JP2819837B2 - Detector for detecting the fullness of the toner recovery box of the photoconductor unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner collecting apparatus for a copying machine using a toner for developing an electrostatic latent image in an electronic copying machine or the like, and more particularly, to a toner collecting box for a photoconductor unit. The present invention relates to a device for reliably detecting that a toner is full.

[0002]

2. Description of the Related Art Conventionally, an electrostatic latent image formed on a photoreceptor such as a drum is developed by a toner in a one-component or two-component developer, and the developed toner image is transferred to a photoreceptor. Most commonly, the collected toner is collected from the photoreceptor by a brush, a blade, or the like of the cleaning device, and stored in a residual toner collection bin or the like attached to the cleaning device. The residual toner collection bin is replaced after it is full of toner, or replaced after a predetermined number of copies, regardless of whether it is full of toner.

Recently, a copier of the type in which a latent image carrier such as a photosensitive drum and a developing device, a cleaning device, and the like are integrated into an exchange unit, and after a predetermined number of copies, this unit is exchanged for a new one has become widespread. It is getting. In such a unit, a method is employed in which the residual toner is stored in a toner collection box provided along with the cleaning device or in a space in a drum. When the residual toner is stored in the toner recovery box, the optical path is interrupted by the floating member floated by the residual toner and the floating of the float member to detect that the inside is full with the recovered residual toner. It is known to use a full detector comprising an optical sensor (for example, Japanese Patent Application Laid-Open No. 62-94883).
issue). FIG. 6 is a cross-sectional view taken along a line perpendicular to the axis of the photosensitive drum of the photosensitive member unit having the toner recovery box employing such a full detector, and is taken along line LL ′ in FIG. FIG. 7 is a cross-sectional view of the apparatus, and FIG. 8 is a perspective view of a float member of the full detector.
0, a cleaning blade 76 as a cleaning means, a toner transport rotary paddle 77 formed in a rectangular cross section for transporting the cleaned residual toner into the toner collection box 80, and a toner adhered to the toner transport rotary paddle 77. Member 7 for scraping off
8 etc. are provided. In the toner collection box 80, a float member 81 suspended by a thin film 83 at both ends from the upper wall thereof is provided. The float member 81 is, as shown by a two-dot chain line in FIGS. When the amount of the residual toner T stored in the toner collection box 80 becomes equal to or more than a predetermined amount, the toner is floated from below by the accumulated toner T. The float member 81 has a length close to the depth of the toner collection box 80, and an opaque shielding member 82 is integrally provided substantially at the upper center thereof. At the upper part of the toner collecting box 80, there is provided a projection 84 made of a transparent wall constituting a space into which the shielding member 82 enters from below when the float member 81 floats and rises. On the other hand, the copier main body is provided with a groove 85 into which the projecting portion 84 enters when the toner collection box 80 is set.
On both sides of 5, a light emitting element 86 and a light receiving element 87 are provided to face each other. Therefore, when the amount of the residual toner in the toner collection box 80 exceeds a predetermined amount, the float member 81 rises so as to follow the surface thereof, and the shielding member 82 also rises. When the shielding member 82 rises inside the projection 84 and reaches a certain height, it comes out of the light emitting element 86 and projects from the projection 8.
Thus, the optical path that reaches the light receiving element 87 through the light receiving element 87 is blocked. Therefore, by detecting this interruption, it is possible to detect that the toner collecting box 80 is full with the collected residual toner. In addition, the float member 81 is used for the toner collection box 80.
Has a long shape close to the depth of the toner, it is possible to reliably detect that the toner collection box 80 is full of the collected toner even if the stored toner T has an uneven distribution. Can be done.

However, in the above-described full detector provided in the photoconductor unit, the transparent protrusion 8 is provided.
4 is at least not shielded from the toner T, so that dust of the toner generated in the cleaning device enters the inside, stains the transparent wall, and protrudes from the light emitting element 86.
Therefore, the optical path that reaches the light receiving element 87 through the light receiving element 87 is blocked, and the toner recovery box 80 malfunctions as if it were full, even though it is not actually full. Further, when the cleaning device provided with the toner collection box 80 is detached from the copier and swings, the toner similarly enters the protruding portion 84, causing a malfunction of the full detector and causing the float member 81 to malfunction. The toner accumulates on the upper side, making it difficult for the float member 81 to float, and conversely, even if the toner collection box 80 is full of the collected toner, a malfunction occurs in that it cannot be detected.

