Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G15/00—Apparatus for electrographic processes using a charge pattern
  • G03G15/65—Apparatus which relate to the handling of copy material
  • G03G15/6555—Handling of sheet copy material taking place in a specific part of the copy material feeding path
  • G03G15/657—Feeding path after the transfer point and up to the fixing point, e.g. guides and feeding means for handling copy material carrying an unfused toner image
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G2215/00—Apparatus for electrophotographic processes
  • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
  • G03G2215/00535—Stable handling of copy medium
  • G03G2215/00611—Detector details, e.g. optical detector
  • G03G2215/00616—Optical detector
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G2215/00—Apparatus for electrophotographic processes
  • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
  • G03G2215/00535—Stable handling of copy medium
  • G03G2215/00717—Detection of physical properties
  • G03G2215/00721—Detection of physical properties of sheet position
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G2215/00—Apparatus for electrophotographic processes
  • G03G2215/00362—Apparatus for electrophotographic processes relating to the copy medium handling
  • G03G2215/00919—Special copy medium handling apparatus
  • G03G2215/00945—Copy material feeding speed varied over the feed path

Definitions

• the present invention relates to an image forming apparatus, and more particularly to a control method in an image forming apparatus that forms an image by an electrophotographic method and fixes the formed image on a recording material.
• a toner image on an image carrier is transferred onto a recording material by a transfer means such as a transfer roller, and is guided to a nip portion of a fixing portion through a conveyance guide to be fixed.
• a transfer means such as a transfer roller
• the recording material conveyance speed of the fixing unit is faster than the recording material conveyance speed of the transfer unit, the recording material is stretched. In the transfer process, image quality such as color misregistration and transfer pre is reduced. Conversely, if the recording material conveyance speed of the transfer section is faster than the recording material conveyance speed of the fixing section, the loop (curve) becomes too large, and there is no space to maintain an appropriate loop shape. Problems such as the surface being rubbed into the device occur.
• a recording material is formed with a loop just before the fixing portion entrance, and the loop amount at that time is adjusted.
• loop control reduces image quality in the transfer process and prevents unfixed images from touching the components in the device during fixed transfer.
• a sensor that detects the upper and lower limits of the loop amount formed by the recording material. When the upper limit of the loop amount is detected, the speed of the driving system drive source (motor) of the fixing unit is increased by a certain amount, and when the lower limit of the loop amount is detected, the speed of the driving system drive source of the fixing unit This is a control for slowing down a certain amount.
• the configuration includes two detection sensors that detect the loop amount of the recording material conveyed from the transfer portion toward the fixing nip portion of the fixing device. Yes.
• the recording material conveyance speed is controlled in the direction to decrease the loop amount, and when the other sensor detects the loop amount, the recording material conveyance speed is controlled to increase.
• An image forming apparatus that suppresses the loop amount of the recording material within a certain range has been proposed. Disclosure of the invention
• the loop control described in Japanese Patent Application Laid-Open No. 0-7-2 3 4 6 0 4 uses a driving system drive source (motor) of the fixing unit of a predetermined high speed (H) and a predetermined low speed (L).
• the loop amount is adjusted by switching between two speeds.
• H high speed
• L low speed
• the recording material conveyance speed in the fixing unit is different even though the rotation speed of the motor is the same.
• the recording material conveyance roller of the fixing unit gradually deteriorates, or the surface characteristics of the recording material deteriorate due to environmental fluctuations in which the image forming device is installed. Because it changes.
• the This recording material conveyance speed fluctuation also occurs in the transfer section.
• the speed (H) must be set to a speed that can reliably reduce the loop amount of the recording material.
