreceptors 462, developing units 463, and primary transfer rollers 464 corresponding to the respective color components are arranged in the order of Y, M, C, and K from upstream.

[0021] The exposure unit 461 is composed of a laser light source, a polygon motor, a polygon mirror, a plurality of lenses, etc. Based on the recording material conveyance speed, the exposure unit 461 irradiates the charged photoreceptor 462 with laser light by the laser light source and the polygon mirror for exposure, and forms an electrostatic latent image on the photoreceptor 462. The developing unit 463 supplies toner of a predetermined color (Y, M, C, or K) onto the exposed photoreceptor 462 to develop the electrostatic latent image formed on the photoreceptor 462. The primary transfer roller 464 is provided opposite to the photoreceptor 462. A primary transfer bias of the opposite polarity to the toner is applied to the primary transfer roller 464, and by pressing a predetermined position on the intermediate transfer belt 465 against the photoreceptor 462, the toner image formed on the photoreceptor 462 is transferred (primary transfer) to the intermediate transfer belt 465. By sequentially pressing the primary transfer rollers 464 for Y, M, C, and K against a predetermined position on the intermediate transfer belt 465 against the photoreceptor 462, a color toner image with layers of each color superimposed is written on the intermediate transfer belt 465.

[0022] The intermediate transfer belt 465 is a semiconductive endless belt suspended by a plurality of rollers and rotatably supported, and is rotationally driven as the rollers rotate to convey the written toner image to the secondary transfer roller 466. A bias of the opposite polarity to the toner is applied to the secondary transfer roller 466, and by sandwiching and conveying the conveyed recording material S, the color toner image written on the intermediate transfer belt 465 is transferred (secondary transfer) to the recording material S.

[0023] The fixing unit 47 heats and presses the toner image transferred onto the recording material S to fix the toner image onto the recording material S. The fixing unit 47 includes a fixing roller 471 incorporating a halogen heater or the like, and a pressure roller 472 as a pressure member that is disposed at a position facing the fixing roller 471 with the conveyance path of the recording material therebetween and presses the fixing roller 471. Further, the fixing unit 47 includes a temperature sensor for detecting the temperature of the fixing roller 471. The fixing unit 47 heats and presses the toner image on the recording material S to fix it while sandwiching and conveying the recording material S onto which the toner image has been transferred in the nip portion formed between the fixing roller 471 and the pressure roller 472. Also, the fixing unit 47 has a position changing mechanism (not shown) for adjusting the position of the fixing roller 471 in order to adjust the nip pressure of the nip portion between the fixing roller 471 and the pressure roller 472, and to release the pressure contact, etc.

[0024] The recovery adjustment unit 50 is installed on the downstream side of the image forming apparatus 40 and the upstream side of the recovery apparatus 60 in the conveyance direction of the recording material S. The recovery adjustment unit 50 is a device that conveys the recording material S conveyed from the image forming apparatus 40 to the recovery apparatus 60, and holds the recording material S slack to absorb the speed difference between the conveyance speed of the recording material S in the image forming apparatus 40 and the conveyance speed of the recording material S in the recovery apparatus 60, and adjusts the paper discharge of the recording material S from the image forming apparatus 40. The recovery apparatus 60 includes a paper discharge unit that winds up the recording material S conveyed from the recovery adjustment unit 50 around a support shaft 61 at a constant speed via a plurality of rollers.

[0025] [Configuration of the Image Forming System] Next, FIG. 2 shows a block diagram of a configuration example of the image forming system 1. FIG. 2 shows the configurations of the paper feeding device 10, the media detection device 30, and the image forming device 40, which are the main configurations of this embodiment, as the image forming system 1, and the descriptions of the configurations of the supply adjustment unit 20, the recovery adjustment unit 50, and the recovery apparatus 60 are omitted.

[0026] As shown in FIG. 2, the image forming apparatus 40 includes a control unit 41, an operation display unit 42, a conveyance unit 44, an image processing unit 45, an image forming unit 46, a fixing unit 47, a non-volatile memory 48, and a communication unit 49. The paper feeding apparatus 10 includes a control unit 12, a communication unit 13, a conveyance unit 14, and a non-volatile memory 15. The media detection apparatus 30 includes a control unit 31, a communication unit 32, a media detection unit 33, and a non-volatile memory 34.

[0027] The control unit 12 of the paper feeding apparatus 10 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), etc., not shown in the figure. The CPU of the control unit 12 reads out various processing programs stored in the ROM and expands them in the RAM, and comprehensively controls the operations of each part of the paper feeding apparatus 10, such as the communication unit 13, the conveyance unit 14, and the non-volatile memory 15, which are connected via the system bus (not shown) of the paper feeding apparatus 10, according to the expanded programs. The non-volatile memory 15 stores programs and the like executed by the control unit 12, and is also used as a work area for the control unit 12. The communication unit 13 transmits and receives data to and from the communication unit 49 of the image forming apparatus 40 constituting the image forming system 1. Further, the communication unit 13 transmits and receives data to and from the communication unit 32 of the media detection apparatus 30 and the communication units of various apparatuses such as a supply adjustment unit 20, a recovery adjustment unit 50, and a recovery apparatus 60, not shown in the figure, via the communication unit 49 of the image forming apparatus 40. The conveyance unit 14 feeds out and conveys the recording material S stored in the paper feeding apparatus 10, and feeds it to the image forming apparatus 40. Note that the recovery apparatus 60 can also have the same configuration as the above-described paper feeding apparatus 10.

