JP4543745B2 - Conductive mechanism for conductive sheet and image forming apparatus - Google Patents

Description

  The present invention relates to a conductive mechanism for a conductive sheet and an image forming apparatus including the conductive mechanism for the conductive sheet.

  As an image forming method of the image forming apparatus, a method using a known electrophotographic process is known. In the known electrophotographic process, an image is formed on a recording medium such as a recording sheet by the following process.

  While rotating the photosensitive drum, the photosensitive drum is uniformly charged to a predetermined potential by a charger. The charged photosensitive drum is exposed to form a latent image. The latent image is developed with a developing device to form a toner image on the photosensitive drum. This toner image is transferred to the recording paper, and the toner image is fixed on the recording paper by a fixing device.

  Further, in a color printer that forms a full-color toner image composed of cyan, magenta, yellow, and black on an intermediate transfer belt with a single photoconductor, the intermediate transfer belt is rotated four times and the intermediate transfer belt is rotated once. The toner images are superimposed one by one on the intermediate transfer belt.

  The residual toner after the transfer on the photosensitive drum and the intermediate transfer belt is removed by a cleaning mechanism and collected in a collection case.

  There is an image forming apparatus that employs the following method as a cleaning mechanism for residual toner after transfer of the intermediate transfer belt.

  A cleaner roll on the brush is brought into contact with the intermediate transfer belt to scrape residual toner. A stainless steel collecting roller is brought into contact with the cleaner roll to adhere the residual toner. Residual toner adhering to the collecting roller is scraped off by a scraper and collected in a collecting case.

  The gap between the collection roller and the collection case is attached to the collection case and sealed with a sheet member that contacts the collection roller. (For example, refer to Patent Document 1).

  Such a sheet member is usually fixed to a housing such as a collection case by using a double-sided tape or the like.

  In order to charge the member in contact with the sheet member, a conductive sheet having conductivity is used as the sheet member, and a bias voltage may be applied to the conductive sheet.

Thus, in order to apply the bias voltage to the conductive sheet, a conductive member that is electrically connected to the conductive sheet and applies the bias voltage is required. Then, the conductive member needs to be fixed to the casing by screwing the conductive sheet to the casing such as a collection case with a double-sided tape. For this reason, work efficiency was not good.
Japanese Patent Laid-Open No. 1-219048

  The present invention has been made to solve the above-described problem, and an object thereof is to improve the work efficiency of attaching a conductive sheet and a conductive member to a housing.

The conductive mechanism for a conductive sheet according to claim 1 is provided with a casing, a conductive sheet attached to a first surface of the casing and contacting an object to be contacted, and the conductive sheet. A conductive member electrically connected to the conductive sheet, wherein the conductive member contacts a second surface substantially perpendicular to the first surface of the housing. And a leaf spring portion extending in a substantially right angle direction from the stationary portion and sandwiching the conductive sheet between the first surface by a spring force, and the leaf spring portion is electrically conductive. A state in which the conductive member is attached to the casing, the plate including a presser part that holds the sheet and a contact piece that extends from the presser part to the side opposite to the tip part side of the presser part. Thus, when the abutting piece is pushed up and bent, the presser portion becomes the conductive sheet. And is configured so as to press the door, it is characterized in that.

  The conductive mechanism of the conductive sheet according to claim 1, wherein the conductive sheet that contacts the object to be contacted is attached to the first surface of the housing, and the conductive sheet is electrically connected to the conductive sheet. The sex member is also attached to the housing.

  As for the electroconductive member, the leaf | plate spring part has pinched | interposed the electroconductive sheet between 1st surfaces. In addition, the fixed portion extends from the leaf spring portion in a substantially right angle direction and abuts on a second surface that is substantially perpendicular to the first surface of the housing. And the leaf | plate spring part is bent in the direction which presses a 1st surface with the spring force of a leaf | plate spring part.

Therefore, when the conductive member is attached to the casing, the conductive sheet and the conductive member are electrically connected, and the conductive member is fixed to the casing by the spring pressure of the leaf spring portion. Therefore, for example, there is no need for screwing after the conductive member is attached to the housing. Therefore, work efficiency is good. Moreover, since the number of parts is small, the cost is low.
In addition, when the conductive member is attached to the casing, the pressing portion presses the conductive sheet and is electrically connected, and is fixed to the casing, so that the work efficiency is good.

According to a second aspect of the present invention, there is provided a conductive mechanism of the conductive sheet according to the first aspect, wherein the conductive sheet is extended from the contact surface that contacts the object to be contacted and the contact surface. And a conductive portion surface attached to the first surface of the housing and sandwiched between the first surface and the leaf spring portion.

The conductive mechanism of the conductive sheet according to claim 2, wherein the conductive sheet includes a contact surface that contacts the object to be contacted, a contact surface that extends from the contact surface , and the housing. And a conduction portion surface sandwiched between the first surface and the leaf spring portion . Accordingly, the abutted object and the leaf spring portion do not interfere with each other. Therefore, a configuration in which the abutted object and the leaf spring portion do not interfere with each other, for example, a conductive sheet wider than the abutting width with the abutted object, and a portion where the abutted object is not in contact with the leaf spring Since there is no need to make the configuration in contact with each other, space is saved.

According to a third aspect of the present invention, there is provided the conductive mechanism of the conductive sheet according to the first or second aspect , wherein the contact piece is pushed up by contacting a tapered surface formed on the first surface. It is characterized by bending.

In the conductive mechanism of the conductive sheet according to the third aspect , the contact piece presses the conductive sheet at the pressing portion when the contact piece is pushed up and bent by contacting the tapered surface formed on the first surface .

  Therefore, when the conductive member is attached to the casing, the pressing portion presses the conductive sheet and is electrically connected, and is fixed to the casing, so that the work efficiency is good.

