JP4312886B2 - Image forming apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus, and in particular, reuses after collecting residual toner remaining on an image carrier after a toner image formed on the image carrier in an electrophotographic system is transferred to a transfer target. The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a complex machine of these.
[0002]
[Prior art]
In the electrophotographic image forming apparatus, a cleaning device that removes and collects residual toner remaining on the photosensitive drum of the image carrier after transferring the formed image to the transfer target with a cleaning blade, Conventionally known.
In recent years, there has been a demand for effective use of resources and reduction in operating costs. Therefore, in order to reuse the residual toner collected by the cleaning device, the collected toner is returned to the developing device by a transfer device for the new toner. And an image forming apparatus that is used again for forming a toner image on a photosensitive drum of an image carrier (see Japanese Patent Laid-Open No. 6-175488).
As the above-described recovered toner transfer device, a powder screw pump, commonly referred to as a Mono pump, is used as a pump that has a high degree of freedom in the transfer path and is capable of transferring powder. It is also known to fluidize and transport air in a mixed state (see Japanese Patent Laid-Open Nos. 10-228170 and 11-73079).
The collected toner transfer device using the powder screw pump, commonly referred to as the Monono pump mentioned above, is transported through the elastic tube as a mixture with air by the powder screw pump, commonly referred to as the Mono pump, which is recovered by the cleaning means. In order to reliably transport the collected toner, the powder screw pump, commonly called the MONO pump, is not always driven because of problems such as life, sealability, temperature rise, and toner scattering. Thus, it is driven only when it is detected that the toner collected in the toner reservoir has reached a predetermined amount.
Furthermore, a powder screw pump, commonly called a Monono pump of the collected toner transfer means, is configured such that when the number of pixels counted by the number of pixels detection means reaches a predetermined number, the collected toner in the toner reservoir is disposed. It has also been proposed to omit the collected toner amount detection means by assuming that the fixed amount has been reached and driving intermittently.
[0003]
The intermittent drive of such a powder screw pump, which is commonly called a Mono pump, of the collected toner transfer means is intermittently driven at the same number of intervals in any sheet passing mode as long as it is the same image. However, for example, in the “1 to 1” copy that forms one copy image, the photosensitive drum rotation of the image carrier per copy is larger than the “continuous” copy that forms a plurality of copy images in succession. Since the moving time is several times longer, the amount of collected toner input to the powder screw pump of the collected toner transfer means also increases due to the background stain on the photosensitive drum of the image carrier. When a “1 to 1” copy of an image with an image ratio of around 5% is made, the amount of collected toner input is about 3 to 5 times that of “continuous” copy.
The interval of intermittent drive of such a powder screw pump, which is commonly referred to as a Mono pump, must be set according to the input amount in “1 to 1” copy, and wasteful drive is performed during “continuous” copy. It was. Similarly, with respect to background stains on the photosensitive drum of the image carrier, it is necessary to set the interval so that it is driven early with a margin assuming the worst case in consideration of the environment and the like.
Therefore, in such a conventional image forming apparatus, there is a lot of useless driving at the time of continuous image formation of the collected toner transfer means for intermittently driving and collecting the collected toner, and the transport quality of the collected toner is rapidly deteriorated. There has been a problem that the mixing ratio of the collected toner to be transported and reused is indefinite and the quality of the formed image is lowered.
[0004]
[Problems to be solved by the invention]
In the conventional image forming apparatus described above, the waste toner driving means for intermittently driving to collect the collected toner has a lot of useless driving time, the quality of the collected toner is rapidly deteriorated, and the new toner is transported and reused. There has been a problem in that the mixing ratio of the collected toner is indefinite and the quality of the formed image is lowered.
Therefore, an object of the present invention is to solve such problems. That is, there is no wasteful driving time even during continuous image formation of the recovered toner transfer means that transfers the recovered toner by intermittent driving, the recovered toner is improved in transfer quality, and recovered toner that is transferred to new toner and reused. An object of the present invention is to provide an image forming apparatus in which the mixing ratio is constant and the quality of the formed image is improved.