[0028] The control unit 41 of the image forming apparatus 40 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), etc., not shown in the figure. The CPU of the control unit 41 reads out various processing programs stored in the ROM and expands them in the RAM, and controls the operations of each part of the image forming apparatus 40, such as the operation display unit 42, the conveyance unit 44, the image processing unit 45, the image forming unit 46, the fixing unit 47, the non-volatile memory 48, and the communication unit 49, which are connected via the system bus of the image forming apparatus 40, in an overall manner according to the expanded programs. Further, the control unit 41 controls the paper feeding device 10 and the media detection device 30 via the communication unit 49.

[0029] The non-volatile memory 48 stores programs and the like executed by the control unit 41, and is also used as a work area for the control unit 41. Further, the non-volatile memory 48 stores image forming conditions set in the image forming job, recording material information including the size and type of the recording material S, etc. Furthermore, the non-volatile memory 48 stores information on the recording material characteristics detected by the media detection device 30. Examples of the image forming conditions to be stored include the execution conditions in the image forming unit 46 and the execution conditions in the fixing unit 47 (fixing target temperature, pressure, etc.).

[0030] The communication unit 49 of the image forming apparatus 40 transmits and receives data with the communication unit 13 of the paper feeding device 10 and the communication unit 32 of the media detection device 30. Further, the communication unit 49 transmits and receives data with the communication units of various devices such as a supply adjustment unit 20, a recovery adjustment unit 50, and a recovery device 60, not shown in the figure.

[0031] The image processing unit 45 acquires image data from the input job information and performs image processing. Under the control of the control unit 41, the image processing unit 45 performs image processing such as shading correction, image density adjustment, and image compression on the acquired image data as necessary. Then, the image data processed by the image processing unit 45 is transmitted to the image forming unit 46. Based on the control of the control unit 41, the conveying unit 44 conveys the recording material S fed from the paper feeding device 10 to the image forming unit 46, the fixing unit 47, and the like. The image forming unit 46 receives the image data image - processed by the image processing unit 45, and forms an image on the recording material S conveyed to the image forming unit 46 by the conveying unit 44 based on this image data.

[0032] The operation display unit 42 includes a display unit composed of a display such as a liquid crystal display device, and an operation unit composed of a touch panel provided over the display, a plurality of keys, and the like. This operation display unit 42 is an example of the display unit and the operation unit, and displays an instruction menu for the user, information regarding the acquired image data, and the like. Further, the operation display unit 42 receives inputs of various instructions, data such as characters and numbers by the user's operation, and outputs an input signal to the control unit 41.

[0033] The control unit 31 of the media detection device 30 is composed of, for example, a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), etc. not shown in the figure. The CPU of the control unit 31 reads out various processing programs stored in the ROM and expands them in the RAM, and comprehensively controls the operations of each part such as the communication unit 32 and the media detection unit 33 connected via the system bus of the media detection device 30 according to the expanded program.

[0034] The media detection unit 33 is composed of an optical sensor, a mechanical sensor, etc., and detects the recording material characteristics of the recording material S passing through the conveying path of the paper feeding device 10 and the conveying path of the image forming device 40 based on the control of the control unit 31. Then, the information on the recording material characteristics detected by the media detection unit 33 is stored in the non - volatile memory 34. The communication unit 32 of the media detection device 30 transmits and receives data with the communication unit 49 of the image forming apparatus 40 that constitutes the image forming system 1. For example, the communication unit 32 transmits information on the recording material characteristics stored in the non-volatile memory 34 to the communication unit 49 of the image forming apparatus 40. Further, the communication unit 32 transmits and receives data with the communication unit 13 of the paper feeding device 10, the supply adjustment unit 20 (not shown), the recovery adjustment unit 50, and the communication units of the recovery device 60, etc. via the communication unit 49 of the image forming apparatus 40.

[0035] [Configuration of Control Unit] Next, the functional configurations of the control unit 12 of the paper feeding device 10, the control unit 31 of the media detection device 30, and the control unit 41 of the image forming apparatus 40 in the above-described image forming system 1 will be described. FIG. 3 shows a functional block diagram of the control unit 12 of the paper feeding device 10, the control unit 31 of the media detection device 30, and the control unit 41 of the image forming apparatus 40.

