JP6561711B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to detection of the amount of waste toner in a container for storing waste toner in an image forming apparatus.

2. Description of the Related Art Conventionally, in an electrophotographic image forming apparatus that develops a toner image on a photosensitive member and transfers it to a medium (paper), the image forming unit having the photosensitive member and the transfer member removes the photosensitive member and the transfer member from the photosensitive member and the transfer member after transfer. The toner is removed and collected, and the collected waste toner is stored in a toner collection container. When the amount of waste toner in the toner collection container reaches a specified amount, the toner collection container is replaced with a new toner collection container.
Since the toner collection container is collected together with the waste toner, it is demanded that the internal capacity can be used without waste with an inexpensive configuration. For this reason, it is a problem that the full detection is reliably performed without a complicated mechanism. ing.
As a detection method that achieves both airtightness and low cost for the toner recovery container, many methods are used to detect the presence of toner by collecting and shielding the waste toner between light emission and light reception of the photo interrupter. It is widely known that when the waste toner is collected in the toner collection container, false detection is caused by fouling the detected part in order to show behavior such as “scattering” and “swelling”. Proposals have been made to ensure full detection by separating the position from the entrance, providing the detected part at a high position, providing a shield, or adding various mechanisms.

For example, Patent Document 1 proposes preventing early detection based on the weight of waste toner as a countermeasure against erroneous detection in a photo interrupter.
Further, in Patent Document 2, an actuator (actuating unit) that operates a photo interrupter on a feeler that is displaced by the rising of the collected toner is provided instead of directly detecting the toner by a photo interrupter. Patent Document 3 proposes a mechanism having a mechanism for cleaning a detected portion.
Further, Patent Documents 4 and 5 propose a technique for controlling a toner storage posture by inserting a screw into a waste toner collection box in order to improve detection accuracy.
In Patent Document 5, the bottom surface of the detected portion is made higher than the bottom surface of the toner containing portion, and an adjacent wall is provided between the toner containing portion and the detected portion, so that an early error due to scattering of toner generated in the toner containing portion can be obtained. Proposals have been made to prevent detection.

JP 2002-296985 A JP-A-2-199495 Japanese Patent Laid-Open No. 10-143038 JP 2015-22199 A JP 2013-178406 A

However, because the bulk density of waste toner is not constant, and the angle of repose is not constant depending on the environment and use conditions, the full judgment is a margin after the sensor detects that it does not overflow in any environment or use conditions. It was necessary to make a judgment that it was full in a safe area with a margin.
Particularly in recent years, the use conditions due to the reduction in the particle size of toner and the increase in use in production printing have led to an increase in the degree of smearing, bulk density, and angle of repose angle.
When an actuator is interposed, it is necessary to place it in a position where it can obtain the force necessary to operate the actuator, and because it is affected by the bulk density, this is also a safe area with a margin after the sensor detects it. It was necessary to judge that it was full.
When a screw, a cleaning mechanism, or the like is provided in the waste toner collection box for improving the reliability of toner detection, the number of components is increased and the number of replacements is added, resulting in a cost increase. Further, when the component parts are made of a plurality of materials, not only the profit is compressed but also a problem in terms of recyclability.

  The present invention has been made in view of the above problems in the prior art, and is an image forming apparatus that collects waste toner from an image forming unit and stores it in a toner collecting container. It is an object to reliably detect a full state of a toner collection container without providing a configuration for detecting the toner storage amount in the container.

The invention according to claim 1 for solving the above-described problems is an image forming apparatus for collecting waste toner from an image forming unit and storing the waste toner in a toner collecting container.
A toner detection sensor for detecting a stay of waste toner for a predetermined detected portion of a waste toner conveyance path upstream of a recovery port of the toner recovery container;
Control means for determining a full state of the toner collection container based on detection by the toner detection sensor ,
In the process of detaching the toner collection container from the discharge port of the waste toner conveyance path, the waste toner conveyance path is detected in the remaining space of the toner collection container at the time of detection by the toner detection sensor. the image forming apparatus you collecting waste toner that has been staying in.

