JP2015191094A - image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of suppressing the leakage of a developer to the outside of the apparatus.SOLUTION: An image forming apparatus includes: a photoreceptor 12; a developing unit 11 that develops an electrostatic latent image on the photoreceptor 12 with a developer; an image forming part 3 that prints an image developed on the photoreceptor 12 on a sheet; a suction duct 31 one end of which is provided in the vicinity of the developing unit 11; a recovery box 40 that is connected to the other end of the suction duct 31 and includes a suction fan 46, and that recovers a developer by suctioning the developer around the developing unit 11 by the suction fan 46 through the suction duct 31; toner detection means 55 and 60 that detect whether or not a prescribed amount or more of toner is accumulated in prescribed locations 32 and 33 in the suction duct 31; an auxiliary fan 55 configured to be capable of blowing air toward the prescribed locations 32 and 33 in the suction duct 31; and control means 60 that activates the auxiliary fan 55 when the accumulation of the prescribed amount or more of toner is detected by the toner detection means 55 and 60.

Description

  The present invention relates to an image forming apparatus.

  For example, as disclosed in Patent Document 1, there is known a developer recovery device that sucks and recovers toner (developer) scattered by a developing device in an image forming apparatus. The developer collecting device includes a toner suction duct having a suction port provided in the vicinity of the developing device, and a toner collecting unit connected to the toner suction duct for sucking and collecting the scattered toner of the developing device through the toner suction duct. I have.

JP 2007-298782 A

  By the way, the developer recovery apparatus described above has a problem that toner (developer) accumulates in the toner suction duct. That is, it is difficult to completely collect the developer scattered by the developing device in the toner collecting unit, and there is a problem that the developer remains in the toner suction duct. When the developer accumulates in the toner suction duct, the suction resistance in the toner suction duct increases, and the recovery rate of the scattered developer decreases. As a result, the developer may leak out of the image forming apparatus and the indoor environment may deteriorate.

    SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus capable of suppressing leakage of a developer to the outside of the apparatus.

  An image forming apparatus according to the present invention includes a photoconductor and a developing unit that develops an electrostatic latent image on the photoconductor with a developer, and prints an image developed on the photoconductor on a sheet. A forming duct; a suction duct provided at one end in the vicinity of the developing unit; and a suction fan connected to the other end of the suction duct, and the developer around the developing unit is removed through the suction duct. A collection box that is sucked and collected by a suction fan, a toner detection unit that detects whether or not a predetermined amount or more of toner has accumulated in a predetermined location in the suction duct, and a predetermined location in the suction duct. An auxiliary fan configured to be able to blow air; and a control unit that activates the auxiliary fan when the toner detection unit detects the accumulation of the toner of the predetermined amount or more.

  According to the present invention, there is provided an image forming apparatus capable of suppressing leakage of developer to the outside of the apparatus.

FIG. 1 is a block diagram illustrating a configuration of an image forming apparatus according to an embodiment. FIG. 2 is a perspective view showing the configuration of the toner recovery device. FIG. 3 is a perspective view showing the configuration of the collection box. FIG. 4 is a block diagram illustrating a control configuration of the toner recovery apparatus. FIG. 5 is a perspective view showing configurations of the toner recovery device and the developing device. FIG. 6 is a time chart illustrating an example of operation control of the toner recovery device when the number of print jobs executed by the image forming apparatus is less than the first predetermined number. FIG. 7 is a time chart illustrating an example of operation control of the toner collection device when the number of print jobs executed by the image forming apparatus is greater than or equal to the first predetermined number and less than the second number. FIG. 8 is a time chart illustrating an example of operation control of the toner recovery device when the number of print jobs executed by the image forming apparatus is equal to or greater than the second predetermined number. FIG. 9 is a view corresponding to FIG.

Embodiment 1
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the following embodiment.

  The image forming apparatus 1 according to the present embodiment is, for example, a laser printer or a multifunction machine, and prints image data on a sheet based on a print job received from a terminal or the like. The image forming apparatus 1 performs printing of the number of sheets corresponding to the number of printed sheets included in the print job. As shown in FIG. 1, the image forming apparatus 1 includes a paper feed unit 2, an image forming unit 3, a fixing unit 4, and a paper discharge unit 5.

  The paper feed unit 2 is a cassette paper feed unit or a manual feed tray that supplies paper to the image forming unit 3. The image forming unit 3 includes a developing device 11 and a photosensitive drum 12 (photosensitive member). In the image forming unit 3, an electrostatic latent image is formed on the photosensitive drum 12 by an optical scanning device (not shown), and the electrostatic latent image is developed by the developing device 11 to become a toner image that is a developer image. This toner image is transferred to the paper supplied from the paper supply unit 2. The fixing unit 4 includes a fixing roller and a pressure roller (both not shown), and fixes the toner image transferred to the sheet by the image forming unit 3 to the sheet. Thus, an image is formed on the paper. The paper discharge unit 5 has a paper discharge tray (not shown) to which the paper on which the image is formed is supplied from the fixing unit 4.

