JP2008076495A - Powder conveying device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a powder conveying device in which a time required to drive and convey a powder pump one time is set as a fixed driving time, a predicted value for a quantity of powder conveyance is more accurately calculated by the number of times of driving the powder pump, and to provide an image forming apparatus that has the powder conveyance device. <P>SOLUTION: The time required to drive and supply the powder pump one time is set as a fixed driving time, a predicted value C<SB>1</SB>for toner supply is calculated by the number of times of driving the powder pump. According to the value of the interval t of the drive of the powder pump, the predicted value C<SB>1</SB>for the toner supply is corrected in accordance with a reference quantity C<SB>0</SB>of supply. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a powder conveyance device that conveys powder in a powder container to a conveyance destination using a powder pump, and a copying machine, printer, FAX, and the like equipped with this powder conveyance device as a developer conveyance means The present invention relates to an image forming apparatus.

2. Description of the Related Art Conventionally, there has been known an image forming apparatus using a powder conveying device using a powder pump as a developer conveying device for conveying a developer. Patent Document 1 describes an image forming apparatus using a powder pump as a toner replenishing device that transports toner for replenishment to a developing device as a developer to be transported.
Further, in the image forming apparatus, a configuration in which the toner conveyed by the toner replenishing device is replaceable in the form of a toner cartridge has been conventionally employed. In the configuration in which the toner cartridge is replaced, since the toner cartridge is replaced before the remaining amount of toner in the toner cartridge decreases and affects the image (toner end), the toner for detecting the remaining amount of toner in the toner cartridge is detected. A remaining amount detecting means is provided. As the toner remaining amount detecting means, there is one in which a piezoelectric sensor is disposed at a toner detection position and the remaining amount of toner is detected by the sensor. As a toner replenishing device that detects the remaining amount of toner using a sensor, there is a device that arranges a sensor on a toner conveyance path from a toner cartridge to a developing device and detects the amount of toner at the position where the sensor is disposed. . However, in such a toner replenishing device, it is necessary to secure a space for storing toner in order to detect the toner amount with a sensor, leading to an increase in the size of the device. Furthermore, if a toner scraping mechanism is provided on the sensor surface in order to prevent toner from adhering to the sensor surface, the device becomes complicated and the cost of the device increases.

  On the other hand, in the image forming apparatus described in Patent Document 1, the product of the amount of toner replenishment per unit time of the powder pump (hereinafter referred to as the replenishment speed) acquired in advance by experiments or the like and the driving time of the powder pump. A predicted toner supply amount for the supply operation at that time is calculated. Then, the toner amount in the toner cartridge is calculated by subtracting the accumulated value of the calculated predicted toner supply amount from the amount of toner in the toner cartridge before being used for replenishment. As a result, it is possible to calculate the timing for replacing the toner cartridge before the end of the toner without using the sensor.

JP 2002-258596 A

  However, in the configuration in which the toner supply amount predicted value is calculated from the product of the supply speed and the driving time of the powder pump as in Patent Document 1, the toner supply amount predicted value cannot be accurately calculated for the following reason. . That is, the replenishment speed used for calculating the predicted toner replenishment value is calculated by dividing the toner replenishment amount when the replenishment drive for a predetermined time is performed using the powder pump by the predetermined time. However, since the negative pressure generated by the powder pump increases after the powder pump starts to be driven, the replenishment amount per unit time of toner replenishment is not constant, and the powder pump is driven once. The shorter the driving time, the smaller the amount of toner replenished per unit time. In this way, the toner replenishment amount per unit time varies depending on the duration of the single replenishment drive time of the powder pump. Therefore, the product of the replenishment speed and the powder pump drive time gives an accurate estimate of the toner replenishment amount. It cannot be calculated well.

In Japanese Patent Application No. 2005-346036 (hereinafter referred to as the prior application), the present applicant has applied for an image forming apparatus using a powder pump for toner supply. In the image forming apparatus described in the prior application, the toner replenishment amount prediction value is calculated based on the number of times of driving, with a single replenishment driving time for replenishing the powder pump as a constant driving time. The toner replenishment amount when the powder pump is driven for a fixed driving time is acquired in advance by an experiment or the like.
With such a configuration, it is possible to accurately calculate the predicted toner replenishment amount even if the toner replenishment amount per unit time varies depending on the length of the single replenishment drive time of the powder pump. Such a configuration is not limited to the case where the powder to be conveyed is a toner replenishing device for replenishing toner. In a powder conveyance device, the powder conveyance amount prediction value is calculated by calculating the powder conveyance amount prediction value by the number of times the powder pump is driven, with the conveyance drive time per time of the powder pump being a constant drive time. Can be calculated with high accuracy.

However, it has been found that even if a single conveyance drive time for conveying and driving the powder pump is set to a constant drive time, the amount of powder conveyed by one conveyance drive varies depending on the drive interval of the conveyance drive. Hereinafter, this variation will be described with reference to FIG.
Fig. 8 shows the ON / OFF timing of the powder pump and the pressure fluctuation in the space where the powder pump generates negative pressure when the powder pump is driven at a constant replenishment drive time. It is a graph which shows the outline of a relationship.
FIG. 8A is a graph showing an outline when the drive interval t is relatively long, and FIG. 8B is a graph showing an outline when the drive interval t is relatively short. As shown in FIG. 8, when the powder pump is turned on, the negative pressure generated by the powder pump starts to increase. Then, when the powder pump is turned off after a certain driving time, the negative pressure generated by the powder pump does not immediately disappear, but does not take a certain amount of time. As shown in FIG. 8A, when the drive interval t is sufficiently long, the magnitude of the negative pressure generated by the powder pump in each conveyance drive similarly varies. On the other hand, as shown in FIG. 8B, the drive interval t is shortened, and when the next conveyance drive is performed in a state where the negative pressure generated by the powder pump in the previous conveyance drive does not disappear completely, The magnitude of the negative pressure fluctuates so as to increase from the state of the negative pressure remaining at the time of setting. In other words, if the next transport drive is started before the negative pressure generated by the previous transport drive has disappeared, the pressure fluctuates in a state where the negative pressure is generally larger than when the drive interval t is long. As described above, since the magnitude of the negative pressure varies depending on the driving interval t with respect to the previous conveying drive, even if the driving time for one time is the same, the amount of powder conveyed by one conveying drive varies. . When the powder conveyance amount by one conveyance drive is constant and the powder conveyance amount by the one conveyance drive is constant and the powder conveyance amount prediction value is calculated, The predicted body transport amount cannot be calculated with high accuracy.