  According to a fourth aspect of the present invention, there is provided a conductive mechanism for a conductive sheet according to the third aspect, wherein a tip portion of the pressing portion is formed with a bent portion bent into a V shape. Yes.

  In the conductive mechanism of the conductive sheet according to the fourth aspect, a bent portion bent into a V shape is formed at the tip of the pressing portion. Therefore, the contact pressure at which the pressing portion presses the conductive sheet is increased, and the reliability of conduction between the pressing portion and the conductive sheet is improved.

  According to a fifth aspect of the present invention, in the conductive mechanism of the conductive sheet, in the configuration according to the third or fourth aspect, when the leaf spring portion is pushed in parallel to the first surface, the presser portion is When it hits the end of the tapered surface and deforms away from the first surface and gets over the end, the contact piece comes into contact with the tapered surface and bends, and the conductive sheet is pressed by the pressing portion. It is characterized by that.

  In the conductive mechanism of the conductive sheet according to the fifth aspect, when the leaf spring portion is pushed in parallel to the first surface, the holding portion hits the end portion of the tapered surface and is deformed in a direction away from the first surface. Therefore, when pushing, since it does not contact the conductive sheet attached in contact with the first surface, for example, the conductive sheet is not damaged.

  And if it gets over an edge part, a contact piece will contact | abut to a taper surface, will bend, and will press an electroconductive sheet with a press part. Therefore, it is electrically connected and fixed to the housing. Moreover, it does not come off easily.

  The conductive mechanism of the conductive sheet according to claim 6 is the configuration according to any one of claims 1 to 5, wherein the first protrusion projecting from the second surface is provided on the housing. The fixing portion is formed with a fitting hole for fitting with the first protrusion.

  In the conductive mechanism for a conductive sheet according to a sixth aspect of the present invention, a first protrusion projecting from the second surface is formed on the housing. And the fitting hole is formed in the fixing | fixed part, and it fits with the 1st protrusion. Therefore, for example, the fixed portion does not shift vertically and horizontally with respect to the second surface.

  The conductive mechanism of the conductive sheet according to claim 7 is the configuration according to any one of claims 1 to 6, wherein the casing is formed of the first surface and the second surface. A second protrusion having a tapered surface is formed, and an engagement hole that engages with the second protrusion is formed at a connecting portion between the pressing part and the fixing part. Is formed.

  According to a seventh aspect of the present invention, there is provided a conductive mechanism for a conductive sheet, wherein the casing is provided with a second protrusion having a tapered surface that protrudes from the first surface and the second surface. And the engagement hole is formed in the connection part of a holding | suppressing part and a fixing | fixed part. Therefore, when the engagement hole is engaged with the second protrusion, the contact piece comes into contact with the tapered surface of the second protrusion.

  Thus, since the engagement hole is engaged with the second protrusion, for example, it does not shift vertically and horizontally.

  The conductive mechanism of the conductive sheet according to claim 8 is the configuration according to any one of claims 1 to 7, wherein the casing has a third protrusion protruding from the second surface. The fixing portion is formed, and a side of the fixing portion is in contact with the third protrusion.

  In the conductive sheet conduction mechanism according to claim 8, since the housing is formed with a third protrusion projecting from the second surface, and the side of the fixed part contacts the third protrusion, Don't slip.

  Further, since the side of the fixed part is used, for example, it is not necessary to separately form a hole or the like in the fixed part, so that the cost is low.

Conducting mechanism of the conductive sheet according to claim 9, in the configuration according to any one of claims 1 to 8, wherein the conductive member is formed of sheet metal, the sheet metal U-shaped The portion left behind by the hole or the notch becomes the contact piece, the same surface as the contact piece becomes the presser part, and the part surrounding the contact piece is bent at a substantially right angle to form the fixed part. It is a feature.

  In the conductive mechanism of the conductive sheet according to claim 9, a U-shaped hole or cut is formed in the sheet metal. The U-shaped hole or the portion left behind by the cut becomes the contact piece, and the same surface as the contact piece becomes the presser part. Then, a portion surrounding the contact piece is bent at a substantially right angle to form a fixed portion.

  Thus, since a conductive member is made only by forming a hole or a notch in a sheet metal and bending it, the processing is simple and the cost is low.

  When a U-shaped hole is formed and bent in the sheet metal, a hole is formed in the connecting portion between the presser portion and the fixing portion. This hole can be the engagement hole described in claim 7.

Conducting mechanism of the conductive sheet according to claim 10, in the structure according to any one of claims 9 claim 1, wherein the conductive member is formed by stamped sheet metal, the The burr generated by die cutting is characterized in that the abutting piece protrudes to the side in contact with the tapered surface.

  The conductive mechanism of the conductive sheet according to claim 10 is formed by die-cutting a sheet metal. And the burr | flash which generate | occur | produces by die cutting has protruded to the side which a contact piece contact | abuts to a taper surface. Therefore, since this burr is caught on the tapered surface, it is more firmly fixed. Further, since a deburring process is not required, the cost is low.

  An image forming apparatus according to an eleventh aspect includes the conductive mechanism for a conductive sheet according to any one of the first to tenth aspects, wherein the object to be contacted is an image carrier on which a toner image is formed. It is characterized by its body.

  An image forming apparatus according to an eleventh aspect includes the conductive mechanism of the conductive sheet according to any one of the first to tenth aspects, and the conductive sheet is applied to an image carrier on which a toner image is formed. Touching.

  For example, the image carrier can be neutralized by grounding the conductive member. Alternatively, the image carrier can be charged by applying a bias voltage to the conductive member.

  An image forming apparatus according to a twelfth aspect of the present invention is the image forming apparatus according to the eleventh aspect, in which the image carrier rotates to charge residual toner remaining after the toner image of the image carrier is transferred to a transfer medium. A bias is fed to the conductive member, and is disposed downstream of the contact portion between the conductive sheet and the image carrier, and a recovery bias having a polarity opposite to the charging bias is applied to recover the residual toner. It is characterized by having a recovery means.

