JP4744067B2 - Image forming apparatus and image forming method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus and an image forming method in which collected toner is supplied into a developing device and reused, and can be applied to, for example, a copier, a printer, a facsimile image forming apparatus, and the like.
[0002]
[Prior art]
In an image forming apparatus equipped with a toner recycling device, a negative charge is charged on the surface of the photosensitive drum, and the latent image is formed by exposing the photosensitive drum with a laser beam based on an image signal (change in surface potential), An image forming process is performed in which a negatively charged toner is adsorbed to form a visible image, and the positively charged visible image is transferred to a sheet and fixed.
[0003]
In such image formation, toner that has already been used for image formation and collected for recycling (hereinafter referred to as recovered toner), and new toner that has not yet been used for image formation (hereinafter referred to as new toner). ) And are used in combination. That is, the collected toner is recycled. The collected toner is recycled by a toner recycling apparatus.
[0004]
[Problems to be solved by the invention]
In the control of the conventional toner recycling apparatus, the recovered toner is replenished within a range that does not impair a stable image. That is, a stable image is obtained by automatically changing the collected toner supply amount, such as decreasing or stopping the collected toner supply amount in accordance with the setting value of the toner specific density of the developer in the developing device. Was in control.
[0005]
In this case, if priority is given to a stable image, the total amount of collected toner does not increase so much that the recycling rate is not very good.
[0006]
An object of the present invention is to reduce the image quality and increase the total amount of collected toner used within an allowable range that is not noticeable and causes no problem in order to increase the recycling rate of the collected toner.
[0007]
[Means for Solving the Problems]
The image forming apparatus and the image forming method of the present invention are made to achieve the above object, and the replenishment amount of the collected toner is increased or decreased according to the change of the printing rate. That is, when the ratio of the area where the toner is applied to the total area of the paper to be printed becomes higher, the replenishment amount of the recovered toner is increased. Further, a change in the distribution ratio may be considered together with the ratio of the area where the toner is applied to the entire area of the paper to be printed. That is, when the ratio of the area to which the toner is applied increases and the distribution of the applied toner reaches the entire paper surface, the replenishment amount of the collected toner may be increased.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of an image forming apparatus and an image forming method according to the present invention will be described below.
[0009]
FIG. 1 is a schematic front view showing a main part of the image forming apparatus of the present embodiment. FIG. 2 is a perspective view showing the new toner supply device of the present embodiment. FIG. 3 is a perspective view showing the image forming apparatus of the present embodiment. FIG. 4 is a perspective view showing the image forming apparatus according to the present embodiment except for the new toner replenishing device. FIG. 5 is a perspective view showing the toner recycling apparatus of the present embodiment. FIG. 6 is a perspective view showing the toner recycling apparatus of the present embodiment from a different viewpoint from FIG. FIG. 7 is a block diagram illustrating a control configuration of the image forming apparatus according to the present exemplary embodiment. FIG. 8 is a flowchart showing an image forming operation in the image forming apparatus of this embodiment.
[0010]
In the following description, it is assumed that the image forming apparatus of this embodiment is provided in a copying machine. An image forming apparatus incorporated in a copying machine is an apparatus for forming an image on a paper to be copied by a reversal development method and transferring it to paper. The overall configuration of the image forming apparatus will be described with reference to FIGS.
[0011]
The image forming apparatus 1 mainly includes a photosensitive drum 2, a charge eliminating unit 3, a charging charger 4, a developing unit 5, a transfer unit 6, a cleaner unit 7, and a new toner supply device 8 as a new toner supply unit. And a toner recycling device 9.
[0012]
The photosensitive drum 2 is a cylindrical drum that rotates in one direction (clockwise direction in FIG. 1; arrow B direction). The surface of the photosensitive drum 2 can be arbitrarily adjusted in its charged state by laser light. As a result, by appropriately adjusting the charged state of an arbitrary portion of the surface of the photosensitive drum 2, an image as data to be transferred can be formed as a latent image on the surface of the photosensitive drum 2. Yes.
[0013]
The charge removal unit 3 is for removing the charge on the surface of the photosensitive drum 2. The neutralization unit 3 includes a neutralization lamp 3A. By applying the light from the neutralization lamp 3A to the surface of the photosensitive drum 2, all residual charges on the surface are removed, and the next printing is prepared.