  The present invention has been made in view of the above problems, and an object of the present invention is to carry a powder conveyance amount depending on the number of times of driving, with a single conveyance driving time for conveying and driving the powder pump as a constant driving time. It is an object of the present invention to provide a powder conveyance device capable of calculating a powder conveyance amount prediction value, which can calculate the powder conveyance amount prediction value with higher accuracy, and an image forming apparatus including the powder conveyance device.

In order to achieve the above object, the invention of claim 1 includes a powder pump that applies a negative pressure to the powder in the powder container and conveys the powder to a conveyance destination, and conveys the powder pump. In a powder conveyance device that calculates a powder conveyance amount predicted value, which is a predicted value of the amount of powder conveyance by the number of times of driving, with a single conveyance drive time to be driven as a constant drive time, the driving interval of the powder pump The powder conveyance amount prediction value is corrected according to the above.
According to a second aspect of the present invention, in the powder conveying apparatus according to the first aspect, the powder conveyance amount predicted value is corrected based on a magnitude relationship between the driving interval of the powder pump and a predetermined time serving as a threshold value. It is a feature.
Further, the invention of claim 3 is the powder conveying apparatus of claim 1 or 2, further comprising temperature / humidity detection means for detecting temperature and humidity in the installation environment, and the powder according to the detection result of the temperature / humidity detection means. The body conveyance amount prediction value is corrected.
According to a fourth aspect of the present invention, in the powder conveying device according to the first, second, or third aspect, the powder container is a powder container that can be attached to and detached from the apparatus main body. And a cumulative conveyance amount recording means for recording a cumulative powder conveyance amount predicted value calculated from the cumulative number of driving times of the powder pump and the powder conveyance amount prediction value.
Further, the invention of claim 5 is the powder conveying apparatus of claim 1, 2, 3 or 4, wherein the powder container is a powder container detachable from the apparatus body, and the powder container The container includes a latest drive time recording means for recording the latest drive time of the powder pump.
According to a sixth aspect of the present invention, in the powder conveying device according to the first, second, third, fourth, or fifth aspect, the screw pump rotates the screw-shaped rotating body when driving is input to the powder pump. Thus, the screw pump applies a negative pressure to the powder in the powder container.
The invention according to claim 7 is the powder conveying apparatus according to claim 6, further comprising a rotation angle detection means for detecting a rotation angle of the rotating body provided in the powder pump, and the detection result of the rotation angle detection means. The above-mentioned powder conveyance based on the following formula (1) using an actual rotation angle of a certain rotating body and a reference rotation angle at which a reference conveyance amount can be obtained for one driving of the powder pump. The quantity prediction value is corrected.
Predicted value of powder conveyance amount per drive = reference conveyance amount x (actual rotation angle) / (reference rotation angle) (1)
The invention according to claim 8 is directed to an image forming unit that forms an image on the surface of a recording medium or a transfer member using a developer that is powder, and a developer transport destination from the developer containing unit that contains the developer. An image forming apparatus comprising a developer conveying means for conveying a developer to the apparatus, comprising the powder conveying apparatus according to claim 1, 2, 3, 4, 5, 6 or 7 as the developer conveying means. It is a feature.
According to a ninth aspect of the present invention, in the image forming apparatus according to the eighth aspect, the developer accommodating portion is a replenishing developer accommodating portion for accommodating a replenishing developer, and the developer transport destination is the image forming portion. The developer conveying means is a developer replenishing means.
According to a tenth aspect of the present invention, in the image forming apparatus according to the ninth aspect, a replenishment developer container that can be attached to and detached from the apparatus main body as the replenishment developer container, and the replenishment developer container. The replenishment developer container includes a latest drive time recording means for recording the latest drive time of the powder pump, and the latest drive when the exterior cover is opened. The latest drive time value is recorded in the time recording means.
The invention of claim 11 is the image forming apparatus according to claim 9 or 10, wherein the developer remaining in the replenishment developer container is determined based on the predicted developer replenishment amount that is the predicted powder transport amount. The quantity is calculated.
According to a twelfth aspect of the invention, in the image forming apparatus of the eighth, ninth, tenth or eleventh aspect, the developer is a toner.
According to a thirteenth aspect of the present invention, in the image forming apparatus according to the eighth, ninth, tenth, or eleventh aspect, the developer is a developer in which a toner and a carrier are mixed.

  In the powder conveying apparatus according to the first to thirteenth aspects, since the driving time for one conveying drive is a fixed driving time, the variation in the amount of powder conveying due to the length of one driving time of the powder pump varies. Does not occur. Further, the predicted powder transport amount is corrected in accordance with the drive interval of the powder pump that causes variations in the actual powder transport amount in one transport drive with a constant drive time. As a result, it is possible to calculate the predicted powder transport amount in consideration of the variation in the actual powder transport amount caused by the drive driving drive interval.

  According to the first to thirteenth aspects of the present invention, the powder transport amount prediction value is calculated in consideration of the variation in the actual powder transport amount caused by the drive driving drive interval, thereby further accurately predicting the powder transport amount. There is an excellent effect that the value can be calculated.