  In the image forming apparatus according to the twelfth aspect, the toner image formed on the image carrier is transferred to a transfer medium. Since residual toner remains on the image carrier after transfer, it must be recovered. For this reason, it collects as follows.

  A charging bias is supplied to the conductive member, and when the residual toner after transfer passes through the conductive sheet, the residual toner comes into contact with the conductive sheet and charges the residual toner. A collecting unit to which a collecting bias having a reverse polarity to the charging bias is disposed on the downstream side of the conductive sheet, and the charged residual toner is electrically collected by the collecting unit.

  As described above, according to the present invention, when the conductive member is attached to the casing, the conductive sheet and the conductive member are electrically connected, and the conductive member is fixed to the casing. Therefore, for example, there is no need for screwing after the conductive member is attached to the housing. Therefore, work efficiency is good. Moreover, since the number of parts is small, the cost is low.

  Hereinafter, as an example of an image forming apparatus to which a conductive mechanism for conductive sheets according to the present invention is applied, a color printer to which a known electrophotographic process is applied will be described with reference to the drawings. The image forming apparatus to which the present invention is applied is not limited to a color printer described below, and may be a monochrome printer. Further, it may be an image forming apparatus such as a copying machine, a facsimile machine, or a multifunction machine. In the following description, detailed descriptions of those not directly related to the essence of the present invention are omitted.

  FIG. 1 shows an outline of a color printer 10 to which a conductive sheet conduction mechanism 99 (see FIG. 6) according to an embodiment of the present invention is applied. The color printer 10 includes a color printer main body 12, and an open / close cover 16 that is rotatable about a rotation fulcrum 14 is provided on the upper portion of the color printer main body 12. In addition, a paper feeding unit 18 is disposed below the color printer main body 12.

  The paper supply unit 18 includes a paper supply unit main body 20 and a paper supply cassette 22 in which the recording paper P is stored. A feed roll 24 that feeds recording paper P from the paper feed cassette 22 and a retard roll 26 that scoops the supplied recording paper P one by one are arranged in the upper part near the rear end of the paper feed cassette 22.

  The conveyance path 28 is a path for the recording paper P from the feed roll 24 to the discharge port 30. The conveyance path 28 is in the vicinity of the back side (right side in FIG. 1) of the color printer main body 12 and is formed substantially vertically from the paper feeding unit 18 to the fixing device 90. A secondary transfer roll 80 and a secondary transfer backup roll 72 are arranged on the upstream side of the fixing device 90 in the conveyance path 28, and a resist roll 32 is arranged on the upstream side of the secondary transfer roll 80 and the secondary transfer backup roll 72. Has been. In addition, a discharge roll 34 is disposed in the vicinity of the discharge port 30 of the conveyance path 28.

  Accordingly, the recording paper P sent out from the paper feeding cassette 22 of the paper feeding unit 18 by the feed roll 24 is turned by the retard roll 26 and only the uppermost recording paper P is guided to the transport path 28, and is fed by the registration roll 32. At this time, the toner image is transferred between the secondary transfer roll 80 and the intermediate transfer belt 64 (secondary transfer backup roll 72) at a timing, and the transferred toner image is transferred by the fixing device 90. The toner is fixed and discharged from a discharge port 30 to a discharge portion 36 provided on the upper part of the opening / closing cover 16 by a discharge roll 34. The discharge portion 36 has a low discharge port portion and is inclined so as to gradually increase toward the front direction (left direction in FIG. 1).

  The color printer main body 12 is provided with a photosensitive drum 50 that rotates about a rotation support shaft 49. In addition, a rotary developing device 38 is arranged at a substantially central portion, and a control unit 39 for controlling each part of the color printer 10 is arranged on the front side (left side in FIG. 1) of the rotary developing device 38.

  The rotary developing device 38 includes developing units 42a to 42d that respectively form toner images of four colors of yellow, yellow, magenta, cyan, and black in the developing unit main body 40. It rotates counterclockwise (counterclockwise in FIG. 1) about the rotary developing device center 44. Each of the developing units 42a to 42d has developing rolls 46a to 46d, and is pressed in the normal direction of the developing unit main body 40 by elastic bodies 48a to 48d such as coil springs.

  The photosensitive drum 50 is disposed in contact with the rotary developing device 38. The developing rolls 46 a to 46 d are not in contact with the photosensitive drum 50, and a part of the outer periphery thereof protrudes from the outer periphery of the developing device main body 40 in the radial direction by about 2 mm. Further, a tracking roll (not shown) having a diameter slightly larger than the diameter of the developing rolls 46a to 46d is provided at both ends of each of the developing rolls 46a to 46d so as to rotate coaxially with the developing rolls 46a to 46d. Yes. In other words, the developing devices 42 a to 42 d are arranged on the outer periphery of the developing device main body 40 at intervals of 90 ° with the rotary developing device center 44 as the center, and the tracking rolls of the developing rollers 46 a to 46 d are disposed at both ends of the photosensitive drum 50. The latent image on the photosensitive drum 50 is developed with toner of each color while abutting against a provided flange (not shown) and forming a predetermined gap between the developing rolls 46a to 46d and the photosensitive drum 50. To do.

  A charging roll 52 is provided below the photosensitive drum 50, and a charging bias is applied to the charging roll 52 to uniformly charge the photosensitive drum 50. Further, a photosensitive drum cleaner 54 is provided so as to hang from the rotation support shaft 49 of the photosensitive drum 50, and the photosensitive drum 50 and the photosensitive drum cleaner 54 are integrated. The photosensitive drum cleaner 54 includes a cleaning blade 56 that scrapes residual toner remaining on the photosensitive drum 50 after primary transfer, and a toner recovery case 58 that recovers residual toner scraped by the cleaning blade 56.

