JP2005077419A - Toner sensor and image forming apparatus provided with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner sensor capable of excellently detecting a state inside a toner container, such as toner quantity, by maintaining the distance between a developing sleeve and a photoreceptor constant without bringing on an increase in cost. <P>SOLUTION: A coil spring 113, a slide block 114 fixed to the other end of the coil spring 113, and a sensor element 115 stored in the slide block 114 are provided. A developing unit 104 is pushed toward a photoreceptor drum 102 by the slide block 114 energized by the coil spring 113 and at the same time, the toner sensor surely abuts on a bottom part of the toner container 101. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus such as a copying machine, a facsimile machine, a printer, or a multifunction machine having both functions.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, as an image forming apparatus, a drum unit including a photosensitive drum and a developing unit including a developing sleeve having a rotation shaft parallel to the rotation shaft of the photosensitive drum are inserted into the main body of the image forming apparatus. There is.
[0003]
Such image forming apparatuses include those having a toner container in the developing unit and those having a toner container separately from the developing unit. FIG. 3 shows an image forming apparatus of a type in which a toner storage container 14 is attached to a developing device housing 13 of a developing device unit 12 having a developing sleeve 11 facing the photosensitive drum 10. Many of these image forming apparatuses include a toner sensor for detecting the presence or absence of toner or the amount of toner. Examples of the toner sensor include a magnetic permeability sensor that detects the magnetic permeability as a change in voltage by using the magnetism of toner from the outside of the toner container. Such a toner sensor is provided on the apparatus main body side and is in contact with the outer wall of the toner container (see, for example, Patent Documents 1 to 4).
[0004]
Specifically, as shown in FIG. 3, with the developing sleeve 11 in contact with the photosensitive drum 10 of the drum unit, the toner sensor 15 is inserted from the opening 13A formed in the developing device housing 13 to store the toner. There has been proposed one in which the toner sensor 15 is brought into contact with the wall portion of the container 14. The toner sensor 15 is housed in a protective cover 16 and is urged so as to come into pressure contact with a wall portion of the toner container 14 by a spring 17 provided on the image forming apparatus main body side.
[0005]
Incidentally, as described above, as a means for causing the developing sleeve 11 to face the photosensitive drum 10, there is a pressing means 18 for urging the side wall of the developing device housing 13 in a substantially horizontal direction as shown in FIG. The pressing means 18 includes a pressing block 19 and a spring 20 that urges the pressing block 19 so as to press-contact the side wall 13B of the developing device housing 13.
[0006]
As another image forming apparatus, as shown in FIG. 5, there is an apparatus that includes both the toner sensor 15 and the pressing unit 18 described above on the image forming apparatus main body side. In this image forming apparatus, when the developing device housing 13 is attached to the main body of the image forming device in the direction indicated by the thick arrow in FIG. 5, the toner sensor 15 is inserted from the opening 13A of the developing device housing 13 and the pressing means 18 The pressing block 19 comes into contact with the side wall 13B.
[0007]
[Patent Document 1]
Japanese Utility Model Publication No. 62-118250 (first page, FIG. 3)
[Patent Document 2]
Japanese Patent Laid-Open No. 11-143206 (page 7, FIG. 1)
[Patent Document 3]
JP 2000-35742 A (page 5, FIG. 1)
[Patent Document 4]
JP2003-98816 (3rd page, FIG. 1).
[0008]
[Problems to be solved by the invention]
However, in the image forming apparatus including the toner sensor and the pressing unit that biases the developing unit toward the photosensitive drum as described above, each of the toner sensor and the pressing unit may be a spring member, a protective case, or a pressing unit. Since many parts such as blocks are required, there is a problem of high cost.
[0009]
In addition, in such an image forming apparatus, it is necessary to secure a space for arranging the toner sensor and the pressing unit, which causes a problem that the apparatus becomes large.
[0010]
Further, in such an image forming apparatus, in addition to securing the arrangement space for the members such as the toner sensor and the pressing means, the process unit such as the developing unit can be attached and detached as the members are arranged. Therefore, there is a problem in that the layout of the unit and each member is restricted due to the need to secure a space for the operation. Such an image forming apparatus has a problem that it is difficult to attach or detach a process unit such as a developing unit to or from the image forming apparatus main body due to an increase in the number of parts. As described above, in the above-described prior art, the ease of attaching and detaching the built-in unit required for maintenance of the image forming apparatus is poor, and in addition, the cost is reduced.