According to a second aspect of the present invention, the toner recovery container has a preliminary recovery port that allows the extra space to communicate with the outside without passing through the recovery port, and the recovery port is located between the recovery port and the preliminary recovery port. A partition member for preventing waste toner flowing in from the outlet from flowing out from the preliminary recovery port;
In the process of the separation operation, the discharge port separated from the collection port is connected to the preliminary collection port, and the waste toner that has stopped in the waste toner conveyance path when detected by the toner detection sensor in the extra space is removed. The image forming apparatus according to claim 1 , wherein the image forming apparatus is collected.

According to a third aspect of the present invention, in a period in which the discharge port and the preliminary recovery port are connected in the process of the detachment operation, vibration is applied to at least the detected part in conjunction with the detachment operation. 3. The image forming apparatus according to claim 2 , further comprising: a discharge mechanism that prompts discharge of waste toner that has stopped in the waste toner conveyance path when detected by the toner detection sensor from the discharge port.

According to a fourth aspect of the present invention, there is provided a shutter that closes the discharge port after the waste toner is collected in the extra space in the process of the separation operation.
A toner recovery container mounting detection sensor for detecting the mounting of the toner recovery container;
The control means, wherein the time of non-detection by the toner detection sensor, the image forming apparatus according to claim 1, claim 2 or claim 3 for permitting the image forming when the detection time and non-detection by the toner recovery container mounting detection sensor It is.

A fifth aspect of the present invention is the image forming apparatus according to any one of the first to fourth aspects, further comprising a cleaning mechanism that cleans the detected portion.

According to the present invention, there is provided a toner detection sensor for detecting the retention of waste toner for a predetermined detected portion of the waste toner transport path upstream of the recovery port of the toner recovery container, and upstream of the discharge port of the waste toner transport path. Therefore, the full state of the toner collection container can be reliably detected regardless of the angle of repose of the waste toner that changes depending on the environment and use conditions.
Further, since a toner detection sensor for detecting the stay of the waste toner is provided for a predetermined detected portion of the waste toner conveyance path upstream of the recovery port of the toner recovery container, a mechanism for detecting the toner storage amount in the toner recovery container is provided. In addition , there is no need to provide a transport mechanism or a cleaning mechanism for stabilizing the detection by the toner detection sensor, and a waste toner transport path in the remaining space of the toner recovery container when detected by the toner detection sensor. Since the waste toner that has been retained in the container is collected, a toner collection container having an excellent collection volume ratio and recyclability can be produced at low cost.

1 is a schematic diagram illustrating an internal structure of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a schematic diagram showing an internal structure of the image forming apparatus according to the first embodiment of the present invention, and shows a state where waste toner is increased from the state shown in FIG. 1. FIG. 3 is a schematic diagram showing an internal structure of the image forming apparatus according to the first embodiment of the present invention, and shows a state in which the toner recovery container is pulled out from the state shown in FIG. FIG. 4 is a perspective view illustrating an example of a structure of a waste toner conveyance path in which a toner detection sensor is installed according to an embodiment of the present invention. FIG. 6 is a schematic diagram illustrating an internal structure of an image forming apparatus according to a second embodiment of the present invention. FIG. 6 is a schematic diagram illustrating an internal structure of an image forming apparatus according to a second embodiment of the present invention, showing a state in the middle of pulling out a toner collection container from the state shown in FIG. FIG. 7 is a schematic diagram illustrating an internal structure of an image forming apparatus according to a second embodiment of the present invention, illustrating a state where a toner collection container is pulled out from the state illustrated in FIG.

  An embodiment of the present invention will be described below with reference to the drawings. The following is one embodiment of the present invention and does not limit the present invention.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, the image forming apparatus A of the present embodiment includes an electrophotographic image forming unit 10, a waste toner conveyance path 20, a toner collection container 30, a control unit 40, a toner detection sensor 41, A toner collection container mounting detection sensor 42, a cleaning mechanism 50, and a shutter 60 are provided. In addition, an operation panel, an image and audio display device, and the like are provided, but the illustration is omitted.
The image forming unit 10 includes a photosensitive member carrying a toner image corresponding to the electrostatic latent image, a charging device for charging the photosensitive member, and laser light to irradiate the electrostatic latent image on the charged photosensitive member. An exposure device that forms a toner image corresponding to the electrostatic latent image formed on the photosensitive member, a developing device that develops the toner image on the photosensitive member, and an intermediate transfer member onto which the toner image developed on the photosensitive member is transferred. And a cleaner that removes toner from the photosensitive member and a cleaner that removes toner from the intermediate transfer member, and transfers the toner image from the intermediate transfer member to a medium (paper).