  Note that a rib or the like is formed on the back side (right side in FIG. 1) of the toner recovery case 58, and the recording paper P is curved to form a part of the transport path 28.

  On the lower back side of the rotary developing device 38, an exposure device 60 for writing a latent image on the photosensitive drum 50 charged by the charging roll 52 with a light beam such as a laser beam is disposed. Further, the toner image visualized by the rotary developing device 38 is primarily transferred above the rotary developing device 38 at the primary transfer position, and the secondary transfer position (the nip between the secondary transfer roll 80 and the secondary transfer backup roll 72) is transferred. An intermediate transfer device 62 is provided.

  The intermediate transfer device 62 includes an intermediate transfer belt 64, a primary transfer roll 66, a wrap-in roll 68, a wrap-out roll 70, a secondary transfer backup roll 72, a conductive sheet backup roll 74, a brush backup roll 76, and the like.

  The intermediate transfer belt 64 has elasticity and is stretched substantially flat so as to have a long side and a short side above the rotary developing device 38. The long sides on the upper and lower sides of the intermediate transfer belt 64 are stretched so as to be substantially parallel to the discharge portion 36 provided on the upper portion of the color printer main body 12.

  The intermediate transfer belt 64 is positioned between a wrap-in roll 68 disposed upstream of the primary transfer roll 66 below the long side of the intermediate transfer belt 64 and a wrap-out roll 70 disposed downstream of the primary transfer roll 66. Thus, the photosensitive drum 50 has a primary transfer portion (photosensitive drum wrap region) that contacts the photosensitive drum 50 in a wrap shape, is wound around the photosensitive drum 50 by a predetermined range, and is driven by the rotation of the photosensitive drum 50. As described above, the intermediate transfer belt 64 primarily transfers the toner image on the photosensitive drum 50 by the primary transfer roll 66 in the order of yellow, magenta, cyan, and black, and the primary transferred toner image is secondary-transferred. It is conveyed toward the transfer roll 80. Note that the wrap-in roll 68 and the wrap-out roll 70 are separated from the photosensitive drum 50.

  As described above, the intermediate transfer belt 64 is stretched by five rolls of the wrap-in roll 68, the wrap-out roll 70, the secondary transfer backup roll 72, the conductive sheet backup roll 74, and the brush backup roll 76. The toner image on the photosensitive drum 50 is transferred by the transfer roll 66.

  Further, a flat portion (short side) is formed on the back side (right side surface in FIG. 1) of the intermediate transfer belt 64 by a wrap-out roll 70 and a secondary transfer backup roll 72, and this flat portion is the secondary transfer portion. It faces the transport unit 28.

  In the secondary transfer portion, the wrap-out roll 70 is disposed so that the intermediate transfer belt 64 and the conveyance path 28 are at an angle of about 12 °.

  The conductive sheet backup roll 74 assists the conductive sheet 100 charging the residual toner remaining on the intermediate transfer belt 64 after the secondary transfer, and the brush backup roll 76 allows the brush roll 86 to scrape the residual toner. To assist. (Details of collecting the residual toner will be described later).

  A reflective photosensor 78 is provided above the long side of the intermediate transfer belt 64 by being fixed to the back surface (inside) of the open / close cover 16. The reflective photosensor 78 reads a toner patch formed on the intermediate transfer belt 64, detects the position of the intermediate transfer belt 64 in the rotational direction, and detects the density of the toner image.

  A secondary transfer roll 80 is opposed to the secondary transfer backup roll 72 of the intermediate transfer device 62 with the conveyance path 28 interposed therebetween. That is, the secondary transfer position in the secondary transfer portion is between the secondary transfer roll 80 and the secondary transfer backup roll 72, and the secondary transfer roll 80 is intermediate with the assistance of the secondary transfer backup roll 72. The toner image primarily transferred to the transfer belt 64 is secondarily transferred to the recording paper P at the secondary transfer position. Here, the secondary transfer roll 80 is rotated while the intermediate transfer belt 64 rotates three times, that is, while the toner images of three colors of yellow, magenta, and cyan are primarily transferred and conveyed on the intermediate transfer belt. It is separated from the intermediate transfer belt 64, and comes into contact with the intermediate transfer belt 64 when a black toner image is transferred.

  In addition, a predetermined potential difference is generated between the secondary transfer roll 80 and the secondary transfer backup roll 72, and when the secondary transfer roll 80 is set to a high voltage, the secondary transfer backup roll 72 is connected to the ground (GND).

  An intermediate transfer belt cleaner 82 is provided at the end of the intermediate transfer belt 64 on the side opposite to the photosensitive drum 50.

  As shown in FIG. 3, the intermediate transfer belt cleaner 82 includes a toner collection case 88 that collects residual toner inside. A conductive sheet 100 that contacts the intermediate transfer belt 64 and charges the residual toner on the intermediate transfer belt 64 to a predetermined polarity is provided on the most upstream side with respect to the rotation direction of the intermediate transfer belt 64.

  The conductive sheet 100 is electrically connected to the contact member 200 attached to the toner recovery case 88. The conductive sheet 100 and the contact member 200 are attached and fixed to the toner recovery case 88, and a mechanism portion for electrically connecting the conductive sheet 100 and the contact member 200 is a conductive mechanism 99 for the conductive sheet. . (Details of the conductive mechanism 99 of the conductive sheet will be described later).

  The contact member 200 includes a contact portion (not shown) outside the toner collection case 88 to be collected, and is in contact with a contact fitting (not shown) connected to the power supply portion 39 of the color printer main body 12.

Therefore, the first recovery bias V ₁ is applied to the conductive sheet 100 from the power supply unit 37 via the contact fitting and the contact member 200 to charge the residual toner passing through the conductive sheet 100 to a predetermined polarity. A collection roll 150 to which a second collection bias V ₂ having a polarity opposite to the first collection bias V ₁ is applied is attached to the downstream side of the conductive sheet 100. A scraper 152 that adheres to the collecting roll 150 and scrapes off residual toner is fixed.