[0014]
The charging charger 4 is for charging the surface of the photosensitive drum 2. The surface of the photosensitive drum 2 that is negatively charged by the charging charger 4 is exposed by laser light emitted from a laser unit (not shown) to form a latent image. That is, the surface of the photosensitive drum 2 is exposed with laser light based on input information such as an original image, and the surface potential approaches 0 according to the density of the image or the like, thereby forming a latent image.
[0015]
The developing device 5 is a device for attaching an appropriate amount of toner to the surface of the charged photosensitive drum 2. Here, since the two-component development system is adopted, the developing device 5 accommodates the carrier and the toner, and the ratio of the toner is about 5% (weight%) with respect to the carrier of about 95% (weight%). It has been adjusted to be. Specifically, the new toner replenishing device 8 and the toner recycling device 9 are appropriately controlled to adjust the ratio of carrier to toner. The amount of toner in the developing device 5 is constantly monitored by the auto toner sensor 11. When the ratio of the toner in the developing device 5 is less than 5%, the control unit 70 described later appropriately controls the new toner supply device 8 and the toner recycling device 9 to supply a necessary amount of toner. The replenished toner and carrier are agitated by the mixer unit 5A in the developing device 5, and a negative charge is given to the toner by frictional charging during the agitation. The negatively charged toner is conveyed to the surface of the photosensitive drum 2 by the mag roller 12 and is attracted to the latent image, so that a visible image is formed.
[0016]
The transfer unit 6 is for transferring the toner adsorbed to the latent image on the surface of the photosensitive drum 2 onto paper. The transfer unit 6 mainly includes a transfer belt 13 and a paper supply unit 14. The transfer belt 13 conveys and supports paper and is brought into contact with the surface of the photosensitive drum 2 to transfer a visible image. The paper supply unit 14 is provided facing a contact portion between the transfer belt 13 and the photosensitive drum 2. The paper supplied from the paper supply unit 14 to the contact portion between the transfer belt 13 and the photosensitive drum 2 is positively charged and adsorbs negatively charged toner that forms a visible image. The paper on which the toner is copied is sent to a fixing device (not shown), and the toner is fused to the paper by thermocompression bonding.
[0017]
The cleaner unit 7 is for cleaning the surface of the photosensitive drum 2. The cleaner unit 7 removes toner remaining on the surface of the photosensitive drum 2 after being transferred to the paper by the transfer unit 6. The cleaner unit 7 includes a toner receiving unit 15 and a discharge auger 16 for discharging the toner removed from the surface of the photosensitive drum 2 to the outside. The toner removed from the surface of the photosensitive drum 2 falls to the toner receiving portion 15 and is discharged to the toner recycling device 9 side by the discharge auger 16.
[0018]
The new toner supply device 8 is a device for supplying new toner to the developing device 5. The new toner replenishing device 8 is disposed in a direction orthogonal to the developing device 5 as shown in FIGS. In this state, it is installed on the front side of the main body of the copying machine. The new toner supply device 8 includes a new toner hopper 18, an agitation transport paddle 19, a toner remaining amount detection sensor 20, and a transport unit 21.
[0019]
The new toner hopper 18 is a container for storing new toner. The new toner hopper 18 is constituted by a substantially semi-cylindrical container whose upper side is open. The semi-cylindrical new toner hopper 18 is divided into a shallow bottom portion 18A and a deep bottom portion 18B at the center in the longitudinal direction. Two stirring conveyance paddles 19 are arranged in parallel in the shallow bottom portion 18A. A toner remaining amount detection sensor 20 and a conveyance unit 21 are disposed on the deep bottom portion 18B.
[0020]
The agitation transport paddle 19 is a device for transporting the new toner stored in the new toner hopper 18 to the transport unit 21 while stirring. As described above, two agitation transport paddles 19 are arranged in parallel on the shallow bottom portion 18A of the new toner hopper 18. As the two agitating and conveying paddles 19 rotate, new toner in the new toner hopper 18 is transferred to the conveying portion 21 of the deep bottom portion 18B. Each agitation transport paddle 19 is driven by a driving device (not shown).