• the speed (L) must be set in advance to a speed that can reliably increase the loop amount of the recording material.
• the speed difference between the fast speed (H) and the slow speed (L), that is, the speed control range is taken into account by taking into consideration the durability fluctuations of the fixing means and transfer means, the environment in which the image forming apparatus is used, and the recording material type There is a need to take widely.
• the fixing unit mounted on the image forming apparatus is generally set to be shorter than the design life of the main body of the image forming apparatus, and is designed to be replaced when the life is reached.
• the difference between the recording material conveyance speed when it is new and the recording material conveyance speed at the end of the service life is considered to be small, so the difference between the motor speed (H) and speed (L) is also Can be small.
• the present invention has been made paying attention to the above points, and stabilizes the recording material loop control. Regardless of the durability of the fixing unit and the conveying unit, the use environment of the image forming apparatus, and the type of the recording material, the image forming is performed. It is an object to provide an image forming apparatus that can prevent problems that occur in the process.
• the image forming apparatus includes an image forming unit that forms a toner image on a recording material, a fixing unit that includes a roller that conveys the recording material, and fixes the toner image formed on the recording material to the recording material, and the roller
• An image forming apparatus comprising: a motor for driving the recording medium; a loop detection unit that is disposed between the image forming unit and the fixing unit and detects a loop of the recording material; and a control unit that controls the motor.
• a fixing unit usage amount detecting unit that detects the usage amount of the fixing unit; and a storage unit that stores a cumulative usage amount of the fixing unit, and the control unit is stored in the storage unit. The rotational speed of the motor is controlled in accordance with the accumulated usage amount information of the fixing unit and the output of the loop detection unit.
• FIG. 1 is a cross-sectional view showing the overall configuration of a color image forming apparatus according to Embodiment 1 of the present invention.
• FIG. 2 is a partially cutaway side view of the fixing unit according to the first embodiment of the present invention.
• FIG. 3 is a diagram illustrating the flow of the usage detection control of the fixing unit according to the first embodiment of the present invention.
• FIG. 4 is a diagram for explaining loop control of the fixing unit according to the first embodiment of the present invention.
• FIG. 5 is a graph plotting the values of V h and V 1 against the total number of prints of the fixing unit according to Example 1 of the present invention.
• FIG. 6 is a graph plotting the values of V h and V 1 against the cumulative number of printed sheets of the fixing unit according to Example 1 of the present invention.
• Figure 7 shows the change in paper conveyance speed of the fixing unit due to durability according to Example 1 of the present invention. It is a figure explaining verification experiment.
• FIG. 8 is a schematic diagram of a recording material type detection sensor according to Embodiment 4 of the present invention.
• FIG. 1 is a cross-sectional view illustrating the overall configuration of the color image forming apparatus according to the first embodiment.
• This apparatus is an example of an electrophotographic color image forming apparatus, which is a tandem color image forming apparatus employing an intermediate transfer member.
• the image signal is transmitted to the image data input unit via the printer controller from a host computer (hereinafter referred to as a host PC) connected to the color image forming apparatus or from a network or from the operation panel.
• a host computer hereinafter referred to as a host PC
• 50 Y, 50M, 50 C, and 5 OK are photosensitive drums, which are installed in image forming stations equipped with toners (developers) of yellow, magenta, cyan, and black, respectively.
• toners developer
• each photosensitive drum 5 OY, 50M Based on the image data sent from the control unit of the image forming device from the laser scanner device 5 1Y, 51 ⁇ , 51 C, 51 K corresponding to each color, each photosensitive drum 5 OY, 50M, Laser light is irradiated onto the surface of 50 C, 5 OK, and a latent image is formed.
• Reference numeral 40 denotes an intermediate transfer belt (intermediate transfer member), which is stretched by a driving roller 41, a tension roller 42, and a driven roller 43. On the intermediate transfer belt 40, the toner images of the respective colors formed by the photosensitive drums 50Y, 50M, 50C, and 50K are primarily transferred.
