JP2012027346A - Belt unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a belt unit that has flexibility in a position at which an information pattern is formed.SOLUTION: A belt unit 70 comprises an endless belt (a conveyance belt 73) and a plurality of rollers (such as a driven roller 72) on which the belt is stretched. In the state before mounting the belt unit to an image formation device, an information pattern IP formed with developer is provided on the belt (the conveyance belt 73) at a location downstream in the revolving direction from a position at which the belt confronts a cleaning member and upstream in the revolving direction from a position at which the belt is detected by a detection sensor.

Description

  The present invention relates to a belt unit having an endless belt.

  2. Description of the Related Art Conventionally, as a belt unit that can be attached to and detached from an image forming apparatus, an intermediate transfer belt to which a toner image is transferred from a photosensitive drum has been provided, and an information pattern indicating a new product is formed on the intermediate transfer belt in a new state. Is known (see Patent Document 1). Specifically, in this technique, when the information pattern is detected by the optical sensor in the image forming apparatus when the intermediate transfer belt is rotated immediately after the belt unit is mounted on the image forming apparatus, the belt unit is determined to be new. ing.

  Also, the information pattern read by the optical sensor is removed by a belt cleaning device in the image forming apparatus. This makes it possible to determine that the belt unit is not new even if the belt unit that has been determined to be new once and has the information pattern removed is removed from the image forming apparatus and remounted. Yes.

  In this technique, an information pattern is formed by applying a paint in which a powder of silicon fine particles is dispersed in a volatile liquid on the intermediate transfer belt in order to satisfactorily detect such a new article.

JP 2009-300618 A

  However, when a conventional paint is applied onto the intermediate transfer belt, depending on the position where the paint is applied, the paint passes through the photosensitive drum when the intermediate transfer belt rotates, and the paint adheres to the photosensitive drum. There was a risk of adversely affecting the photosensitive drum. Therefore, there has been a problem that the position where the paint is applied on the intermediate transfer belt is limited.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a belt unit capable of giving a degree of freedom to a position where an information pattern is formed.

  The present invention for solving the above-mentioned problems is a belt unit having an endless belt and a plurality of rollers for stretching the belt, and the belt unit is provided with a photoreceptor provided in contact with the belt. A detection sensor that is provided downstream of the photoreceptor in the rotation direction of the belt and that detects the developer adhering to the belt; and provided downstream of the detection sensor in the rotation direction of the belt, A cleaning member that removes the developer that has adhered to the image forming apparatus, and is configured to be attached to the image forming apparatus. Also, an information pattern formed of a developer is provided at a position downstream of the rotation direction and upstream of the portion detected by the detection sensor. And wherein the digit.

  According to the present invention, since the information pattern is formed of the developer, the information pattern does not adversely affect the photoconductor even when the information pattern is disposed at a position passing through the photoconductor.

  According to the present invention, since the information pattern is formed with the developer that does not adversely affect the photosensitive member, the position where the information pattern is formed can have a degree of freedom.

1 is a diagram schematically illustrating a color printer according to an embodiment of the present invention. It is an enlarged view showing the structure around the grip part of the belt unit. FIG. 4A is a diagram showing an output voltage of a detection sensor at the time of color misregistration correction control, and FIG. 4B is a diagram showing an output voltage of the detection sensor at the time of new article detection control. It is an enlarged view which shows the modification of the position of an information pattern.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, an overall configuration of a color printer as an example of an image forming apparatus will be described, and then details of characteristic portions of the present invention will be described.

  In the following description, the direction will be described with reference to the user when using the color printer. That is, in FIG. 1, the left side toward the paper surface is “front side (front side)”, the right side toward the paper surface is “rear side (back side)”, the back side toward the paper surface is “left side”, and it faces the paper surface. Let the near side be the “right side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

<Overall configuration of color printer>
As shown in FIG. 1, the color printer 1 includes an image forming unit in which a paper feeding unit 20 that supplies paper P, an image forming unit 30 that forms an image on the fed paper P, and an image are formed. And a paper discharge section 90 for discharging the paper P.