[0005]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention of claim 1 collects residual toner remaining on an image carrier after a toner image formed on the image carrier in an electrophotographic system is transferred to a transfer target. In an image forming apparatus that forms an image by reusing the image, an image carrier that is rotatably supported and carries a formed image, a developing unit that forms a toner image on the image carrier, and the developing unit A transfer unit that transfers the toner image formed by the transfer unit to the transfer member; a cleaning unit that collects residual toner that remains on the image carrier after the transfer of the toner image by the transfer unit to the transfer member; A powder screw pump comprising: a fixed stator; a rotor that is contained in the stator and rotates in contact with the stator; And a recovered toner transfer means for transferring the recovered toner recovered by the cleaning means to the developing means as a mixed gas flow with the gas. And the amount of recovered toner input to the recovered toner transfer means is set to a predetermined amount at a driving interval in which the recovered toner transfer means is intermittently driven to transfer the recovered toner as a mixed airflow with gas. Intermittent drive means for intermittently driving the collected toner transfer means, the intermittent drive means,Set the toner consumption amount addition value based on the background density on the image carrier at the start of rotationFirst signal setting means for setting a first signal, and an image formed on the image carrierConvert and set the toner consumption fromSecond signal setting means;The intermittent driving means adds the set value set by the first signal setting means and the set value set by the second signal setting means, adds them, and adds them to a predetermined value. After reaching, the drive of the collected toner transfer means is started.It is an image forming apparatus.
[0006]
ContractClaim2The invention of claim1In the image forming apparatus described in the item 1, the first signal setting unit is an image forming apparatus including a reflected light detection sensor.
  Claim3The invention of claim1 or 2In the image forming apparatus described in (1), the driving interval of the intermittent driving unit is changed according to the paper mode.
[0007]
  In the image forming apparatus configured as described above, in claim 1, the collected toner obtained by collecting the residual toner remaining on the image carrier after the toner image by the transfer unit is transferred to the transfer target is collected by the cleaning unit. The amount of recovered toner that is input to the powder screw pump of the recovered toner transfer means is preset in the drive interval in which the powder screw pump of the recovered toner transfer means that transfers the toner to the developing means as a mixed gas stream is intermittently driven by the intermittent drive means. An image is formed by intermittently driving the powder screw pump of the collected toner transfer means so as to reach a predetermined amount, and the powder screw pump is contained in a fixed stator and the stator and rotates in contact with the stator. The recovery toner transfer means supplies gas to the powder screw pump. That the intermittent drive means together comprising a gas feed pumpSet the toner consumption amount addition value based on the background density on the image carrier at the start of rotationFirst signal setting means for setting the first signal and the number of pixels of the image formed on the image carrierConvert and set the toner consumption fromSecond signal setting means;The intermittent driving means adds the set value set by the first signal setting means and the set value set by the second signal setting means, adds them, and adds them to a predetermined value. After reaching, the drive of the collected toner transfer means is started.In this way, there is no wasted driving time during the continuous image formation of the recovered toner transfer means that transfers the recovered toner by intermittent driving, the transfer quality of the recovered toner is improved, and the new toner is transferred and reused. It is possible to provide an image forming apparatus in which the mixing ratio of the collected toner is constant and the quality of the formed image is improved.
  In addition, there is no wasted driving time during the continuous image formation of the powder screw pump of the recovered toner transfer means that transfers the recovered toner by intermittent driving, the transfer quality of the recovered toner is improved, and the new toner is transferred. An image forming apparatus in which the mixing ratio of recovered toner to be reused is constant and the formed image quality is improved can be provided.
  In addition, the degree of freedom of the transfer path for transferring the collected toner is increased, and there is no useless driving time even during continuous image formation of the powder screw pump of the collected toner transfer means for transferring the collected toner by intermittent driving, and the collected toner Therefore, it is possible to provide an image forming apparatus in which the mixing ratio of the recovered toner to be transported and reused with respect to the new toner is constant and the quality of the formed image is improved.