Hereinafter, an embodiment of an electrophotographic printer (hereinafter simply referred to as a printer 200) will be described as an image forming apparatus to which the present invention is applied.
First, the basic configuration of the printer 200 will be described. FIG. 1 is a schematic configuration diagram illustrating a printer 200. In FIG. 1, a printer 200 includes four process units 1Y, M, C, and K as image forming units that generate yellow, magenta, cyan, and black (hereinafter referred to as Y, M, C, and K) toner images. It has. These use Y, M, C, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same and are replaced when the lifetime is reached.
FIG. 2 is an enlarged view showing a schematic configuration of one of the four process units 1Y, 1M, 1C, and 1K.
As shown in FIG. 2, the process unit 1 includes a drum-shaped photosensitive member 2 that is an image carrier, a drum cleaning device 3, a charge eliminating device (not shown), a charging device 4, a developing device 5, and the like. The process unit 1 can be attached to and detached from the main body of the printer 200 so that consumable parts can be replaced at a time.

  The charging device 4 uniformly charges the surface of the photoreceptor 2 that is rotated clockwise in the drawing by a driving unit (not shown). In the figure, a charging roller 6 that is driven to rotate counterclockwise in the figure is brought into contact with the photosensitive member 2 while a charging bias is applied by a power source (not shown) to uniformly charge the photosensitive member 2. The charging device 4 is shown. Instead of the charging roller 6, a roller that contacts a charging brush may be used. Moreover, you may use what performs the charging process to the photoconductor 2 non-contact like a scorotron charger. The surface of the photoreceptor 2 uniformly charged by the charging device 4 is exposed and scanned by a laser beam emitted from an optical writing unit described later, and carries an electrostatic latent image for each color.

  The developing device 5 has a first agent storage portion 8 in which a first transport screw 7 is disposed. Further, it also has a second agent storage portion 13 in which a toner concentration sensor (hereinafter referred to as a T sensor) 9 including a magnetic permeability sensor, a second transport screw 10, a developing roller 11, a doctor blade 12, and the like are disposed. In these two agent accommodating portions, respective color developers (not shown) made up of magnetic carriers and negatively charged toners are included. The first transport screw 7 is driven to rotate by a driving unit (not shown), thereby transporting each color developer in the first agent container 8 from the front side to the back side in the drawing. And it penetrates in the 2nd agent accommodating part 13 through the communication port which is not shown in the partition wall provided between the 1st agent accommodating part 8 and the 2nd agent accommodating part 13. FIG. The second transport screw 10 in the second agent storage unit 13 is driven to rotate by a driving unit (not shown) to transport the developer from the back side to the front side in the drawing. The toner density of the developer being conveyed is detected by a T sensor 9 fixed to the bottom of the second agent storage unit 13. A developing roller 11 including a magnet roller 15 in a nonmagnetic pipe 14 that is driven to rotate counterclockwise in the figure is disposed in parallel above the second conveying screw 10 that conveys the developer in this manner. Has been. The developer conveyed by the second conveying screw 10 is pumped up to the surface of the nonmagnetic pipe 14 by the magnetic force generated by the magnet roller 15. Then, after the layer thickness is regulated by the doctor blade 12 arranged so as to maintain a predetermined gap with the nonmagnetic pipe 14, the layer thickness is transported to the developing area facing the photoconductor 2, and each color on the photoconductor 2. Toner is deposited on the electrostatic latent image. Due to this adhesion, a toner image is formed on the photoreceptor 2. The developer that has consumed the toner by the development is returned to the second conveying screw 10 as the nonmagnetic pipe 14 of the developing roller 11 rotates. And if it conveys to the front end in the figure, it will return in the 1st agent accommodating part 8 through the communication port which is not shown in figure.

  The result of detecting the magnetic permeability of the developer by the T sensor 9 is sent to a control unit (not shown) as a voltage signal. Since the magnetic permeability of the developer shows a correlation with the toner concentration of the developer, the T sensor 9 outputs a voltage having a value corresponding to the toner concentration. In accordance with this output voltage, a toner replenishing device described later is driven. By this driving, an appropriate amount of toner is supplied from the first agent storage unit 8 to the developer whose toner density has been reduced by consuming the toner during development. For this reason, the toner concentration of the developer in the second agent container 13 is maintained within a predetermined range.

  The toner image formed on the photoreceptor 2 is intermediately transferred to the intermediate transfer belt 41. The drum cleaning device 3 removes toner remaining on the surface of the photoreceptor 2 after the intermediate transfer process. As a result, the surface of the photoreceptor 2 that has been subjected to the cleaning process is neutralized by a neutralizing device (not shown). By this charge removal, the surface of the photoreceptor 2 is initialized and prepared for the next image formation. Such image formation is performed in the process units 1Y, 1M, 1C, and 1K for each color, and intermediate transfer is performed on the intermediate transfer belt.

  An optical writing unit 20 is disposed below the process units 1Y, M, C, and K in the drawing. The optical writing unit 20 serving as a latent image forming unit irradiates each photoconductor in each of the process units 1Y, 1M, 1C, and 1K with a laser beam L emitted based on the image information. As a result, electrostatic latent images for Y, M, C, and K are formed on the photoreceptors 2Y, M, C, and K. The optical writing unit 20 deflects the laser light L emitted from the light source by the polygon mirror 21 that is rotationally driven by a motor, and passes through the photoconductors 2Y, M, C, and K via a plurality of optical lenses and mirrors. Is irradiated.