In order to solve such a problem, the present applicant disclosed in Japanese Patent Application No. 2-249046 a thin film connecting the entire circumference of the float member 81 and the ceiling of the toner collection box 80. Then, the float member 81 is suspended from the ceiling of the toner collection box 80 by the thin film, and the upper surface of the float member 81 and the transparent protrusion 84 are shielded from the toner T by the thin film surrounding the entire periphery thereof. The inventors proposed a device in which generated dust of toner is prevented from entering the toner.

[0006]

By the way, in the above-mentioned full detector, in order to float the float member from below with the collected toner, it is necessary to make the weight of the float member as light as possible. If the weight of the float member is too heavy, the collected toner is gradually solidified by the weight of the float member, the bulk specific gravity becomes too large, and the toner collection box is detected before the float member is sufficiently floated to detect the fullness. It is no longer possible to collect the residual toner inside, and the cleaning blade and the film seal (as indicated by reference numeral 79 in FIG. 6, the toner collection box 80 and the photosensitive drum 75).
It is provided between. ) Causes a problem that toner spills out of the photoconductor unit. On the contrary,
If the float member is made sufficiently light, the float member floats following the surface of the collected toner pool, and the object of full detection can be achieved.

However, when the float member is sufficiently lightened in this manner, the residual toner collected from the surface of the photoreceptor by the cleaning blade removes the toner transport rotary paddle 77 (see FIG. 1) provided between the cleaning blade and the toner collection box. 6), the toner is conveyed to the toner collection box side. With the rotation of the paddle 77, a spring-like pressure is applied to the polygonal surface, and the tip comes into contact with the polygonal surface to scrape off the toner attached to the surface. Since the plate-like scraping member 78 to be dropped vibrates back and forth, the pressure inside the toner collection box 80 fluctuates rapidly, and the float member lightened by this pressure fluctuation moves up and down, and the toner collection box 80 becomes full. Whether the optical sensor composed of the light emitting element 86 and the light receiving element 87 moves up and down regardless of whether Resulting in erroneously detected is full by the shielding member 82 of the member 81.

[0008] In addition to the above, the same type of full detector,
JP-A-63-35070, JP-A-2-19949
No. 5, Japanese Utility Model Laid-Open No. 1-142970,
Although all of them are disclosed in Japanese Patent Application Laid-Open No. 162277, there is a problem that the same false detection is performed as described above.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and an object of the present invention is to reliably detect the fullness of a toner collecting box only when the toner collecting box is truly filled with the collected toner. It is to provide a full detection device capable of performing the above.

[0010]

According to a first aspect of the present invention, there is provided a photoconductor unit for detecting a fullness of a toner collection box of a photoreceptor unit. A fullness detection device for detecting that the toner collection box is full or nearly full with the collected residual toner by measuring the height of a float member floating with the collected toner, wherein the float member is Having a shape slightly smaller than the inner width and depth of the residual toner collection box, and having an upright member standing upright on the upper surface thereof. The float is located at a position corresponding to the upright member on the ceiling of the residual toner collection box. An opening is provided to allow the upright member to pass upward as the member floats, and the opening is a transparent projection projecting outward. The entire periphery of a region corresponding to the shape of the float member on the inner ceiling surface of the residual toner collection box and including the opening, and the entire periphery of the float member are connected by a band-shaped film. hand,
In a fullness detection device in which a residual toner recovery space of a residual toner recovery box and a space on an upper surface of the float member are separated by the film, the separated space on the upper surface of the float member is separated from the outside of the residual toner recovery box by a vent hole. The number and diameter of the ventilation holes are such that a sudden pressure fluctuation in the residual toner collecting space of the residual toner collecting box does not substantially lead to a sudden rise of the float member. It is characterized by being selected to give.