The waste toner removed by the cleaner is collected through the waste toner conveyance path 20, flows into the toner collection container 30, and is stored therein. That is, the image forming apparatus A collects waste toner from the image forming unit 10 and stores it in the toner collecting container 30.
In the present embodiment, the waste toner conveyance path 20 includes a horizontal path 21 and a vertical path 22 having an upper end connected to the subsequent stage. The horizontal path 21 is appropriately provided with a transport mechanism such as a screw. The lower end of the vertical path 22 is a discharge port 22 a of the waste toner transport path 20.
A recovery port 31 is provided on the upper surface of the toner recovery container 30. As shown in FIGS. 1 and 2, when the toner collection container 30 is attached to the image forming apparatus A, the discharge port 22 a is connected to the collection port 31 of the toner collection container 30. The toner collection container mounting detection sensor (microswitch) 42 detects the mounting of the toner collection container 30.

As shown in FIG. 3, the shutter 60 closes the discharge port 22a when the recovery port 31 is detached from the discharge port 22a.
As a mechanism for operating the shutter 60, when the toner collection container 30 is pushed into the image forming apparatus A, an opening operation is performed by using the pushing force to retreat from the discharge port 22a, and the toner collection container 30 is moved to the main body. This is a mechanism that realizes a closing operation for closing the discharge port 22a in conjunction with this when the image forming apparatus A is pulled out from the inside. For example, it is a mechanical mechanism that urges the shutter 60 with a spring in a direction to close the discharge port 22a and engages and retracts the toner collection container 30 that enters the image forming apparatus A. The mechanical engagement between the shutter 60 and the toner collection container 30 may be direct or may be via a transmission mechanical element such as a link mechanism.
The lower end portion of the vertical path 22 is formed of a cylindrical flexible part made of a rubber material or the like, and the lower end thereof is a discharge port 22a. The close contact with the periphery of the recovery port 31 and the closing surface (upper surface) of the shutter 60 Realize close contact.

The toner detection sensor 41 detects the retention of the waste toner for a predetermined detected portion 22b of the waste toner conveyance path 20 upstream of the recovery port 31 of the toner recovery container 30. In the present embodiment, the detected part 22 b is provided in the vertical path 22. The toner detection sensor 41 is disposed on the peripheral wall portion of the vertical path 22 as shown in FIG. The toner detection sensor 41 in the example shown in FIG. 4 is a pressure-sensitive sensor using a piezoelectric element, and is installed so that the pressure-sensitive portion 41a is exposed on the inner surface of the vertical path 22.
When toner adheres to the pressure-sensitive portion 41a, it may react, so the pressure-sensitive portion 41a is cleaned by the cleaning mechanism 50. As shown in FIG. 4, the cleaning mechanism 50 has a shaft 51 penetrating through the vertical path 22 as shown in FIG. 4, and is fixed to the shaft 51, and rotates as the shaft 51 is driven to rotate. And a cleaning blade 52 in contact with the surface of the portion 41a. The control means 40 acquires the signal from the toner detection sensor 41 after cleaning the pressure sensitive part 41 a by the cleaning mechanism 50.
A photo interrupter may be applied as the toner detection sensor 41. However, if the photo interrupter is used, even if the inner surface of the conveyance path on the optical axis is cleaned, toner smoke is generated on the same optical axis in the conveyance path. If it is full, the detection light may be blocked and react, but if it is a pressure sensor, it is possible to accurately detect the retention of waste toner without such problems. In addition, if it is a pressure-sensitive sensor, it is sufficient to install it on one side, and there is no need to arrange other parts on the optical axis in the case of a photo interrupter, and the degree of freedom of installation of the cleaning mechanism is also high. .

  The toner detection sensor 41 is preferably in the vicinity of the discharge port 22a upstream of the discharge port 22a. In the present embodiment, since the final stage that terminates at the discharge port 22a of the waste toner conveyance path 20 is a downstream path, it is preferably provided in the downstream path. As shown in FIG. 2, it is for early and surely detecting the stoppage of the waste toner in the waste toner conveyance path 20 due to overflow from the collection port 31 of the toner collection container 30.