  In addition, the degree of freedom of the transfer path for more reliably transferring the collected toner is increased, and there is no wasted driving time even during continuous image formation of the collected toner transfer means that transfers the collected toner by intermittent driving, and the collected toner is transferred. It is possible to provide an image forming apparatus in which the quality is improved and the mixing ratio of the recovered toner to be transported and reused with respect to the new toner is constant and the quality of the formed image is improved.
  In addition, the collected toner amount detection sensor is not required and the cost is low, and there is no useless driving time during the continuous image formation of the collected toner transfer means that transfers the collected toner by intermittent driving, and the quality of the collected toner is improved. Thus, it is possible to provide an image forming apparatus in which the mixing ratio of the recovered toner to be transferred and reused with respect to the new toner is constant and the quality of the formed image is improved.
[0009]
  AlsoThe intermittent drive means adds the set value set by the first signal setting means and the set value set by the second signal setting means and adds them up to reach a predetermined value, and then starts driving the collected toner transfer means. In this way, there is no wasteful driving time even during continuous image formation of the recovered toner transfer means for intermittently driving and recovering the recovered toner, the drive is started reliably, and the transfer quality of the recovered toner is improved. It is possible to provide an image forming apparatus in which the mixing ratio of recovered toner that is transported and reused with respect to toner is constant and the image quality that is formed is improved.
[0010]
  AlsoThe intermittent drive means includes a first signal setting means for setting a first signal for detecting a background density on the image carrier when the image carrier starts to rotate, and the number of pixels of an image formed on the image carrier. The second signal setting means to be set is not necessary, and the collected toner amount detection sensor is not required and the cost is low, and it is easy even during continuous image formation of the collected toner transfer means for intermittently driving and collecting the collected toner. The present invention provides an image forming apparatus that has no wasteful driving time, improves the quality of collected toner, improves the quality of the image that is formed with a constant mixing ratio of collected toner that is transported and reused for new toner. To be able to.
  Claim2The intermittent drive means is formed on the image carrier and first signal setting means for setting a first signal for detecting the background density on the image carrier by the reflected light detection sensor when the image carrier starts to rotate. And a second signal setting unit that is set by the number of pixels of the image to be collected, the collected toner amount detection sensor is unnecessary and the cost is reduced, and the continuous toner collecting unit that intermittently drives the collected toner to transfer the collected toner. Even during image formation, a simple device eliminates wasted drive time, improves the quality of collected toner, improves the quality of the image that is formed with a constant mixing ratio of collected toner that is transferred to new toner and reused. An image forming apparatus can be provided.
  Claim3Since the drive interval of the intermittent drive means is changed according to the paper mode, there is no wasted drive time even during continuous image formation of the recovered toner transfer means for intermittently driving and transferring the recovered toner, The transfer quality of the recovered toner is also improved, the mixing ratio of the recovered toner that is transferred to the new toner and reused is constant, and the quality of the formed image can be improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings.
In FIG. 1, a digital copying machine of an image forming apparatus 0 uses a known electrophotographic system, and is a drum-shaped photoconductor of an image carrier 1 that is rotatably supported by a support member (not shown) and carries a formed image. It has.
An electrophotographic copying process is performed around the drum-shaped photoconductor of the image carrier 1 along the rotation direction indicated by the arrow A in the figure, and the drum-type photoconductor of the image carrier 1 is uniformly charged. Charging means 7, exposure means 8 for exposing a formed image on the drum-shaped photoconductor of the image carrier 1 uniformly charged by the charging means 7, and forming an electrostatic latent image, and the image carrier 1. Developing means 2 for developing the electrostatic latent image on the drum-shaped photosensitive member to form a toner image, transferring means 3 for transferring the toner image formed by the developing means 2 onto the transfer paper of the transfer medium P, the transfer A cleaning means 4 for collecting residual toner remaining on the drum-like photoconductor of the image carrier 1 after the toner image transferred by the means 3 is transferred to the transfer medium P is collected.
