JP2006047842A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for easily exchanging a single component. <P>SOLUTION: The image forming apparatus includes a photoreceptor for making a toner image by forming a latent image on the surface and adhering toner according to the latent image, a rotatable image carrier, and a transfer part for transferring the toner image from the photoreceptor to the image carrier. The image carrier and the transfer part are detachable from the image forming apparatus as an image carrying unit. The transferring part is detachable in a direction orthogonal to a rotation direction of the image carrier. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus using an electrophotographic system such as a printer or a copying machine.

  2. Description of the Related Art Conventionally, an image forming apparatus using an electrophotographic method is known as an apparatus for recording a color image from image information such as a computer. Since the electrophotographic system has many printing processes, there are many parts that must be replaced before the lifetime of the entire apparatus is reached. For example, a photoconductor, a charger, a cleaning machine that removes residual toner on the photoconductor, a developing machine, a transfer unit, an intermediate transfer body, a fixing device, and the like can be listed as replacement parts. Since it is very time-consuming to replace these parts one by one, it is a mainstream to replace adjacent parts as a unit, especially in a printer used on a desktop.

  For example, a configuration is known in which a developing unit and a toner supply unit of a developing machine are separated, and the developing unit and the photoconductor are integrated into a single unit and can be integrally replaced. However, in such a system in which several parts are unitized and replaced together, the life of each part included in the unit varies, and the entire unit is replaced according to the life of the shortest part. Parts are wasted.

In order to deal with such problems, the form and material of at least one unit are such that the time when the predetermined performance cannot be maintained for two or more types of parts or materials constituting the unit becomes substantially the same. An example in which a use condition is defined is known. As an example (for example, Patent Document 1), the intermediate transfer unit is mainly composed of an image carrier, a transfer means for applying a transfer bias to be transferred to the image carrier, a cleaning unit for cleaning the image carrier, and cleaning from the image carrier The waste toner storage portion for storing the discharged toner is detected, and when the waste toner is full, the intermediate transfer unit is replaced. However, in the case of this configuration, if one of the parts included in the unit is damaged before the end of its life, parts that have not reached the end of their life must be replaced together. Also, the amount of toner on the image carrier is different between when monochrome printing is continued and when color printing is continued, so the time until the waste toner container becomes full differs, and the time when the waste toner is full is intermediate. As for the replacement timing of the transfer unit, other parts do not always reach the end of their lives.
JP 2000-221847 A

  An object of the present invention is to provide an image forming apparatus capable of easily exchanging a single component.

  At least one printing mechanism member included in the image carrier can be brought into a non-contact state with the image carrier, and can be slid and separated from the image carrier unit in a direction perpendicular to the rotation direction of the surface of the image carrier. Configured as a separate unit.

  The printing mechanism member included in the image carrier can be separated by sliding in the direction orthogonal to the rotation direction of the surface of the image carrier without removing the image carrier. By setting the unit as a small part unit, it is possible to replace the part with the minimum necessary unit.

  Examples of the present invention will be described below with reference to FIGS.

  First, the operation of each part of the image forming apparatus will be described. FIG. 2 is a schematic diagram of a color image forming apparatus using the electrophotographic process of the present invention. This apparatus mainly has four image forming units and an image conveying unit. One image forming unit includes a photoreceptor 1, a charger 11, a laser exposure device 21, a developing device 31, and a cleaning device 51. Similarly, the other three image forming units are each provided with photoreceptors 2 to 4, chargers 12 to 14, laser exposure devices 22 to 24, developing devices 32 to 34, and cleaning devices 52 to 54, respectively. The image transport unit includes an image transport body 60, a tension roller 61, a driving roller 62, belt stretching rollers 63 and 64, a secondary transfer counter roller 72, and primary transfer rollers 41 to 44.

  First, the surfaces of the photoreceptors 1 to 4 rotating in the direction of the arrow are uniformly charged by the chargers 11 to 14. Next, the electrostatic exposure images according to the image patterns of the respective colors (yellow, magenta, cyan, black) are formed by irradiating the photoreceptors 1 to 4 with the laser exposure devices 21 to 24. The electrostatic latent image is developed by developing units 31 to 34 for each color (yellow, magenta, cyan, and black). The developed image is transferred to the image carrier 60 by an electric field formed between the primary transfer rollers 51 to 54 and the photoconductors 1 to 4. The toner remaining on the photoreceptors 1 to 4 without being completely transferred is collected by the cleaners 51 to 54 and collected in a waste toner container (not shown). The four color images on the image carrier are conveyed by rotationally driving the image carrier 60, and are transferred to a transfer material by a transfer electric field formed between the secondary transfer roller 72 and the secondary transfer counter roller 71. The Reference numeral 73 denotes a cleaning machine that cleans toner, paper dust, and the like attached to the surface of the secondary transfer roller. Toner that is not completely transferred to the transfer material and remains on the image carrier 60 is collected by a cleaning device 65 and collected in a waste toner container (not shown). Subsequently, the transfer material carrying the image is subjected to charge removal from the image transport body 60, moves to the transfer material transport unit 81, and is transported to the fixing unit 91. Finally, a fixing unit 91 including a heating roller and a pressure roller is heated and fixed and fused to a transfer material to complete image recording.