The control unit 40 controls all operations of the image forming apparatus A such as an image forming operation in the image forming unit 10 as well as processing of input image data. The control unit 40 includes a processor 43 and a storage unit 44. When the processor 43 executes a program stored in the storage unit 44, an input from the toner detection sensor 41 and an input from the toner collection container mounting detection sensor 42 are performed. And the cleaning mechanism 50 is controlled.
Based on the detection by the toner detection sensor 41, the control unit 40 determines whether the toner collection container 30 is full and notifies the user of the necessity of replacing the toner collection container 30.

When the amount of waste toner collected in the toner collection container 30 gradually increases after the new empty toner collection container 30 is mounted on the image forming apparatus A, the conventional toner collection container includes a detected portion. In the toner detection mechanism provided with a margin, a relatively large margin as shown in FIG. This is because the angle of repose of the waste toner varies depending on the environment and use conditions, and is set so that the waste toner does not overflow from the collection port 31 at the assumed steepest angle of repose.
In the image forming apparatus A, as shown in FIG. 2, the waste toner T accumulates in the toner collection container 30, reaches the collection port 31 at the top, and further accumulates in the vertical path 22. The waste toner T stops in the part 22b, and the toner detection sensor 41 detects this.
Since the detected part 22b is provided in the vertical path 22 and the toner detection sensor 41 directly detects, the rest angle of the waste toner T on the vertical path 22, that is, the waste toner T overflowing from the collection port 31 is taken as the angle of repose. It can be reliably detected regardless. Based on the detection signal, the control means 40 determines that it is full. Therefore, it is possible to reliably detect the full state of the toner collection container regardless of the angle of repose of the waste toner that changes depending on the environment and use conditions, and the remaining space where the waste toner T in the toner collection container 30 is not filled is filled. Can be reduced.

When the user pulls out the toner collection container 30 from the image forming apparatus A as shown in FIG. 3, the discharge port 22a is closed by the shutter 60, and the waste toner that has stopped in the vertical path 22 when detected by the toner detection sensor 41 T1 is held in the vertical path 22 as it is, and leakage is prevented.
On the other hand, the waste toner T <b> 2 that has been transported first is accommodated in the toner recovery container 30 and recovered. A seal is affixed to the upper surface of the toner collection container 30 pulled out by the user, and the collection port 31 is covered and sealed. This seal is provided with a new empty toner collection container 30.
Thereafter, when a new empty toner collection container 30 is inserted and attached to the image forming apparatus A, the shutter 60 is opened and the collection port 31 of the toner collection container 30 is connected to the discharge port 22a. The waste toner T1 held in the vertical path 22 is dropped and stored in the container 30. Therefore, the waste toner T2 includes the waste toner T1 held in the vertical path 22 when the toner collection container 30 before the new empty toner collection container 30 is pulled out.