  Further, a brush roll 86 is disposed on the downstream side of the collection roll 150 and scrapes off residual toner that has not adhered to the collection roll 150. The brush roll 86 is made of a brush such as acrylic that has been subjected to a conductive treatment.

  Further, it has a rotation support shaft 89 and swings about the rotation support shaft 89 as an axis. While the intermediate transfer belt 64 conveys the toner image, the collecting roll 150 and the brush roll 86 are separated from the intermediate transfer belt 64, and these are integrated with the intermediate transfer belt 64 at a predetermined timing. Touch.

  As shown in FIG. 1, a fixing device 90 is disposed above the secondary transfer position. The fixing device 90 includes a heating roll 92 and a pressure roll 94, and fixes the toner image secondarily transferred to the recording paper P by the secondary transfer roll 80 and the secondary transfer backup roll 72 to the recording paper P. It is conveyed toward the discharge roll 34. The discharge roll 34 discharges the recording paper P from the discharge port 30 to a discharge unit 36 provided at the upper part of the opening / closing cover 16.

  On the front side (left side in FIG. 1) of the rotary developing device 38, a control unit 39 that controls each unit constituting the color printer 10 is provided.

  Above the paper supply unit 18, a power supply unit 37 that applies a bias voltage to the developing rolls 46 a to 46 d, the charging device 52, the primary transfer roll 66, the secondary transfer roll 80, the collection roll 150, and the conductive sheet 100. Is provided. The power supply unit 37 is controlled by the control unit 39.

  The intermediate transfer device 62, the photosensitive drum 50, the charging roll 52, the photosensitive drum cleaner 54, and the intermediate transfer belt cleaner 82 are integrated to form an image forming unit 96.

  The image forming unit 96 is detachable from the color printer main body 12 and is attached to and detached from the color printer main body 12 by opening the opening / closing cover 16 as shown in FIG. Therefore, since the respective components of the image forming unit 96 can be exchanged at once, maintenance is easy.

  When the image forming unit 96 is mounted on the color printer main body 12, the contact portion (not shown) of the above-described contact member 200 contacts and is electrically connected to the contact fitting (not shown) of the color printer main body 12.

  Next, an outline of an image forming method on the recording paper P will be described.

  When the image forming signal is sent, the photosensitive drum 50 is uniformly charged by the charging roll 52, and a light beam is emitted from the exposure device 60 to the charged photosensitive drum 50 based on the image signal. The light beam from the exposure device 60 exposes the surface of the photosensitive drum 50 to form a latent image. The latent image on the photosensitive drum 50 formed by the exposure device 60 is developed with yellow, magenta, cyan, and black toner images by the rotary developing device 38, and is primarily transferred onto the intermediate transfer belt 64.

  In the primary transfer, residual toner remaining on the photosensitive drum 50 is scraped off by the cleaning blade 56 and collected in the toner collection case 58.

  On the other hand, the recording paper P stored in the paper feed cassette 22 by a paper feed signal or the like is sent out by the feed roll 24, turned by the retard roll 26, led to the transport path 28, and temporarily stopped by the registration roll 32, It is conveyed toward the guide member 29 with timing. When the recording sheet P is guided to the secondary transfer position A, the toner image primarily transferred to the intermediate transfer belt 64 is secondarily transferred to the recording sheet P by the secondary transfer roll 80 and the secondary transfer backup roll 72. The The residual toner remaining on the intermediate transfer belt 64 after the secondary transfer is collected by the intermediate transfer belt cleaner 82.

Specifically, the first recovery bias V ₁ is applied from the power supply unit 37 to the conductive sheet 100 via the contact fitting (not shown) and the contact member 200. When the residual toner passes through the conductive sheet 100, the residual toner is in contact with the conductive sheet 100 is charged by the first retrieving bias V _1. The charged residual toner is sent to the collecting roll 150. A second collection bias V ₂ having a polarity opposite to that of the first collection bias V ₁ is applied to the collection roll 150, and the residual toner is electrically attached to and removed from the collection roll 150 while rotating by a driving mechanism (not shown). Residual toner adhering to the collection roll 150 is scraped off by the scraper 152 and collected in the toner collection case 88. Further, the residual toner that has not adhered to the collection roll 150 is scraped by the brush roll 86 and collected in the toner collection case 88.

  On the other hand, the recording paper P onto which the toner image has been transferred is guided to the fixing device 90, and the toner image is fixed by the thermal pressure of the heating roll 92 and the pressure roll 94. The recording paper P on which the toner image is fixed is discharged from the discharge port 30 to the discharge unit 36 by the discharge roll 34.

  Next, the conductive mechanism 99 of the conductive sheet will be described in detail.

  As shown in FIGS. 4 to 6, the conductive sheet 100 and the contact member 200 are attached and fixed to the toner recovery case 88, and the mechanism portion that electrically connects the conductive sheet 100 and the contact member 200 is electrically conductive. Conductive sheet 97.

  As the conductive sheet 100, the resistance is adjusted by, for example, carbon, an ionic conductive agent, etc., for example, urethane, silicon polyester, polyamide, polyethylene, polycarbonate, polyolefin, polyurethane, polyvinylidene fluoride, polyimide, PEN, Silicon rubber, EPDM, ethylene propylene with adjusted resistance by mixing resin such as PEK, PES, PPS, PFA, PVdF, ETFE, CTFE, or conductive powder such as carbon black, metal powder, metal oxide, etc. Synthetic rubber such as rubber, butyl rubber, acrylic rubber, urethane rubber and nitrile rubber, or polar rubber such as epichlorohydrin rubber, chloroprene rubber and EPDM rubber can be used. (However, since polar rubber and the like have high adhesion, it may be necessary to devise techniques such as coating the surface with a low adhesion material). Alternatively, a woven fabric woven with conductive fibers may be used.