• Reference numeral 80 denotes a paper feed cassette on which recording paper ⁇ which is a recording material is loaded.
• Recording paper ⁇ is fed by the feed roller 3 1 and fed to the retard roller It is conveyed by pair 3 2 and conveyance roller pair 3 3, and is conveyed to registration roller pair 3 4 that has stopped driving.
• a recording material type detection sensor 6 8 (recording material type detection means) that detects the type of recording paper P (recording material type) is arranged near the registration roller pair 3 4 to detect the type of recording paper P. It is possible.
• the recording paper P is conveyed to the secondary transfer unit 60 at a predetermined timing, and the toner image on the intermediate transfer belt 40 is transferred.
• the toner remaining on the intermediate transfer belt 40 after the secondary transfer is removed by a cleaning device 44 (cleaning means).
• the recording paper P is conveyed to the fixing unit 61 by a secondary transfer roller 60 a which also serves as a recording material conveying means and an intermediate transfer belt 40 (details will be described later).
• a loop sensor 10 between the secondary transfer section 60 and the fixing unit 61, and the loop amount of the recording paper P that can be formed by the speed difference between the secondary transfer section 60 and the fixing unit 61 ( Speed control is performed to adjust the curve amount (details are described later).
• Speed control is performed to adjust the curve amount (details are described later).
• the fixing unit 61 the recording paper P is held between the fixing roller 6 2 and the pressure roller 6 3, and the toner image on the recording paper P is heated and fixed.
• the fuser unit 61 has a replaceable unit structure, and is equipped with a fuse 8 4 (fixing unit new article detection means) for detecting whether or not the fuser unit 61 is new.
• the recording paper P that has passed through the fixing unit 61 is conveyed to the fixing discharge roller pair 6 4 and the discharge roller pair 65 and discharged onto the discharge tray 6 6.
• the recording paper P is transported to the transport roller pair 7 1, 7 2, 7 3 with the transport direction reversed by the discharge roller pair 65. It is transported to the registration roller pair 34 whose driving is stopped again.
• this image forming device is equipped with an environmental sensor 67 (environment detection means) to detect the temperature (environmental temperature) and humidity (environmental humidity) where the image forming device is used. Is possible.
• Secondary transfer section 60 (conveying means) In the secondary transfer unit 60, the recording paper P is nipped and conveyed between the intermediate transfer belt 40 and the secondary transfer roller 60a.
• the intermediate transfer belt 40 has a thickness of 0.1 mm in which carbon is dispersed in polyimide resin and the volume resistivity is adjusted to 10 8 ⁇ ⁇ cm.
• the intermediate transfer belt 40 is driven by a driving roller 41 which is one of the stretching rollers. It is rotationally driven.
• the secondary transfer roller 60a is composed of a core metal covered with foamed rubber having a medium resistance (actual resistance at the nip forming portion when 500 V is applied is 10 7 to 10 9 ⁇ ).
• the secondary transfer roller 60 a is arranged so that the amount of erosion and insertion is about 0.4 mm with respect to the intermediate transfer belt 40.
• FIG. 2 is a partially cutaway side view of the fixing unit 61.
• the fixing roller 62 and the pressure roller 63 have substantially the same structure in this embodiment.
• it has a three-layer structure in which a single bow layer 5 made of silicone rubber, an intermediate layer 20 made of fluororubber latex, and a release layer 2 made of PFA coat are provided on a core metal 6 of an aluminum (A 1 6063). Is formed.
• a halogen heater 8 is installed inside the cored bar 6.
• Silicone rubber of elastic layer 5 has a thermal conductivity of about 0.4 OW / m ⁇ K, test piece hardness of JIS-A hardness of about 10 °, and fixing roller 62 of about 1.9 mm, pressure roller 63 has a wall thickness of about 2.1 mm.
• the fluororubber latex of the intermediate layer 20 is obtained by dispersing PFA particles in fluororubber and is provided with a thickness of about 40 to 6 ⁇ .
• the PFA coat of release layer 2 has a thickness of about 2 ⁇ .
• Both the fixing roller 62 and the pressure roller 63 have an outer diameter of 45 mm.
• the roller hardness is about 67 ° for the fixing roller 62 and about 65 ° for the pressure roller 63 (Asker C, lkgf load). 9 mm nip width is obtained.