In this case, it is desirable in terms of arrangement that the ventilation hole is provided in the transparent projecting cover.

[0012]

In the fullness detecting device according to the present invention, the space on the upper surface of the float member separated from the residual toner collecting space of the residual toner collecting box is communicated with the outside of the residual toner collecting box by the ventilation hole. The diameter is selected so as to provide resistance to the ingress and egress of air so that a sudden pressure change in the residual toner collecting space of the residual toner collecting box does not substantially lead to a sudden rise of the float member. Even if the pressure inside the toner collection box fluctuates rapidly due to operation, etc., this pressure fluctuation does not raise the float member and erroneously detects that the toner collection box is full, and the toner collection box is collected. Only when the toner is truly full, it is possible to reliably detect the fullness.

[0013]

Next, an embodiment of the present invention will be described with reference to the accompanying drawings.

The overall configuration of an example of a copying machine to which the toner recovery box fullness detection device of the present invention is applied includes a photosensitive drum unit including a photosensitive drum, a cleaning device, and a charging device, in addition to an exposure device fixed to the device. It includes a developing unit, a transfer unit, a fixing unit, and a paper tray.Each of these units can be independently pulled out toward the front side of the apparatus, and each unit is installed for maintenance such as paper jam and cleaning. It can be removed from. The photoreceptor unit is configured to be replaced with a new one every 100,000 copies, for example. During 100,000 copies, the residual toner collected from the photosensitive drum by the cleaning device is automatically and reliably collected and stored in the photoconductor unit, and the user contacts the residual toner collected in the photoconductor unit. Never.

FIG. 1 shows a cross section taken perpendicularly to the rotation axis of the photosensitive drum of the photosensitive unit 1. FIG. 2 shows a line II-
The section taken along II 'is shown. In the figure, cylindrical side plates 5 and 7 made of die-cast are fitted on both ends of the photosensitive drum 3, and a first container 4 for storing the residual toner by a space separated by the photosensitive drum 3 and the side plates 5 and 7. Is composed. A rotary shaft 9 is integrally provided at the center of the side plate 7 on the rear side of the photosensitive drum 3, and is rotatably attached to a housing 11 of the photosensitive unit 1 via a bearing. A circular opening is provided at the center of the side plate 5 on the near side, and is rotatably fitted to a cylindrical portion 13 projecting from the housing 11 to the inside of the unit via a bearing. Further, a gear 15 is cut on the outer periphery of the rear side plate 7 so that when the unit 1 is pushed into the apparatus main body from the front and set, the gear 15 meshes with a drum rotation drive gear (not shown) on the apparatus main body side. ing. In addition, in the device body,
A positioning hole (not shown) into which the tip of the rotating shaft 9 protruding from the housing 11 is fitted, and a shaft (not shown) fitted into a positioning hole 16 provided in the housing 11 of the unit 1 are provided. This constitutes a positioning mechanism when the unit 1 is pushed into the apparatus main body and set.