In the image forming apparatus A, the detected portion 22 b is provided in the waste toner conveyance path 20 upstream of the recovery port 31 of the toner recovery container 30.
Therefore, it is not necessary to provide the toner collection container 30 with a mechanism for detecting the toner storage amount, a transported mechanism for cleaning detection by the detected structure, and a cleaning mechanism. That is, a container body having a relatively simple shape can be employed as the toner collection container 30, and a complicated structure that narrows the toner storage space, such as providing unevenness to provide a mechanism for detecting the toner storage amount and a structure to be detected. Therefore, the present invention can be carried out without arranging the parts in the container body and narrowing the toner accommodating space.
For this reason, the collection volume ratio represented by the volume of waste toner stored relative to the volume of the toner collection container 30 (at the time of full replacement) is improved.
Further, since the number of components is small, it is possible to provide a toner collecting container with excellent recyclability that can be recycled without disassembly and separation.
Such a toner collection container having an excellent collection volume ratio and recyclability can be manufactured at low cost, and the operation cost can be kept low.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIGS. As in the first embodiment, the same reference numerals are given to the portions and description thereof is omitted.
As shown in FIGS. 5 to 7, the image forming apparatus B of the present embodiment is different from the image forming apparatus A of the first embodiment in the process of detachment from the discharge port 22 a of the toner collection container 30. The difference is that the waste toner T <b> 1 that has stopped in the vertical path 22 at the time of detection by the toner detection sensor 41 is collected in the extra space 32 of the toner collection container 30 at the time of detection by the detection sensor 41.
For this purpose, the toner recovery container 30 of the present embodiment has a preliminary recovery port 33 that allows the extra space 32 to communicate with the outside without passing through the recovery port 31, and the recovery port is located between the recovery port 31 and the preliminary recovery port 33. A partition member 34 is provided for preventing waste toner flowing in from 31 from flowing out from the preliminary collection port 33.
Specifically, a preliminary collection port 33 is provided in front of the collection port 31 in the insertion direction of the toner collection container 30. The preliminary collection port 33 opens on the upper surface of the toner collection container 30 in the same manner as the collection port 31. As shown in FIG. 5, a preliminary collection port 33 is disposed above the extra space 32 of the toner collection container 30 when detected by the toner detection sensor 41.
The partition member 34 partitions the internal space of the toner recovery container 30 into an internal space that contacts the recovery port 31 and an internal space that contacts the preliminary recovery port 33. The partition member 34 is not limited to a member that blocks the waste toner from coming and going between the both side spaces, and a gap and a hole are provided so that the waste toner T1 flows from the preliminary collection port 33 side to the collection port 31 side. May be.

In the process of detachment operation from the discharge port 22a of the toner recovery container 30 shown in FIGS. 5 → 6 → 7, the discharge port 22a released from the recovery port 31 is connected to the preliminary recovery port 33 as shown in FIG. The waste toner T1 that has stopped on the vertical path 22 at the time of detection by the toner detection sensor 41 is collected in the extra space 32.
In this image forming apparatus B, in order to improve the discharge of the waste toner T1 from the discharge port 22a to the preliminary recovery port 33, the period during which the discharge port 22a and the preliminary recovery port 33 are connected in the process of the detachment operation. In addition, a discharge mechanism that prompts the discharge of the waste toner T1 that has stopped in the vertical path 22 when detected by the toner detection sensor 41 by applying vibration to at least the detected portion 22b in conjunction with the above-described separation operation. The discharge mechanism 70 includes a valley-like shape 71 on the lower surface of the toner collection container 30 and a striking mechanism 72 that protrudes upward by a spring force from a support surface that supports the lower surface of the toner collection container 30. A period in which the discharge port 22a and the preliminary recovery port 33 are connected by temporarily stopping or decelerating the drawn toner recovery container 30 in the scene shown in FIG. 6 is necessary for the fall and discharge of the waste toner T1 from the discharge port 22a. And the lower surface of the toner collection container 30 is struck by the striking mechanism 72, and the vertical path 22 is vibrated through the toner collection container 30 to cause waste toner T1 from the discharge port 22a. Is expelled from falling.
Therefore, the period during which the discharge port 22a and the preliminary collection port 33 are connected is long, and the period necessary for the fall and discharge of the waste toner T1 from the discharge port 22a can be forced to be short. Therefore, the waste toner T1 is placed in the toner collection container 30. Can be reliably recovered.

As described above, since the waste toner T1 is collected in the toner collecting container 30 in the process of the separation operation, it is possible to carry out without providing the shutter 60.
In the image forming apparatus B, the shutter 60 is provided. As shown in FIGS. 6 to 7, in the present image forming apparatus B, it is essential that the shutter 60 operates so as to close the discharge port 22a after the waste toner T1 is collected in the surplus space 32 in the process of the separation operation. is there.
With the shutter 60 operating as described above, the toner collection container 30 is not attached to the image forming apparatus B as shown in FIG. 7, and the discharge port 22a is closed without waste toner remaining in the vertical path 22. .
When the toner detection sensor 41 does not detect, the control unit 40 permits image formation when the toner collection container mounting detection sensor 42 detects or does not detect.
For this reason, the toner detection sensor 41 is used not only during the period before the toner collection container 30 is installed and becoming full, but also during the replacement period during which the toner collection container 30 is pulled out and a new empty toner collection container 30 is installed. Image formation is possible until detection.
As a result, the interruption time of the image forming operation that can occur when the toner recovery container 30 is replaced can be reduced.