[0021]
The toner remaining amount detection sensor 20 is a sensor for detecting the remaining amount of new toner stored in the new toner hopper 18. Since the image formation cannot be performed when the toner runs out, the remaining amount detection by the toner remaining amount detection sensor 20 is always performed. As the toner remaining amount detection sensor 20, a known sensor such as a magnetic sensor or an optical sensor can be applied. It is selected as appropriate depending on how accurately the remaining amount of toner is detected.
[0022]
The transport unit 21 is for supplying new toner stored in the new toner hopper 18 to the developing device 5. The transport unit 21 includes a toner transport auger 23 and an auger drive unit 24. The toner transport auger 23 is a screw conveyor, and is provided in parallel with the new toner hopper 18 at the bottom of the deep bottom 18B. The toner conveying auger 23 is provided facing a toner receiving tray 64 described later, and supplies new toner stored in the new toner hopper 18. The auger drive unit 24 includes a drive motor (hereinafter referred to as a toner hopper motor) 26 and a speed reducer 27. The toner hopper motor 26 is constituted by a stepping motor, for example. The toner hopper motor 26 controls the rotation amount and rotation time of the toner transport auger 23 so that the supply amount of new toner is accurately controlled. The speed reducer 27 includes a belt 28, a pulley 29, and gears 30 to 36. The gears 30 to 36 are appropriately adjusted according to the reduction ratio. A stirring rod (not shown) disposed on the deep bottom 18B is attached to the rotation shaft of the gear 32.
[0023]
The toner recycling device 9 is for conveying the collected toner collected by the cleaner unit 7 to the developing unit 5 for reuse. The toner recycling device 9 is disposed substantially in parallel below the new toner supply device 8. As shown in FIGS. 3 to 6, the toner recycling device 9 includes a collected toner coupled transport auger 41 as a coupled transport device, a collected toner sub hopper 42 as a collected toner storage unit, and a supply auger 43. Yes.
[0024]
The collected toner connecting and conveying auger 41 is for conveying the collected toner collected by the cleaner unit 7 to the developing device 5 side. The recovered toner connection / conveying auger 41 is constituted by, for example, a long screw conveyor, and a lower end portion thereof is connected to the discharge auger 16 of the cleaner portion 7 and an upper end portion thereof is connected to the recovered toner sub hopper 42. The drive unit 45 of the collected toner coupled transport auger 41 includes a drive motor 47 provided adjacent to the upper end of the collected toner coupled transport auger 41, a pulley 48 coupled to the collected toner coupled transport auger 41, a drive motor 47 and a pulley. The belt 49 etc. which connect 48 are comprised. The drive motor 47 is controlled in conjunction with the drive motor of the discharge auger 16 of the cleaner unit 7.
[0025]
The collected toner sub hopper 42 is a container for temporarily storing the collected toner collected by the collected toner connection transport auger 41 and sending a necessary amount to the developing device 5. In the collected toner sub hopper 42, a stirring rod (not shown) is provided for stirring the collected toner stored inside. A collected toner replenishing auger 51 as a collected toner replenishing means is provided in the lower part of the collected toner sub hopper 42. The rotation of the collected toner replenishing auger 51 is controlled by the drive unit 52 so that an accurate amount of collected toner is replenished to the supply auger 43. The drive unit 52 includes a drive motor (sub hopper motor) 53 and a speed reducer 54. The sub hopper motor 53 is composed of, for example, a stepping motor. The speed reducer 54 is configured by combining a belt 55, a pulley 56, and gears 57 to 61. The gears 59 and 60 are provided to be connected to each other by a single rotating shaft on both sides of the collected toner sub hopper 42, and a stirring rod (not shown) is provided on the rotating shaft.
[0026]
The supply auger 43 is for receiving the collected toner and the new toner from the collected toner replenishing auger 51 and the toner conveying auger 23 of the new toner replenishing device 8 and supplying them to the developing device 5. The supply auger 43 opens toward the auger portion 63 provided to extend from the mixer portion 5A of the developing device 5, the recovered toner supply auger 51 of the toner recycling device 9, and the toner conveyance auger 23 of the new toner supply device 8. And a toner receiving tray 64. A drive motor (not shown) of the auger unit 63 is provided on the developing device 5 side. The collected toner supply auger 51 is provided on the developing device 5 side. In the toner tray 64, the new toner from the toner transport auger 23 of the new toner supply device 8 is supplied upstream of the recovered toner from the recovered toner supply auger 51. The new toner and the recovered toner supplied to the toner tray 64 are mixed with the carrier by the mixer unit 5A of the developing device 5 and stirred.