A brush 17 for the toner deter bar is rotatably mounted between the extended side walls of the housing 11 provided at both ends of the photosensitive drum 3 via a bearing. The brush 17 for the toner debar is in contact with the photosensitive drum 3. , The toner remaining on the drum 3 without being transferred by the transfer device is swept away. A gear 21 is fixed to the rear end (rear side of the apparatus) of the rotating shaft 19 of the brush 17 for the toner deter bar, and meshes with a gear 29 for driving the rotation of the toner transport rotary paddle 27 described later. Further, downstream of the contact point between the photosensitive drum 3 and the brush 17 for the toner deter bar, an elastic cleaning blade 23 is fixed so that one side is fixed to the housing 11 and the other side is in contact with the drum 3 at an acute angle to the rotation direction. The toner 17 is scraped off from the photosensitive drum 3 by the toner deter bar brush 17. Further, a scraping member 22 for scraping the toner attached to the toner deter bar brush 17 downward is attached to a partition wall 32 described later, and the tip thereof is in contact with the toner deter bar brush 17. . Further, in order to transport the residual toner scraped onto the bottom plate 25 of the housing 11 by the brush 17 for the toner deter bar and the cleaning blade 23 in a direction away from the cleaning device 30, the brush 17 for the toner debar bar in the housing 11 is moved. On the rear side (far side from the drum 3), a toner conveying rotary paddle 27 is provided rotatably via a bearing in parallel with the rear side. A gear 29 is fixed to the rear end of the shaft of the rotary paddle 27 and meshes with the gear 21 for rotating the brush 17 for the toner deter bar.
The rotating paddle 27 and the brush 17 for toner deter bar rotate in the direction of the arrow shown in the figure. By the way, the housing 11
Is a second device for storing the residual toner on the rear side of the cleaning device 30 including the toner deter bar brush 17, the cleaning blade 23, and the toner conveying rotary paddle 27.
Forming a toner collection box 31 which is a container of
The cleaning device 30 and the toner collection box 31 are partially separated by a partition wall 32. An elastic scraping plate member 34 is provided so that one end is fixed to the partition wall 32 and extends downward, and the lower end thereof is in elastic contact with the plane of the rotary paddle 27. The rotating paddle 27 has a regular polygonal cross section as shown in the figure, and by rotating in the direction of the arrow shown in the figure, scrapes residual toner accumulated on the rear side of the brush 17 for the toner deter bar into the toner collecting box 31. Works. The scraping plate member 34, the tip of which is in elastic contact with the surface of the polygonal cross section, has a function of scraping off the toner adhered to the surface, and the toner accumulated in the toner collection box 31 is returned to the cleaning device 30 again. It works to prevent returning.

A rotation shaft 33 is rotatably provided on the rear housing 11 near the bottom of the toner collection box 31. On the toner collection box 31 side, a strip-shaped plate member is provided with a normal to its surface. An elastic toner conveying auger 35 formed in a helical shape (spiral shape) so that it faces in the axial direction of the cylinder is coaxially fixed. Further, a gear 37 for auger rotation is attached to the rear end of the rotating shaft 33 via a torque limiter mechanism 38 that is disconnected when a predetermined torque or more is applied. The toner transport auger 35 extends in parallel with the toner transport rotary paddle 27 and the like along the bottom of the toner recovery box 31, and the tip thereof has a circular opening 3 provided in a front wall of the housing 11.
9 protrudes. The circular opening 39 and the hole 41 inside the cylindrical portion 13 protruding from the housing 11 are connected by a pipe 43 having an inner diameter slightly larger than the cross section of the toner conveying auger 35 and protruding through the circular opening 39. The toner conveying auger 35 bends along the pipe 43, and the tip 45 projects into the inner space 4 of the drum 3. The toner conveying auger 35 has a shape of a flexible spiral spring as described above. When the toner auger 35 is rotated, the toner conveying auger 35 has an operation of axially conveying the toner that has entered between its blades by the principle of a spiral pump. Is what you do. Therefore, the toner collection box 31
By rotating this inside, the residual toner at the bottom in the toner collection box 31 can be transported along the pipe 43 to the space 4 in the drum 3. The gear 37 for rotating the toner auger 35 and the gear 29 for rotating the rotary paddle 27 are both engaged with a driving gear 47 rotatably provided on the rear wall of the housing 11. When the photoconductor unit 1 is set in the apparatus main body, the driving gear 47 engages with a driving gear (not shown) that rotates in conjunction with a photosensitive drum rotation driving gear (not shown) provided in the main body. Then, the brush 17, the toner transport rotation paddle 27, and the toner transport auger 35 are rotated. The toner transport auger 35 may be, for example, a flexible wire having a helical plate-shaped protrusion around the toner in addition to the spiral spring as described above.