The recovered toner transfer means 5 comprises a powder screw pump 5a, commonly called a Mono pump, and a gas supply pump 5b for supplying gaseous air to the powder screw pump 5a. The collected toner collected by the cleaning unit 4 is transported to the developing unit 2 as a mixed airflow with gas.
The intermittent drive means 6 is a drive that intermittently drives the powder screw pump 5a and the gas supply pump 5b, which are commonly called Mono pumps of the recovered toner transfer means 5, in order to transfer the recovered toner as a mixed airflow with gas. The interval between the recovery toner transfer means 5 and the so-called Monono pump, which is commonly referred to as the Monono pump of the recovery toner transfer means 5, is such that the amount of recovery toner input to the powder screw pump 5 a becomes a predetermined amount. The powder screw pump 5a and the gas supply pump 5b are intermittently driven.
The exposure means 8 is a drum of the image carrier 1 based on the image signal read by the reading means 8b from the original O screen placed on the original placement table 8a on the upper surface of the main body 0a of the image forming apparatus 0. An electrostatic latent image is formed by scanning the photoconductor with a laser beam.
The electrostatic latent image formed on the drum-shaped photosensitive member of the image carrier 1 is converted into a toner image by the developing unit 2, and the toner image is fed from the paper feeding unit 9 to the transfer target P. The transfer means 3 electrostatically transfers the transfer paper. The transfer paper on the transfer medium P onto which the toner image has been transferred is conveyed and fixed to the fixing means 10 and then discharged from the paper discharge roller 11 to the paper discharge tray 12 for storage.
[0012]
In FIG. 2, the developing means 2 is a two-component developing device, and a developer tank 2a contains a developer composed of a carrier and toner. When the developing unit 2 forms a toner image, the toner of the developer is consumed, the ratio is reduced, the toner density is lowered, and the image density of the formed image is lowered.
Therefore, in order to suppress a decrease in the density of the formed image, when the toner concentration in the developer becomes a predetermined value or less, the toner is supplied from the toner hopper 2b to maintain the toner concentration in the developer. . The toner concentration in the developer is measured by a magnetic permeability sensor 2c attached under the developing tank 2a.
The toner replenished from the toner hopper 2b through the replenishing roller 2d is frictionally charged while being agitated with the carrier by the agitating member 2e in the developing tank 2a.
The developer composed of the carrier and the toner is splashed up to the developing roller 2g by the paddle wheel 2f, and is adsorbed on the developing roller 2g by a magnet (not shown) in the developing roller 2g.
The developer is conveyed by an outer sleeve (not shown) of the developing roller 2g, and the excess is scraped off by the developing doctor 2h. The toner in the developer conveyed to the drum-shaped photoconductor side of the image carrier 1 adheres onto the drum-shaped photoconductor of the image carrier 1 by a developing bias corresponding to the electrostatic latent image.
The toner adhering to the drum-shaped photoconductor of the image carrier 1 by the development of the developing means 2 is electrostatically transferred onto the transfer paper of the transfer medium P by the transfer means 3, but about 10% of the toner Becomes untransferred and adheres to the drum-shaped photoconductor of the image carrier 1 and remains as residual toner.
Residual toner that remains as untransferred toner and adheres to and remains on the drum-shaped photoconductor of the image carrier 1 is removed by the cleaning blade 4a and the brush roller 4b of the cleaning means 4. It is scraped off from above.
[0013]
The collected toner scraped off and collected by the cleaning blade 4a and the brush roller 4b of the cleaning means 4 is dropped by its own weight from the discharge port 4c to be reused as a reused toner, and the toner guide member 4d. As a result, the toner is transported as recovered toner to the powder screw pump 5a, which is commonly referred to as a monono pump of the recovered toner transfer means 5.
The toner guide member 4d serves as a recovery toner transfer path for sending the recovery toner from the cleaning means 4 to the powder screw pump 5a, commonly referred to as a monono pump of the recovery toner transfer means 5. It is also like.