  As shown in FIG. 4, the conductive sheet 100 includes a contact surface 102 on the intermediate transfer belt 64 (see FIG. 3) side and a conductive surface 104 that extends from the contact surface 102 in a direction perpendicular to the contact surface 102. Yes. The upper surface 102 </ b> A of the contact surface 102 is attached to the first side surface 300 of the toner recovery case 88 with a double-sided tape. However, the lower surface 102B is not attached and is not in contact with the toner recovery case 88. The lower surface 102B comes into contact with the intermediate transfer belt 64. The conductive surface 104 is affixed to the contact surface 304 of the upper surface 302 of the toner recovery case 88 with double-sided tape.

  As shown in FIGS. 5 and 6, a contact member 200 made of a metal plate 500 having a spring property (see FIG. 9) is attached to the toner recovery case 88.

  The contact member 200 includes a plate spring surface 202, a fixed surface 208 extending from the plate spring surface 202 in a right angle direction, and a power feeding surface 210 extending from the fixed surface 208.

  The leaf spring surface 202 includes a pressing portion 204 that presses the conductive surface 104 of the conductive sheet 100 with the contact surface 104 interposed therebetween. The front end side of the presser portion 204 is divided into two forks, and a bent portion 204 </ b> A whose tip is bent into a V shape is formed, and this bent portion 204 </ b> A presses the conductive surface 104 of the conductive sheet 100. (Conductive surface 104 is sandwiched between bent portion 204A and contact portion surface 304). Therefore, the contact pressure for pressing the conduction surface 104 is high.

  A contact piece 206 extends from the side of the holding portion 204 opposite to the bent portion 204A. An engagement hole 218 is formed in the fixed surface 208 below the presser portion 204.

  Two fixed pieces 212 are formed at one end of the fixed surface 208. A fitting hole 214 is formed at the other end on the power feeding surface 210 side.

  Although not shown, the power supply surface 210 is bent along the inner wall of the toner collection case 88, the tip portion extends to the outside of the toner collection case 88, and a contact portion (not shown) is provided at the tip portion. Is formed. When the image forming unit 96 is mounted on the color printer main body 12, the contact portion comes into contact with a contact fitting (not shown) of the color printer main body 12.

  In addition, a plurality of fixing pins project from the inner wall of the toner recovery case 88 so that the power supply surface 210 does not come off the toner recovery case 88 even when the power supply surface 210 is turned around, and the power supply surface 210 engages with the fixing pins. A fixing hole is formed. 5 and 6 illustrate a fixing pin 314 and a fixing hole 216 as an example.

  The toner recovery case 88 forms the first side surface 300, the second side surface 308, and the upper surface 302 described above, and the first side surface 300 and the second side surface 308 are parallel to each other with the upper surface 302 interposed therebetween, and the first side surface. 300 and the second side surface 308 are perpendicular to the upper surface 302. Two ribs 306 and 307 are formed on the upper surface 302, and a contact portion surface 304 is formed between the ribs 306 and 307.

  As shown in FIG. 4, an upper surface 102 </ b> A of the contact surface 102 of the conductive sheet 100 is attached to the first side surface 300. The first side surface 300 protrudes to the transfer belt 64 side (right side in FIG. 4).

  As shown in FIGS. 5 and 6, the second side surface 308 is engaged with the engagement pin 310 that is sandwiched and engaged with the fixing piece 212 formed on the fixing surface 208 of the contact member 200, and the engagement hole 214. The fitting pin 312 to project is projected.

  In addition, a rib 318 that is connected to the rib 306 and is erected on the side is formed on the upper portion of the second side surface 308. The upper side 208A of the fixed surface 208 is in contact with the lower surface 318A of the rib 318. (See FIG. 8).

  A protruding portion 316 protrudes obliquely upward from a corner portion between the contact surface 304 and the second side surface 308 of the upper surface 302, and an engagement hole 218 is engaged with the protruding portion 316.

  Further, a tapered surface 316A is formed on the contact portion surface 304 side of the protruding portion 316. The tapered surface 316A is lowered from the second side surface 308 side toward the first side surface 300 side. Then, the end portion of the contact piece 206 of the leaf spring surface 202 of the contact member 200 is brought into contact with the tapered surface 316A and pushed up, and the bent portion 204A of the holding portion 204 of the contact member 200 presses the conductive surface 104. It bends in the direction (direction pressed against the contact surface 304).

  Next, a method for attaching the contact member 200 to the toner recovery case 88 will be described.

  As shown in FIGS. 6 and 7A, after attaching the conductive sheet 100 to the toner recovery case 88 with double-sided tape (not shown), the contact member 200 is connected to the contact surface 304 of the toner recovery case 88. Install by pushing in parallel (arrow S direction).

  As shown in FIGS. 7B and 7C, after the pressing portion 204 of the contact member 200 comes into contact with the upper end portion 316B of the projecting portion 316, when the pressing portion 204 is further pressed, the tip end portion of the pressing portion 204 moves upward. Turn to. Further pushing, as shown in FIG. 7D, when the upper end 316B of the protrusion 316 is climbed, the end of the contact piece 206 comes into contact with the tapered surface 316A and is pushed up, and the presser 204 of the contact member 200 is folded. The bent portion 204A is bent in a direction in which the conductive surface 104 is pressed (a direction in which the conductive portion 104A is pressed against the contact portion surface 304).

  As described above, the contact member 200 and the conductive sheet 100 are electrically connected only by being pushed in parallel to the contact portion surface 304 of the toner recovery case 88, and the contact member 200 is fixed to the toner recovery case 88. Also, it cannot be taken easily. Therefore, it is not necessary to fix and fix with a screw separately after attachment, for example. Therefore, work efficiency is good. Moreover, since the number of parts is small, the cost is low.