  Further, the image forming apparatus 1 includes a toner container 20 and a toner recovery device 30 (developer recovery device). The toner container 20 contains toner as a developer supplied to the developing device 11. The toner collecting device 30 sucks and collects the toner (developer) scattered by the developing device 11.

  The configuration of the toner recovery device 30 will be described with reference to FIGS. As shown in FIGS. 2 and 5, the toner recovery device 30 includes a toner recovery box 40, and a suction duct 31 and an exhaust duct 35 connected to the recovery box 40.

  As shown in FIG. 3, the collection box 40 includes a box body 41 formed in a rectangular box shape. A substantially U-shaped passage 45 is formed inside the box body 41. In the box body 41, an inlet 42 is formed at a position corresponding to one end of the passage 45, and an outlet 43 is formed at a position corresponding to the other end of the passage 45. A suction duct 31 is connected to the inlet 42, and an exhaust duct 35 is connected to the outlet 43. One end of the suction duct 31 is located in the vicinity of the developing device 11 and can suck the toner scattered by the developing device 11 (see FIG. 5).

  The box body 41 houses a suction fan 46 (suction mechanism) and two filters 47 and 48 for capturing toner. The suction fan 46 is provided at a position corresponding to the outlet 43 in the passage 45. The two filters are an upstream filter 47 and a downstream filter 48, and are sequentially provided on the upstream side (that is, the suction side) of the suction fan 46 in the passage 45.

  In the toner recovery device 30, by operating the suction fan 46, the toner scattered by the developing device 11 is sucked into the recovery box 40 together with air through the suction duct 31. In the collection box 40, the sucked toner flows through the passage 45 and is captured by the upstream filter 47. The toner that has passed without being captured by the upstream filter 47 is captured by the downstream filter 48. On the other hand, the air sucked into the collection box 40 together with the toner passes through the two filters 47 and 48 in order and flows from the outlet 43 to the exhaust duct 35. The air that has flowed into the exhaust duct 35 is finally discharged to the outside of the image forming apparatus 1. As described above, the collection box 40 sucks the toner scattered by the developing device 11 (toner around the developing device 11) by the suction fan 46, and collects it by the filters 47 and 48.

  Further, as shown in FIG. 4, the toner collection device 30 includes a vibration motor 51 (vibration mechanism) that vibrates the upstream filter 47, an air assist fan 55 (auxiliary fan), and a control unit 52.

  The vibration motor 51 is configured to vibrate the upstream filter 47 and to screen off the toner captured by the upstream filter 47. Thereby, clogging by the toner of the upstream filter 47 is suppressed.

  As shown in FIG. 2, the air assist fan 55 blows air into the duct in the middle of the suction duct 31 and winds up toner accumulated in the duct with the blown air. Thus, the air assist fan 55 assists the suction of toner by the suction fan 46 provided in the collection box 40.

  The suction duct 31 has bent portions 32 and 33 bent slightly upward at a substantially right angle. A toner detection sensor 56 is provided in each of the bent portions 32 and 33. Each toner detection sensor 56 is an optical detection sensor having a light emitting unit and a light receiving unit. Each toner detection sensor 56 outputs a toner detection signal by blocking light reception by the light receiving unit when toner is present between the light emitting unit and the light receiving unit. In the present embodiment, each toner detection sensor 56 outputs a toner detection signal when the amount of accumulated toner in each of the bent portions 32 and 33 becomes a predetermined amount or more. The toner detection signal output from the toner detection sensor 56 is transmitted to the control unit 60 described later. Two blowout passages 56 and 57 are connected to the air assist fan 55. The first blowing passage 56 has one end connected to the air assist fan 55 and the other end connected to the first bent portion 32 of the suction duct 31. The second blowing passage 57 has one end connected to the first blowing passage 56 and the other end connected to the second bent portion 33 of the suction duct 31. That is, the air assist fan 55 is configured to blow air to the bent portions 32 and 33 of the suction duct 31 through the blowing passages 56 and 57.

  As shown in FIG. 4, the control unit 60 controls the operation of the suction fan 46, the vibration motor 51, and the air assist fan 55 based on a signal from the toner detection sensor 56 and the like.

  The control unit 60 operates the suction fan 46 during execution of the print job in the image forming apparatus 1. As a basic control, the control unit 60 stops the suction fan 46 and the air assist fan 55 when the vibration motor 51 is operated. Further, the control unit 60 operates the suction fan 46 when the air assist fan 55 is operated.