On the other hand, a transfer cleaning means 3b is provided on the transfer belt 3a of the transfer means 3 because residual toner adheres to the non-transferred part and the non-image part on the drum-shaped photosensitive member of the image carrier 1. It has been.
Residual toner remaining on the transfer belt 3a is scraped off by the cleaning blade of the transfer cleaning means 3b that is in sliding contact with the transfer belt 3a.
Since the toner scraped off by the cleaning blade of the transfer cleaning means 3b is likely to contain foreign matters such as paper dust, the toner drops by its own weight from the discharge port 3c and passes through the toner guide member 3d to be discarded toner. After being sent to the container 13, it is discarded.
[0014]
In FIGS. 3 and 4, the powder screw pump 5a, which is commonly referred to as the Monono pump of the recovered toner transfer means 5, is the developing means as a mixture of recovered toner and gaseous air supplied by the gas supply pump 5b. 2 to be transported.
The powder screw pump 5a, which is commonly referred to as the Monono pump of the recovered toner transfer means 5, is a stator 5a.₁The rotor 5a moves the collected toner in the axial direction by rotating in contact with the rotor₂And the stator 5a₁Is holder 5a_ThreeFixed to the stator 5a₁Is the rotor 5a.₂A passage is formed so as to wrap around.
Rotor a₂Is engaged with the shaft of the lateral conveying screw 5c. The other end of the lateral conveying screw 5c is engaged with a seal member 5d, a bearing 5e, and a rotating shaft 6c of the driving motor of the intermittent driving means 6, and intermittent rotation driving of the rotating shaft 6c of the driving motor of the intermittent driving means 6 is performed. By the force, the rotor 5a₂The lateral conveying screw 5c is driven intermittently.
The powder screw pump 5a and the gas supply pump 5b, which are commonly referred to as the monono pump of the recovered toner transfer means 5, are the signal settings of the first signal setting means 6a and the second signal setting means 6b of the intermittent drive means 6. Then, by a micro processing unit (MPU) 6d, the rotation shaft 6c of the drive motor, the lateral conveying screw 5c, the rotor 5a₂, Starts intermittent rotation driving and starts the transfer operation of the collected toner, then continues to rotate for a predetermined time and then stops, and intermittently drives to stop the recovery toner transfer operation and transfers the recovered toner. The operation is controlled to be performed intermittently.
[0015]
The first signal setting means 6a of the intermittent drive means 6 is arranged between the transfer means 3 and the cleaning means 4 arranged around the drum-shaped photoconductor of the image carrier 1, The density of the background portion of the drum-shaped photoconductor of the image carrier 1 before the image portion of the drum-shaped photoconductor of the first image carrier 1 after the start of the image forming operation is expressed as optical density = Log1 / T. However, T is a reflected light detection sensor 6a which detects optical density (Vsg) defined by reflectance.₁LED 6a₂For example, when the optical density (Vsg) <3.80 in which the background of the drum-shaped photoconductor of the image carrier 1 is poorly stained, the toner consumption amount addition value is 90 mg, and the image When the degree of contamination of the background portion of the drum-shaped photosensitive member of the carrier 1 is 3.90 ≦ optical density (Vsg) ≦ 4.10, the toner consumption additional value is 60 mg, and the drum-shaped photosensitive member of the image carrier 1 When the optical density (Vsg)> 4.10 is good for the degree of contamination of the body background, the toner consumption amount addition value is set to 30 mg and added.
The second signal setting means 6b of the intermittent driving means 6 determines the number of pixels of the image formed by the exposure means 8 on the drum-shaped photoconductor of the image carrier 1 as a pixel number counter 6b.₁The number of pixels counted for each transfer sheet of the transfer medium P is set in terms of toner consumption.