  Furthermore, when attaching, as shown in FIG.7 (c), the front-end | tip part of the holding | suppressing part 204 deform | transforms upwards, ie, the direction away from the conduction surface 104 of the electroconductive sheet 100. FIG. Therefore, even if the toner collecting case 88 is pushed in parallel to the contact surface 304 and attached, the presser 204 does not rub the conductive surface 104 of the conductive sheet 100 to peel off or damage the conductive surface 104.

  Further, as shown in FIGS. 4 to 6, the contact surface 102 where the conductive sheet 100 contacts the intermediate transfer belt 64 and the conductive surface 104 attached to contact with the toner recovery case 88 are different planes. Yes. That is, the intermediate transfer belt 64 and the pressing portion 202 are different planes. Accordingly, the intermediate transfer belt 64 and the contact member 200 do not interfere with each other. Therefore, for example, the conductive sheet 100 having a width wider than the contact width with the intermediate transfer belt 64 does not need to be configured so as not to interfere with each other, which saves space.

  Further, as shown in FIG. 8, after the mounting, the engaging pin 310 is sandwiched and engaged with the fixing piece 212, the engaging pin 312 is engaged with the engaging hole 214, and the lower surface 318A of the rib 318 is fixed to the fixing surface 208. By contacting the upper side 208A, the contact member 200 is more securely fixed to the toner recovery case 88.

  Specifically, since the engagement pin 310 is sandwiched and engaged with the fixed piece 212, the withdrawal in the opposite direction (the front side in FIG. 8) from the pushed-in direction (arrow S direction) is further prevented. . Note that the slipping in this direction is prevented by the contact piece 206 coming into contact with the tapered surface 316A, but can be more reliably prevented by sandwiching the engagement pin 310 with the fixed piece 212. Further, the fitting pin 312 is fitted into the fitting hole 214, so that the vertical and horizontal movement is prevented. Further, the upper side 208 </ b> A of the fixing surface 208 is in contact with the lower surface 318 </ b> A of the rib 318, thereby preventing the fitting pin 312 from rotating.

  Next, a method for forming the contact member 200 will be described.

  As shown in FIGS. 9 (a) and 9 (b), with respect to one sheet metal 500 (for example, SUS) having a spring property, a mold corresponding to the shape of the contact member 200 (broken line in FIG. 9 (a)). , Die-molding. The two fixed pieces 212 are formed by opening an H-shaped hole 504. Further, by opening the U-shaped hole 502, the portion left in the hole 502 becomes the contact piece 206. Further, the mold release direction is extracted in a direction in which burrs are generated from the upper side to the lower side in FIG.

  The contact point member 200 is formed as shown in FIG. 9C by bending the broken line portion shown in FIG. 9B at a right angle and slightly bending the fixed piece 212. The bending position (broken line 510) for forming the contact piece 206 needs to be a position away from the back end 206A of the hole 502. Further, the portion of the contact piece 206 and the hole 502 become the engagement hole 218.

  Then, as shown in FIG. 9C, after forming, annealing (annealing) is performed to remove residual stress.

  Note that although the burrs are generated from the upper side to the lower side in FIG. 9, the deburring process is not performed. For this reason, when the contact member 200 is attached to the toner recovery case 88, a burr appears in the direction of the arrow V shown in FIG. Therefore, when the contact member 200 is attached to the toner recovery case 88, the burr coming from the end of the contact piece 206 is caught on the tapered surface 316A, and the burr coming from the fixed surface 208 is caught on the second side surface 308. Securely fixed.

  Thus, the deburring process is unnecessary and the working efficiency is good. Furthermore, the contact member 200 is securely fixed by the toner recovery case 88 using this burr.

  The present invention is not limited to the above embodiment.

  For example, in the above embodiment, as shown in FIG. 8, after the mounting, (1) the engaging pin 310 is sandwiched and engaged with the fixing piece 212, (2) the fitting pin 312 is fitted into the fitting hole 214, 3) Since the upper side 208A of the fixing surface 208 contacts the lower surface 318A of the rib 318, the contact member 200 is more securely fixed to the toner recovery case 88, but the present invention is not limited to this. Of these, only one or two may be provided. Alternatively, either may be omitted.

  Alternatively, as shown in FIG. 10, the protrusions 416 and the engagement holes 418 have substantially the same size, and the protrusions 416 and the engagement holes 418 are tightly engaged so that the protrusions 416 and the engagement holes 418 can be fixed more reliably. Anyway. In addition, this structure can control both the right-and-left up-and-down movement and rotation of (2) and (3) mentioned above by one.

  For example, the contact member 200 may not have a complicated shape as in the above embodiment. As an example of a simple configuration, as shown in FIG. 11, a U-shaped hole 600 may be formed in a sheet metal and bent. Alternatively, as shown in FIG. 12, a notch 700 may be used instead of a hole.

  Further, for example, the contact surface 102 and the conductive surface 104 of the conductive sheet 100 are at right angles, but the present invention is not limited to this. For example, as shown in FIG. 13, the contact surface 102 and the conduction surface 104 may be on the same plane. In FIG. 13, the right side of the figure is the downward direction and the left side is the upward direction.

  For example, in the above embodiment, the intermediate transfer belt cleaner 82 has been described as an example, but the present invention is not limited to this. For example, the cleaning method of the same configuration may be applied to the photosensitive drum cleaner 54, and the conductive mechanism of the conductive sheet of the present invention may be applied. Alternatively, the present invention may be applied to a charging mechanism in which a conductive sheet is brought into contact with the image carrier and charged. Or you may apply to the static elimination mechanism which earth | grounds a contact member and neutralizes an image carrier. Alternatively, the present invention may be applied to other than the image forming apparatus.