  In the present embodiment, the control unit 60 executes different control depending on the number of print sheets of the print job executed in the image forming apparatus 1 (the number of print sheets included in advance in the print sheet number information of the print job).

  Specifically, the control unit 60 activates the vibration motor 51 when the number of print jobs executed by the image forming apparatus 1 is less than the first predetermined number (for example, 1000 in this embodiment). Instead, after the end of the print job, a process of determining whether or not a toner detection signal from the toner detection sensor 56 has been received (hereinafter referred to as toner detection process) is executed. When it is determined that the toner detection signal has been received, the control unit 60 operates the air assist fan 55 (see FIG. 6). At this time, the control unit 60 operates the suction fan 46 together with the air assist fan 55. If the control unit 60 does not receive the toner detection signal from the toner detection sensor 56, the next print job may be started without executing the operation A in the drawing.

  On the other hand, when the number of print jobs being executed by the image forming apparatus is equal to or greater than the first predetermined number, the control unit 60 causes the vibration motor 51 to be turned on for a predetermined time (for example, 10 seconds) after the end of the print job. Operate. When the control unit 60 activates the vibration motor 51 and then executes toner detection processing and determines that the toner detection signal from the toner detection sensor 56 has been received, the control unit 60 activates the air assist fan 55. (See FIG. 7). At this time, the control unit 60 operates the suction fan 46 together with the air assist fan 55. If the control unit 60 does not receive the toner detection signal from the toner detection sensor 56, the next print job may be started without executing the operation A in the drawing.

  However, if the number of printed sheets of one print job is equal to or greater than the second predetermined number (for example, 5000 sheets in the present embodiment; second predetermined number> first predetermined number), the control unit 60 does not finish the print job. Even when the number of prints reaches the second predetermined number, the print job is interrupted and the vibration motor 51 is operated for a predetermined time (for example, 10 seconds) (see FIG. 8). After that, the control unit 60 interrupts the print job and activates the vibration motor 51 every time printing for the second predetermined number of sheets is completed. At this time, the control unit 60 executes the toner detection process every time the operation of the vibration motor 51 is finished, and determines that the toner detection signal from the toner detection sensor 56 has been received, the air assist fan 55. Is activated. When the control unit 60 does not receive the toner detection signal from the toner detection sensor 56, the interrupted print job may be resumed without executing the operation A in the drawing.

  As described above, in the above-described embodiment, the air assist fan 55 that blows out air is provided inside the duct in the middle of the suction duct 31, so that the toner accumulated in the suction duct 31 can be wound up. Therefore, the toner accumulated in the suction duct 31 can be easily sucked by the suction fan 46. Accordingly, toner accumulation in the suction duct 31 can be suppressed, and an increase in flow resistance in the suction duct 31 can be suppressed. As a result, it is possible to suppress a decrease in the toner recovery rate, and thus to prevent the scattered toner from leaking out of the image forming apparatus 1.

  In addition, in the toner recovery device 30 of the above-described embodiment, air is blown out to the bent portions 32 and 33 in which the toner easily accumulates in the suction duct 31, so that the toner accumulation in the suction duct 31 is effectively suppressed. Is possible. In particular, in the present embodiment, since the bent portions 32 and 33 are bent upward, the toner is more easily deposited, but the accumulation can be effectively suppressed.

  In the above embodiment, the control unit 60 has a predetermined amount inside the bent portions 33 and 34 based on a signal from the toner detection sensor 56 provided in the bent portions 33 and 34 (predetermined locations) of the suction duct 31. The air assist fan 55 is configured to operate only when it is detected that the above toner has accumulated. Therefore, when a predetermined amount or more of toner is not accumulated in the bent portions 33 and 34, it is not necessary to operate the air assist fan 55, so that energy saving is achieved as compared with the case where the toner detection sensor 56 is not provided. be able to.

  In the above embodiment, the control unit 60 is configured to operate the suction fan 46 while the air assist fan 55 is operating. As a result, the toner wound up by the air blown from the air assist fan 55 can be reliably guided into the collection box 40 by the suction fan 46. Here, when the vibration motor 51 is operated while the suction fan 46 is operating, there is a possibility that the toner that has been sieved off from the upstream filter 47 returns to the filter 47 and adheres. On the other hand, in the above-described embodiment, the vibration motor 51 is not operated while the air assist fan is operating (the suction fan 46 is operating), so that the vibration motor 51 is prevented from operating unnecessarily. Can do. Therefore, energy saving can be further promoted.