In the image forming apparatus having such a configuration, primary transfer rollers 41 to 44 are listed as the printing mechanism members included in the image carrier 60. The primary transfer rollers 41 to 44 are generally made of a semiconductor having a resistance of about 10 ⁵ to 10 ¹⁰ Ω. However, since the resistance varies with time, the primary transfer rollers 41 to 44 need to be periodically replaced. When the primary transfer rollers 41 to 44 are replaced, the direction of removal can be the front side (or the depth direction) in FIG. 2 and the direction of the photoconductor. It is necessary to keep the image carrier away from the camera. On the other hand, when extracting in the front side (or the depth direction) in FIG. 2, that is, in a direction orthogonal to the rotation direction of the surface of the image carrier, there is no need to remove the image carrier 60, and there is no other obstruction, and transfer is easy. The printing mechanism member such as a roller can be exchanged.

Hereinafter, in the embodiment, the image transport unit according to the present invention will be described in detail. FIG. 3 is a cross-sectional view of the image transport unit. This is an image forming apparatus in which four photoreceptors 1 to 4 for forming an image are arranged, but members such as a charger are not shown because they are not related to this embodiment. A tension roller 61, a driving roller 62, belt stretching rollers 63 and 64, and a secondary transfer counter roller 72 for stretching the image carrier 60 are fixed to the two side plates 101 through bearings. The image carrier 60 in this embodiment is an intermediate transfer belt, and uses a semiconductive polyimide belt having a resistivity of 10 ⁷ Ω · cm to 10 ¹¹ Ω · cm and a perimeter exceeding 1 m. The image carrier 60 in this embodiment is applied with a constant tension by a tension roller 61, and rotates at 300 to 600 mm / sec in the arrow direction while holding the toner image transferred from the photoreceptors 1 to 4 on the surface. is doing. The tension roller 61 is also provided with a steering mechanism for adjusting the meandering of the belt, but detailed description thereof is omitted. In such an image forming apparatus that conveys an image at high speed and creates a printed matter, the cost of each component is also high. Therefore, a method of exchanging the unit for each unit like a small printer increases the cost. In the image transport unit shown in this embodiment, the image transport body 60, the primary transfer rolls 41 to 44, and the like are main replacement parts. The primary transfer rolls 41 to 44 are members that form an electric field for transferring the toner images formed on the photoreceptors 1 to 4 to the image carrier 60, and are foams having a thickness of several millimeters around a metal cored bar. Is used. This foam has a tendency that the resistance value of the foam layer gradually increases because a high voltage is applied to the cored bar. When the resistance value increases, it is necessary to increase the voltage supplied to the core of the primary transfer roll. However, since the power supply capacity cannot be increased infinitely, it is necessary to replace the primary transfer roll.

  There are two possible directions for removing the primary transfer roll: the photoconductor direction and the side plate direction. When taking out in the direction of the photoconductor, the image carrier 60 must be removed. Since the image carrier 60 is a thin film having a thickness of about 100 μm and is difficult to handle and appears on the image when a crease or the like is formed, it is not preferable to remove it frequently. Therefore, in the present invention, the primary transfer roll is configured to be removed in the side plate direction.

  That is, as shown in FIG. 1, an opening 102 is provided in the side plate 101, and the primary transfer roll can be slid and removed from the opening 102. With the above configuration, the primary transfer roll can be exchanged without damaging the image carrier 60.

  FIG. 4 is a diagram for explaining another embodiment of the present invention. Each of the printing mechanism members included in the image carrier is provided with the opening 102 of the side plate, and the printing mechanism member is configured to be fitted into the opening of the side plate. With this configuration, the printing mechanism can be easily inserted.