[0027]
FIG. 7 is a block diagram showing a control configuration of the image forming apparatus 1 of this embodiment.
[0028]
The control unit (indicated as CPU in FIG. 7) 70 is constituted by, for example, a CPU, a ROM, a RAM, and the like, and is based on a processing program stored in the ROM, the RAM, etc. It controls the entire image forming apparatus 1 according to data stored in the above and outputs from various sensors.
[0029]
To the input port of the control unit 70, the above-described toner remaining amount detection sensor 20 and auto toner sensor 11 are connected, and a front cover switch 71 is also connected.
[0030]
As described above, the remaining toner detection sensor 20 detects the remaining amount of new toner in the new toner hopper 18, and for example, a magnetic sensor including a magnet and a reed switch can be applied. When the remaining amount of new toner is large, new toner enters between the magnet and the reed switch, creating a gap between them, and the reed switch is turned off. Disappears and the reed switch is turned on by the magnet's attractive force. The controller 70 detects such reed switch on / off.
[0031]
As described above, the auto toner sensor 11 is a toner concentration ratio sensor that detects the ratio of the carrier (iron) and the toner (resin) in the developer. The output of the auto toner sensor 11 is read by the control unit 70. When the toner density decreases, the control unit 70 drives the toner hopper motor 26 and the like to replenish toner to the developing device 5 or displays on the control panel (not shown) etc. that there is no toner to notify the user.
[0032]
The front cover switch 71 is a switch that is turned off / on by opening / closing a main body cover (here, referred to as a front cover) of the copying machine. The output signal of the front cover switch 71 is read by the control unit 70, and the control unit 70 recognizes the state of the front cover.
[0033]
The output port of the control unit 70 is connected to two motor drivers 72 and 73 and a charging transformer 74.
[0034]
The photosensitive drum 2 and the cleaner unit 7 are driven by a drum motor 75 that is driven to rotate by a motor driver 72 under the control of the control unit 70 during copying or the like.
[0035]
Similarly, the developing device 5 and the transfer belt 13 are driven by the developing device motor 76 and the transfer belt motor 77, respectively, which are driven to rotate by the motor driver 72 during copying or the like under the control of the control unit 70.
[0036]
Similarly, the new toner hopper 18, the connected transport auger 41, and the collected toner sub hopper 42 are driven by a toner hopper motor 26, a connected transport auger motor 47, and a sub hopper motor 53 that are rotationally driven by a motor driver 73, respectively.
[0037]
The toner hopper motor 26, the coupled transport auger motor 47, and the sub hopper motor 53 are connected to the same motor driver 73, but can be individually driven under the control of the control unit 70.
[0038]
Under the control of the control unit 70, the charging charger 4 applies a high voltage by the charging transformer 74 to charge the photosensitive drum 2 during copying or the like as described above.
[0039]
Further, the control unit 70 stores the processing functions of the flowchart shown in FIG.
[0040]
On the control panel (not shown), a toner save mode switching button (not shown) is provided as toner save mode setting means for switching the control mode of the control unit 70. When the control panel is a touch panel, the toner save mode switching button is an icon.
[0041]
With this toner save mode switching button, a normal mode in which the collected toner having a preset mixing ratio is mixed with the new toner and reused, and the total supply amount of the collected toner and the new toner supplied to the developing device 5 are made constant. When the printing rate increases, the toner save mode for increasing the supply amount of the collected toner is manually switched arbitrarily. Here, the printing rate refers to the printing rate, which is the ratio of the area where the toner is applied by printing to the entire area of the paper on which characters are printed.
[0042]
Next, a toner recycling method using the toner recycling apparatus 9 will be described. Here, since a copying machine is described as an example, a toner recycling method in the operation of the copying machine will be described. FIG. 8 is a flowchart showing an image forming operation by the image forming apparatus 1.
[0043]
After turning on the main switch, the user selects whether to copy in the normal mode or in the toner save mode. When copying in the toner save mode, the toner save mode switching button on the control panel is pressed to switch to the toner save mode side. Next, set the document and press the start button. Thereby, in the control part 70, the following process is performed.
