JP2006350119A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which damage to a paper conveyance belt 101, caused by rocking of rock brackets during transport, is made less likely to occur compared to a conventional image forming apparatus. <P>SOLUTION: A transfer unit 100 is designed such that the rock brackets 113 supporting both ends of each of a plurality of rollers in the direction of the width of the belt are rocked around rock shafts, not shown, thereby separating the surface of the paper conveyance belt 101 from part of a photoreceptor, and fixing pins 212 capable of being engaged with a second support 150 rockably supporting the rock brackets 113 around the rock shafts at both the ends in the direction of the width of the belt are made into engagement, thereby preventing rocking of the rock brackets, caused by vibrations during transport. In the transfer unit 100, the fixing pin 212 is engaged with both ends of the second support 150 in the direction of the width of the belt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile as follows. That is, the first support that supports the plurality of stretching members that stretch the belt member at both ends in the belt width direction swings around the swinging shaft, so that the surface of the belt member has a plurality of surfaces. The image forming apparatus is configured to come in contact with and separate from the image carrier.

  Conventionally, a multicolor toner image is formed by forming monochromatic toner images of different colors on a plurality of photoconductors as image carriers and superposing them on the surface of a belt member that moves endlessly or on a transfer paper held by the belt member. An image forming apparatus for obtaining the above is known. In this type of image forming apparatus, when only the black toner image is formed in the monochrome mode, the toner image is formed only on the black photoconductor corresponding to the black toner image among the plurality of photoconductors. For this reason, it is not necessary to drive other photoconductors (hereinafter referred to as color photoconductors). Nevertheless, when the color photoconductor is also driven while being in contact with the belt member, the color photoconductor is worn out in vain.

  Therefore, by swinging the first support that supports the plurality of stretching rollers as the stretching members, the surface of the belt member stretched by these stretching rollers can be brought into contact with and separated from the color photoconductor as necessary. There is known an image forming apparatus configured to do this (for example, one described in Patent Document 1). According to this image forming apparatus, in the monochrome mode, the belt member can be separated from the color photoconductor to avoid unnecessary wear of the color photoconductor.

  However, in such a configuration, during transportation from the factory to the end user, the first support may swing due to vibration, and the belt member may repeatedly hit the color photoconductor and be damaged.

  Therefore, the present applicant connects and fixes the above-mentioned first support body in a swingable manner around the swing shaft and the first support body by means of a pin so that the first support body is being transported. Measures were taken to prevent the first support from swinging.

JP 2001-242680 A

  However, even if such a measure is taken, there may be a case where a scratch that seems to be in contact with the color photoconductor may occur at one end in the width direction of the belt member during transportation. In particular, from the viewpoint of facilitating the recycling of resources, in recent years when a folding type made of a resin material has been frequently used as a fixing packing for fixing an image forming apparatus in a packing box. Many scratches have been seen.

  Then, when this inventor earnestly researched about the cause which such a damage | wound generate | occur | produces, the following things have become clear. That is, in the related art, a pin is attached only to one end of the above-mentioned first support that supports a plurality of stretching rollers at both ends, and the first support is fixed to the second support. It was. The second support supports the both ends of the first support so as to be swingable, but the fixing as described above can almost completely prevent the swing of the one end of the first support, The swinging of the other end cannot be sufficiently prevented. Therefore, depending on the strength of the impact applied to the image forming apparatus, the other end of the first support is forcibly swung, and the one end in the width direction on the surface of the belt member is brought into contact with the color photoconductor. End up. The above-described foldable fixing packing has a low buffering action compared to a cushioning material made of foamed polystyrene, etc., which has been used for a long time. Therefore, even a relatively weak vibration generated during transportation gives a strong impact to the image forming apparatus. . As a result, the other end of the first support was forcibly swung.

  The present invention has been made in view of the above background, and an object of the present invention is to suppress damage to the belt member caused by rocking the first support during transportation compared to the conventional art. An image forming apparatus is provided.