  A first paper feed cassette 31 and a second paper feed cassette 32 are arranged on the lower side of the optical writing unit 20 in the drawing so as to overlap in the vertical direction. Each of these paper feed cassettes accommodates a plurality of transfer papers P as recording bodies in a stacked state, and the uppermost transfer paper P includes a first paper feed roller 31a, The second paper feed rollers 32a are in contact with each other. When the first paper feeding roller 31a is driven to rotate counterclockwise in the drawing by a driving means (not shown), the uppermost transfer paper P in the first paper feeding cassette 31 is vertically oriented on the right side of the cassette in the drawing. The paper is discharged toward the paper feed path 33 arranged so as to extend. When the second paper feed roller 32a is rotated counterclockwise in the figure by a driving means (not shown), the uppermost transfer paper P in the second paper feed cassette 32 is directed toward the paper feed path 33. Discharged. A plurality of transport roller pairs 34 are arranged in the paper feed path 33, and the transfer paper P sent to the paper feed path 33 is sandwiched between the rollers of the transport roller pair 34 while being fed between the paper feed paths 33. 33 is conveyed from the lower side to the upper side in the figure.

  A registration roller pair 35 is disposed at the end of the paper feed path 33. The registration roller pair 35 temporarily stops the rotation of both rollers as soon as the transfer paper P sent from the transport roller pair 34 is sandwiched between the rollers. Then, the transfer paper P is sent out toward a later-described secondary transfer nip at an appropriate timing.

  Above each of the process units 1Y, 1M, 1C, and 1K, a transfer unit 40 that is endlessly moved counterclockwise in the drawing while an intermediate transfer belt 41 that is an intermediate transfer member is stretched is disposed. In addition to the intermediate transfer belt 41, the transfer unit 40 includes a belt cleaning device 42, a first bracket 43, a second bracket 44, and the like. Also provided are four primary transfer rollers 45Y, 45M, 45C, 45K, secondary transfer backup roller 46, drive roller 47, auxiliary roller 48, tension roller 49, and the like. The intermediate transfer belt 41 is endlessly moved counterclockwise in the figure by the rotational driving of the driving roller 47 while being stretched by these eight rollers. The four primary transfer rollers 45Y, 45M, 45C, 45K sandwich the intermediate transfer belt 41 moved endlessly in this way between the photoreceptors 2Y, 2M, 2C, and 2K to form primary transfer nips. ing. Then, a transfer bias having a polarity opposite to that of the toner (for example, plus) is applied to the back surface (loop inner peripheral surface) of the intermediate transfer belt 41. The intermediate transfer belt 41 sequentially passes through the primary transfer nips for Y, M, C, and K as the endless movement of the intermediate transfer belt 41, and on the photoreceptor 2Y, M, C, and K on the front surface. The Y, M, C, and K toner images are superimposed and primarily transferred. As a result, a four-color superimposed toner image (hereinafter referred to as a four-color toner image) is formed on the intermediate transfer belt 41.

  The secondary transfer backup roller 46 sandwiches the intermediate transfer belt 41 with the secondary transfer roller 50 disposed outside the loop of the intermediate transfer belt 41 to form a secondary transfer nip. The registration roller pair 35 described above sends the transfer paper P sandwiched between the rollers toward the secondary transfer nip at a timing at which the transfer paper P can be synchronized with the four-color toner image on the intermediate transfer belt 41. The four-color toner image on the intermediate transfer belt 41 is affected by the secondary transfer electric field formed between the secondary transfer roller 50 to which the secondary transfer bias is applied and the secondary transfer backup roller 46, and the influence of the nip pressure. The secondary transfer is batch-transferred onto the transfer paper P in the secondary transfer nip. Then, combined with the white color of the transfer paper P, a full color toner image is obtained.

  Transfer residual toner that has not been transferred to the transfer paper P adheres to the intermediate transfer belt 41 after passing through the secondary transfer nip. This is cleaned by the belt cleaning device 42.

  A fixing device 60 including a pressure roller 61 and a fixing belt unit 62 is disposed above the secondary transfer nip in the drawing. The fixing belt unit 62 of the fixing device 60 moves the fixing belt 64 endlessly in the counterclockwise direction in the drawing while being stretched by the heating roller 63, the tension roller 65, and the driving roller 66. The heating roller 63 includes a heat source such as a halogen lamp, and heats the fixing belt 64 from the back side. The pressure roller 61 that is driven to rotate clockwise in the drawing is in contact with the surface of the fixing belt 64 that is heated in this manner from the front surface side. Thereby, a fixing nip where the pressure roller 61 and the fixing belt 64 abut is formed.

  The transfer paper P that has passed through the secondary transfer nip is separated from the intermediate transfer belt 41 and then fed into the fixing device 60. Then, in the process of being conveyed from the lower side to the upper side in the figure while being sandwiched by the fixing nip, the full-color toner image is fixed by being heated or pressed by the fixing belt 64.

  The transfer sheet P subjected to the fixing process in this manner is discharged outside the apparatus after passing between the rollers of the discharge roller pair 67. A stack unit 68 is formed on the upper surface of the housing of the printer main body, and the transfer sheets P discharged to the outside by the pair of discharge rollers 67 are sequentially stacked on the stack unit 68.

  Above the transfer unit 40, four toner cartridges 100Y, 100M, 100C, and 100K that store Y, M, C, and K toners are disposed. The Y, M, C, and K toners in the toner cartridges 100Y, 100M, and 100K are appropriately supplied to the developing devices of the process units 1Y, 1M, 1C, and 1K, respectively. The toner cartridges 100Y, 100M, 100C, and 100K can be attached to and detached from the printer body independently of the process units 1Y, 1M, 1C, and 1K.