[0044]
First, when the main switch is turned on, a standby state in which the charger 4 and the like can function is set (step ST1). Next, it is determined whether or not the user has pressed the toner save mode switching button on the control panel (step ST2).
[0045]
When the toner save mode switching button is not pressed, the normal mode is set. In the normal mode, waiting for the user to press the copy start button (step ST3), it is determined whether or not the toner specific density in the developing device 5 is equal to or higher than a specified value (step ST4). If the toner specific density is not less than the specified value, the first copy is performed (step ST5), and it is determined whether or not the copy is completed (step ST6). When copying is completed, the process returns to the standby state in step ST1. If the copying has not ended, the processing from step ST4 to step ST6 is repeated.
[0046]
On the other hand, if it is determined in step ST4 that the toner specific density in the developing device 5 is not equal to or higher than the specified value, the collected toner replenishing auger 51 of the toner recycling device 9 is operated for 2 seconds, whereby the collected toner in the collected toner sub hopper 42 is collected. The toner is supplied to the supply auger 43, and the toner conveying auger 23 of the new toner replenishing device 8 is operated for 2 seconds to supply new toner in the new toner hopper 18 to the supply auger 43 (step ST7). Thereby, the supply auger 43 replenishes the collected toner and the new toner into the developing device 5 at the same mixing ratio.
[0047]
Next, it is determined whether or not the new toner in the new toner hopper 18 is empty (step ST8). If it is not empty, the process returns to step ST4 to determine whether or not the toner specific density in the developing device 5 has become equal to or higher than a specified value. Step ST4, step ST7 and step ST8 are repeated to return the toner specific density to a specified value or more.
[0048]
On the other hand, if it is determined in step ST8 that the new toner in the new toner hopper 18 is empty, the copying operation is stopped (step ST9), and a message indicating that the new toner is empty is displayed (step ST10). Next, it waits until new toner is replenished in the new toner hopper 18 (step ST11), and when it is replenished, it returns to step ST4 and repeats the above processing.
[0049]
On the other hand, if the toner save mode switching button is pressed in step ST2, the toner save mode is entered. Waiting for the user to press the copy start button (step ST12), the rotational speed of the mag roller 12 of the developing device 5 is decreased (step ST13). When the mag roller 12 has a normal normal rotation speed, the developer having a large collection ratio of the collected toner is likely to be scattered, and therefore the speed is reduced by several percent from the normal rotation speed.
[0050]
Next, it is determined whether or not the toner specific density in the developing device 5 is not less than a specified value (step ST14). If the toner specific density is equal to or higher than the specified value, the first copy is performed (step ST15), and it is determined whether or not the copy is finished (step ST16). When copying is completed, the process returns to the standby state in step ST1. If the copying has not ended, the processing from step ST14 to step ST16 is repeated.
[0051]
On the other hand, if it is determined in step ST14 that the toner specific density in the developing device 5 is not equal to or higher than the specified value, it is determined whether the printing rate is less than 10% (step ST17).
[0052]
If the printing rate is less than 10%, normal replenishment similar to step ST7 is performed (step ST18). That is, the recovered toner replenishing auger 51 of the toner recycling device 9 is operated for 2 seconds, and the toner transporting auger 23 of the new toner replenishing device 8 is operated for 2 seconds. To supply. Next, the process proceeds to step S22.
[0053]
If the printing rate is 10% or more, it is further determined whether or not the printing rate is 10% or more and less than 50% (step ST19). When the printing rate is 10% or more and less than 50%, the collected toner supply auger 51 of the toner recycling device 9 is operated for 2.6 seconds, and the toner transport auger 23 of the new toner supply device 8 is operated for 1.4 seconds. (Step ST20). As a result, the supply auger 43 supplies the collected toner and the new toner into the developing device 5 at a mixing ratio of 13: 7. Next, the process proceeds to step S22.
[0054]
When the printing rate is 50% or more, the collected toner supply auger 51 of the toner recycling device 9 is operated for 3.6 seconds, and the toner transport auger 23 of the new toner supply device 8 is operated for 0.4 seconds (step ST21). ). As a result, the supply auger 43 replenishes the developing unit 5 with the collected toner and the new toner at a mixing ratio of 9: 1.
[0055]
Next, it is determined whether or not the new toner in the new toner hopper 18 is empty (step ST22). If it is not empty, the process returns to step ST14 to determine whether or not the toner specific density in the developing device 5 has exceeded a specified value. Step ST14 and steps ST17 to ST22 are repeated to return the toner specific density to a specified value or more.