[0011]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a toner sensor and an image forming device that can improve the ease of attaching and detaching a developer unit, a drum unit, and the like without causing an increase in cost, and that can well detect the state of the toner container such as the toner amount To provide an apparatus.
[0012]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a toner storage container for storing toner containing a magnetic material, and a developer unit including a developing sleeve for supplying toner to an electrostatic latent image formed on the photosensitive member for development. The present invention relates to a toner sensor that is used in an image forming apparatus that is detachably attached to an image forming apparatus main body, and that has a detection unit that abuts against a wall of the toner storage container and detects the remaining state of toner in the toner storage container It is. In the toner sensor according to the present invention, the detection unit is urged in the pressing direction toward the wall of the toner container, and the distance between the developing sleeve and the photosensitive member is kept constant. An urging means for urging the developing unit toward the photosensitive member side is provided.
[0013]
According to a second aspect of the present invention, there is provided a toner storage container that stores toner containing a magnetic material, and a developer unit that includes a developing sleeve that supplies toner to an electrostatic latent image formed on the photosensitive member for development. The present invention relates to an image forming apparatus detachably attached to an image forming apparatus main body. In the image forming apparatus according to the present invention, the residual state of the toner is detected by contacting the outer surface of the wall at the substantially bottom position of the toner container, and the distance between the developing unit and the photosensitive member is made constant. A toner sensor that biases the developing unit toward the photosensitive member so as to be held is provided.
[0014]
The invention described in claim 3 relates to the image forming apparatus described in claim 2. The image forming apparatus according to the present invention is characterized in that the toner container is included in the developing unit.
[0015]
The invention described in claim 4 relates to the image forming apparatus described in claim 2 or claim 3. The image forming apparatus according to the present invention is characterized in that the photosensitive member is formed integrally with the developing unit.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a toner sensor and an image forming apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view of main parts of the image forming apparatus 100 according to the present embodiment, and FIG. 2 is an enlarged cross-sectional view of main parts of the image forming apparatus 100.
[0017]
An image forming apparatus 100 according to the present embodiment includes a toner storage container 101 that stores toner including a magnetic material, and a developing sleeve 103 that supplies toner to an electrostatic latent image formed on a photosensitive drum 102 and performs development. And a developing unit 104 having a configuration in which the image forming apparatus main body 105 is detachably mounted.
[0018]
In particular, the image forming apparatus 100 abuts on the outer surface of the wall 101A at the substantially bottom position of the toner container 101 to detect the remaining state of the toner, and the distance between the developing sleeve 103 and the photosensitive drum 102 is constant. And a toner sensor 106 that urges the developing unit 104 toward the photosensitive drum 102 so as to be held by the toner.
[0019]
The drum unit side is supported on the image forming apparatus main body 105 side by a rotating shaft (not shown) of the photosensitive drum 102. The developing unit 104 is supported by being pressed toward the drum unit by a toner sensor 106 that also serves as a pressing unit. In this embodiment, the drum unit and the developer unit 104 are arranged in the horizontal direction, and the developer unit 104 is set at a slightly higher position.
[0020]
(Schematic configuration of image forming apparatus)
The image forming apparatus 100 according to the present embodiment includes an image forming unit 110 that transfers a toner image onto a sheet-like recording material that is fed from a sheet feeding tray (not shown) and conveyed along a sheet conveying path, and the image. A fixing device (not shown) that fixes the toner image onto the recording material onto which the toner image has been transferred by the forming unit 110, a discharge unit that discharges the recording material on which the toner image is fixed via the fixing device onto a paper discharge tray (not shown), and the like Is generally configured.
[0021]
As shown in FIG. 1, the image forming unit 110 includes a photoconductor unit (not shown) including a photoconductor drum 102 and a developing device including a developing sleeve 103 that forms a toner image on the photoconductor drum 102 of the photoconductor unit. The unit 104 includes a transfer unit 111 that transfers a toner image onto a recording material. The developing unit 104 is urged in a substantially horizontal direction toward the photosensitive drum 102 by a toner sensor 106 interposed between the developing unit 104 and the image forming apparatus main body 105.
