JP4526336B2 - Toner recovery apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to a toner recovery device that stores used toner in a container, and an image forming apparatus including the toner recovery device.

  There are various types of image forming apparatuses that form images on sheets such as copying machines, printers, and facsimiles. Among them, an electrophotographic system that forms an image on a sheet by forming a latent image on the surface of the photoreceptor, developing the toner by attaching the toner to the latent image, and transferring the toner from the surface of the photoreceptor to the sheet. Is frequently used. In this type of image forming apparatus, it is necessary to remove the remaining toner from the surface of the photoreceptor after toner transfer for the next image formation. The toner separated from the surface of the photoreceptor is stored in a detachable container by a toner recovery device.

  The container for storing the used toner needs to be replaced when it is full, and the toner recovery device is provided with means for detecting whether or not the container is full. Further, since the toner cannot be stored unless the container is mounted, the toner recovery device is also provided with means for detecting whether or not the container is mounted.

The means for detecting whether or not the container is full is generally composed of a light emitting part that emits light toward the container and a detection part that detects from the light emitting part that has passed through the container, and the light emitting part and the light receiving part are The upper portion of the container, that is, the vicinity of the opening for passing the toner is sandwiched (see, for example, Japanese Patent No. 2925419). Until the container is full, light from the light emitting part reaches the detection part without being blocked by toner, and when the container is full, light from the light emitting part is blocked by toner and does not reach the detection part. Whether or not the container is full can be determined by detecting whether or not light is detected.
Japanese Patent No. 2925419

  On the other hand, as a means for detecting whether or not the container is mounted, a push switch that is pushed and closed by the container is used.

  As described above, the conventional toner recovery apparatus has two types of detection principles different as a means for detecting whether or not the container is full and a means for detecting whether or not the container is mounted. The configuration was complicated. In addition, toner may adhere to the vicinity of the opening of the container, and it may be erroneously determined that the container is not full.

  As a method for preventing the above misjudgment, in the above-mentioned patent publication, the vicinity of the opening of the container is doubled and the opening is provided in the inner wall, so that light from the light emitting part of the outer wall is transmitted. It has been proposed to prevent the toner from adhering to the site where the toner is applied. However, this container has a complicated shape and is not suitable for mass production.

  The present invention has been made in view of such problems, and detects whether or not a container for storing toner is mounted and whether or not the container is full while having a simple configuration. It is an object of the present invention to provide a toner collecting device. It is another object of the present invention to provide such a toner recovery device that does not erroneously determine that a container is full due to toner adhesion and that does not require a specially structured container.

  In order to achieve the above object, according to the present invention, a toner recovery device for storing used toner in a removable container having an opening through an opening uses a translucent container in the vicinity of the opening. A light emitting unit that emits light toward the vicinity of the opening, a detection unit that detects light from the light emitting unit that has passed through the vicinity of the opening of the container, and a light source that controls light emission and switches the intensity of the light emitted by the light emitting unit Based on the intensity of light detected by the control unit and the detection unit, a determination unit for determining whether or not the container is mounted and whether or not the toner is contained up to the vicinity of the opening of the container Shall be provided.

  In this toner collecting apparatus, the light emitting unit and the detecting unit for detecting whether or not the container is full are used for detecting whether or not the container is mounted. Therefore, the configuration is simple. By using a translucent container in the vicinity of the opening and guiding the light from the light emitting section to this part, it is possible to detect the presence or absence of the container by an optical method. Further, by switching the intensity of light from the light emitting unit, it is possible to accurately perform both detection of the presence / absence of the container and detection of whether or not the container is full.

  The determination unit may further determine whether or not the vicinity of the opening of the container that does not contain toner up to the vicinity of the opening is contaminated with toner. In this way, it is possible to prevent erroneous determination that the container is full when the container is not full. The container only needs to be translucent in the vicinity of the opening, and a container with a special structure is not necessary.

  Here, based on how many times the light is detected by the detection unit during a predetermined number of cycles, the control unit causes the light emission unit to periodically emit light with different intensity as one cycle. The determination unit determines whether the toner is stored up to the vicinity of the opening of the container, whether the vicinity of the opening of the container where the toner is not stored up to the vicinity of the opening is dirty with the toner, and the container is mounted. It is good to determine whether or not it is. If each of the lights with different intensities is detected only once, there is a risk that an error may occur in the determination result depending on the degree of noise or contamination in the vicinity of the opening. However, the detection can be reliably performed by performing detection several times. Can do.