  In the above embodiment, the control unit 60 is configured to operate the suction fan 46 during execution of a print job in the image forming apparatus 1. As a result, the scattered toner generated in the developing device 11 during execution of the print job can be guided to the collection box 40 by the suction force of the suction fan 46. The control unit 60 is configured not to execute the toner detection process during execution of the print job in the image forming apparatus 1. By doing so, it is possible to prevent the toner detection sensor 56 from erroneously detecting the scattered toner passing through the bent portions 32 and 33 of the duct 31 as the accumulated toner.

  In the above embodiment, the control unit 60 operates the vibration motor 51 for a predetermined time after the end of the print job when the number of print jobs executed by the image forming apparatus 1 is equal to or greater than the first predetermined number. It is supposed to let you. Thus, even if a large amount of scattered toner is generated due to a large number of print jobs, the filter 47 can be regenerated by screening the scattered toner from the upstream filter 47. In the above embodiment, the suction fan 46 and the air assist fan 55 are not operated during the operation of the vibration motor 51, so that the toner screened off from the upstream filter 47 due to the operation of the vibration motor 51 is removed. Reattachment to the filter 47 can be prevented.

  The control unit 60 performs the toner detection process after operating the vibration motor 51 for a predetermined time when the number of print jobs executed by the image forming apparatus 1 is equal to or greater than the first predetermined number. It is configured. As a result, the interruption time of the print job can be shortened while preventing erroneous detection by the toner detection sensor 56. FIG. 9 shows a case where the vibration motor 51 is operated after the toner detection process is executed as a comparative example. Comparing FIG. 9 and FIG. 7, it can be seen that the print job interruption time is shorter in this embodiment than in the comparative example (in this example, it is 5 seconds shorter). In the case of the present embodiment, since the toner detection process is executed using the timing at which the suction fan 46 stops by operating the vibration motor 51, it is possible to shorten the interruption time of such a print job. It becomes.

<< Other embodiments >>
In the above-described embodiment, the toner detection sensor 56 is configured by an optical sensor, but is not limited thereto, and may be configured by, for example, a piezoelectric sensor.

  In the above embodiment, air is blown to the bent portions 32 and 33 of the duct 31 by the air assist fan 55. However, it is not always necessary to blow the bent portions 32 and 33, and for example, it may be blown to the straight portion. .

  As described above, the present invention includes a photoconductor and a developing unit that develops the electrostatic latent image on the photoconductor with a developer, and prints an image developed on the photoconductor on a sheet. It is useful for an image forming apparatus including an image forming unit.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 11 Developing device 12 Photosensitive drum (photoconductor)
30 Toner Recovery Device (Developer Recovery Device)
32 bent portion 33 bent portion 40 collection box 46 suction fan 47 upstream filter 51 vibration motor (vibration mechanism)
55 Air assist fan (auxiliary fan)
56 Toner detection sensor (toner detection means)
60 control unit (control means, toner detection means)

Claims (5)

An image forming unit that has a photoconductor and a developing unit that develops the electrostatic latent image on the photoconductor with a developer, and prints an image developed on the photoconductor on a sheet;
A suction duct having one end provided in the vicinity of the developer;
A suction box connected to the other end of the suction duct and having a suction fan, and a developer box that sucks and collects the developer around the developing device via the suction duct;
Toner detecting means for detecting whether or not a predetermined amount or more of toner has accumulated at a predetermined location in the suction duct;
An auxiliary fan configured to blow out air to the predetermined location in the suction duct;
An image forming apparatus comprising: a control unit that activates the auxiliary fan when the toner detection unit detects the accumulation of the toner of the predetermined amount or more. The image forming apparatus according to claim 1.
A filter that is disposed upstream of the suction fan in the collection box and captures toner in the air;
A vibration mechanism that vibrates the filter and sifts toner from the filter; and
The image forming apparatus, wherein the control unit is configured to operate the suction fan while the auxiliary fan is operating, but not to operate the vibration motor. The image forming apparatus according to claim 1 or 2,
The control means is configured to operate the suction fan during execution of a print job in the image forming apparatus,
The image forming apparatus, wherein the toner detection unit is configured not to perform the detection during execution of a print job in the image forming unit. The image forming apparatus according to claim 2.
The control means is configured to operate the vibration motor for a predetermined time after the end of the print job when the number of print jobs executed by the image forming apparatus is equal to or greater than a predetermined number. During the operation of the vibration motor, the suction fan and the auxiliary fan are configured not to operate,
The toner detection means detects the detection after operating the vibration motor for a predetermined time after the end of the print job when the number of print jobs executed by the image forming apparatus is equal to or greater than the predetermined number. An image forming apparatus configured to execute. The image forming apparatus according to any one of claims 1 to 4,
The suction duct has a bent portion,
The image forming apparatus, wherein the predetermined location is a location where the bent portion is located in the suction duct.

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