The micro processing unit (MPU) 6d of the intermittent drive means 6 sets the set value set by the first signal setting means 6a of the intermittent drive means 6 and the second signal setting means 6b. For example, when the integrated value of the toner consumption reaches 3000 mg, the rotor 5a is added.₂And the gas supply pump 5b are simultaneously turned ON. Thereafter, the rotor 5a₂And the gas supply pump 5b in this order. After the gas supply pump 5b is turned off, the toner consumption integrated value is reset.
At this time, the difference in the driving interval due to the difference in the paper passing mode is, for example, an image ratio of 5% of the image formed on the A4 size transfer paper of the transfer material P, and the background portion of the drum-shaped photoconductor of the image carrier 1. Therefore, the toner consumption amount addition value is 60 mg, the driving start toner consumption amount is 3000 mg, and the transfer material P is A4 size transfer paper per sheet. In the case of “1 to 1” copy, A = 3000 ÷ (60 + 30) = 34 sheets, in the case of “1 to 3” copy, B = 3000 ÷ (60/3 + 30) = 60 sheets, “continuous” copy In this case, C = 3000 ÷ (30) = 100 sheets.
[0016]
In FIG. 5, the above-described recovery processing is performed at a driving interval in which the recovery toner transfer means 5 is intermittently driven to transfer the recovery toner as a mixed airflow with the gas by the micro processing unit (MPU) 6 d of the intermittent drive means 6. The collected toner transfer means 5 is controlled to be intermittently driven so that the collected toner amount input to the toner transfer means 5 becomes a predetermined amount. Here, the pixel count is converted into the toner consumption amount, but the pixel count integrated value and the collected toner amount are not particularly problematic in terms of control.
By the first signal setting means 6a of the intermittent drive means 6, the drum shape of the image carrier 1 before the image portion of the drum-like photosensitive body of the first image carrier 1 after the start of the image forming operation. The reflected light detection sensor 6a determines the degree of dirt on the background of the photoreceptor.₁Then, the optical density (Vsg) is detected (step S1), and a toner consumption amount corresponding to the value of the optical density (Vsg) of the background portion of the drum-shaped photoconductor of the image carrier 1 is set and added. (Step S2), and the second signal setting means 6b of the intermittent drive means 6 sets the number of pixels of the image formed by the exposure means 8 on the drum-like photoconductor of the image carrier 1 to the number of pixels. Counter 6b₁In step S3, the number of pixels counted for each transfer sheet of the transfer medium P is converted into toner consumption and added (step S3), and the first signal setting of the intermittent drive means 6 is performed. The set value set by the means 6a and the set value set by the second signal setting means 6b are added to determine whether or not the integrated value of the toner consumption amount has reached 3000 mg (step S4). If it is 3000 mg or less (No in step S4), it is determined whether or not there is a next copy (step S5). If there is a next copy (Yes in step S5), the process returns to step S3, and there is no next copy. (No in step S5), the process ends.
If the integrated value is 3000 mg or more (Yes in step S4), the rotor 5a₂And the gas supply pump 5b are simultaneously turned on (step S6), and after the toner is transferred, the rotor 5a₂(Step S7), the gas supply pump 5b is turned off (step S8), the integrated value of toner consumption is reset (step S9), and the presence or absence of the next copy is determined (step S10). If there is a next copy (Yes in step S10), the process returns to step 3. If there is no next copy (No in step S10), the process is terminated.
As described above, the image forming apparatus according to the present exemplary embodiment has no wasteful driving time even during continuous image formation of the recovered toner transfer unit that intermittently drives and transfers the recovered toner, and improves the transfer quality of the recovered toner. The mixing ratio of the collected toner that is transported and reused with respect to the toner becomes constant, and the quality of the formed image can be improved.