[0056]
On the other hand, if it is determined in step ST22 that the new toner in the new toner hopper 18 is empty, the copying operation is stopped (step ST23), and a message indicating that the new toner is empty is displayed (step ST24). Next, the process waits until new toner is replenished in the new toner hopper 18 (step ST25). When the new toner is replenished, the process returns to step ST14 to repeat the above processing.
[0057]
As described above, as the printing rate increases, the supply amount of the collected toner is increased to increase the total usage amount, thereby increasing the recycling rate of the collected toner. At this time, as the supply amount of the collected toner increases, stains such as spots appear on the white paper surface separately from the print portion, but these stains appear between many printed characters on the paper surface, so It does not stand out and does not become a problem. That is, since the supply amount of the collected toner is increased as the printing rate increases, the supply amount of the collected toner is small and the contamination is small when the blank paper surface is wide (when the printing rate is small). When the blank paper surface is narrow (when the printing rate is high), the amount of collected toner supplied is large and there are many stains, but the stains appear between characters and do not stand out. For this reason, it is possible to increase the recycling rate of the collected toner by increasing the supply amount of the collected toner as the printing rate increases, reducing the image quality within the allowable range, and increasing the total amount of the collected toner used.
[0058]
[Modification]
In the above-described embodiment, the printing rate has been described as an example of the printing rate. However, in the case of other printing modes such as figures and patterns, the same operations and effects as those in the above-described embodiment can be achieved.
[0059]
Further, although the printing rate is the ratio of the area where the toner is applied to the entire area of the paper, the distribution rate may be added as a determination factor. That is, the change in the distribution ratio may be considered together with the ratio of the area where the toner is applied to the area of the entire paper to be printed. When the ratio of the area to which the toner is applied becomes high and the distribution of the applied toner reaches the entire paper surface, the replenishment amount of the collected toner is increased. In the case where printing is performed in a part, even if the printing rate is large, the area of the white background portion is large, so that the stains are conspicuous. For this reason, even if the printing rate is large, if the distribution of the applied toner does not reach the entire paper surface, the replenishment amount of the collected toner is not increased.
[0060]
The distribution ratio of the applied toner is appropriately determined according to the reading method of the document. For example, when the image information read by the scanner is a dot and its position information, the printing rate can be calculated by a dot counter, and the distribution rate can be calculated by the dot position information. Further, the image information may be processed by pattern recognition to determine the distribution rate. Conversely, the distribution ratio may be determined by calculating or image processing a portion without dots or a white background. Furthermore, the distribution rate may be used together with the printing rate, or may be used alone.
[0061]
Further, in steps ST17 to ST21 in FIG. 8, the printing rate is controlled in three stages, but it goes without saying that it may be one stage, two stages, or four stages or more. In this case, a plurality of control steps may be provided in advance, and the user may switch appropriately as necessary on the control panel or the like.
[0062]
In each of the above-described embodiments, the rotation speed of the mag roller 12 of the developing device 5 is reduced by several percent from the normal rotation speed. This reduction is such that the developer is not scattered depending on the mixing ratio of the collected toner. Set as appropriate.
[0063]
Furthermore, the charge amount of the developer may be increased in order to prevent the developer from scattering. In this case, by controlling the rotation of the mixer section 5A in the developing device 5 to increase the charge amount of the developer, it becomes easy to be adsorbed to the photosensitive drum 2, and as a result, the developer scattering amount is reduced.
[0064]
Either one of the means for decreasing the rotation speed of the mag roller 12 or the means for increasing the charge amount may be used, or both of them may be performed.
[0065]
In each of the above embodiments, the copying machine has been described as an example. However, the present invention can be applied not only to the copying machine but also to other devices such as a printer and a facsimile that perform image formation using toner.
[0066]
Further, it can be applied to a color copying machine. In this case, the present invention is applied to each of the four image forming apparatuses 1 of the three primary colors and black. When the remaining amount of developer in any of the four image forming apparatuses 1 decreases, the toner supply amount is adjusted in accordance with the remaining amount of developer with respect to the other image forming apparatuses 1.
[0067]
【The invention's effect】
As described above in detail, the image forming apparatus and the image forming method of the present invention can provide the following effects.