  FIG. 3 is a perspective view showing one of the four toner cartridges 100Y, 100M, 100C, and 100K. FIG. 4 is an enlarged cross-sectional view showing the front end portion of the toner cartridge 100. The toner cartridge 100 includes a bottle-shaped bottle portion 101 formed of a material such as PET that stores toner (not shown), and a cylindrical holder portion 102. The holder portion 102 rotatably holds the bottle portion 101 while engaging the tip portion of the bottle portion 101 so as to cover an opening (not shown) formed at the tip of the bottle portion 101. Further, the outer wall of the holder portion 102 is provided with a nonvolatile memory 106 which will be described in detail later. On the inner wall of the bottle portion 101, a spiral protrusion 103 protruding from the outside toward the inside is embossed along the circumferential surface thereof. The bottle part 101 is integrally formed with a gear, and a driving force is given by a driving gear (not shown). The bottle part 101 and the holder part 102 are integrally engaged by a snap fit. Then, the front end surface of the bottle portion 101 is put on a seal member 118 made of foamable polyurethane (foamed PUR) or the like attached to the holder portion 102 to prevent toner leakage.

When the bottle unit 101 rotates, the toner in the bottle unit 101 moves along the spiral projection 103 from the bottle bottom side toward the bottle tip side. Then, the toner flows into the toner storage portion 114 in the cylindrical holder portion 102 through an opening (not shown) provided at the tip of the bottle portion 101 which is a toner container. Then, the toner is supplied from the bottle unit 101 so that the toner is always present in the toner suction unit 105 of the toner replenishing device described in detail later.
The driving of the bottle unit 101 has a control specification such that it rotates 500 [msec] in synchronization with the operation of the powder pump 70 (see FIG. 5). The rotation speed of the bottle unit 101 is 46 [rpm]. Even if the toner cartridge is rotated for a longer period of time, there is no conveyance force enough to push the toner near the toner suction portion 105, which is not a problem. However, since the bottle portion 101 is configured to rotate with its tip pressed against the seal member 118, the seal member 118 is broken due to sliding between the tip of the bottle portion 101 and the seal member 118. There is a concern. Therefore, only the minimum necessary rotation time is rotated.

  When the toner cartridge 100 is set on a cartridge mounting table of a toner replenishing device, which will be described later, first, an exterior cover as an opening / closing door (not shown) provided on the side plate of the printer casing is opened. Then, the cartridge mounting table of the toner supply device in the housing is exposed. This cartridge mounting table is provided with four semi-cylindrical recesses for mounting four toner cartridges for Y, M, C, and K in parallel. The operator holds the toner cartridge 100 in such a posture that the holder portion 102 is positioned at the head. Then, after placing the holder part 102 on the end of each color depression among the four depressions on the half cylinder provided on the cartridge mounting table, it slides along the bottle rotation axis direction so that the entire cartridge is inserted. Let By this sliding movement, the toner cartridge 100 is pushed into a predetermined position and set on the cartridge mounting table.

Next, a toner replenishing device as a powder conveying device provided in the printer 200 will be described. FIG. 5 is a schematic explanatory diagram of the toner supply device 300. As shown in FIG. 5, the toner replenishing device 300 includes a powder pump 70 above the developing device 5, and toner is supplied into the developing device 5 by the operation of the powder pump 70.
Note that the printer 200, which is an image forming apparatus that forms a color image, includes four toner replenishing devices that replenish yellow, magenta, cyan, and black toners to the four developing devices 5Y, 5M, 5C, and 5K, respectively. 300.

  As the powder pump 70, a suction type uniaxial eccentric screw pump (commonly known as a MONO pump) or the like is used. The structure is composed of a rotor 71 formed in a screw shape eccentrically made of a rigid material such as metal, a stator 72 which is molded into a screw shape with two inner parts made of rubber material, and is wrapped and powdered. The housing 73 is formed of a resin material or the like that forms a body transfer path. The rotating shaft 74 of the rotor 71 is connected to a supply clutch 75 that is a drive transmission unit, and the rotational drive of the drive gear 76 a is transmitted through the supply clutch 75. Due to the rotation of the rotor 71, a strong self-priming force (suction pressure) is generated in the pump, and the toner can be sucked from the toner suction portion 105 of the toner cartridge 100.

The drive control of the toner replenishing device 300 uses a conventionally known developer concentration detection / control system.
FIG. 6 is a block diagram of the toner supply device 300. In the toner replenishing device 300, the detection result of the T sensor 9 provided in a part of the developing device 5 is transmitted to the control unit 301. Based on the detection result, a change in the mixing ratio of the toner and the carrier in the developing device 5 is detected. When it is detected that the toner amount is small, the control unit 301 controls the driving of the powder pump 70. More specifically, by controlling the drive motor 76 and the replenishment clutch 75 that transmit the drive to the drive gear 76a, the drive is transmitted to the rotary shaft 74 of the powder pump 70, and the rotary shaft 74 rotates and the powder pump 70 Operate. When the toner transferred into the developing device 5 by the powder pump 70 exceeds a certain amount, the control unit 301 stops driving and stops the driving of the powder pump 70 by the detection signal of the T sensor 9. As other methods, conventionally known techniques such as a method of detecting the reflection density of the toner image on the photosensitive member 2 and controlling the same toner replenishment amount can be used.
The tube 78, which is a toner transfer member that forms a toner replenishment path, has a tube shape with an inner diameter of 4 to 10 mm, is flexible and has excellent toner resistance, such as rubber materials (ex polyurethane, nitrile, EPDM, silicon, etc.) It is very effective to use a plastic material (polyethylene, nylon, etc.).

  The sucked toner falls into the developing device 5 through a toner introduction hole 77 provided in a part of the developing device 5, and is further transferred to the developing unit by the first transport screw 7 and the second transport screw 10 described above. The When the two-component developing method is used, the toner (sucked toner) replenished during the transfer process is agitated and mixed with the developer in the developing device 5 to obtain a uniform agent concentration and an appropriate charge amount.