In the toner collecting box 31, a full detector 6 constituting a sensor of the full detector according to the present invention is provided.
0, and the full detector 60 has a float member 49 that floats from below with the accumulated toner when the residual toner contained in the toner collection box 31 has exceeded a predetermined amount. An opaque shielding member 50 is integrally provided on the upper part of the member 49. And
At the upper part of the housing 11, a transparent protruding cover 53 is provided which forms a space into which the shielding member 50 enters from below when the float member 49 floats and rises. On the other hand, the apparatus main body is provided with a groove 55 into which the transparent projecting cover 53 enters when the photoconductor unit 1 is set, and a light emitting element 57 and a light receiving element 59 are provided on both sides of the groove 55 so as to face each other. Therefore, when the amount of the residual toner in the toner collection box 31 exceeds a predetermined amount, the float member 49 rises so as to follow its surface, and the shielding member 50 also rises. When the shielding member 50 rises inside the transparent projecting cover 53 and reaches a certain height, the light emitting element 5
7 through the transparent projecting cover 53 and the light receiving element 59
The light path that reaches is blocked. Therefore,
By detecting this interruption, the toner collection box 3
1 can be detected as being full by the collected residual toner. The detailed configuration of the full detector 60 will be further described later.

In FIG. 1, a main charger 61 for uniformly charging the cleaned photosensitive drum for forming a latent image is integrally provided downstream of the cleaning blade 23 in the photosensitive member unit 1. ing.

The operation of the residual toner collecting device having the above-described structure will be described. The photosensitive drum 3 uniformly charged by the main charger 61 is subjected to image exposure in an exposure unit (not shown), An electrostatic latent image is formed on the three surfaces. Next, in a developing device (not shown), the toner charged to the opposite polarity to the charge of the electrostatic latent image is brought into contact with the surface of the photosensitive drum 3 to form a toner image. This toner image contacts a sheet conveyed at the same speed as the peripheral speed of the photosensitive drum 3 and is transferred onto this sheet in a transfer device (not shown) provided at the next position. The sheet on which the toner image has been transferred is conveyed to a fixing device, where the toner image is fixed on the sheet and discharged from the apparatus. On the other hand, the photosensitive drum 3 reaches the cleaning device 30, and the toner remaining on the surface thereof without being transferred by the transfer device is scraped off onto the bottom plate 25 of the housing 11 by the brush 17 for toner deter bar and the cleaning blade 23. .
Residual toner collected at this position is removed by a toner transport rotary paddle 27 rotating at this position by a toner collection box 31 provided adjacent to the cleaning device 30.
It is raked out. Residual toner scraped into the toner collection box 31 passes through a photosensitive drum via a pipe 43 by rotation of a toner conveyance auger 35 provided near the bottom of the toner collection box 31, preferably near the toner conveyance rotation paddle 27. It is conveyed to the space 4 in 3. The toner transport auger 35 can rotate around the shaft and transport the residual toner in the axial direction while being bent by the elasticity even in the pipe 43. During this time, the residual toner scraped into the toner recovery box 31 is sequentially transported to the space 4 in the photosensitive drum 3 by the toner transport auger 35, so that the residual toner does not accumulate in the toner recovery box 31. When the space 4 in the photosensitive drum 3 is filled with the residual toner, the toner transport auger 35
Begins to take great resistance. When this resistance exceeds a predetermined value, a torque limiter mechanism 38 provided between the rotation shaft 33 of the toner transport auger 35 and the auger rotation gear 37 acts, and the toner transport auger 35 stops rotating. Then, the conveyance of the residual toner to the space 4 in the photosensitive drum 3 stops. Therefore, the toner transport rotary paddle 2
The residual toner scraped out by 7 starts to accumulate in the toner collection box 31. When the amount of the residual toner contained therein exceeds a predetermined amount, the float member 49 rises so as to follow its surface, and the shielding member 50 also rises. When the shielding member 50 rises inside the transparent protruding cover 53 and reaches a certain height, the light path exiting the light emitting element 57 and penetrating the transparent protruding cover 53 and reaching the light receiving element 59 is blocked. As a result, it is possible to detect that the toner collection box 31 is full with the collected residual toner. This signal may be used to stop the copying apparatus. However, at a position where the shielding member 50 first blocks the optical path from the light emitting element 57 to the light receiving element 59, the remaining toner is further stored in the toner collection box 31 by a predetermined amount. So that there ’s room for it,
This signal may be used as a warning signal to warn that the space 4 in the photosensitive drum 3 and the toner collecting box 31 will be full with the collected residual toner after a predetermined number of copies.