[0068]
By increasing the supply amount of the collected toner and increasing the total amount of use as the printing rate increases, the recycling rate of the collected toner can be increased without conspicuous spots such as spots.
[Brief description of the drawings]
FIG. 1 is a schematic front view illustrating a main part of an image forming apparatus according to an exemplary embodiment.
FIG. 2 is a perspective view showing a new toner supply device of the present embodiment.
FIG. 3 is a perspective view illustrating the image forming apparatus according to the exemplary embodiment.
FIG. 4 is a perspective view illustrating the image forming apparatus according to the exemplary embodiment, excluding a new toner supply device.
FIG. 5 is a perspective view illustrating a toner recycling apparatus according to the exemplary embodiment.
6 is a perspective view showing the toner recycling apparatus of the present embodiment from a different viewpoint from FIG. 5. FIG.
FIG. 7 is a block diagram illustrating a control configuration of the image forming apparatus according to the present exemplary embodiment.
FIG. 8 is a flowchart illustrating an image forming operation in the image forming apparatus according to the present exemplary embodiment.
[Explanation of symbols]
1: image forming apparatus, 2: photosensitive drum, 3: charge eliminating unit, 4: charging charger, 5: developing device, 6: transfer unit, 7: cleaner unit, 8: new toner replenishing device, 9: toner recycling device, 11: auto toner sensor, 12: mag roller, 13: transfer belt, 14: paper supply unit, 15: toner receiving unit, 16: discharge auger, 18: new toner hopper, 18A: shallow bottom, 18B: deep bottom, 19: stirring Transport paddle, 20: Toner remaining amount detection sensor, 21: Transport section, 23: Toner transport auger, 24: Auger drive section, 26: Drive motor, 27: Reducer, 28: Belt, 29: Pulley, 30 to 36: Gear: 41: Collected toner coupled transport auger, 42: Collected toner sub-hopper, 43: Supply auger, 45: Drive unit, 47: Drive motor, 48: Pulley, 49: Belt, 51: Collected toner Feed auger, 52: driver, 53: drive motor, 54: reduction gear, 55: Belt 56: pulley, 57-61: gear, 63: auger section, 64: a toner receiving tray section,

Claims (14)

Collected toner supply means for supplying the collected toner to the developing device;
New toner supply means for supplying new toner to the developer;
A first amount of the collected toner when the printing rate is a first value;
A second amount of the collected toner that is greater than the first amount when the printing rate is a second value greater than the first value;
When the printing rate is a third value larger than the second value, a third amount of the collected toner that is larger than the second amount is supplied to the developer together with the new toner, As the print rate exceeds the plurality of specified values stepwise, the replenishment amount of the collected toner is set to increase stepwise, and the toner for the carrier before the copy operation for each copy operation of one sheet of paper When the toner specific density in the developing device detected by the sensor based on the ratio is not equal to or higher than a preset specified value and the printing rate is the above values, the replenishment amount of the recovered toner corresponding to the value is selected. An image forming apparatus comprising: a control unit that controls the image forming apparatus. Collected toner storage means for temporarily storing the collected toner;
A connected conveying device for conveying the collected toner from the cleaner unit to the collected toner containing means;
Recovered toner replenishing means for replenishing the developer with the recovered toner stored in the recovered toner storage means;
New toner storage means for storing new toner,
New toner supply means for supplying new toner stored in the new toner storage means to the developer;
Toner save mode setting means for setting the toner save mode;
When the toner save mode is set and the toner specific density in the developing device detected by the sensor based on the ratio of the toner to the carrier prior to the copying operation is not more than a specified value,
A first amount of the collected toner when the printing rate is a first value;
A second amount of the collected toner that is greater than the first amount when the printing rate is a second value greater than the first value;
When the printing rate is a third value larger than the second value, a third amount of the collected toner that is larger than the second amount is supplied to the developer together with the new toner, As the print rate exceeds the plurality of specified values stepwise, the replenishment amount of the collected toner is set to increase stepwise, and the toner for the carrier before the copy operation for each copy operation of one sheet of paper When the toner specific density in the developing device detected by the sensor based on the ratio is not equal to or higher than a preset specified value and the printing rate is the above values, the replenishment amount of the recovered toner corresponding to the value is selected. An image forming apparatus comprising: a control unit that controls the image forming apparatus.   3. The image forming apparatus according to claim 1, wherein the printing rate is a ratio of an area where the toner is applied to an area of the entire paper to be printed. 4.   3. The image forming apparatus according to claim 1, wherein the printing rate is one or both of an area where toner is applied and a distribution ratio with respect to an area of the entire paper to be printed.   