[0036] The control unit 12 of the paper feeding device 10 includes a communication control unit 121 and a conveyance control unit 122. Note that the control unit of the recovery device 60 can also be configured in the same manner as the control unit 12 of the paper feeding device 10. The control unit 31 of the media detection device 30 includes a communication control unit 311 and a media detection control unit 312. The control unit 41 of the image forming apparatus 40 includes a communication control unit 411, a fixing management unit 412, a media detection management unit 413, a conveyance control unit 414, a determination unit 415, a condition setting unit 416, and a condition history management unit 417.

[0037] The communication control unit 121 of the control unit 12 of the paper feeding device 10 controls the transmission and reception of data via the communication unit 13 (Fig. 2) of the paper feeding device 10. The communication control unit 311 of the control unit 31 of the media detection device 30 controls the transmission and reception of data via the communication unit 32 (Fig. 2) of the media detection device 30. The communication control unit 411 of the control unit 41 of the image forming device 40 controls the transmission and reception of data via the communication unit 49 (Fig. 2) of the image forming device 40. Then, the control unit 12 of the paper feeding device 10, the control unit 31 of the media detection device 30, and the control unit 41 of the image forming device 40 control mutual communication via the communication units 13, 32, and 49 of the respective devices by the communication control units 121, 311, and 411, respectively.

[0038] The conveyance control unit 122 of the control unit 12 of the paper feeding device 10 controls the driving of the conveyance unit 14 of the paper feeding device 10, thereby controlling the adjustment of the conveyance speed of the recording material S and the start, stop, etc. of the conveyance of the recording material S. The media detection control unit 312 of the control unit 31 of the media detection device 30 controls the detection of the recording material characteristics of the recording material S by the media detection device 30.

[0039] The fixing management unit 412 of the control unit 41 of the image forming device 40 manages the fixing unit 47 (Fig. 1), for example, gives an execution instruction for warm-up to the fixing unit 47, performs temperature control of the fixing unit 47, etc. For example, the fixing management unit 412 controls the temperature rise rate of the fixing unit 47 during warm-up by controlling the lighting rate of the heater that heats the fixing unit 47.

[0040] The media detection management unit 413 instructs the media detection device 30 to perform detection of recording material characteristics during the execution of warm-up. Then, based on this instruction, the control unit 31 of the media detection device 30 detects the recording material characteristics of the recording material S by the media detection control unit 312.

[0041] Based on the temperature t of the fixing unit 47 detected by the temperature sensor of the fixing unit 47, the determination unit 415 determines the warm-up state of the fixing unit 47 by comparing the temperature t of the fixing unit 47 during warm-up execution with a predetermined temperature threshold, for example, the first temperature threshold tA and the second temperature threshold tB (where tA < tB). Then, it determines the comparison results between the temperature t of the fixing unit 47 and the temperature threshold T, such as t < tA, tA ≤ t < tB, and t ≥ tB, etc. Also, during warm-up execution, the determination unit 415 compares the time it takes for the temperature t of the fixing unit to rise to the first temperature threshold tA and the second temperature threshold tB with the detection completion time of the recording material characteristics, and determines whether the temperature rise time of the fixing unit 47 is less than or equal to the temperature detection completion time.

[0042] The conveyance control unit 414 controls the driving of the conveyance unit 44 of the image forming apparatus 40 to adjust the conveyance speed of the recording material S and control the start, stop, etc. of the conveyance of the recording material S. For example, based on the determination result of the above-described determination unit 415, it controls the adjustment of the conveyance speed of the recording material S and the start, stop, etc. of the conveyance of the recording material S. Note that this conveyance control is performed in conjunction with the conveyance control in the paper feeding device 10 and the recovery device 60.

[0043] Based on the recording material characteristics detected by the media detection device 30 during warm-up execution, the condition setting unit 416 sets the execution conditions for image formation in the image forming apparatus 40, such as the image formation conditions in the image forming unit 46 and the execution conditions for the fixing process in the fixing unit 47.

[0044] The condition history management unit 417 manages the history of the recording material characteristics detected by the media detection device 30 during warm-up execution and the execution conditions for image formation set by the condition setting unit 416 in accordance with these characteristics. For example, the condition history management unit 417 stores a data table including the history of the recording material characteristics and the execution conditions in a non-volatile memory 48 (Figure 2), etc. For example, when the condition setting unit 416 sets the execution conditions for image formation based on the conditions of the recording material characteristics acquired from the media detection device 30, the condition history management unit 417 reads out the history of the recording material characteristics and the execution conditions from the non-volatile memory 48. Then, the condition setting unit 416 selects the execution conditions corresponding to the acquired recording material characteristics from the history data read out by the condition history management unit 417, thereby setting the execution conditions for image formation in the image forming apparatus 40. Further, when the media detection device 30 cannot acquire the recording material characteristics, the condition setting unit 416 can select arbitrary execution conditions from the history data read out by the condition history management unit 417 and set the execution conditions for image formation in the image forming apparatus 40. For example, the execution conditions implemented immediately before can be selected from the history data and set for image formation in the image forming apparatus 40.