[0022]
Although not shown, the configuration of the drum unit will be briefly described here.
[0023]
The drum unit includes a photosensitive drum 102 at a lower portion on the side facing the developing unit 104. Above the photosensitive drum 102 in the drum unit, a charger, a cleaner, a static eliminator and the like (not shown) are arranged. Further, for example, laser light can enter the photosensitive drum 102 from an exposure device (not shown).
[0024]
(Developer unit configuration)
As shown in FIG. 1, the developing unit 104 is provided with a developing sleeve 103 in contact with the photosensitive drum 102 when mounted on the lower portion facing the photosensitive drum 102. In addition, a toner storage container 101 that stores toner is stored on the side of the developing unit 104 opposite to the side facing the photosensitive drum 102. Note that the developing unit 104 in which the toner storage container 101 is stored has an opening 104 </ b> A that exposes the bottom of the toner storage container 101. A unit side wall 104B is formed on the developing sleeve 103 side of the opening 104A. The toner sensor 106 comes into contact with the unit side wall 104B. Further, the unit side wall 104B is inclined such that a lower part protrudes so that a slide block 114 of the toner sensor 106, which will be described later, does not come down.
[0025]
A toner supply unit (not shown) such as a paddle is provided between the toner container 101 and the developing sleeve 103 to supply toner to the developing sleeve 103 side. Further, according to the inclination in the developing unit 104, a load acts on the toner storage container 101 obliquely downward (in the direction toward the photosensitive drum 102) indicated by a thick arrow in FIG.
[0026]
(Configuration of toner sensor)
As shown in FIG. 2, the toner sensor 106 is provided in a stepped portion 112 formed in the image forming apparatus main body 105. Here, the structure of the step 112 will be briefly described. The stepped portion 112 is set so as to be located at the lower portion of the developing unit 104 opposite to the developing sleeve 103 when the developing unit 104 is mounted. The step 112 includes a horizontal wall 112A along the horizontal direction, a vertical wall 112B rising from the edge of the horizontal wall 112A, and a slide wall 112C extending horizontally from the upper edge of the vertical wall 112B. It is made up of.
[0027]
As shown in FIG. 2, the toner sensor 106 has a coil spring 113 with one end fixed to the vertical wall 112B side, a slide block 114 fixed to the other end of the coil spring 113, and the slide block 114. And a sensor element 115 as a detection unit. The slide block 114 includes a lower slide portion 114A that slides on the vertical wall portion 112A, and an upper slide plate 114B that slides on the slide wall portion 112C. When the lower slide portion 114A and the upper slide plate 114B slide in the expansion / contraction direction (axial direction) of the coil spring 113, the slide block 114 biased by the coil spring 113 causes the developer unit 104 to move to the photosensitive drum 102 side. It is supposed to be pressed toward.
[0028]
As shown in FIG. 2, the sensor element 115 is disposed in the slide block 114 so as to face obliquely upward with respect to the biasing direction of the coil spring 113. The detection surface of the sensor element 115 is set so as to slightly protrude obliquely upward from the slide block 114, and is inserted into an opening 104 A formed in the developing unit 104, so that the bottom of the toner storage container 101 is inserted. It comes to contact with. The tip of the slide block 114 of the toner sensor 106 is in contact with the unit side wall 104B formed on the developing sleeve 103 side in the opening 104A, and transmits the urging force of the coil spring 113 to the developing unit 104 side. .
[0029]
(Operation and operation of toner sensor and image forming apparatus)
Here, operations and operations of the toner sensor 106 and the image forming apparatus 100 will be described.
[0030]
The toner sensor 106 according to the present exemplary embodiment urges the developing unit 104 toward the photosensitive drum 102 by a coil spring 113 and, at the same time, a slide block 114 containing a sensor element 115 at the bottom of the toner storage container 101. Has the effect of pressure contact. Thus, the force for pushing the developing unit 104 and the force for pushing the toner container 101 are component forces of the urging force of the coil spring 113 in the expansion / contraction direction. As described above, in this embodiment, a single coil spring 113 can exert a pressing action in two directions.