  In order to suck and convey the toner by the powder pump 70, it is necessary that the toner always exists in the vicinity of the toner suction portion 105. The toner cartridge 100 that supplies toner to the vicinity of the toner suction portion 105 has a spiral protrusion on the inner wall of the storage container shown in FIGS. 3 and 4, and conveys the toner to the tip of the container by the rotation of the storage container itself. A form is mentioned. Moreover, it is not restricted to such a form. For example, the toner accommodating portion of the toner cartridge 100 may be provided with a coil spring, or the toner may be conveyed to the tip of the container by rotating the coil spring.

Next, a method for calculating the predicted toner supply amount of the toner supply device 300 will be described.
In the toner replenishing device 300, a single replenishment driving time for driving the powder pump 70 to be replenished is defined as a constant driving time (200 [msec] in the present embodiment), and the amount of toner replenishment depends on the number of times the powder pump 70 is driven. Calculate the predicted value.
When calculating the predicted toner replenishment amount, a reference replenishment amount as a reference transport amount, which is a toner replenishment amount in one replenishment drive of the powder pump 70, is previously determined from experimental data and the like. Then, the reference replenishment amount is stored in the main body side memory 302 which is a storage unit provided in the toner replenishing device 300. The calculation of the predicted toner replenishment value in the toner replenishing device 300 is a system that calculates the predicted toner replenishment amount from the actual number of times of driving using the reference replenishment amount. In order to establish this system, it is necessary to consider the case where the toner in the toner cartridge 100 is replaced before it is used up. On the other hand, in the toner replenishing device 300, the toner consumption amount as a cumulative toner replenishment amount prediction amount that is a cumulative developer replenishment amount prediction value is stored in the nonvolatile memory 106 that is a cumulative replenishment amount prediction value recording unit provided in the toner cartridge 100. This is supported by always writing the data. When the toner cartridge 100 removed from the printer 200 before the toner is used up is mounted in the printer 200 again, the toner consumption data in the non-volatile memory 106 is called and used to detect the remaining amount of toner. The writing of data to the nonvolatile memory 106 and the calling of data from the nonvolatile memory 106 are performed by the external memory communication unit 303 provided on the cartridge mounting of the printer 200 main body. As described above, by writing the toner consumption data in the nonvolatile memory 106 included in the toner cartridge 100, the remaining amount of toner can be detected by attaching the data to the printer 200 again even if the toner is replaced before it is used up. it can. It should be noted that the toner end is detected when the difference between the total toner amount inputted in advance to the nonvolatile memory 106 provided in the toner cartridge 100 and the remaining amount of toner falls below a predetermined value.

Next, the characteristic part of this embodiment is demonstrated.
As described with reference to FIG. 8, as a characteristic of the powder pump 70, when the driving interval is short, there is no opportunity for depressurization when the driving interval is short, so the negative pressure generated tends to increase. is there. It has been found that even if the total drive time is the same, the amount of toner replenishment differs in each case. Therefore, even if the driving time of one replenishment driving of the powder pump 70 is fixed to 200 [msec], the toner replenishment amount predicted value when the driving interval is short (0 to 2 [sec] interval) and the driving When the toner replenishment amount predicted value when the interval is long (2 [sec] interval or more) is integrated as the same value, the calculated accumulated toner replenishment amount is the actual accumulated toner in the toner consumption amount of one toner cartridge 100. It can be very far from the replenishment amount.

  Therefore, in the toner replenishing device 300 of this embodiment, 2 [sec] is set as a threshold, and the driving interval is short (0 to 2 [sec] interval), and the driving interval is long (2 [sec] interval or more). Correction is performed so that the predicted toner replenishment amount increases. This improves the accuracy of the predicted toner supply amount. Specifically, the latest driving time of the powder pump 70 is stored in the main body side memory 302 of the toner replenishing device 300, and the correction value is changed depending on how much the driving of the powder pump 70 has elapsed from that time. It is a mechanism.

Hereinafter, one embodiment of correction control of the toner supply amount prediction value according to the drive interval of the powder pump of the toner supply device 300 will be described.
FIG. 7 is a flowchart showing correction control of the predicted toner supply amount of the toner supply device 300.
When driving is input to the powder pump 70, the driving start time t _ON is calculated and written in the main body side memory 302 (S1). Then, the drive interval t is calculated as t = t _ON −t _{Off from the} drive stop time t _Off and the drive start time t _ON stored in the main body side memory 302 (S2). If the calculated drive interval t is 10 [min] or more (Y in S3), and calculated by _C 1 = 0.9 × _{C 0} to the reference supply amount _{C 0} the toner supply amount predicted value _{C 1} (S4) . On the other hand, the calculated drive interval t is 10 [min] below (in S3 Y), and, in the case of 2 [s] or more (Y in S5), the toner supply amount predicted value _{C 1} with respect to the reference supply amount _{C 0} Calculation is performed with C ₁ = C ₀ (S6). The driving distance t is of less than 2 [s] (N in S5), and calculated by _C 1 = 1.1 × _{C 0} the toner supply amount predicted value _{C 1} with respect to the reference supply amount _{C 0} (S7) .
Then, the driving stop time t _Off of the powder pump 70 is calculated and written in the main body side memory 302 (S8). Then, in addition the calculated toner supply amount predicted value C ₁ in the cumulative toner supply amount predicted value C until the previous dispense driving, and updates the cumulative toner supply amount predicted value C (S9). The updated cumulative toner supply amount predicted value C is compared with the total toner amount _CE of the toner cartridge 100 stored in the nonvolatile memory 106, and the cumulative toner supply amount predicted value C is equal to or greater than the total toner amount _CE . If this is the case (Y in S10), toner end processing is performed (S11). When the cumulative toner supply amount predicted value C is less than the total toner amount _CE (N in S10), normal correction control is repeated.