  Specifically, the control unit causes the light emission unit to periodically emit light with three levels of light emission as one cycle, and based on the number of times the detection unit detects high-intensity light, Based on the number of times the detection unit detects medium-intensity light, determining whether the toner is stored up to the vicinity of the opening of the container, the vicinity of the opening of the container where the determination unit is not storing the toner up to the vicinity of the opening It is determined whether or not the portion is stained with toner, and the determination portion determines whether or not the container is mounted based on the number of times the detection portion detects low-intensity light.

  In the present invention, a latent image is formed on the surface of the photoconductor, the toner is attached to the surface of the photoconductor on which the latent image is formed, the latent image is developed, and the toner is transferred from the surface of the photoconductor to the sheet. An image forming apparatus that forms an image on a sheet and separates remaining toner from the surface of the photoconductor after transfer. The image forming apparatus includes any one of the toner collecting devices described above, and collects the toner separated from the surface of the photoconductor. The device is accommodated in a container.

  The toner recovery device of the present invention has a simple configuration because the light emitting unit and the detection unit for detecting whether or not the container is full are used for detecting whether or not the container is mounted. Moreover, since the container should just be translucent in the opening vicinity part and does not require a special structure, mass production is easy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. A configuration of a copying machine 1 according to an embodiment of the present invention is schematically shown in FIG. The copying machine 1 includes an image forming unit 10 that forms an image on a sheet, a sheet supply unit 20 that supplies a sheet to the image forming unit 10, an image reading unit 30 that reads an image from a document, an operation guide, and the like. The operation display unit 40 displays the image and the sheet discharge unit 50 discharges the sheet on which the image is formed.

  The sheet supply unit 20 includes a plurality of trays 21. Sheets having different sizes and orientations are placed for each tray 21, and sheets designated via the operation display unit 40 are transferred from the corresponding trays 21. The image is supplied to the image forming unit 10. The image reading unit 30 includes a contact glass, a movable line sensor disposed below the contact glass to read an image from a document on the contact glass, a scanner unit 31 having an illuminator that illuminates the document on the contact glass, and The document transfer unit 32 includes a document transfer unit 32 that sequentially transfers stacked documents on the contact glass.

  The operation display unit 40 includes a plurality of operation keys, a liquid crystal display panel, and a touch panel disposed on the liquid crystal display panel. The operation keys are used to input numerical values such as the number of copies, and the touch panel is used to select functions of the copying machine 1. In addition to operation guidance, the liquid crystal display panel displays the status of the copying machine 1, a warning to the user, and the like. The sheet discharge unit 50 includes a plurality of bins 51 that are movable in the vertical direction. The sheet on which an image is formed by the image forming unit 10 can be sorted into different bins 51 and discharged.

  The image forming unit 10 includes a photosensitive drum 11, a charging unit 12, a latent image forming unit 13, a developing unit 14, a transfer unit 15, a fixing unit 16, a toner collecting unit 17, and a charge eliminating unit 18. The photosensitive drum 11 has a surface whose charging potential is changed by light, and rotates in the arrow A direction. The charging unit 12 uniformly charges the surface of the photosensitive drum 11 by discharging, and the latent image forming unit 13 forms a latent image on the surface of the photosensitive drum 11 by irradiation with laser light. The developing unit 14 develops the latent image by attaching toner to the latent image on the surface of the photosensitive drum 11, and the transfer unit 15 applies the toner on the surface of the photosensitive drum 11 to the sheet supplied from the sheet supply unit 20. Transcript. The fixing unit 16 heats and presses the sheet on which the toner has been transferred to fix the toner to the sheet.

  The toner collecting unit 17 separates the remaining toner from the surface of the photosensitive drum 11 after the toner transfer, and collects the separated toner. The collected toner is stored in a detachable container 19. The neutralization unit 18 removes electric charges on the surface of the photosensitive drum 11 from which the toner is removed.

  Although not shown, the copying machine 1 includes a communication unit for connecting to a public telephone line and a local area network (LAN), and transmits and receives image data to and from an external facsimile apparatus via the public telephone line. As a facsimile machine, a printer that receives data from a personal computer on the LAN and forms an image represented by the data on a sheet, or transmits image data representing an image read from a document to a personal computer on the LAN. It also functions as an image scanner.