• the effective roller length is about 33 Omm. Thin rubber wall thickness to obtain a wide set-up width,-Increase the pressure at the top to about 2.
• the rotation of the fixing roller 62 is performed via a gear (not shown) provided at the end of the fixing roller 62, and the pressure roller 63 is driven to rotate.
• the fixing drive unit will be described in the loop control explanation section described later.
• the fuser unit 6 1 has a fuse 8 4 for detecting a new article, and a fixing discharge sensor 8 5 (fixer used for detecting the amount of use of the fuser unit 6 1 if J AM (paper conveyance failure) is detected. Use amount detecting means).
• New article detection is performed by determining whether or not the article is new by using an identification member such as a fuse 84 provided on the fixing unit 61. That is, when it is detected by the new article detecting means provided in the image forming apparatus main body that the fuse 84 is not blown, it is determined that the fixing unit 61 is new. Thereafter, the fuse 84 is blown out so as not to identify the fixing unit 61 as being new.
• Fig. 3 shows a flow chart of the flow of usage detection control for the fixing mute 61. In addition, the following description will be given with reference to a diagram illustrating loop control of the fixing unit 61 shown in FIG.
• Step S 1 1 After the power is turned on or the door of the image forming apparatus is opened / closed (Step S 1 1, “Step” is omitted), whether or not the fuser unit 6 1 is new depending on the presence or absence of the fuse 8 4 of the fuser unit 6 1 Detect (S 1 2). If the fuser unit 6 1 is not new (in the case of “no fuse” in S 1 2), the device is in the READY state as usual. On the other hand, if the fuser unit 6 1 is new (S 1 2 "If fuse is present"), image The total number of printed sheets (cumulative usage) of the fixing unit 61 stored in the nonvolatile memory (EEPROM92) (storage section) in the control section 91 of the forming apparatus main body is reset (S13). Thereafter, based on a command from the CPU 95, the fuse 84 in the fixing unit 61 is blown (S14), and then the device is in a READY state.
• EEPROM92 nonvolatile memory
• the length of the recording paper P is detected by the fixing paper discharge sensor 85 provided in the fixing unit 61 and the timer 93 in the control unit 91 ( Measure the recording material length (S 16).
• the length of the recording paper P is converted (converted) into the sheet count with the LETTER width (215. 9 mm) as one unit (S 17).
• the sheet count is calculated to the unit of one decimal point and added to the total number of printed sheets of the fixing unit 61 stored in the EEPROM 92 (nonvolatile memory) in the control unit 91 (S18).
• the life of the fuser unit 61 is 100,000 sheets. If the cumulative number of printed sheets exceeds 100,000 sheets, it shall be fixed at 100,000 sheets. That is, the control unit 91 manages the cumulative usage amount of the fixing unit 61 by converting it into the cumulative number of printed sheets.
• the identification member for detecting a new article may be a memory that can store information provided in the fixing unit 61.
• the memory stores new information.
• the fixing unit 61 is attached to the main body of the image forming apparatus (hereinafter also simply referred to as a main body)
• the memory information is read through the main body electrical contacts provided in the main body. If the memory information is new, the fixing unit 61 is determined to be new. After that, the information in the memory is rewritten to information that is not new.
• the operation for reading the information in the memory is performed when the main unit is turned on or when the main unit door is opened or closed.
• the color image forming apparatus of this embodiment detects the loop amount (carp amount) of the recording paper P between the fixing unit 61 and the secondary transfer unit 60 (transfer means).
• a loop sensor 1 0 loop detection means is provided.
• This loop sensor 10 has a lever member that rotates when the recording paper abuts.
• the flag 21 at the base of the lever member determines whether or not the detection sensor 2 2 constituted by an optical sensor shields the light. It detects whether the loop amount of recording paper P has exceeded a certain level.
• C P U 9 5 (control means) in the control unit 9 1 performs the following control to adjust the loop amount of the recording paper P. That is, based on the result of the signal detected by the detection sensor 2 2 and the speed setting value obtained from the total number of printed sheets of the fixing unit 6 1 provided in the EEPR OM 9 2 in the control unit 91, Controls the speed of the motor 8 1 a.