In the flowchart of FIG. 7, the correction position for multiplying the reference supply amount C ₀ used for calculating the toner supply amount prediction value C ₁ is acquired in advance from the experimental results. Also, it provided more correction value, the more you finer threshold driving time interval t, the accuracy toner supply amount predicted value C ₁ is improved.
The toner replenishing device 300 includes temperature / humidity detecting means (not shown), and if the installation environment of the device is 32 [° C.] or higher, the toner replenishing amount predicted value C ₁ calculated based on the reference replenishing amount C ₀ is obtained. Corrections such as multiplying the value by 0.9 are further performed. The same correction is performed when the humidity is equal to or higher than a predetermined humidity. The toner fluidity is lowered in high temperature and high humidity environments, by performing the correction in response to changes in the environment, the accuracy toner supply amount predicted value C ₁ is improved.

  In addition, the toner replenishing device 300 includes an encoder (not shown) as a rotation angle detection unit that can detect the rotation angle of the rotation shaft 74 of the rotor 71 that is a rotating body included in the powder pump 70. Then, the amount of loss due to clutch slip or the like with respect to the reference rotation angle at which the reference replenishment amount can be obtained with respect to one driving (200 [msec]) of the powder pump 70 obtained by experiment, or when the clutch is stopped It also corrects for errors such as follow-up and motor connection time loss. That is, the correction is performed by multiplying the reference supply amount by the value of {(actual rotation angle) / (reference rotation angle)}.

By performing the correction as described above, it is possible to calculate the toner supply amount predicted value with higher accuracy than the calculation of the toner supply amount predicted value based on the simple number of rotations.
In addition, the nonvolatile memory 106 provided in the toner cartridge 100 records the latest powder pump driving time when the exterior cover is opened and closed. As a result, even when the toner cartridge 100 that has not used up the toner is detached, the correction value is accurately determined without making the driving interval of the powder pump 70 unclear. Note that the toner consumption data is always written in the nonvolatile memory 106.
In the flowchart shown in FIG. 7, the drive stop time t _off is stored, but since the drive time for one time is constant, only the drive start time t _on is stored, and the drive start time t _on of the latest replenishment operation is stored. And the drive start time t _on of the previous replenishment operation may be compared to calculate the drive interval t.
Although the cumulative toner supply amount prediction value is recorded, the cumulative number of times may be recorded. In such a case, the number of replenishment operations in the drive interval that require correction by multiplying the reference replenishment amount by the correction value is normally accumulated by correcting the count of 1 to 0.9 or 1.1. Record as a count.
In addition, although the driving time of one replenishment drive of the powder pump 70 of the present embodiment is assumed to be 200 [msec], how long is the driving time of one replenishment drive that is a constant driving time? Whether or not to be changed may be changed according to the setting.
The above is a description of a toner replenishing device that transports and replenishes new toner used in image forming apparatuses such as copying machines, among other powders. However, as a powder transporting device equipped with the features of the present invention, toner replenishment is described. It is not limited to a device. In order to satisfy various demands for environmental problems and resource recycling in recent years, various toner recycling mechanisms for returning the collected residual toner to the developing device and recycling it as a developer have been proposed. The powder supply device of the present invention can also be applied to a recycling mechanism that transports recycled toner as powder. Further, the configuration in which the replenishment developer is toner has been described. However, the present invention is not limited to this, and the present invention can also be applied to a developer replenishment device that replenishes a developer in which a carrier is mixed with the replenishment toner. In this way, by supplying the developer in which the carrier is mixed with the replenishing toner, the carrier in the developing device 5 can be replaced, and the life of the developer in the developing device 5 can be extended. .

As described above, according to the present embodiment, a single replenishment drive time for driving the powder pump 70 to be replenished is set to a fixed drive time (200 [msec]). The toner replenishment amount does not vary. Furthermore, causing a single replenishment driving time and calculates the toner replenishment predicted value C ₁ by the drive number as a constant, the actual toner conveyance amount of the driving time in a single dispense driving with a constant variation depending on the value of the driving time interval t of the powder pump 70, to correct the toner supply amount predicted value C ₁ with respect to the reference supply amount C _0. Thus, the calculation of the toner supply amount predicted value C ₁ in view of the actual toner supply amount of variation caused by the driving interval t of the replenishment driving of the powder pump 70 can be performed, the more accurately the toner replenishment amount predicted value There is an excellent effect that it can be calculated.
Further, the driving interval of the powder pump 70 is corrected by correcting the predicted toner replenishment amount based on the magnitude relationship between the driving interval t of the powder pump and a predetermined time of 10 [min] or 2 [sec] as a threshold. Correction of the predicted toner supply amount according to the value of t can be realized.
Further, by correcting the toner supply amount predicted value according to the detection result of the temperature / humidity detecting means, it is possible to correct the toner supply amount predicted value according to the fluidity of the toner which changes according to the change in the installation environment. it can.
Further, the toner cartridge 100 as a powder container includes a non-volatile memory 106 as a cumulative conveyance amount recording unit that records a cumulative toner replenishment amount prediction value that is a cumulative powder conveyance amount prediction value. Since the toner consumption amount information is provided, the toner consumption amount information can be reliably managed.
Further, the non-volatile memory 106 of the toner cartridge 100 records the latest driving time of the powder pump 70 as the latest driving time recording means, so that the powder pump can be removed even if the toner cartridge 100 that has not used up the toner is detached. The correction value is accurately determined without making the driving interval 70 unclear.
Further, since the powder pump 70 is a screw pump that applies a negative pressure to the toner by rotating the rotor 71 that is a screw-shaped rotating body, the space occupied by the powder pump 70 can be reduced, and the apparatus The overall size can be reduced.
Further, the toner supply amount prediction value is determined as the reference supply amount by the actual rotation angle of the rotating shaft 74 of the rotor 71 and the reference rotation angle at which the reference conveyance amount can be obtained for one driving of the powder pump 70. By calculating by the amount x (actual rotation angle) / (reference rotation angle), it is possible to correct a loss due to clutch slip, an error such as a follow-up when the clutch is stopped, and a motor connection time loss. .
In addition, by providing the toner replenishing device 300 as a toner replenishing unit of the image forming apparatus, it is possible to calculate a highly accurate predicted toner replenishing amount.
In addition, the nonvolatile memory 106 provided in the toner cartridge 100 records the latest powder pump driving time when the exterior cover is opened and closed. As a result, even when the toner cartridge 100 that has not used up the toner is detached, the correction value is accurately determined without making the driving interval of the powder pump 70 unclear.
Further, by calculating the remaining amount of toner in the toner cartridge 100 based on the calculated predicted toner supply amount, the remaining amount of toner can be detected more accurately. Accordingly, it is possible to realize the printer 200 as an image forming apparatus including the toner replenishing device 300 that is free from defects such as image fading just before the toner end.
In addition, by using a developer in which toner and a carrier are mixed instead of the toner of the toner replenishing device 300, the carrier in the developer in the developing device 5 can be replaced, and the life of the developer is extended. be able to.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 2 is an enlarged configuration diagram illustrating a process unit of the printer. FIG. 3 is a perspective view illustrating a toner cartridge of the printer. FIG. 3 is an enlarged cross-sectional view of a front end portion of the toner cartridge. FIG. 2 is a schematic explanatory diagram of a toner supply device provided in the printer. FIG. 3 is a block diagram of the toner supply device. 7 is a flowchart showing correction control of a predicted toner supply amount of the toner supply device. The graph which shows the outline of the relationship between the ON-OFF timing of a powder pump, and the pressure fluctuation by a powder pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Process unit 2 Photoconductor 3 Drum cleaning apparatus 4 Charging apparatus 5 Developing apparatus 6 Charging roller 9 T sensor 41 Intermediate transfer belt 70 Powder pump 71 Rotor 72 Stator 73 Housing 74 Rotating shaft 75 Replenishment clutch 76 Drive motor 76a Drive gear 100 Toner Cartridge 105 Toner suction unit 106 Non-volatile memory 200 Printer 300 Toner supply device