[0045] In the above description, an example in which the control units 12, 31, and 41 in the paper feeding device 10, the media detection device 30, and the image forming device 40 cooperate to control has been shown. However, the present invention is not limited to this, and these functional configurations can also execute all functions for controlling the entire image forming system 1 in any of the control units 12, 31, and 41. For example, the control unit 41 of the image forming device 40 may control the entire image forming system 1. Similarly, all functions of the control units for controlling the entire image forming system 1 can also be executed in the control unit 12 of the paper feeding device 10 or the control unit 31 of the media detection device 30.

[0046] [Image forming process and detection of recording material characteristics] In the image forming system 1 using the roll-shaped recording material S as shown in FIG. 1 above, the recording material S is continuous from the paper feeding device 10 to the image forming unit 46 and the recovery device 60. For this reason, in such a configuration, during the image forming process, the image forming operation is affected by a decrease in the conveyance speed of the recording material or a stop in the conveyance of the recording material S. Therefore, it is difficult to accurately detect the recording material characteristics of the recording material S by the media detection device 30 during the image forming process. Further, when the conveyance of the recording material S stops, the fixing unit 47 also stops. In such a state where the fixing unit 47 has stopped, uneven heating or the like is likely to occur in the fixing unit 47, and thus an adverse effect is likely to occur during the fixing process of the fixing unit 47.

[0047] Therefore, in the image forming system 1 of the present embodiment, during the fixing warm-up of the fixing unit 47 in the image forming apparatus 40, the media detection device 30 detects the recording material characteristics of the recording material S. For example, when an image forming job is input to the image forming apparatus 40 in a state where the conveyance of the recording material S has stopped, before the image forming unit 46 starts the image forming operation, the fixing management unit 412 instructs the fixing unit 47 to perform warm-up. At this point, since image formation is not being performed, the conveyance stop of the recording material S or a decrease in the conveyance speed does not affect the image forming operation. For this reason, the recording material characteristics of the recording material S can be detected by the media detection device 30 without affecting the image forming operation.

[0048] FIG. 4 shows a flowchart of the image forming process and the process related to the detection of the recording material characteristics in the image forming system 1 shown in FIG. 1 above. First, when an image forming job is input to the image forming apparatus 40, the conveyance control unit 122 of the paper feeding device 10 and the conveyance control unit 414 of the image forming apparatus 40 stop the conveyance of the recording material S (step S10). At this time, the conveyance control unit 122 of the control unit 12 also stops the conveyance of the recording material S in the paper feeding device 10 and the recovery device 60 as well. Note that if the conveyance of the recording material S has already stopped, this process may be omitted.

[0049] Next, the fixing management unit 412 determines whether to execute the warm-up of the fixing unit 47 (step S11). If the temperature of the fixing unit 47 is equal to or higher than a predetermined fixing temperature (fixing target temperature), there is no need to perform the warm-up of the fixing unit 47. On the other hand, if the temperature of the fixing unit 47 is lower than the predetermined fixing temperature (fixing target temperature), the fixing management unit 412 instructs the execution of the warm-up for the fixing unit 47. The fixing target temperature serving as the criterion for the execution determination of the warm-up in the fixing unit 47 is set in advance by the control unit 41 based on, for example, the paper type, the image forming surface, the coverage, and other conditions registered as an image forming job, and the image forming apparatus 40 is configured accordingly. Note that the fixing temperature when actually performing image formation is set according to the recording material characteristics of the recording material S detected by the media detection device 30 regardless of the fixing target temperature.

[0050] When executing the warm-up of the fixing unit 47 (Yes in step S11), the fixing management unit 412 of the control unit 11 instructs the execution of the fixing warm-up at the fixing temperature 47 (step S12). Next, the media detection management unit 413 determines whether the detection of the recording material characteristics of the recording material S is required in the image forming job (step S13). When the detection of the recording material characteristics is required (Yes in step S13), the processing of detecting the recording material characteristics by performing warm-up control and conveyance control according to the temperature of the fixing unit 47 (hereinafter referred to as processing I) is performed (step S14). The details of the processing I in step S14 will be described later.

[0051] Next, based on the recording material characteristics detected by the processing I, the condition setting unit 416 sets the execution conditions for image formation in the image forming apparatus 40, such as the image forming conditions in the image forming unit 46 and the execution conditions for the fixing process in the fixing unit 47, in the image forming job (step S15).

[0052] After the process of step S15, when the warm-up of the fixing unit 47 is not executed (No in step S11), or when the detection of the recording material characteristics is not required (No in step S13), the fixing management unit 412 determines whether the warm-up of the fixing unit 47 has been completed (step S16). When the warm-up of the fixing unit 47 has not been completed (No in step S16), this process is continued until the warm-up of the fixing unit 47 is completed.

[0053] When the warm-up of the fixing unit 47 has been completed (Yes in step S16), the image forming apparatus 40 executes image formation in the image forming unit 46 according to the execution conditions of image formation set by the condition setting unit 416 (step S17).