[0017]
【The invention's effect】
  Since the present invention is configured as described above, according to the first aspect of the present invention, after the toner image by the transfer unit is transferred to the transfer target, the residual toner remaining on the image carrier after cleaning is cleaned. Toner transfer means for transferring the recovered toner collected by the means to the developing means as a mixed gas flow with gasPowder screw pumpThe collected toner transfer means at a driving interval for intermittently driving the toner by the intermittent driving meansPowder screw pumpThe collected toner transfer means so that the collected toner amount inputted to the printer becomes a predetermined amount.Powder screw pumpIs intermittently driven to form an image.The powder screw pump is composed of a fixed stator and a rotor that is contained in the stator and rotates in contact with the stator, and the recovered toner transfer means supplies gas to the powder screw pump. The intermittent drive means includes a first signal setting means for setting a first signal before image formation on the first image carrier after the image forming operation is started, and an image carrier. And second signal setting means set by the number of pixels of the image formed on the body.As a result, there is no wasted driving time during the continuous image formation of the recovered toner transfer means that transfers the recovered toner by intermittent driving, the transfer quality of the recovered toner is improved, and the new toner is transferred and reused. It is now possible to provide an image forming apparatus in which the mixing ratio of the collected toner is constant and the quality of the formed image is improved..
Also,Even during continuous image formation of the powder screw pump of the recovered toner transfer means that transfers the recovered toner by intermittent driving, there is no wasted driving time, the quality of the recovered toner is improved, the new toner is transferred and reused Accordingly, it is possible to provide an image forming apparatus in which the mixing ratio of the collected toner is constant and the quality of the formed image is improved.
In addition, the degree of freedom of the transfer path for transferring the collected toner is increased, and there is no useless driving time even during continuous image formation of the powder screw pump of the collected toner transfer means for transferring the collected toner by intermittent driving, and the collected toner Therefore, it is possible to provide an image forming apparatus in which the mixing ratio of the recovered toner to be transported and reused with respect to the new toner is constant and the quality of the formed image is improved.
In addition, the degree of freedom of the transfer path for more reliably transferring the collected toner is increased, and there is no wasted driving time even during continuous image formation of the collected toner transfer means that transfers the collected toner by intermittent driving, and the collected toner is transferred. It is possible to provide an image forming apparatus with improved quality and improved image quality with a constant mixing ratio of recovered toner to be transferred and reused with respect to new toner.
In addition, the collected toner amount detection sensor is not required and the cost is low, and there is no useless driving time during the continuous image formation of the collected toner transfer means that transfers the collected toner by intermittent driving, and the quality of the collected toner is improved. In addition, it is possible to provide an image forming apparatus in which the mixing ratio of the recovered toner to be transported and reused with respect to the new toner is constant and the quality of the formed image is improved.
[0019]
  AlsoThe intermittent drive means adds the set value set by the first signal setting means and the set value set by the second signal setting means and adds them up to reach a predetermined value, and then starts driving the collected toner transfer means. Since there is no wasted driving time even during continuous image formation of the recovered toner transfer means for transferring the recovered toner by intermittent driving, the driving is started reliably, and the transfer quality of the recovered toner is improved. It has become possible to provide an image forming apparatus in which the mixing ratio of recovered toner to be transported and reused with respect to new toner is constant and the quality of the formed image is improved.
[0020]
  AlsoThe intermittent drive means includes a first signal setting means for setting a first signal for detecting a background density on the image carrier when the image carrier starts to rotate, and the number of pixels of an image formed on the image carrier. Since the second signal setting means is set, the collected toner amount detection sensor is not required and the cost is low, and it is easy even during continuous image formation of the collected toner transfer means for intermittently driving and collecting the collected toner. Provides an image forming apparatus that improves the quality of the formed toner with a constant mixing ratio of the collected toner to be transported and reused for a new toner, improving the quality of the collected toner and improving the quality of the collected toner. I was able to do that.
  Claim2According to the invention, the intermittent drive means includes the first signal setting means for setting the first signal for detecting the background density on the image carrier by the reflected light detection sensor when the image carrier starts to rotate, and the image carrier. Since the second signal setting means is set according to the number of pixels of the image formed on the upper side, the recovered toner amount detecting sensor is unnecessary and the cost is low, and the recovered toner that is intermittently driven to transfer the recovered toner is used. Even during continuous image formation by the transfer means, a simple device eliminates wasted driving time, improves the transfer quality of recovered toner, and forms a mixture ratio of recovered toner that is transferred to new toner and reused. An image forming apparatus with improved image quality can be provided.