[0031]
For this reason, the remaining amount of toner in the toner storage container 101 can be detected satisfactorily, and a toner image is transmitted to the photosensitive drum 102 by transmitting an urging force that keeps the distance between the photosensitive drum 102 and the developing sleeve 103 constant. Can be formed reliably and satisfactorily. Therefore, this image forming apparatus 100 can form a good image on a recording material.
[0032]
Further, according to the present embodiment, since the number of parts of the toner sensor 106 that also serves as the pressing unit is small, the image forming apparatus 100 can be kept low in cost without increasing the size, and the developing unit 104, the photosensitive unit The process unit such as the body unit can be easily attached and detached, and the state of the toner container such as the remaining amount of toner can be detected well.
[0033]
(Other embodiments)
It should not be understood that the description and the drawings, which form part of the disclosure of the above-described embodiments, limit the present invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.
[0034]
For example, in the above-described embodiment, the toner sensor 106 is provided in the stepped portion 112 of the image forming apparatus main body 105. However, the end portion of the cylindrical body is formed in the image forming apparatus main body 105 as a cylindrical configuration in which the slide block 114 is projected and retracted. It may be fixed.
[0035]
In the above-described embodiment, the toner storage container 101 is separated from the developing unit 104, but it is of course possible to have a configuration in which the toner storage unit is integrally provided in the developing unit 104.
[0036]
Further, in the above-described embodiment, the photosensitive drum 102 is included in the photosensitive unit (not shown). However, the photosensitive drum 102 may be integrated with the developing unit 104.
[0037]
【The invention's effect】
As is apparent from the above description, according to the present invention, an appropriate contact state between the toner sensor and the toner storage container can always be ensured, and the distance between the photosensitive drum and the developing sleeve is kept constant. be able to.
[0038]
Further, according to the present invention, since the toner sensor does not increase the number of parts by serving also as the pressing unit, the image forming apparatus can be made compact, and space saving and cost reduction can be realized. it can.
[0039]
Furthermore, according to the present invention, since the photosensitive drum and the developing sleeve can be held at an appropriate distance by the toner sensor, there is an effect that a good toner image can be formed.
[0040]
Further, according to the present invention, it is possible to easily attach and detach a process unit such as a developer unit, and quick maintenance is possible.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part showing an image forming apparatus according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a main part of the image forming apparatus according to the embodiment of the present invention.
FIG. 3 is a cross-sectional view of a main part showing a conventional image forming apparatus.
FIG. 4 is a cross-sectional view of a main part showing another conventional image forming apparatus.
FIG. 5 is a cross-sectional view of a main part showing another conventional image forming apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus, 101 ... Toner container, 102 ... Photosensitive drum, 103 ... Developing sleeve, 104 ... Developer unit, 105 ... Image forming apparatus main body, 106 ... Toner sensor, 110 ... ... Image forming part, 112 ... Step part, 113 ... Coil spring, 114 ... Slide block, 115 ... Sensor element (detection part)

Claims (4)

A toner container for storing toner containing a magnetic material and a developing unit having a developing sleeve for supplying toner to an electrostatic latent image formed on the photosensitive member for development are detachably attached to the image forming apparatus main body. A toner sensor having a detection unit that is used in the image forming apparatus and detects a remaining state of toner in the toner storage container by contacting the wall of the toner storage container;
The detecting unit is urged in the pressing direction toward the wall of the toner storage container, and the developing unit is moved to the photoconductor side so as to keep a constant distance between the developing sleeve and the photoconductor. A toner sensor comprising biasing means for biasing the toner. A toner storage container for storing toner containing a magnetic material, and a developing unit having a developing sleeve for supplying toner to an electrostatic latent image formed on the photosensitive member for development are detachable from the image forming apparatus main body. A mounted image forming apparatus,
The developer unit is detected so as to contact the outer surface of the wall at the substantially bottom position of the toner container to detect the remaining state of the toner, and to keep the distance between the developer unit and the photosensitive member constant. An image forming apparatus comprising: a toner sensor that urges toward the photosensitive member side. The image forming apparatus according to claim 2, wherein the toner container is included in the developing unit. 4. The image forming apparatus according to claim 2, wherein the photosensitive member is formed integrally with the developing unit.

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