[0054] Next, the control unit 41 of the image forming apparatus 40 determines whether all the image forming jobs have been completed (step S18). When there are remaining unfinished image forming jobs (No in step S18), the process returns to the process of step S11. When all the image forming jobs have been completed (Yes in step S18), the process according to this flowchart ends.

[0055] (Process I) Next, the details of process I in step S14 in the flowchart shown in FIG. 4 described above will be described. The flowchart of process I is shown in FIG. 5.

[0056] First, the determination unit 415 of the control unit 41 of the image forming apparatus 40 determines whether the temperature t of the fixing unit 47 during warm-up is less than the first temperature threshold value tA (step S20). When the temperature t of the fixing unit 47 is equal to or higher than the first temperature threshold tA (No in step S20), the determination unit 415 determines whether the temperature t of the fixing unit 47 during warm-up is lower than the second temperature threshold tB (step S21). Note that the first temperature threshold tA and the second temperature threshold tB are stored in advance as threshold temperature data in a non-volatile memory 48 or the like of the control unit 41 of the image forming apparatus 40. For example, the first temperature threshold tA and the second temperature threshold tB are set based on the paper type, image forming surface, coverage, and other conditions registered as an image forming job and the threshold temperature data stored in advance in the non-volatile memory 48 or the like.

[0057] Here, the relationship between the temperature t of the fixing unit 47, the first temperature threshold tA, and the second temperature threshold tB will be described. FIG. 6 shows the relationship between the temperature t of the fixing unit 47, the first temperature threshold tA, and the second temperature threshold tB. In FIG. 6, the vertical axis represents temperature [° C.], and shows the first temperature threshold tA, the second temperature threshold tB, and the warm-up (WU) completion temperature (fixing target temperature), respectively. Also, patterns (1) to (3) of the temperature t of the fixing unit 47 during warm-up (WU) are shown on the horizontal axis.

[0058] The first temperature threshold tA is the upper limit temperature at which no damage or malfunction occurs to the recording material S when the conveyance of the recording material S is stopped while in contact with the fixing unit 47. Also, the second temperature threshold tB is the upper limit temperature at which damage or malfunction occurs to the recording material S when the conveyance of the recording material S is stopped while in contact with the fixing unit 47, but no damage or malfunction occurs to the recording material S when the recording material S is conveyed at a speed lower than the normal conveyance speed during the image forming process. Note that the first temperature threshold tA and the second temperature threshold tB are thresholds set in advance based on experiments using a plurality of types of recording materials.

[0059] That is, as in the pattern (1) of the temperature t of the fixing unit 47 during warm-up shown in FIG. 6, if the temperature t of the fixing unit 47 is less than the first temperature threshold value tA, the conveyance of the recording material S can be stopped during the warm-up of the fixing unit 47. For this reason, the media detection device 30 can detect the recording material characteristics of the recording material S in a state where the conveyance of the recording material S is stopped in the image forming system 1.

[0060] Also, as in the pattern (2) of the temperature t of the fixing unit 47 during warm-up, if the temperature t of the fixing unit 47 is equal to or greater than the first temperature threshold value tA and less than the second temperature threshold value tB, the recording material S can be conveyed at a speed lower than the normal conveyance speed during the image forming process. For this reason, the media detection device 30 can detect the recording material characteristics of the recording material S while conveying the recording material S at a speed lower than the normal conveyance speed in the image forming system 1.

[0061] And, as in the pattern (3) of the temperature t of the fixing unit 47 during warm-up, when the temperature t of the fixing unit 47 is equal to or greater than the second temperature threshold value tB, in order to suppress damage to the recording material S by the fixing unit 47 and the occurrence of defects in the fixing unit 47, it is necessary to convey the recording material S at the normal conveyance speed during the image forming process. For this reason, it becomes difficult for the media detection device 30 to accurately detect the recording material characteristics of the recording material S.

[0062] Returning to the description of FIG. 5, when the temperature t of the fixing unit 47 is less than the first temperature threshold value tA (Yes in step S20), the determination unit 415 compares the time when the temperature t of the fixing unit 47 during warm-up reaches the first temperature threshold value tA with the detection completion time of the recording material characteristics, and determines whether the time to reach the first temperature threshold value tA is less than or equal to the detection completion time (step S22). When the temperature t of the fixing unit 47 is less than the second temperature threshold value tB (Yes in step S21), the determination unit 415 compares the time when the temperature t of the fixing unit 47 during warm-up reaches the second temperature threshold value tB with the detection completion time of the recording material characteristics, and determines whether the time to reach the second temperature threshold value tB is less than or equal to the detection completion time (step S23). Also, when the temperature t of the fixing unit 47 is equal to or higher than the second temperature threshold value tB (No in step S21), the image forming job is stopped and the processing according to this flowchart is terminated. When the temperature t of the fixing unit 47 is equal to or higher than the second temperature threshold value tB, even if the conveyance of the recording material S is stopped or conveyed at a low speed, the recording material S may be damaged or a problem may occur in the fixing unit 47. For this reason, not only the detection of the recording material characteristics but also image formation cannot be performed, and the image forming job is stopped.