  As described above, the toner collecting unit 17 stores the toner separated from the surface of the photosensitive drum 11 in the detachable container 19. The toner collecting unit 17 detects whether the container 19 is attached and the container 19 is full. It also detects whether or not there is. The container 19 and the configuration for detecting the presence / absence and fullness of the container 19 are schematically shown in FIG.

  The toner is accommodated in the container 19 by using the fall of the toner due to gravity. Accordingly, the container 19 has an opening 19a at the upper end. Further, in order to prevent the toner T once entering the container 19 from splashing and coming out of the container 19, or to cover the container 19 removed from the toner recovery unit 17 for easy handling, The upper part of 19, that is, the vicinity 19 b of the opening 19 a is made thinner than the lower part.

  The toner collecting unit 17 includes a light emitting diode (LED) 61 and a photodiode (PD) 62 for detecting the presence / absence of the container 19 and fullness. The light emitting diode 61 and the photodiode 62 are disposed so as to face each other with the opening vicinity 19b of the container 19 in between. The opening vicinity 19 b of the container 19 is set to be semitransparent to the light emitted from the light emitting diode 61. In FIG. 2, the shaded area on the opening vicinity 19 indicates that this part is translucent.

  The container 19 other than the vicinity of the opening 19b may be transparent or opaque. However, in order to make it easy to visually recognize that the toner T is contained in the container 19, it is desirable to make it transparent or translucent except for the vicinity of the opening 19 b. Moreover, making the opening vicinity part 19b semi-transparent can be easily realized by making the entire container 19 of a transparent material and attaching a semi-transparent seal thereto. If the entire container is made of a translucent material, it can be used as it is.

  If the container 19 is not mounted, the light emitted from the light emitting diode 61 directly reaches the photodiode 62. If the intensity of the light emitted from the light emitting diode 61 exceeds a certain level, the photodiode 62 emits light from the light emitting diode 61. Can be reliably detected.

  On the other hand, if the container 19 is mounted, the light emitted from the light emitting diode 61 is attenuated to reach the photodiode 62 by passing through the semitransparent opening vicinity 19 b of the container 19. Therefore, when the intensity of light emitted from the light emitting diode 61 is low, the photodiode 62 cannot detect light.

  If the mounted container 19 is full, that is, if the toner T is accommodated up to the opening vicinity 19b of the container 19, the light emitted from the light emitting diode 61 is blocked by the toner T, and the photodiode 62 is not reached. Of course, the photodiode 62 cannot detect light.

  Furthermore, although the container 19 is not full, the light emitted from the light emitting diode 61 is partially blocked by the toner T when the vicinity of the opening 19b is soiled due to adhesion of the scattered toner T. Therefore, whether or not the photodiode 62 can detect the light from the light emitting diode 61 depends on the intensity of the light emitted by the photodiode 62 and the degree of adhesion of the toner T to the opening vicinity 19b.

  The toner recovery unit 17 determines whether or not the container 19 is mounted and whether or not the container 19 is full based on the relationship between the state of the container as described above and whether or not light can be detected by the photodiode 62. Further, it is detected whether or not the opening vicinity 19b of the container 19 which is not full is dirty. For this purpose, the intensity of the light emitted from the light emitting diode 61 is changed stepwise. Specifically, the intensity of the light emitted from the light emitting diode 61 is high enough that the photodiode 62 can detect even if the opening vicinity 19b is stained to some extent with toner, and the opening vicinity 19b is stained to some extent with toner. There are three levels: medium intensity that cannot be detected by the photodiode 62 and low intensity that can be detected by the photodiode 62 only when the container 19 is not mounted.

  Furthermore, if the light of each intensity is emitted only once and the determination is made based on the result, the detection result may be inaccurate due to noise or the amount of toner adhering to the opening vicinity 19b. The light emitted from the light emitting diode 61 and the detection by the photodiode 62 are periodically performed with light of each intensity as one cycle.

  A circuit configuration for driving the light emitting diode 61 and the photodiode 62 is schematically shown in FIG. The toner recovery unit 17 includes three resistors 63a, 63b, and 63c, three transistors 64a, 64b, and 64c, a power supply line 65, and a CPU 69 for driving the photodiode 61. These are connected as shown, and the CPU 69 switches which of the three transistors 63a, 63b, and 63c the current flows depending on which of the three transistors 64a, 64b, and 64c is made conductive. The resistance values of the resistors 63a, 63b, and 63c are different from each other. Therefore, the voltage applied to the light-emitting diode 61 is switched depending on which of the resistors 63a, 63b, and 63c the current flows, and accordingly, the light-emitting diode 61 emits light. The intensity switches.