The image forming apparatus according to claim 1, wherein the control unit can arbitrarily adjust a ratio of a supply amount of the collected toner to a new toner.   When the toner save mode is set, the control means sets the ratio of the supply amount of the recovered toner to the new toner while keeping the total supply amount of the recovered toner and the new toner supplied to the developing unit constant. The image forming apparatus according to claim 2, wherein the number is increased.   The developing device includes a mag roller for holding toner, and the control means controls the rotational speed of the mag roller to prevent toner scattering when the toner save mode is set. Item 3. The image forming apparatus according to Item 2.   The developing device includes a mixer unit that stirs the toner, and the control unit controls the number of rotations of the mixer unit to increase the charge amount of the toner when the toner save mode is set. The image forming apparatus according to claim 2.   The image forming apparatus according to claim 2, wherein the toner save mode setting unit includes a manual key, and sets the toner save mode in accordance with an operation of the manual key.   3. The image according to claim 2, wherein the toner save mode setting means includes means for detecting near empty of the new toner, and sets the toner save mode when the new toner becomes near empty. Forming equipment. Collected toner storage means for temporarily storing the collected toner;
A connected conveying device for conveying the collected toner from the cleaner unit to the collected toner containing means;
Recovered toner replenishing means for replenishing the developer with the recovered toner stored in the recovered toner storage means;
New toner storage means for storing new toner,
New toner supply means for supplying new toner stored in the new toner storage means to the developer;
Toner save mode setting means for setting the toner save mode;
When the toner save mode is set and the toner specific density in the developing device detected by the sensor based on the ratio of the toner to the carrier prior to the copying operation is not more than a specified value,
A first amount of the collected toner when the printing rate is a first value;
A second amount of the collected toner that is greater than the first amount when the printing rate is a second value greater than the first value;
When the printing rate is a third value larger than the second value, a third amount of the collected toner that is larger than the second amount is supplied to the collected toner that is supplied to the developing unit and the collected toner. while the supply amount of new toner is constant with the new toner replenish into the developing device, so that the printing rate is stepwise increased replenishment amount of the collected toner according exceeds stepwise the plurality of prescribed values set, and and not the toner specific concentration in the developing device sensed by the sensor based on the ratio of the toner to the carrier prior to the copying operation one each copying operation paper or preset specified value above An image forming apparatus comprising: a control unit that controls to select the replenishment amount of the collected toner corresponding to each value when the printing rate is the above values .   The image forming apparatus according to claim 11, wherein the printing rate is a ratio of an area to which toner is applied to an area of the entire paper to be printed.   12. The image forming apparatus according to claim 11, wherein the printing rate is one or both of an area where the toner is applied and a distribution ratio with respect to an area of the entire paper to be printed. The collected toner from the cleaner unit is transported and accumulated by the connected conveyance device to the collected toner storage unit, and the control unit individually controls the collected toner supply unit or the new toner supply unit and accumulates the collected toner in the collected toner storage unit. In the image forming method for supplying the developer with the collected toner and the new toner stored in the new toner storage means,
A toner save mode setting means, and when the toner save mode is set and the toner specific density in the developing device detected by the sensor based on the ratio of the toner to the carrier prior to the copying operation is not equal to or higher than a specified value; ,
A first amount of the collected toner when the printing rate is a first value;
A second amount of the collected toner that is greater than the first amount when the printing rate is a second value greater than the first value;
When the printing rate is a third value larger than the second value, a third amount of the collected toner that is larger than the second amount is supplied to the developer together with the new toner, As the print rate exceeds the plurality of specified values stepwise, the replenishment amount of the collected toner is set to increase stepwise, and the toner for the carrier before the copy operation for each copy operation of one sheet of paper When the toner specific density in the developing device detected by the sensor based on the ratio is not equal to or higher than a predetermined value set in advance and the printing rate is the above values, the replenishment amount of the recovered toner corresponding thereto is selected. An image forming method.

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