• the fixing drive unit is provided with a fixing motor 8 1 a and a motor driver 8 1 b, and a microstep five-phase stepping motor is used as the fixing motor 8 1 a.
• a driving signal for the fixing motor 8 1 a is generated by the motor driver 8 1 b, and a clock signal as a basis for the driving signal is generated from the CPU 9 5 in the control unit 91. If the clock cycle is shortened, the fixing motor 8 1 a can be rotated at a high speed, and if the clock cycle is lengthened, the fixing motor 8 la is rotated at a low speed.
• the driving speed of the fixing roller 62 in the fixing unit is controlled by the CPU 95, which is also a speed switching means, by switching a plurality of speed setting values (motor rotation frequencies) having different speeds.
• the speed can be switched in two stages, and the speed setting value (motor rotation frequency) in the two stages is set to V h (the motor speed is higher) (the first transport speed) ) And VI (lower motor speed) (second transport speed).
• V h the motor speed is higher
• VI lower motor speed
• the speed setting of the fixing roller 6 2 is set to V 1 and Decrease the conveyance speed of recording paper P in this case, and when detection sensor 22 is on, set the speed setting of fixing roller 62 to Vh and increase the conveyance speed of recording paper P in the fixing section.
• Vh and V1 are variable according to the amount of use of the fixing unit 61 (total number of printed sheets).
• Vh and VI are functions of the cumulative number of printed sheets X of the fixing unit 61 stored in the internal memory (EEP ROM 92). It was supposed to be given as Fig. 5 shows a graph plotting the values of Vh and V1 against the total number of printed sheets of the fixing unit 61.
• Vh and V1 are the fixing motors of Vh (motor rotation speed is higher) and VI (motor rotation speed is lower) when the fixing mute is new (0 k sheets).
• the average of the steady rotation frequency was defined as 100%, and the other was calculated as a ratio.
• the cumulative number of printed sheets X of the fixing unit 61 is the number calculated by the method described in “(4) Detection of fixing unit usage” divided by 1000 (k).
• Vh and V1 are changed step by step as a function of the cumulative number of printed sheets X of the fixing unit 61. However, it is possible to change them step by step as shown in FIG. .
• Vh-Vl control width
• Vh-Vl control width
• the cumulative number of printed sheets of the fixing unit 61 that is, the cumulative usage amount increases, but this takes into account variations due to the durability history of the fixing unit 61. It is a thing. However, if fluctuation due to endurance of the paper speed of the fixing unit does not change due to various usage histories such as paper type, usage environment, usage frequency, etc., it is possible to reduce Vh—V l (control width) as much as possible. For recording It is desirable from the viewpoint of stable transport of paper P.
• FIG. 7 shows the result of measurement of the paper conveyance speed of the fixing unit with the fixing durability when the rotation frequency of the fixing motor 81a is constant.
• the passing time of the toner image formed on the paper was measured with a high speed camera (PHOTO RON FASTCAM-1024 PC I). After that, it was obtained by calculation by actually measuring the image length of the part where the transit time was measured.
• the experiment was performed using three fixing units (Fixer # 1, Fixer # 2, and Fixer # 3).
• the paper speed of the fixing unit increases.
• the reason for the increase in speed is that the surface property of the surface of the fixing roller 62 deteriorates due to the sliding of the pressure roller 63 or the recording paper P and the fixing roller 62, or minute irregularities are generated on the surface of the fixing roller 62. It is thought that.
• Vh and VI speed settings are fixed.
• Unit 6 1 has a constant value throughout the durability. For this reason, it is necessary to determine Vh and V1 in consideration of the effect of fluctuations in the paper conveyance speed due to the durability of the fixing unit 61.
• VI must be determined to increase the loop amount of the fixing unit during loop control even when the paper conveyance speed of the fixing unit 61 increases due to durability.
• Vh must be set so that the loop amount of the fixing unit is reduced during loop control when a new fixing unit 61 is used.
• the control width (Vh-VI) is 5.4%.
• Vh and V 1 linked to the total number of prints of the fixing unit 61 are selected as described in “(5) Loop control”.
• the comparative experiment was conducted using a new fixing unit and a fixing unit that had been able to withstand 100,000 sheets.
• the test method is to print 1 000 sheets, perform comprehensive evaluation of the level from paper evaluation, image rubbing frequency and image evaluation, which is considered to be caused by loop control hunting.