[0063] When the temperature t of the fixing unit 47 becomes equal to or higher than the first threshold temperature tA while the media detection device 30 is detecting the recording material characteristics, there is a possibility that the recording material S may be damaged or a problem may occur in the fixing unit 47 in a state where the conveyance of the recording material S is stopped. Further, when the temperature t of the fixing unit 47 becomes equal to or higher than the second threshold temperature tB while the media detection device 30 is detecting the recording material characteristics, there is a possibility that the recording material S may be damaged or a problem may occur in the fixing unit 47 in a state where the conveyance of the recording material S is performed at a speed lower than the normal conveyance speed. For this reason, before the media detection device 30 detects the recording material characteristics, it is determined whether the time when the temperature t of the fixing unit 47 becomes equal to or higher than the first threshold temperature tA or the second threshold temperature tB is equal to or less than the detection completion time of the recording material characteristics of the recording material S.

[0064] When the arrival time of the first temperature threshold value tA is equal to or less than the detection completion time (Yes in step S22), the fixing management unit 412 performs control to reduce the temperature increase rate of the fixing unit 47 during warm-up (step S24). Also, when the arrival time of the second temperature threshold value tB is equal to or less than the detection completion time (Yes in step S23), the fixing management unit 412 performs control to reduce the temperature increase rate of the fixing unit 47 during warm-up (step S25).

[0065] Here, the control of the temperature increase rate of the fixing unit 47 during warm-up will be described. FIGS. 7 to 10 show graphs of the temperature increase of the fixing unit 47 during warm-up. In the graphs shown in FIGS. 7 to 10, the vertical axis represents the temperature t [° C.] of the fixing unit 47 of the fixing unit 47, and the horizontal axis represents the elapsed time from the start of warm-up. Also, in the graphs shown in FIGS. 7 to 10, as an example of the temperature threshold, the first temperature threshold tA is set to 80° C. and the second temperature threshold tB is set to 120° C. Also, in the graphs shown in FIGS. 7 to 10, it is an example in which the detection of the recording medium characteristics of the recording medium S is started simultaneously with the start of warm-up, and an example in which the time until the completion of the detection of the recording medium characteristics is set to 40 seconds is shown.

[0066] FIG. 7 shows a case where the temperature t of the fixing unit 47 at the start of warm-up is 50° C. Even when normal warm-up is performed by lighting all the heaters to heat the fixing unit 47, the detection of the recording medium characteristics is completed before the temperature t of the fixing unit 47 becomes equal to or higher than the first temperature threshold tA. Thus, if the temperature of the fixing unit 47 when the recording medium characteristics of the recording medium S are completed is less than the first temperature threshold tA, it is possible to detect the recording medium characteristics of the recording medium S in a stopped state without causing damage or problems to the recording medium S.

[0067] On the other hand, FIG. 8 shows a case where the temperature t of the fixing unit 47 at the start of warm-up is 65° C. In this case, in the graph when all the heaters indicated by the broken line are lit, the temperature t of the fixing unit 47 becomes equal to or higher than the first temperature threshold tA before the detection of the recording medium characteristics is completed. Therefore, as shown in the graph indicated by the solid line, the temperature increase rate of the fixing unit 47 is decreased compared to normal warm-up. Specifically, it is decreased to a temperature increase rate at which the detection of the recording medium characteristics is completed before the temperature t of the fixing unit 47 becomes equal to or higher than the first temperature threshold tA. Thus, by decreasing the temperature increase rate of the fixing unit 47 so that the temperature of the fixing unit 47 when the recording medium characteristics of the recording medium S are completed is less than the first temperature threshold tA, it is possible to detect the recording medium characteristics of the recording medium S in a stopped state without causing damage or problems to the recording medium S.

[0068] Further, FIG. 9 shows the case where the temperature t of the fixing unit 47 at the start of warm-up is 95°C. In this case, the temperature t of the fixing unit 47 at the start of warm-up is equal to or higher than the first temperature threshold tA. Therefore, the detection of the recording material characteristics of the recording material S cannot be performed in the stopped state. However, the temperature t of the fixing unit 47 at the start of warm-up is less than the second temperature threshold tB. And even if normal warm-up is performed by turning on all the heaters to heat the fixing unit 47, the detection of the recording material characteristics is completed before the temperature t of the fixing unit 47 becomes equal to or higher than the second temperature threshold tB. In this case, when the recording material S is in the stopped state, the recording material characteristics of the recording material S cannot be detected without causing damage or defects to the recording material S. However, by transporting the recording material S at a speed lower than the normal speed during image formation (low-speed transport), the recording material characteristics can be detected without causing damage or defects to the recording material S.