  The toner recovery unit 17 includes a resistor 66 and a power line 67 for driving the photodiode 62. The toner recovery unit 17 uses the voltage appearing between the photodiode 62 and the resistor 66 as a detection result of the photodiode 62. This voltage is supplied to the CPU 69 via the amplifier 68, and the CPU 69 that controls the light emitting diode 61 determines whether or not light is detected by the photodiode 62.

  The photodiode 62 conducts when receiving a predetermined amount or more of light, and does not conduct even if a certain amount of light is received unless the amount reaches a predetermined amount. Therefore, the voltage that is the detection result of the photodiode 62 has a binary value of high level and low level.

  The relationship between the light emission of the light emitting diode 61 and the detection of light by the photodiode 62 is shown in FIG. In FIG. 4, (a) represents the light emission of the light emitting diode 61, and the vertical axis represents the light emission intensity. (B1) to (b7) represent the detection results of the photodiode 62, and the vertical axis represents the voltage of the detection results. The horizontal axis is time. As described above, the light emitting diode 61 emits light periodically with light emission at three levels of intensity as one cycle.

  In (b1), high intensity, medium intensity, and low intensity light are all detected. This corresponds to a state where the container 19 is not attached. In (b2), all high-intensity and medium-intensity light is detected, and all low-intensity light is not detected. This corresponds to a state in which the container 19 is mounted and the opening vicinity 19b is not soiled unless the container 19 is full.

  In (b3), all high-intensity light is detected, and all medium-intensity light and low-intensity light are not detected. This corresponds to a state where the container 19 is attached and the container 19 is not full, but the opening vicinity 19b is dirty. In (b4), all of high-intensity, medium-intensity, and low-intensity lights are not detected. This corresponds to a state in which the container 19 is mounted and the container 19 is full.

  In (b5), all high-intensity light is detected, all low-intensity light is not detected, and only medium-intensity light is detected. This corresponds to a state where the container 19 is attached and the container 19 is not full, but the opening vicinity 19b is dirty.

  In (b6), only a part of the high-intensity light is detected, and all the medium-intensity light and the low-intensity light are not detected. This corresponds to a state in which the container 19 is mounted and the container 19 is full. Even in (b7), only a part of the high-intensity light is detected, and all of the medium-intensity light and the low-intensity light are not detected. However, the number of times that high-intensity light is not detected is less than (b6). This corresponds to a state in which the container 19 is attached and the container 19 is not full, but the opening vicinity 19b is dirty.

  As shown in (b1) to (b4), when light of the same intensity is always detected or not always detected, the state of the container 19 can be clearly determined. However, as shown in (b5) to (b7), the light of the same intensity may be detected or not detected. In such a case, although it is difficult to determine the state of the container 19, the toner recovery device 17 performs the determination based on the number of times that light of the same intensity was not detected during a predetermined cycle, and the result is accurate. Increase the height.

  The state of the container 19 is determined by the above-described CPU 69 that controls the light emitting diode 61 and receives the detection result of the photodiode 62. FIG. 5 shows the flow of determination processing performed by the CPU 69.

  First, the CPU 69 causes the light emitting diode 61 to emit light for a plurality of cycles (for example, 8 cycles), and at the same time, obtains a light detection result by the photodiode 62 (step # 5). Next, it is determined whether or not the number of times the high-intensity light cannot be detected is 3 or more (# 10). When the number of high-intensity light non-detections is 3 or more, it is determined that the container 19 is full (# 15), and a message requesting replacement of the container 19 is displayed on the operation display unit 40 (# 20). .

  When the number of high-intensity light undetections is less than 3, it is determined whether the number of times the medium-intensity light was not detected is 5 or more (# 25). When the number of times of non-detection of medium intensity light is 5 or more, it is determined that the container 19 is dirty with toner (# 30), and a message requesting cleaning of the opening vicinity 19b of the container 19 is displayed on the operation display unit 40. (# 35).

  When the number of times of non-detection of medium intensity light is less than 5, it is determined whether or not the number of times of detection of low intensity light is 2 or more (# 40). When the number of low-intensity light non-detections is less than 2, it is determined that the container 19 is not attached (# 45), and a message requesting the attachment of the container 19 is displayed on the operation display unit 40 (# 50). ).