As described above, according to the residual toner collecting device of this embodiment, in the photosensitive unit 1 in which at least the photosensitive drum 3 and the cleaning device 30 are integrally formed, the toner collecting box 31 is disposed adjacent to the cleaning device 30. And the toner collection box 31 and the space 4 in the photosensitive drum 3 are separated from the toner collection box 31 by the space in the photosensitive drum 3. 4 is connected by a toner transport auger 35 for transporting the residual toner, and a torque limiter mechanism for disconnecting the toner transport auger 35 and the means 37 for rotating the same when a predetermined torque or more is applied between them. 38, the space 4 in the photosensitive drum 3 and the toner circulating device are self-contained, automatically and reliably. By the cleaning device 30 to both the box 31 housing the residual toner collected from the photosensitive drum 3, can be filled. Then, since the position of the toner conveying auger 35 in the toner collecting box 31 is selected near the bottom of the toner collecting box 31, first, the space 4 in the photosensitive drum 3 is first filled with residual toner. The auger 35 stops, then the toner collection box 31 becomes full, and this is reliably detected by the full detector 60 including the float member 49 and the like. Note that a torque limiter mechanism 38 is not provided between the rotation shaft 33 of the toner conveying auger 35 and the auger rotating gear 37, and the two are fixed. Instead, the space 4 in the photosensitive drum 3 is filled with residual toner. Alternatively, a torque detecting means may be provided in the means for detecting that the toner conveying auger 35 has been driven or in the drive system of the toner conveying auger 35, and the rotation of the toner conveying auger 35 may be stopped by a signal from the detecting means to switch the toner storage destination. In this case, as means for detecting that the space 4 in the photosensitive drum 3 is full of the residual toner, for example, a light emitting element and a light receiving element are provided from the center of the side plate 7 of the photosensitive drum 3 to the upper part of the space 4 in the drum. Can be used by inserting a detecting device for detecting when the gap is filled with the residual toner in the gap therebetween. Further, as the torque detecting means provided in the drive system of the toner conveying auger 35, for example, a known torque detecting means may be attached to the rotating shaft 33. Further, it is detected whether or not the torque limiter mechanism 38 has been operated, and this operation signal (indicating that the toner conveying auger 35 has stopped),
Alternatively, a full signal from a means for detecting that the space 4 in the photosensitive drum 3 is full with the residual toner, or that a predetermined torque or more is applied to the toner conveying auger 35 by the torque detecting means. The AND of the signal and the full signal from the full detector 60 of the toner collecting box 31 is ANDed, and only when both of these signals are full, it is determined that the residual toner collecting device has normally operated. Alternatively, the apparatus may be stopped or the above-mentioned warning signal may be output, and when only the full signal from the full detector 60 of the toner recovery box 31 is detected, it is determined that there is an abnormality.

As shown in FIG. 1, the full detector 60 has a float member 49, a support member 51, and a thin film 52 that covers the float member 49 and the support member 51 and connects them. The float member 49 and the support member 51 have substantially the same shape as shown in the developed perspective view of FIG. 3, and have a length slightly shorter than the width of the inner side of the toner collection box 31 in the depth direction. . And FIG.
As shown in the plan view (a) and the cross-sectional view (b), the float member 49 and the support member 51 are arranged in parallel with a distance a apart from each other. The periphery is surrounded, and the film 52 and the periphery of the float member 49 and the support member 51 are adhered.
In this arrangement, as is evident from FIGS. 1 and 3,
The shielding member 50 provided above the float member 49 slightly protrudes from an opening 63 provided substantially at the center of the support member 51. The float member 49 and the support member 51 integrated by the film 52 as described above are connected to the transparent protruding cover 5.
3 and the upper surface of the support member 51 and the upper wall of the toner recovery box 31 are attached to each other by using a double-sided adhesive tape 62. Since the bulk specific gravity of the toner is generally about 0.4, the float member 49 must be able to float on such a fluid having a low specific gravity. Therefore, for example, a polystyrene foam plate is used. Also, as the film 52,
A member having a stiffness that hinders the buoyancy of the float member 49 cannot be used. Therefore, for example, a polyethylene film of about 10 μm is used. Also, a gap a between the float member 49 and the support member 51
Is set to be larger than the maximum floating stroke of the float member 49, and is usually set to 10 mm or more.