  Actually, as shown in FIG. 5, the primary transfer roll 41 is attached to the transfer roll support 141, and the primary transfer roll is taken in and out as a unit. As shown in FIG. 6, the image conveying unit passes the bottom plate 103 between the side plates 101 at the portion where the printing mechanism member is arranged, and the unit shown in FIG. As shown in FIG. 7, the bottom plate 103 is provided with the convex portion 104, the transfer roll support 141 is provided with the concave portion 105, and the printing mechanism member configured to fit the convex portion 104 and the concave portion 105 is always in a predetermined position. Can be placed.

  FIG. 8 shows that the image carrying body 60 and the printing mechanism member are prevented from being damaged without being rubbed with the image carrying body 60 when being separated by sliding in the direction orthogonal to the rotation direction of the surface of the image carrying body. It is a figure which shows the structure for. By providing the rotation shaft 110 between the two side plates and rotating the transfer roll support 141 around the rotation shaft 110, the image carrier 60 and the transfer roll support 141 can be brought into a non-contact state. At this time, if the transfer roll support 141 also rotates, the rotation trajectory intersects with the image carrier 60 and damages the image carrier 60. Therefore, when the transfer roll support 141 is configured not to rotate, that is, when the recess of the transfer roll support 141 is configured to face the image transport body 60, the transfer roll support 141 is removed without damaging the image transport body 60. Is possible.

  As described above, according to the embodiment described above, the printing mechanism member included in the image carrier can be separated by sliding in the direction orthogonal to the rotation direction of the surface of the image carrier without removing the image carrier. By maintaining the printing mechanism member as a small component unit with excellent maintainability, it is possible to replace the component with the minimum necessary unit.

  In addition, in an image transport unit having side plates on both sides or one side toward the rotation direction of the image transport body surface, an opening is provided in the side plate so that the printing mechanism member can be slid and inserted and removed from the opening. Therefore, it is excellent in maintainability, and parts can be replaced in the minimum necessary unit.

  Further, by configuring the separation unit included in the image carrier so as to fit into the opening of the side plate, the configuration is more excellent in maintainability.

  In addition, by adopting a configuration that can be brought into a non-contact state with the image carrier, the image carrier is not rubbed with the image carrier when being slid and separated in a direction perpendicular to the rotation direction of the surface of the image carrier. Further, the printing mechanism member can be prevented from being damaged.

It is a schematic diagram explaining the Example of this invention. 1 is a schematic diagram of an image forming apparatus to which the present invention is applied. It is a schematic diagram explaining the Example of this invention. It is a schematic diagram explaining the other Example of this invention. It is a schematic diagram explaining an example of a printing mechanism member. FIG. 3 is a schematic diagram for explaining an arrangement relationship between a printing mechanism member and an image forming unit. It is a schematic diagram explaining the junction part of a printing mechanism member and the baseplate of an image forming unit. It is a schematic diagram explaining the structure which makes a printing mechanism member and an image conveyance body a non-contact state.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1-4 ... Photoconductor, 11-14 ... Charger, 21-24 ... Laser exposure apparatus, 31-34 ... Developing machine, 41-44 ... Primary transfer roller, 51-54 ... Cleaning machine, 60 ... Image carrier, DESCRIPTION OF SYMBOLS 61 ... Tension roller, 62 ... Drive roller, 63, 64 ... Belt tension roller, 65 ... Cleaning machine, 71 ... Secondary transfer counter roller, 72 ... Secondary transfer roller, 73 ... Cleaning machine, 81 ... Transfer material conveyance unit , 91: Fixing unit, 101: Side plate, 102: Opening portion, 103 ... Bottom plate, 104 ... Convex portion, 105 ... Concavity, 110 ... Rotating shaft, 141 ... Transfer roll support.

Claims (5)

A photosensitive member that forms a latent image on the surface and attaches toner according to the latent image to form a toner image; a rotatable image carrier; and a transfer unit that transfers the toner image from the photosensitive member to the image carrier. In an image forming apparatus having
The image carrying body and the transfer unit are configured to be detachable from the image forming apparatus as an image carrying unit,
The image forming apparatus, wherein the transfer unit is detachable from the image transport unit in a direction orthogonal to a rotation direction of the image transport body.   The image forming apparatus according to claim 1, wherein the image transport unit includes a side plate on a side surface in a rotation direction of the image transport body, and an opening is provided in the side plate.   The image forming apparatus according to claim 2, wherein the transfer unit is configured to fit into an opening of the side plate.   4. The image forming apparatus according to claim 3, wherein the transfer unit is separated from the image transport unit after being brought into a non-contact state with the image transport body. The image forming apparatus according to claim 4, wherein the transfer unit is brought into a non-contact state with the image carrier by rotating the transfer unit around the longitudinal direction of the transfer unit.

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