• A, B, C Judgment was performed.
• A is defined as the case where the paper scrape image is not rubbed at all, and B is a minor level but occurs, and C is the frequency of occurrence and the level is relatively high.
• the speed setting values Vh and VI of the fixing motor 81a and the control width (Vh-VI) are also shown. (table 1 )
• the control width is small throughout the durability, and it is understood that control hunting is difficult to occur.
• the recording paper P may be disturbed between the secondary transfer unit 60 and the fixing unit, and the orientation of the recording paper P cannot be detected correctly by the loop sensor 10. In this case, the paper can be transported stably with a small control width.
• the paper can be stably conveyed through the durability of the fixing unit 61. Is possible. Then, it is possible to form a good image free from image defects due to paper sheets, image rubbing, and other paper conveyance disturbances.
• the fixing speed control is based on the usage amount (cumulative usage amount) information of the fixing unit (fixing means) and the usage amount (cumulative number of printed sheets) of the transfer unit that also functions as the transport means. Is to change.
• New transfer detection fuse (transfer unit new article detection means) for detecting that the transfer unit having the secondary transfer roller 60a and the secondary transfer section 60 is new.
• the unit usage is detected in the same way as the usage detection of the fixing unit 61. That is, it is performed by counting the number of recording materials of the recording paper P and detecting a new transfer unit.
• the flow of the transfer mute usage detection control is the same as that described in Example 1 except that the length of the recording paper P is measured by a registration roller pair 3 4 (conveyance unit usage detection unit). (4) Fixing unit usage detection ”, the description is omitted.
• the life of the transfer mute is 150,000 sheets. If the total number of printed sheets exceeds 150,000 sheets, it shall be fixed at 150,000 sheets.
• V h and V 1 are variable depending on the amount of use (cumulative printing number) of the transfer unit and the fixing unit 61.
• Vh and VI are the cumulative number of printed sheets of the fixing unit 6 1 stored in the internal memory (EEPROM9 2) (memory means). It is assumed to be given as a function of X and the total number of prints y of the transfer mute.
• Vh and VI are the values of Vh (motor speed higher) and VI (motor speed lower) at the time of shipment from the factory, that is, when the fixing unit 61 and transfer mute are new.
• the average was defined as 100%, and the other was calculated as a ratio.
• the total number of printed sheets X of the fixing unit 6 1 and the total number of printed sheets y of the transfer unit were obtained by dividing the number of sheets obtained by the above method by 1 000.
• the rotation frequency of the fixing roller 62 is increased as the amount of use of the secondary transfer roller 60a increases. Corrections are made to match it.
• the reason why the paper speed of the secondary transfer section 60 becomes slower depending on the durability (increase in usage) is mainly due to the fact that the outer diameter of the secondary transfer roller 60a that transports the paper decreases with durability. .
• the speed Vh and the speed V 1 of the fixing unit motor 8 1 a used at the time of loop control are changed based on the usage amount information of the transfer unit and the fixing unit 61.
• it is also effective to change the speed Vh and speed V 1 of the fixing motor based only on the transfer unit usage information. .
• the control value of the loop control is determined according to the usage amount (cumulative number of printed sheets) of the transfer unit and the fixing unit 61. Transport is possible. And paper sheet, image rub In other words, it is acceptable to form a good image without image defects due to other paper conveyance disturbances.
• Vh and V1 are the cumulative number of printed sheets X of the fixing unit 61 and the environmental sensor 67 stored in the internal memory. The determination was made based on the temperature result t (° C).
• Vh and VI are the average of Vh (motor speed is higher) and VI (motor speed is lower) at the time of shipment from the factory, that is, when fuser unit 61 and transfer unit are new. It was defined as%, and the other was calculated as a ratio.
• the total number of printed sheets X of fixing unit 61 was divided by 1000 from the number obtained by the method described above.