  The paper feed unit 20 includes a paper feed tray 21 that accommodates the paper P and a paper transport device 22 that transports the paper P from the paper feed tray 21 to the image forming unit 30.

  The image forming unit 30 includes a scanner unit 40 (exposure member), a process unit 50, a belt unit 70, a belt cleaner 100, and a fixing unit 80.

  The scanner unit 40 is provided in an upper part of the apparatus main body 10 and includes a laser light emitting unit, a polygon mirror, a lens, a reflecting mirror, and the like not shown. In the scanner unit 40, the laser beam is irradiated on the surface of each photosensitive drum 51 of the process unit 50 by high-speed scanning through a path indicated by a two-dot chain line in the drawing.

  The process unit 50 is attachable to and detachable from the apparatus main body 10 through an opening 10 </ b> A formed by opening the front cover 12 disposed on the front wall 11 of the apparatus main body 10. The process unit 50 includes a drawer 60, four photosensitive drums 51 that are rotatably supported by the drawer 60, and four developing cartridges 52 that are detachably provided on the drawer 60 so as to correspond to the photosensitive drums 51. ing.

  The respective photosensitive drums 51 are arranged along the front-rear direction (predetermined direction) in a state where the process unit 50 is mounted on the apparatus main body 10. The drawer 60 is appropriately provided with a known charger (not shown), and the developing cartridge 52 is rotatably provided with a developing roller 53 for supplying toner (developer) to the photosensitive drum 51 and contains a known toner. A chamber, a supply roller and the like are provided.

  The belt unit 70 is provided between the paper feeding unit 20 and the process unit 50, and can be attached to and detached from the apparatus main body 10 through an opening 10A formed by opening the front cover 12. That is, the belt unit 70 can be attached to and detached from the apparatus main body 10 through the opening 10 </ b> A with the process unit 50 removed from the apparatus main body 10.

  The belt unit 70 includes a driving roller 71 as an example of a second roller, a driven roller 72 as an example of a first roller, a conveyance belt 73, a transfer roller 74, and a backup roller 75. The details of the structure of the belt unit 70 will be described later.

  The driving roller 71 and the driven roller 72 are arranged in parallel in a spaced manner in the front-rear direction, and an endless conveyance belt 73 is stretched therebetween. The outer surface of the conveyance belt 73 is in contact with each photosensitive drum 51. In addition, four transfer rollers 74 that sandwich the conveyor belt 73 between the photosensitive drums 51 are arranged inside the conveyor belt 73 so as to face the photosensitive drums 51. A transfer bias is applied to the transfer roller 74 by constant current control during transfer.

  The belt cleaner 100 is a device that slidably contacts the conveyance belt 73 and collects toner and the like attached on the conveyance belt 73, and is disposed below the conveyance belt 73. Specifically, the belt cleaner 100 includes a cleaning roller 101 as an example of a cleaning member, and a waste toner container 102.

  The cleaning roller 101 is disposed so as to be in contact with the outer peripheral surface of the transport belt 73, and a recovery bias is applied between the cleaning roller 101 and the backup roller 75 disposed on the inner peripheral surface of the transport belt 73, so that the cleaning roller 101 is placed on the transport belt 73. The deposit is removed. The toner collected by the cleaning roller 101 is collected by a collecting roller that is in sliding contact with the cleaning roller 101, then scraped off by a blade that is in sliding contact with the collecting roller, and stored in a waste toner container 102.

  The fixing unit 80 is disposed on the back side of the process unit 50 and the belt unit 70, and includes a heating roller 81 and a pressure roller 82 that is disposed to face the heating roller 81 and presses the heating roller 81.

  In the image forming unit 30 configured as described above, first, the surface of each photosensitive drum 51 is uniformly charged by a charger and then exposed by the scanner unit 40. As a result, the potential of the exposed portion is lowered, and an electrostatic latent image based on the image data is formed on each photosensitive drum 51. Thereafter, the toner in the developing cartridge 52 is supplied to the electrostatic latent image on the photosensitive drum 51 by the developing roller 53, so that the toner image is carried on the photosensitive drum 51.