  Claim3According to this invention, there is no wasteful driving time even during continuous image formation of the recovered toner transfer means for transferring the recovered toner by intermittent driving, the transfer quality of the recovered toner is improved, and the new toner is transferred to the new toner. The mixing ratio of the recovered toner to be used is constant, and the quality of the formed image can be improved.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for explaining an outline of an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged partial cross-sectional view for explaining a main part of an image forming apparatus showing an embodiment of the present invention.
FIG. 3 is a perspective view illustrating another main part of the image forming apparatus according to the exemplary embodiment of the present invention.
FIG. 4 is an enlarged partial cross-sectional view for explaining another main part of the image forming apparatus showing the embodiment of the present invention.
FIG. 5 is a flowchart illustrating the operation of another main part of the image forming apparatus according to the exemplary embodiment of the present invention.
[Explanation of symbols]
0 Image forming device, 0a body
1 Image carrier
2 developing means, 2a developing tank,
2b toner hopper,
2c permeability sensor,
2d supply roller,
2e stirring member,
2f paddle wheel,
2g developing roller,
2h Development doctor
3 transfer means, 3a transfer belt,
3b transfer cleaning means,
3c outlet,
3d toner guide member
4 Cleaning means, 4a Cleaning blade,
4b brush roller,
4c outlet,
4d Toner guide member
5 Collected toner transfer means, 5a Powder screw pump, 5a₁  Stator,
5a₂  Rotor,
5a_Three  holder,
5b gas supply pump,
5c lateral conveying screw,
5d sealing member,
5e Bearing
6 intermittent drive means, 6a first signal setting means, 6a₁  Reflected light detection sensor,
6a₂  LED,
6b Second signal setting means, 6b₁  Pixel counter,
6c Rotating shaft of drive motor,
6d Micro processing unit (MPU)
7 Charging means
8 exposure means, 8a document table,
8b Reading means
9 Paper feeding means
10 Fixing means
11 Discharge roller
12 Output tray
13 Waste toner container

Claims (3)

In an image forming apparatus for forming an image by reusing a residual toner remaining on an image carrier after a toner image formed on an image carrier in an electrophotographic system is transferred to a transfer target,
An image carrier that is rotatably supported and carries a formed image;
Developing means for forming a toner image on the image carrier;
Transfer means for transferring the toner image formed by the developing means to a transfer medium;
Cleaning means for recovering residual toner remaining on the image carrier after the toner image transferred by the transfer means is transferred to the transfer body;
A powder screw pump comprising a fixed stator and a rotor that is contained in the stator and rotates in contact with the rotor to transfer the collected toner in the axial direction;
A gas supply pump for supplying gas to the powder screw pump;
A recovered toner transfer means that includes the powder screw pump and the gas supply pump, and transfers the recovered toner recovered by the cleaning means to the developing means as a gas stream mixed with gas;
The recovery toner transfer means is configured so that the amount of recovery toner input to the recovery toner transfer means becomes a predetermined amount at a driving interval in which the recovery toner is intermittently driven to transfer the recovery toner as a gas stream mixed with gas. Intermittent drive means for intermittently driving the toner transfer means,
The intermittent driving means includes first signal setting means for setting a toner consumption amount addition value based on a background density on the image carrier at the start of rotation, and the number of pixels of an image formed on the image carrier. And a second signal setting means for converting and setting the toner consumption amount, and the intermittent drive means includes a set value set by the first signal setting means and a second signal setting means. A set value to be set is added and integrated, and after reaching a predetermined value, driving of the collected toner transfer means is started . The image forming apparatus according to claim 1 , wherein the first signal setting unit includes a reflected light detection sensor. 3. The image forming apparatus according to claim 1, wherein a driving interval of the intermittent driving unit is changed according to a paper mode.

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