Since the float member 49 of the full detector 60 is attached in this manner, the toner collection box 3
When the amount of residual toner stored in the printer 1 exceeds a predetermined amount, the float member 49 is levitated by the collected toner. At this time, the upper surface of the float member 49, the support member 51
, The shielding member 50, and the transparent wall of the transparent projecting cover 53 are completely isolated from the toner collected by the film 52, so that the scraping plate member 34, the rotating paddle 27, the movement of the toner conveying auger 35, etc. Therefore, even if dust is generated in the toner collection box 31, the transparent wall of the transparent protruding cover 53 is not stained by the toner. Therefore, such a dirt blocks the optical path from the light-emitting element 57 to the light-receiving element 59, so that a malfunction in which a full signal is erroneously output is eliminated. In addition, since the above-mentioned soared toner does not accumulate on the upper surface of the float member 49, the floating of the float member 49 is prevented, and the malfunction that the float member 49 cannot be detected despite being full is also eliminated. Further, as described above, the float member 49 has a length slightly shorter than the width of the inside of the toner collection box 31 in the depth direction, so that even if the distribution of the collected residual toner is biased, a malfunction occurs. Never signal full.

By the way, even if the above-described full detector 60 is used, as described above, the toner transport rotary paddle 27
With the rotation of, the scraping plate member 34 elastically contacting the surface vibrates back and forth, and the pressure inside the toner collection box 31 fluctuates rapidly, and the float member 49 lightened by this pressure fluctuation moves up and down. Irrespective of whether the toner collection box 31 is full or not, the optical sensor including the light emitting element 57 and the light receiving element 59 may be erroneously detected as full by the shielding member 50 of the float member 49 that moves up and down. There is. Therefore, in the present invention, such a rapid pressure fluctuation is directly applied to the float member 4.
9 so that the rise of the float member 49 slowly and surely follows only the amount of the residual toner stored in the toner collection box 31 without causing the vertical movement of the float member 9. 51, and
The space surrounded by the transparent projecting cover 53 is used as an air damper.

That is, as shown in the perspective view of the photoreceptor unit 1 in FIG. 5, for example, ventilation holes 64 of a controlled diameter and number are provided on the ceiling wall of the transparent projecting cover 53. Usually, one or two holes having a diameter of 0.7 to 1 mm are provided, but the optimum diameter and number are determined by the volume of the space and the like, and thus may be determined by experiments. Conventionally, since a large hole is simply formed for ventilation and air can freely enter and exit the space, the float member 49 moves up and down in response to a sudden pressure change inside the toner collection box 31 as described above. , A false detection signal of fullness tends to be output, but in such a case, the rapid pressure fluctuation as described above cannot allow air to freely enter and exit the space due to the resistance of the ventilation hole 64, so that Offset by air pressure. Therefore, the rapid pressure fluctuation as described above is not directly transmitted to the float member 49,
No full error detection signal based on the vertical movement is output. On the other hand, the amount of the residual toner collected in the toner collecting box 31 gradually increases, and the volume of the space gradually decreases based on the increase. Therefore, the float member 49 reliably follows the surface of the collected residual toner, and can detect the full state only when the toner collection box 31 is truly filled with the collected toner.

In the above description, the float member 49,
Film 52, support member 51, and transparent projecting cover 5
In order to allow the space surrounded by 3 to function as an air damper, a ventilation hole 64 is provided in the ceiling wall of the transparent projecting cover 53. However, such a ventilation hole connects the support member 51 and the ceiling wall of the housing 11 to each other. It may be provided as a hole that communicates with the outside through a hole. The means for detecting the height of the shielding member 50 accompanying the floating of the float member 49 has been premised on the use of photoelectric means including the light emitting element 86 and the light receiving element 87, but such means is not necessarily required. It is not limited to. It will be apparent that any known detection means, such as other electrical, magnetic, mechanical, acoustic means, etc., can be used. Further, the shapes of the float member 49 and the support member 51 are not limited to those shown in the drawings, and should be designed according to the shape inside the toner collection box 31.