  When the number of low-intensity light non-detections is 2 or more, it is determined that the container 19 is normal, that is, the container 19 that is not full and the opening vicinity 19b is not soiled (# 55). Finish.

  The number of cycles in step # 5 and the number of times used as a reference in the determinations in steps # 10, # 25, and # 40 are not limited to the above values, and may be other values. These values are preferably determined in consideration of various conditions related to light detection, such as the light emission intensity of the light emitting diode 61 and the light receiving performance of the photodiode 62.

  The CPU 69 performs the processing shown in FIG. 5 when the copying machine 1 is started up and every time an image is formed on the sheet. Therefore, it is possible to reliably prevent the image formation when the container 19 is in an inappropriate state.

  You may make it perform the process which detects the state of the container 19 always. In that case, in step # 5, the light emission of the light emitting diode 61 and the light detection by the photodiode 62 are performed for only one cycle, and after steps # 20, # 35, # 50, and # 55, the process returns to step # 5. To do. Further, in steps # 10, # 25, and # 40, the number of times that light of each intensity cannot be detected continuously is determined.

  As the CPU 69, a dedicated toner recovery unit 17 may be provided, or a CPU that controls the entire copying machine 1 may be used. Here, the light emitting diode 61 is employed to emit light and the photodiode 62 is employed to detect light. However, other light emitting elements or light receiving elements may be used. The material and shape of the container 19 are also arbitrary. However, it is preferable to use a material suitable for mass production and to have a simple shape suitable for mass production.

1 is a diagram schematically illustrating a configuration of a copier according to an embodiment of the present invention. FIG. 3 is a diagram schematically illustrating a container used by a toner recovery unit of the copying machine and a configuration for detecting the state of the container. The figure which shows typically the circuit structure for driving the light emitting diode and photodiode of the said toner collection | recovery part. The figure which shows the relationship between the light emission of the light emitting diode of the said toner collection | recovery part, and the detection of the light by a photodiode. 6 is a flowchart illustrating a flow of a container state determination process performed by a CPU of the toner recovery unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Copier 10 Image forming part 11 Photosensitive drum 12 Charging part 13 Latent image forming part 14 Developing part 15 Transfer part 16 Fixing part 17 Toner recovery part 18 Electric discharge part 19 Toner container 19a Opening 19b Opening vicinity part 20 Sheet supply part 21 Sheet loading tray 30 Image reading section 40 Operation display section 50 Sheet discharge section 51 Sheet loading bin 61 Light emitting diode 62 Photo diode 63a, 63b, 63c Resistor 64a, 64b, 64c Transistor 65 Power line 66 Resistor 67 Power line 68 Amplifier 69 CPU

Claims (3)

In a toner recovery device for storing used toner in a removable container having an opening through the opening,
While using a translucent container in the vicinity of the opening,
A light emitting unit that emits light toward the vicinity of the opening of the container;
A detection unit for detecting light from the light emitting unit that has passed through the vicinity of the opening of the container;
A control unit that controls the light emission of the light emitting unit, switches the intensity of the light emitted by the light emitting unit, and causes the light emitting unit to periodically emit light, with light emission at different intensities as one cycle ;
Based light of which intensity detection unit several times detected for a predetermined number of cycles, whether the toner to the opening vicinity of the container is accommodated, the container in which the toner is not accommodated to the opening part near A toner collection device comprising: a determination unit that determines whether or not the vicinity of the opening of the toner is stained with toner and whether or not the container is mounted . Based on the number of times the control unit emits light at three levels of intensity as one cycle, the light emitting unit periodically emits light, and the detection unit detects high-intensity light, the discrimination unit is the vicinity of the opening of the container Until the toner is contained in the container, and based on the number of times the detection unit detects medium-intensity light, the vicinity of the opening of the container in which the toner is not contained is stained with toner. and it discriminates whether or not the that the detection unit is based on the number of times of detecting the low intensity light, toner recovery according to claim 1 in which discriminating unit and discriminates whether the container is mounted apparatus. The latent image is formed on the surface of the photoconductor, the toner is attached to the surface of the photoconductor on which the latent image is formed, the latent image is developed, and the toner is transferred from the surface of the photoconductor to the sheet, whereby the image is formed on the sheet. In the image forming apparatus for forming and separating the remaining toner from the surface of the photoreceptor after transfer,
Includes a toner recovery device according to claim 1 or claim 2, the image forming apparatus, characterized in that contained in the container the toner separated from the surface of the photosensitive member by the toner collecting unit.

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