[0069] On the other hand, FIG. 10 shows the case where the temperature t of the fixing unit 47 at the start of warm-up is 105°C. In this case, similar to the case shown in FIG. 9, the detection of the recording material characteristics of the recording material S cannot be performed in the stopped state. Furthermore, in the graph when all the heaters indicated by the broken line are turned on, the temperature t of the fixing unit 47 becomes equal to or higher than the second temperature threshold tB before the detection of the recording material characteristics is completed. Therefore, as in the case of FIG. 9, even if the recording material S is transported at a low speed, damage or defects will occur to the recording material S due to the detection of the recording material characteristics. Therefore, in the example shown in FIG. 10, as in the graph indicated by the solid line, the rate of temperature rise of the fixing unit 47 is decreased compared to normal warm-up. Specifically, it is decreased to a rate of temperature rise at which the detection of the recording material characteristics is completed before the temperature t of the fixing unit 47 becomes equal to or higher than the second temperature threshold tB. In this way, by decreasing the rate of temperature rise of the fixing unit 47 so that the temperature of the fixing unit 47 when the recording material characteristics of the recording material S are completed is less than the second temperature threshold tB, it becomes possible to detect the recording material characteristics by transporting (low-speed transport) at a speed lower than the normal speed during image formation.

[0070] In the examples shown in FIGS. 7 to 10 described above, the detection of the recording material characteristics is performed simultaneously with the start of warm-up. However, the detection of the recording material characteristics does not necessarily have to be performed simultaneously with warm-up. The detection of the recording material characteristics may be configured to start within a predetermined time from the start of warm-up so that the detection of the recording material characteristics is completed by the time the warm-up is completed. For this reason, in the above description, based on the temperature t of the fixing unit 47 at the start of warm-up, the comparison determination with the first temperature threshold value tA and the second temperature threshold value tB is performed. However, the above comparison determination may be performed based on the temperature of the temperature t of the fixing unit 47 within a predetermined time from the start of warm-up.

[0071] Adjustment of the temperature rise rate of the fixing unit 47 and adjustment of the time to reach the temperature threshold value of the temperature t of the fixing unit 47 can be performed, for example, in the fixing management unit 412 by adjusting the ratio of the lighting time / extinguishing time of the heater (adjustment of the duty ratio), adjusting the number of times the heater is lit, and the like. The adjustment of the temperature rise rate by the fixing management unit 412 can be obtained, for example, from the temperature difference between the temperature t of the fixing unit 47 and the first temperature threshold value tA or the second temperature threshold value tB, the detection time of the recording material characteristics, and the like.

[0072] In this way, the temperature rise rate of the fixing unit 47 during warm-up is adjusted so that the time to reach the threshold temperature of the temperature t of the fixing unit 47 is equal to or longer than the detection completion time of the recording material characteristics in the media detection device 30. Thereby, the fixing management unit 412 adjusts the time for the temperature t of the fixing unit 47 to reach the threshold temperature so as to be later than the detection completion time of the recording material characteristics. Thereby, damage to the recording material S and occurrence of defects in the fixing unit 47 can be suppressed, and highly accurate detection of recording material characteristics becomes possible.

[0073] Also, when adjusting the temperature increase rate of the fixing unit 47 in step S24 or step S25, after detecting the recording material characteristics, as shown in FIGS. 8 and 10, it is preferable to return the temperature increase rate of the temperature t of the fixing unit 47 to the same state as normal warming up. By the fixing management unit 412 returning the temperature increase rate of the fixing temperature to the state before adjustment, it is possible to minimize the delay in the completion time of the warming up of the fixing unit 47 and the delay in the start time of the image forming job, and suppress the decrease in productivity.

[0074] Returning to the description of FIG. 5, when the arrival time of the second temperature threshold value tB exceeds the detection completion time (No in step S23), or after the process of step S25, the conveyance control unit 122 of the paper feeding device 10 and the conveyance control unit 414 of the image forming apparatus 40 execute the conveyance of the recording material S at a speed lower than the normal conveyance speed (step S26). The conveyance control unit 122 and the conveyance control unit 414 can detect the recording material characteristics with high accuracy in the media detection device 30, and start the conveyance of the recording material S at a conveyance speed at which damage to the recording material S in the fixing unit 47 and malfunctions in the fixing unit 47 are less likely to occur.

[0075] When the arrival time of the first temperature threshold value tA exceeds the detection completion time (No in step S22), after the process of step S24, or after the process of step S26, the media detection device 30 executes the detection of the recording material characteristics (step S27). After detecting the recording material characteristics, the processing according to this flowchart is terminated, and the above-described processing I is terminated.

[0076] According to the processing shown in FIGS. 4 and 5 described above, by detecting the recording material characteristics of the recording material S during the warm-up of the fixing unit 47 where image formation is not being performed, the conveyance of the recording material S is stopped or the conveyance speed is decreased, enabling highly accurate detection of the recording material characteristics. Furthermore, by adjusting the conveyance state of the recording material S according to the temperature t of the fixing unit 47, damage and malfunctions of the recording material S can be suppressed, enabling highly accurate detection of the recording material characteristics. Also, by detecting the recording material characteristics of the recording material S during the warm-up of the fixing unit 47 where image formation is not being performed, it is possible to suppress the decrease in productivity.