  Next, the paper P supplied onto the conveyance belt 73 passes between each photosensitive drum 51 and each transfer roller 74, so that the toner image formed on each photosensitive drum 51 is transferred onto the paper P. The Then, as the paper P passes between the heating roller 81 and the pressure roller 82, the toner image transferred onto the paper P is thermally fixed.

  The paper discharge unit 90 includes a plurality of transport rollers 91 that transport the paper P. The sheet P on which the toner image has been transferred and heat-fixed is transported by the transport roller 91 and discharged outside the apparatus main body 10.

<Structure of belt unit etc.>
Next, the structure of the belt unit 70 which is a characteristic part of the present invention will be described. First, before describing the structure of the belt unit 70, the detection sensor 110 and the control device 200 will be described with reference to FIG.

  The detection sensor 110 is a sensor that reads the toner adhering on the conveyance belt 73 by using reflection of light, and is disposed obliquely below the drive roller 71. Specifically, the detection sensor 110 is disposed at a position downstream of the photosensitive drum 51 in the rotation direction of the conveyance belt 73 and at a position upstream of the cleaning roller 101 in the rotation direction. It is provided so as to face the driving roller 71 with 73 therebetween. Information detected by the detection sensor 110 is output to the control device 200.

  When the control device 200 receives a signal for executing the color misregistration correction control, the control device 200 idles (rotates with no paper P placed) and rotates the conveyor belt 73 on the conveyor belt 73 by each photosensitive drum 51. The toner is directly printed, the toner (patch) is detected by the detection sensor 110, and color misregistration correction control is performed. Further, the control device 200 conveys when the belt unit 70 is attached to the device main body 10 (for example, when a signal indicating that the front cover 12 is closed is received from a sensor that detects opening / closing of the front cover 12). The belt 73 is idled and new article detection control described later is executed based on a signal from the detection sensor 110.

  As shown in FIG. 2, the belt unit 70 includes the driven roller 72 and the conveyance belt 73 described above, a pair of left and right side frames 76 that rotatably hold the driven roller 72 and the like, and each side frame 76. And a gripping portion 77 provided on the front side (opening portion 10A side in a state of being mounted on the apparatus main body 10). Here, FIG. 2 shows the belt unit 70 in a new state.

  The gripping portion 77 is a portion that is gripped by an operator when the belt unit 70 is attached to the apparatus main body 10, and as shown in FIG. 1, the gripping portion 77 rotates more than the portion of the conveyor belt 73 that faces the cleaning roller 101. It is provided on the downstream side so as to cover a part on the upstream side in the rotational direction from the portion facing the photosensitive drum 51 (the photosensitive drum 51 on the most upstream side). Specifically, as shown in FIG. 2, the grip portion 77 is formed so as to connect the front side portions of the side frames 76, and mainly includes an upper wall portion 77A, a front wall portion 77B, and a lower wall portion. 77C and a handle portion 77D.

  The upper wall portion 77A is a wall that is disposed above the transport belt 73 and faces the driven roller 72 in the vertical direction, and extends rearward from the upper end of the front wall portion 77B so as to cover the front upper portion of the transport belt 73. It is formed as follows. The upper wall portion 77A, together with the lower wall portion 77C, is gripped by an operator when the belt unit 70 is attached to the apparatus main body 10.

  The front wall portion 77 </ b> B is a wall that is disposed in front of the conveyance belt 73 and faces the driven roller 72 in the front-rear direction, and is formed so as to cover the front portion of the conveyance belt 73.

  The lower wall portion 77C is a wall that is disposed below the conveyor belt 73 and faces the driven roller 72 in the vertical direction, and extends rearward from the lower end of the front wall portion 77B so as to cover the front lower portion of the conveyor belt 73. It is formed as follows. An information pattern IP indicating that the belt unit 70 is new is formed on the front lower portion of the conveyance belt 73 covered with the lower wall portion 77C with toner.