It is sectional drawing which shows typically the inside of the color printer to which the conduction | electrical_connection mechanism of the electroconductive sheet which concerns on embodiment of this invention is applied. FIG. 2 is a cross-sectional view schematically showing how an image forming unit is attached to and detached from a color printer main body. It is sectional drawing of the cleaner for intermediate transfer belts which applied the conduction | electrical_connection mechanism of the electroconductive sheet which concerns on embodiment of this invention. It is a perspective view which shows the principal part of the cleaner for intermediate transfer belts to which the conduction mechanism of the electroconductive sheet which concerns on embodiment of this invention is applied. It is a perspective view which shows the principal part of the cleaner for intermediate transfer belts to which the conduction mechanism of the electroconductive sheet which concerns on embodiment of this invention is applied. FIG. 6 is a perspective view showing a state before a contact member is attached to a toner recovery case. It is a figure which shows the process which attaches a contact member to a toner collection | recovery case in order from (a) to (d). It is a figure which shows the principal part of the cleaner for intermediate transfer belts which applied the conduction mechanism of the electroconductive sheet which concerns on embodiment of this invention. It is a figure which shows the formation process of a contact member in order from (a) to (c). It is a figure which shows the contact member and protrusion part of the conduction | electrical_connection mechanism of the electroconductive sheet which concern on other embodiment of this invention. It is a figure which shows the contact member of the conduction mechanism of the electroconductive sheet which concerns on other embodiment of this invention. It is a figure which shows the contact member of the conduction mechanism of the electroconductive sheet which concerns on other embodiment of this invention. It is a perspective view which shows the conduction mechanism of the electroconductive sheet which concerns on other embodiment of this invention.

Explanation of symbols

10 Color printer (image forming device)
12 Color printer body (image forming device body)
64 Intermediate transfer belt (image carrier)
88 Toner Collection Case (Case)
99 Conductive mechanism of conductive sheet 100 Conductive sheet 102 Contact surface 104 Conductive surface (conductive portion surface)
150 Collection roll (collection means)
152 Scraper (recovery means)
200 Contact member (conductive member)
202 Leaf spring surface (leaf spring part)
204 Pressing part 204A Bending part 206 Abutting piece 208 Fixing surface (fixing part)
208A Upper side (side)
214 Fitting hole 218 Engaging hole 304 Contact surface (first surface)
308 Second side (second side)
312 mating pin (first protrusion)
316 Protrusion (second protrusion)
316A Tapered surface 316B Upper end (end)
318 rib (third protrusion)
502 hole (U-shaped hole)
600 holes (U-shaped holes)
700 notches
P Recording paper (transfer medium)
V ₁ first recovery bias (charging bias)
V ₂ second recovery bias (recovery bias)

Claims (12)

A housing,
A conductive sheet attached to the first surface of the housing and in contact with the object to be contacted;
A conductive member attached to the housing and electrically connected to the conductive sheet;
A conductive mechanism for a conductive sheet comprising:
The conductive member is
A fixing portion that contacts a second surface substantially perpendicular to the first surface of the housing;
A leaf spring portion extending in a substantially right angle direction from the fixed portion, and sandwiching the conductive sheet between the first surface by a spring force ;
With
The leaf spring part is
A presser part for pressing the conductive sheet;
A contact piece extending from the presser part to the side opposite to the tip end side of the presser part;
Comprising a flat plate having
In the state where the conductive member is attached to the housing, the pressing portion is configured to press the conductive sheet by being pushed up and bent.
Conducting mechanism of the conductive sheet, characterized in that. The conductive sheet is
A contact surface that contacts the object to be contacted;
A conductive portion surface extending from the contact surface, attached to the first surface of the housing, and sandwiched between the first surface and the leaf spring portion;
The conductive mechanism for a conductive sheet according to claim 1, comprising: 3. The conductive mechanism according to claim 1 , wherein the contact piece is pressed and bent by contacting a tapered surface formed on the first surface. 4.   The conductive mechanism for a conductive sheet according to claim 3, wherein a bent portion bent into a V shape is formed at a tip portion of the presser portion. When the leaf spring part is pushed in parallel to the first surface,
The pressing portion hits an end of the tapered surface and is deformed in a direction away from the first surface.When the pressing portion gets over the end, the contact piece comes into contact with the tapered surface and bends. The conductive mechanism for a conductive sheet according to claim 3 or 4, wherein the conductive sheet is pressed. A first protrusion projecting from the second surface is formed on the housing,
The conductive mechanism for a conductive sheet according to claim 1, wherein a fitting hole for fitting with the first protrusion is formed in the fixing portion. The casing is provided with a second protrusion that protrudes from a corner formed by the first surface and the second surface, and is formed with the tapered surface.
The coupling portion between the pressing portion and the fixed portion, according to any one of claims 1 to 6, characterized in that the engagement hole for engaging the second projection is formed Conductive mechanism of the conductive sheet. The housing is formed with a third protrusion protruding from the second surface,
8. The conductive mechanism for a conductive sheet according to claim 1, wherein a side of the fixed portion is in contact with the third protrusion. 9. The conductive member is formed of sheet metal,
The U-shaped hole in the sheet metal, or the part left behind by cutting becomes the contact piece,
The same surface as the contact piece becomes the presser part,
The conductive mechanism for a conductive sheet according to claim 1, wherein a portion surrounding the contact piece is bent at a substantially right angle to form the fixed portion. The conductive member is formed by punching a sheet metal,
Burrs generated by the die-cut is conducting conductive sheet according to any one of claims 1 to 9, characterized in that the contact piece is projecting to the tapered surface and the side contacting mechanism. A conductive mechanism for a conductive sheet according to any one of claims 1 to 10,
The image forming apparatus according to claim 1, wherein the contacted object is an image carrier on which a toner image is formed. The image carrier rotates;
Supplying the conductive member with a charging bias for charging residual toner remaining after transferring the toner image of the image carrier to a transfer medium;
And a recovery unit that is disposed downstream of a contact portion between the conductive sheet and the image carrier and applies a recovery bias having a polarity opposite to the charging bias to recover the residual toner. Item 12. The image forming apparatus according to Item 11.

Images