  According to the second embodiment of the present invention described above, the same effects as those of the first embodiment can be obtained, and further, the recovery volume ratio of the toner recovery container 30 can be improved as compared with the first embodiment. . Further, as described above, the effect of reducing the interruption time of the image forming operation can be obtained.

[Other Embodiments]
The outer wall of the container at a position far from the recovery port 31 at the top of the toner recovery container 30 in the first embodiment may be formed obliquely according to the repose angle of the obsolete toner T (the partition member 34 shown in FIG. 5). Is the outer wall of the container.) As a result, the space for accommodating the toner recovery container 30 in the image forming apparatus A can be reduced, and the recovery volume ratio of the toner recovery container 30 can be improved.
Moreover, in the said 1st Embodiment, although the collection port 31 has approached to one side as shown in FIGS. 1-3, since a preliminary collection port is not necessarily provided like the said 2nd Embodiment, it is center. You may arrange in.

In the discharge mechanism 70 in the second embodiment, the vertical path 22 is vibrated via the toner recovery container 30. However, the present invention is not limited to this, and the vertical path 22 is not connected to the toner recovery container 30. You may give a vibration. For example, a configuration in which a valley mountain shape is provided in a side region that does not pass directly below the vertical path 22 on the upper surface of the toner recovery container 30 and a spring member that interferes with this is fixed to the outer peripheral portion of the vertical path 22 can be implemented.
The discharge mechanism 70 according to the second embodiment has a configuration in which vibration is applied by a single blow, but is not limited thereto, and may be a force that repeatedly acts a plurality of times. For example, it can be implemented by a configuration in which the above-mentioned valley mountain shape is repeatedly provided like a rack.

DESCRIPTION OF SYMBOLS 10 Image formation part 20 Waste toner conveyance path 21 Horizontal path 22 Vertical path 22a Discharge port 22b Detected part 30 Toner recovery container 31 Recovery port 32 Extra space 33 Preliminary recovery port 34 Partition member 40 Control means 41 Toner detection sensor 42 Toner recovery container Attachment detection sensor 50 Cleaning mechanism 60 Shutter 70 Discharge mechanism T Waste toner

Claims (5)

In an image forming apparatus that collects waste toner from an image forming unit and stores it in a toner recovery container,
A toner detection sensor for detecting a stay of waste toner for a predetermined detected portion of a waste toner conveyance path upstream of a recovery port of the toner recovery container;
Control means for determining a full state of the toner collection container based on detection by the toner detection sensor ,
In the process of detaching the toner collection container from the discharge port of the waste toner conveyance path, the waste toner conveyance path is detected in the remaining space of the toner collection container at the time of detection by the toner detection sensor. the image forming apparatus you collecting waste toner that has been staying in. The toner recovery container has a preliminary recovery port that allows the extra space to communicate with the outside without passing through the recovery port, and the waste toner that has flowed in from the recovery port is between the recovery port and the preliminary recovery port. Has a partition member to prevent outflow from the preliminary recovery port,
In the process of the separation operation, the discharge port separated from the collection port is connected to the preliminary collection port, and the waste toner that has stopped in the waste toner conveyance path when detected by the toner detection sensor in the extra space is removed. The image forming apparatus according to claim 1 , wherein the image forming apparatus is collected. In a period in which the discharge port and the preliminary recovery port are connected in the process of the detachment operation, the vibration is applied to at least the detected portion in conjunction with the detachment operation, so that the detection by the toner detection sensor is performed. The image forming apparatus according to claim 2 , further comprising a discharge mechanism that urges discharge of the waste toner that has stopped in the waste toner conveyance path from the discharge port. A shutter that closes the discharge port after waste toner is collected in the extra space in the process of the separation operation;
A toner recovery container mounting detection sensor for detecting the mounting of the toner recovery container;
The control means, wherein the time of non-detection by the toner detection sensor, the image forming apparatus according to claim 1, claim 2 or claim 3 for permitting the image forming when the detection time and non-detection by the toner recovery container mounting detection sensor . The image forming apparatus as claimed in any one of claims 1 to 4 comprising a cleaning mechanism for cleaning the detected portion.

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