  In other words, the information pattern IP and the gripping portion 77 are downstream in the rotational direction from the portion of the transport belt 73 that faces the cleaning roller 101 (see FIG. 1) in the new state before the belt unit 70 is mounted on the apparatus body 10. This is provided at a position on the upstream side in the rotational direction with respect to the portion detected by the detection sensor 110.

  Here, the information pattern IP is formed on the conveyance belt 73 using transfer means such as a photosensitive drum in the factory before shipment from the factory. When forming the information pattern IP on the transport belt 73, it is desirable to use toner charged with a charge amount larger than the charge amount of toner used for normal printing. According to this, it is possible to prevent the information pattern IP from being peeled off from the conveyor belt 73 due to vibration during transportation during the transportation of the new belt unit 70.

  The handle portion 77D is formed in a bowl shape that extends obliquely downward from the upper end of the front wall portion 77B and then extends downward, and hooks the operator's finger when removing the belt unit 70 from the apparatus main body 10. It is possible.

Next, color misregistration correction control and new article detection control will be described.
In the color misregistration correction control, the control device 200 outputs the output voltage of the detection sensor 110 when the detection sensor 110 detects a portion of the conveyor belt 73 where no patch is formed, as shown in FIG. The control is executed using a first threshold value V1 set to a value that is somewhat distant from (hereinafter also referred to as “reference value V0”).

  Specifically, when the output voltage of the detection sensor 110 after the elapse of a predetermined time (time t1) from the start of driving (0) of the conveyor belt 73 exceeds (below) the first threshold value V1, It is determined that the patch is formed at an accurate position, and color misregistration correction (correction of light emission timing of the scanner unit 40) is not performed. Further, when the output voltage of the detection sensor 110 at the time t1 is equal to or higher than the first threshold value V1, the control device 200 is configured to perform color misregistration correction by determining that the patch has deviated from an accurate position. Has been.

  On the other hand, in the new article detection control, as shown in FIG. 3B, the control device 200 executes control using the second threshold value V2 that is closer to the reference value V0 than the first threshold value V1 used in the color misregistration correction control. is doing.

  Specifically, when the output voltage of the detection sensor 110 after the elapse of a predetermined time (time t2) from the start of driving of the conveyor belt 73 (time t2) exceeds (below) the second threshold value V2, It is determined that the information pattern IP is formed, that is, a new state, and the counter indicating the number of times the belt unit 70 is used is reset to zero. In addition, the control device 200 forms the information pattern IP when the output voltage of the detection sensor 110 after the predetermined time has elapsed (time t2) from the drive start (0) of the conveyor belt 73 is equal to or higher than the second threshold value V2. If it is not, that is, it is not new, the control is terminated as it is.

  In this way, in the new article detection control, by using the second threshold value V2 that is closer to the reference value V0 than the first threshold value V1 used in the color misregistration correction control, the information pattern IP is somewhat peeled off due to vibration during transportation, etc., and the output voltage Even when the output voltage becomes small, it is possible to determine the detection of a new article well if the output voltage is ensured only to the extent that it falls below the second threshold value V2 close to the reference value V0.

  The control device 200 is configured to apply a transfer bias to each transfer roller 74 in the new article detection control. Thereby, when the information pattern IP is arranged on the upstream side in the rotation direction from the photosensitive drum 51 as in the present embodiment, the information pattern IP can be pressed against the transport belt 73 by the transfer bias, and the information pattern IP Can be reliably moved to the detection sensor 110.

According to the above, the following effects can be obtained in the present embodiment.
Since the information pattern IP is formed of toner, even if the information pattern IP is arranged upstream of the photosensitive drum 51 in the rotational direction as in the present embodiment, the information pattern IP adversely affects the photosensitive drum 51. There is no effect. Therefore, a degree of freedom can be given to the position where the information pattern IP is formed.

  Since the information pattern IP is covered with the gripping portion 77 which is an essential configuration of the belt unit 70, the number of parts is reduced and the information pattern IP is protected as compared with a configuration in which a cover member different from the gripping portion 77 is newly provided. It can be carried out.