[0077] Note that the present invention is not limited to the configuration described in the above-described embodiment examples, and various modifications and changes are possible without departing from the configuration of the present invention.

Explanation of Reference Numerals

[0078] 1 Image forming system, 10 Paper feeding device, 11, 61 Support shafts, 12, 31, 41 Control units, 13, 32, 49 Communication units, 14, 44 Conveying units, 15, 34, 48 Non-volatile memories, 20 Supply adjustment unit, 30 Media detection device, 33 Detection unit, 40 Image forming device, 42 Operation display unit, 43 Scanner unit, 45 Image processing unit, 46 Image forming unit, 47 Fixing unit, 50 Recovery adjustment unit, 60 Recovery device, 121, 311, 411 Communication control units, 122, 414 Conveying control units, 312 Media detection control unit, 412 Fixing management unit, 413 Media detection management unit, 415 Determination unit, 416 Condition setting unit, 417 Condition history management unit, 461 Exposure unit, 462 Photoconductor, 463 Developing unit, 464 Primary transfer roller, 465 Intermediate transfer belt, 466 Secondary transfer roller, 471 Fixing roller, 472 Pressure roller

Claims

1. A conveyance unit configured to convey a recording material; A recording material property detection unit disposed in the conveyance path of the recording material and configured to detect the properties of the recording material; A fixing unit configured to fix a toner image formed on the recording material; A control unit configured to cause the recording material property detection unit to detect the properties of the recording material while the fixing unit is performing warm-up for an image forming job, and to set image forming conditions in the image forming job based on the detected properties of the recording material; and The control unit controls a temperature rise rate of warm-up during a period in which the properties of the recording material are detected based on a temperature of the fixing unit within a predetermined time from the start of warm-up. An image forming system.

2. When the temperature of the fixing unit within a predetermined time from the start of warm-up is less than a first temperature threshold, the control unit determines whether a time for the temperature of the fixing unit to rise to the first temperature threshold is less than or equal to a detection completion time of the properties of the recording material, and when the determination result is less than or equal to the detection completion time, sets the temperature rise rate of warm-up of the fixing unit to be lower than a predetermined temperature rise rate at least during a period in which the properties of the recording material are detected. The image forming system according to claim 1.

3. When the temperature of the fixing unit within a predetermined time from the start of warm-up is greater than or equal to the first temperature threshold and less than a second temperature threshold, the control unit determines whether a time for the temperature of the fixing unit to rise to the second temperature threshold is less than or equal to the detection completion time of the properties of the recording material, and when the determination result is less than or equal to the detection completion time, sets the temperature rise rate of warm-up of the fixing unit to be lower than a predetermined temperature rise rate at least during a period in which the properties of the recording material are detected, and conveys the recording material at a conveyance speed lower than a conveyance speed during image formation. The image forming system according to claim 1.

4. The control unit controls the temperature rise rate by controlling a lighting rate of a heater that heats the fixing unit. The image forming system according to any one of claims 1 to 3.

5. After the detection of the properties of the recording material is completed, the control unit returns the temperature rise rate to the predetermined temperature rise rate. The image forming system according to claim 2 or 3.

6. Based on the result of comparing the temperature of the fixing unit within a predetermined time from the start of warm-up with a predetermined temperature threshold value, the control unit determines whether to stop or convey the recording material during the period of detecting the recording material characteristics. The image forming system according to claim 2.

7. When the temperature of the fixing unit within a predetermined time from the start of warm-up is less than the first temperature threshold value, the control unit stops the conveyance of the recording material at least during the period of detecting the recording material characteristics. The image forming system according to claim 6.

8. When the temperature of the fixing unit within a predetermined time from the start of warm-up is greater than or equal to the first temperature threshold value, the control unit sets the conveyance speed of the recording material to a speed lower than the conveyance speed during image formation at least during the period of detecting the recording material characteristics. The image forming system according to claim 6 or 7.

9. The recording material is continuous paper. The image forming system according to any one of claims 1 to 8.

10. The recording material is continuous paper wound in a roll shape. The image forming system according to claim 9.

11. It has an image forming unit that forms the toner image on the recording material, Based on the recording material characteristics detected during the execution of warm-up, the control unit sets the execution conditions of at least one of the image forming unit and the fixing unit as the image forming conditions. The image forming system according to any one of claims 1 to 10.

12. The execution conditions of the fixing unit include a fixing target temperature. The image forming system according to claim 11.

13. The recording material characteristics detection unit is arranged upstream of the path of the recording material from the image forming unit. The image forming system according to claim 11 or 12.

14. The recording material characteristics detection unit is arranged between the supply unit of the recording material and the image forming unit. The image forming system according to any one of claims 11 to 13.

15. Between the supply unit of the recording material and the image forming unit that forms an image on the recording material, there is a supply adjustment unit that adjusts the supply of the recording material, The recording material characteristics detection unit is provided between the supply unit and the supply adjustment unit. The image forming system according to claim 14.

Images