Claims (13)

A negative pressure is applied to the powder in the powder container, and a powder pump is provided to convey the powder to a conveyance destination.
In the powder conveyance device for calculating a powder conveyance amount prediction value which is a predicted value of the conveyance amount of the powder according to the number of driving times, with a single conveyance drive time for conveying and driving the powder pump as a constant drive time,
A powder conveyance device, wherein the powder conveyance amount prediction value is corrected in accordance with a driving interval of the powder pump. In the powder conveying apparatus according to claim 1,
The powder conveyance device, wherein the powder conveyance amount prediction value is corrected based on a magnitude relationship between a driving interval of the powder pump and a predetermined time as a threshold value. In the powder conveying apparatus according to claim 1 or 2,
A powder conveyance apparatus comprising temperature and humidity detection means for detecting temperature and humidity in an installation environment, and correcting the powder conveyance amount predicted value according to a detection result of the temperature and humidity detection means. In the powder conveying apparatus according to claim 1, 2, or 3,
The powder container is a powder container detachable from the apparatus main body,
The powder container includes cumulative conveyance amount recording means for recording a cumulative powder conveyance amount predicted value calculated from the cumulative number of driving times of the powder pump and the powder conveyance amount prediction value. Powder conveying device. In the powder conveying apparatus according to claim 1, 2, 3, or 4,
The powder container is a powder container detachable from the apparatus main body,
The powder container includes a latest drive time recording means for recording the latest drive time of the powder pump. In the powder conveying apparatus according to claim 1, 2, 3, 4, or 5,
The powder conveying apparatus according to claim 1, wherein the powder pump is a screw pump that applies a negative pressure to the powder in the powder container by rotating a screw-shaped rotating body when driving is input. In the powder conveying apparatus of Claim 6,
A rotation angle detecting means for detecting a rotation angle of the rotating body provided in the powder pump;
The following (1) using the actual rotation angle of the rotating body, which is the detection result of the rotation angle detecting means, and the reference rotation angle at which a reference conveyance amount can be obtained for one driving of the powder pump. The powder conveyance device is characterized in that the powder conveyance amount prediction value is corrected based on the equation (1).
Predicted value of powder conveyance amount per driving = reference conveyance amount × (actual rotation angle) / (reference rotation angle) (1) An image forming unit that forms an image on the surface of a recording medium or a transfer member using a developer that is powder;
In an image forming apparatus comprising: a developer conveying unit that conveys the developer from a developer accommodating unit that accommodates the developer to a developer conveying destination;
An image forming apparatus comprising the powder conveying device according to claim 1 as the developer conveying means. The image forming apparatus according to claim 8.
The developer accommodating portion is a replenishing developer accommodating portion for accommodating a replenishing developer, the developer conveying destination is the image forming portion, and the developer conveying means is a developer supplying means. An image forming apparatus. The image forming apparatus according to claim 9.
A replenishment developer container detachably attached to the apparatus main body as the replenishment developer container;
An exterior cover that opens when the developer container for replenishment is attached or detached,
The replenishment developer container includes a latest driving time recording means for recording the latest driving time of the powder pump,
An image forming apparatus, wherein the latest drive time value is recorded in the latest drive time recording means when the exterior cover is opened. The image forming apparatus according to claim 9 or 10,
An image forming apparatus, wherein the remaining amount of developer in the replenishment developer container is calculated based on a predicted developer replenishment amount that is a predicted powder transport amount. The image forming apparatus according to claim 8, 9, 10, or 11.
The image forming apparatus, wherein the developer is toner. The image forming apparatus according to claim 8, 9, 10, or 11.
The image forming apparatus according to claim 1, wherein the developer is a developer in which a toner and a carrier are mixed.

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