Although the apparatus for detecting the fullness of the toner collection box of the photosensitive unit according to the present invention has been described based on the embodiment, the present invention is not limited to the above embodiment, and various modifications are possible. . For example, the present invention is also applicable to a photoreceptor unit including a cleaning device using only one of a cleaning blade and a brush.
As means for transporting toner from the cleaning device to the toner collection box, a device using means other than the toner transport rotary paddle can be applied.

[0028]

As described above, according to the fullness detecting device of the present invention, the space on the upper surface of the float member separated from the residual toner collecting space of the residual toner collecting box is communicated with the outside of the residual toner collecting box by the hole. The number and diameter of the holes are selected so as to provide resistance to the ingress and egress of air so that sudden pressure fluctuations in the residual toner collecting space of the residual toner collecting box do not substantially lead to a sudden rise of the float member. Therefore, even if the pressure inside the toner collection box fluctuates suddenly due to the operation of the toner conveying means or the like, the pressure fluctuation may raise the float member and erroneously detect that the inside of the toner collection box is full. Thus, only when the toner collection box is truly filled with the collected toner, the full state can be reliably detected.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view taken perpendicular to a rotation axis of a photosensitive drum of a photosensitive unit provided with a full state detection device for a toner collection box according to one embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II 'of FIG.

FIG. 3 is an exploded perspective view of a float member and a support member thereof.

FIG. 4 is a plan view (a) of a film in which a float member and a support member are connected to each other, and a sectional view (b) taken along line BB ′ of FIG.

FIG. 5 is a perspective view of the photoconductor unit of FIG. 1;

FIG. 6 is a cross-sectional view of a photosensitive drum of a photosensitive unit having a conventional toner collection box taken perpendicularly to an axis.

FIG. 7 shows a sectional view taken along line LL ′ of FIG. 7;

FIG. 8 is a perspective view of a float member of the full detector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Photoreceptor unit 3 ... Photosensitive drum 17 ... Toner deter bar brush 23 ... Cleaning blade 27 ... Toner conveyance rotation paddle 30 ... Cleaning device 31 ... Toner collection box 34 ... Scrape-off plate member 49 ... Float member 50 ... Shielding member REFERENCE SIGNS LIST 51 support member 52 film 53 transparent projecting cover 57 light emitting element 59 light receiving element 60 full detector 64 vent

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-118781 (JP, A) JP-A-2-199495 (JP, A) JP-A-60-162277 (JP, A) 179764 (JP, U) Japanese Utility Model Sho 63-35070 (JP, U) Japanese Utility Model Utility Model Hei 1-142970 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 21/10-21 / 12

Claims (2)

(57) [Claims] An image forming apparatus according to claim 1, wherein the residual toner collection box for storing the residual toner collected from the surface of the electrostatic latent image carrier by a cleaning unit is filled with the collected residual toner or becomes close to being full. A fullness detection device for detecting by measuring the height of a floating float member, wherein the float member has a shape slightly smaller than the width and depth inside the residual toner collection box, and stands on an upper surface thereof. An opening is provided at a position corresponding to the upright member on the ceiling of the residual toner collection box to allow the upright member to pass therethrough as the float member floats. Is covered by a transparent projecting cover that projects to
Further, the entire periphery of the region including the opening corresponding to the shape of the float member on the inner ceiling surface of the residual toner collection box and the entire periphery of the float member are connected by a band-shaped film, and In a fullness detection device in which a residual toner collection space and a space on the upper surface of the float member are separated by the film, the separated space on the upper surface of the float member is communicated with the outside of the residual toner collection box by a vent, The number and diameter of the ventilation holes are selected so as to provide resistance to the ingress and egress of air so that a sudden pressure fluctuation in the residual toner collecting space of the residual toner collecting box does not lead to a sudden rise of the float member. An apparatus for detecting a full state of a toner collection box of a photoconductor unit. 2. The apparatus according to claim 1, wherein the ventilation hole is provided in the transparent protruding cover.