• the outer diameter of the secondary transfer roller 60a which also serves as a paper transport means, varies depending on the temperature environment in the device, and the relative paper transport speed between the fixing unit and the secondary transfer unit 60 changes. It is because it ends. Therefore, the detection result of environmental sensor 67 Therefore, the correction control is used to correct the speed Vh and the speed VI respectively and realize more stable paper transport.
• the usage amount (cumulative number of printed sheets) of the fixing unit 61 and the usage environment (use temperature) the usage amount (cumulative number of printed sheets) of the fixing unit 61 and the usage environment (use temperature)
• the usage environment and durability state of the device Regardless of whether or not, stable paper conveyance is possible. Then, it is possible to form a good image free from image defects due to paper sheet, image rubbing, and other paper conveyance disturbances.
• the speed Vh and speed of the motor 81a for the fixing unit 6 1 used during loop control based on the detection result of the recording material type detection sensor 68 (recording material type detection means) provided in the main body of the apparatus are the same as Example 1, so only the differences are described.
• the recording material type detection sensor 68 will be described with reference to FIG.
• the recording material type detection sensor 68 is a CMO S (Complementary Metal Oxide Semiconductor) that reads and outputs the image of the light irradiation area by the LED 21 1 that irradiates the surface of the recording paper P and the LED 2 1 1 on the surface of the recording material. It has area sensor 212. Then, an LED lens 213, a CMOS area sensor lens 214, and a recording material conveyance guide 215 are provided. The light emitted from the LED 21 1 is irradiated obliquely onto the recording paper P moving along the recording material conveyance guide 215 through the LED lens 2 1 3.
• CMO S Complementary Metal Oxide Semiconductor
• the reflected light from the recording paper P is collected through the CMOS area sensor lens 214 and imaged on the CMOS area sensor 21 2 to read the surface image of the recording paper P.
• a shadow is formed according to the irregularities on the surface of the recording paper P. Therefore, it is possible to detect the glossiness and transparency of the recording paper P from the average light amount of the image read by the CMOS area sensor 212. Ma Further, it is possible to detect the depth of unevenness on the surface of the recording paper P from the difference between the maximum value and the minimum value of the contrast of the image read by the CMOS area sensor 212.
• the CMOS area sensor 212 Furthermore, it is possible to detect the interval between the irregularities on the surface of the recording paper P from the number of edges of the image obtained by binarizing the image read by the CMOS area sensor 212. By detecting the glossiness and transparency of recording paper P, the depth of the surface irregularities (depression depth) and the interval (roughness interval), according to the classification listed in Table 2, plain paper, rough paper, coated paper, OHT, resin It is possible to detect a recording material type such as a film.
• V h and V 1 are defined as an average of 100% at the time of shipment from the factory, that is, when the fuser unit 61 is new, the average of Vh (the higher motor speed) and VI (the lower motor speed). Others were calculated as percentages.
• the total number of printed sheets X of the fixing unit 61 is divided by 1000 from the number obtained by the method described above.
• the recording material type and durability are determined by determining the control value of the loop control according to the amount of use of the fixing unit 61 (total number of prints) and the recording material type detection sensor 68 result. Stable paper transport is possible regardless of the state. Then, it is possible to form a good image free from image defects due to paper sheet, image rubbing, and other paper conveyance disturbances.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Fixing For Electrophotography (AREA)
• Control Or Security For Electrophotography (AREA)

Priority Applications (1)

Applications Claiming Priority (2)

Related Child Applications (1)

Publications (1)

Family

ID=40387427

Family Applications (1)

Country Status (3)

Families Citing this family (18)

Citations (5)

Family Cites Families (9)

• 2007
  • 2007-08-29 JP JP2007222570A patent/JP4579953B2/ja not_active Expired - Fee Related
• 2008
  • 2008-08-29 WO PCT/JP2008/066014 patent/WO2009028731A1/ja not_active Ceased
• 2009
  • 2009-01-16 US US12/355,233 patent/US7941063B2/en active Active

Patent Citations (5)

Also Published As

Similar Documents

Legal Events