  Since the information pattern IP and the gripping portion 77 are provided on the upstream side of the photosensitive drum 51 in the rotation direction, the information pattern IP is pressed against the conveyance belt 73 by the transfer bias applied to the transfer roller 74 at the time of new article detection control, and the detection sensor 110 is surely reached. Can be moved to.

  Since the detection sensor 110 is disposed so as to face the driving roller 71 with the conveyance belt 73 interposed therebetween, a portion of the conveyance belt 73 supported by the driving roller 71 can be detected by the detection sensor 110. The information pattern IP can be detected without being affected by the bending of the belt 73, and the detection accuracy can be improved.

  In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below. In the drawings to be referred to below, components that are substantially the same as those in the above embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the embodiment, the information pattern IP is formed on the lower surface of the conveyance belt 73. However, the present invention is not limited to this, and for example, as shown in FIG. 4, the information pattern IP is formed on the upper surface 73A of the conveyance belt 73. Also good. Specifically, an upper wall portion 77E of the gripping portion 77 (an opposing wall facing the upper surface 73A of the conveyor belt 73 in the vertical direction) is formed so as to extend rearward from the above-described embodiment, and is covered by the upper wall portion 77E. The information pattern IP may be formed on the upper surface 73A of the conveying belt 73 that faces (opposes).

  According to this, since the information pattern IP is formed on the upper surface 73 </ b> A of the transport belt 73, it is possible to suppress the information pattern IP from being peeled off from the transport belt 73 during transport as compared with the form formed on the lower surface of the transport belt 73. it can.

  In the embodiment, the information pattern IP is arranged at a position covered with the gripping portion 77. However, the present invention is not limited to this, and the information pattern IP may be arranged at a position not covered with the gripping portion 77.

  In the above-described embodiment, the conveyance belt 73 that conveys the paper P is used as the belt. However, the present invention is not limited to this, and may be an intermediate transfer belt on which toner is directly printed from a photoconductor during printing control. . Further, the number of rollers for stretching the belt is not limited to the above embodiment, and may be three or more.

In the above-described embodiment, the photosensitive drum 51 is employed as the photosensitive member. However, the present invention is not limited to this, and for example, a belt-shaped photosensitive member may be employed.
In the above embodiment, the present invention is applied to the color printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.

  In the above-described embodiment, the information pattern IP indicating that the information is new is used as the information pattern. However, the present invention is not limited to this, and an information pattern indicating the manufacturer of the belt unit may be used. In this way, when the information pattern is information indicating the manufacturer, even if the material of the belt and the performance of the transfer roller are different for each manufacturer, it is possible to prepare a control table corresponding to each manufacturer. Control suitable for each manufacturer can be executed.

  In the above-described embodiment, the belt unit 70 can be attached to and detached from the apparatus main body 10, but the present invention is not limited to this, and the belt unit can be attached to the apparatus main body only once, and then a screw or the like is attached. The structure which cannot be removed if it removes may be sufficient. Even in this case, for example, when the information pattern is information indicating the manufacturer, even when a belt unit of a different manufacturer is randomly attached to the apparatus main body when the image forming apparatus is manufactured in the factory, Control suitable for each manufacturer can be executed by reading the information pattern with the detection sensor at the time of inspection.

  In the above embodiment, the opening 10A for mounting the belt unit 70 is provided in the front wall 11 of the apparatus main body 10. However, the present invention is not limited to this, and if the side wall of the apparatus main body is used, for example, the rear wall An opening may be provided. In this case, a gripping portion that is gripped by an operator for mounting the belt unit may be provided at the rear end of the belt unit.

In the embodiment, the transfer roller 74 is used as the transfer member. However, the present invention is not limited to this, and for example, a non-contact type may be used.
In the embodiment, the scanner unit 40 that emits a laser beam is used as the exposure member. However, the present invention is not limited to this, and an exposure member having, for example, an LED may be used.

  In the embodiment, the transfer bias is applied to all of the plurality of transfer rollers 74 in the new article detection control. However, the present invention is not limited to this, and it is sufficient to apply the transfer bias to at least the most upstream transfer member.

  In the above-described embodiment, the control device 200 that performs color misregistration correction control and new article detection control is employed, but the present invention is not limited to this. That is, the control device only needs to be able to execute exposure control for controlling the exposure member based on the signal detected by the detection sensor and initial control of the belt unit based on the signal detected by the detection sensor.

  Here, “exposure control” includes color misregistration correction control as in the above-described embodiment, and toner density correction control (control for increasing / decreasing the amount of light of an exposure member in accordance with density: control as in Patent Document 1. ) Etc. “Initial control of the belt unit” is control performed when the belt unit is mounted on the apparatus main body, and includes control for each manufacturer as described above, including new article detection control as in the above-described embodiment. Includes control to select a table.

  In the embodiment, the information pattern IP is formed with toner (toner used for printing in the image forming apparatus). However, the present invention is not limited to this, and any material can be used as long as it can be removed with a cleaning member. It may be a material.

DESCRIPTION OF SYMBOLS 1 Color printer 10 Apparatus main body 10A Opening part 11 Front wall 51 Photosensitive drum 70 Belt unit 71 Drive roller 72 Driven roller 73 Conveying belt 77 Grip part 101 Cleaning roller 110 Detection sensor 200 Control apparatus IP Information pattern

Claims (6)

An endless belt,
A belt unit having a plurality of rollers for stretching the belt,
The belt unit
A photosensitive member provided in contact with the belt; a detection sensor provided on a downstream side of the photosensitive member in a rotation direction of the belt; and detecting a developer attached on the belt; and the belt more than the detection sensor. And a cleaning member that removes the developer adhered on the belt, and is configured to be attachable to an image forming apparatus.
In a state before being attached to the image forming apparatus, the belt is located on the downstream side in the rotational direction with respect to the portion facing the cleaning member and on the upstream side in the rotational direction with respect to the portion detected by the detection sensor. A belt unit comprising an information pattern formed with a developer at a position. An opening for mounting the belt unit is formed on the side wall of the image forming apparatus,
A grip portion that is gripped by an operator when the belt unit is attached to the image forming apparatus is provided on the opening side of the belt unit.
The grip portion is provided so as to cover a part of the belt on the downstream side in the rotation direction with respect to the portion facing the cleaning member and on the upstream side in the rotation direction with respect to the portion detected by the detection sensor. And
The belt unit according to claim 1, wherein the information pattern is provided on a part of the belt covered with the grip portion.   The belt unit according to claim 2, wherein the grip portion is provided so as to cover a part of the belt on the upstream side in the rotation direction with respect to a portion facing the photoconductor. The plurality of rollers includes a first roller disposed on the opening side, and a second roller disposed on the side opposite to the opening,
The grip portion is provided to face the first roller, and the second roller is arranged to face the detection sensor with the belt interposed therebetween. Item 4. The belt unit according to Item 3. The gripping portion has a facing wall facing the upper surface of the belt in the vertical direction,
The belt unit according to any one of claims 2 to 4, wherein the information pattern is disposed on an upper surface of a belt facing the facing wall. An endless belt,
A belt unit having a plurality of rollers for stretching the belt,
The belt unit
A photosensitive member provided in contact with the belt; a detection sensor provided on a downstream side of the photosensitive member in a rotation direction of the belt; and detecting a developer attached on the belt; and the belt more than the detection sensor. A cleaning member that removes the developer attached on the belt, and is configured to be attachable from an opening of an image forming apparatus.
A grip portion that is gripped by an operator when the belt unit is attached to the image forming apparatus is provided on the opening side of the belt unit.
The grip portion is provided so as to cover a part of the belt on the downstream side in the rotation direction with respect to the portion facing the cleaning member and on the upstream side in the rotation direction with respect to the portion detected by the detection sensor. And
An information pattern that can be removed by the cleaning member is formed on a part of the belt covered by the grip portion.

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