In order to achieve the above object, the invention of claim 1 is characterized in that a plurality of image carriers carrying a plurality of image carriers carrying a toner image and a surface of an endless belt member stretched by a plurality of stretch members. The toner image on each image carrier is transferred onto the surface of the belt member or the transfer sheet held on the belt member while moving endlessly so as to sequentially enter the contact position with the body. A first support that includes a transfer means and supports each of the plurality of stretching members at both ends in the belt width direction, by swinging the first support around the swing shaft so that the entire surface of the belt member is Or a second support that is brought into contact with or separated from a part of the image carrier and supports the first support so as to be swingable around the swing axis at both ends in the belt width direction, and Engageable with at least one of the first supports In the image forming apparatus in which the transfer unit is configured to prevent the swinging of the first support body due to vibration during transportation by engaging a joint member, the engagement member is connected to the second support body. And at least one of the first supports is engaged with both ends in the belt width direction.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the first engaging member engages with one end in the belt width direction of at least one of the second support and the first support as the engagement member. Two of the engaging member and the second engaging member that engages with the other end in the belt width direction of at least one of the second support and the first support are used. .
According to a third aspect of the present invention, in the image forming apparatus of the first aspect, the engagement member is a rod-like member longer than the width of the belt member, and one end of the second support in the belt width direction. And the other end of the second support in the belt width direction are each provided with a through hole, and the rod-like engaging member is sequentially passed through these through holes, whereby the first support and the second support are provided. The engagement members are respectively engaged with at least both ends of the second support member in the belt width direction.
According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect, the rod-shaped engaging member is passed through the loop of the belt member.
According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, the tip of the rod-shaped engaging member is tapered.
According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect of the present invention, the tip of the rod-shaped engaging member is cut obliquely from one end side to the other end side in the diameter direction. To do.
According to a seventh aspect of the present invention, in the image forming apparatus according to any one of the third to sixth aspects, the rod-shaped engaging member that is passed through a through hole provided in one end of the second support in the belt width direction. The transfer means is provided with a guide member that guides the leading end portion thereof toward a through hole provided at the other end portion in the belt width direction of the second support.

  In these inventions, the engagement member prevents the swinging of the first support member, which supports the plurality of stretching members at both ends in the belt width direction, at both ends in the belt width direction. This avoids a situation in which the swinging of one end of the both ends of the first support in the belt width direction is not sufficiently prevented, and the belt is caused by swinging the first support during transportation. The damage of a member can be suppressed more than before.

Hereinafter, a tandem color laser printer (hereinafter referred to as “printer”) will be described as an embodiment of an image forming apparatus to which the present invention is applied.
First, the basic configuration of the printer will be described. FIG. 1 is a schematic configuration diagram illustrating a printer according to the present embodiment. This printer includes four sets of toner image forming portions 1Y, 1M, 1C, and 1K for forming images of respective colors of yellow (Y), magenta (M), cyan (C), and black (K). . Also provided are an optical writing unit 2, paper feed cassettes 3, 4, registration roller pair 5, transfer unit 100, belt fixing type fixing unit 8, paper discharge tray 9, and the like. Further, a manual feed tray, a toner supply container, a waste toner bottle, a power supply unit, and the like (not shown) are also provided. Hereinafter, the subscripts Y, M, C, and K of the respective symbols indicate members for yellow, magenta, cyan, and black, respectively.

  The toner image forming portions 1Y, 1M, 1C, and 1K have a drum-shaped photosensitive member 11Y, 11M, 11C, and 11K that is a latent image carrier that carries a latent image and that is an image carrier that carries a toner image. is doing. These photoreceptors 11Y, 11M, 11C, and 11K are driven to rotate clockwise in the figure by driving means (not shown).

  An optical writing unit 6 is disposed above the four toner image forming units 1Y, 1M, 1C, and 1K. The optical writing unit 6 emits four laser beams L modulated based on image information sent from a personal computer (not shown) or the like, and reflects the laser beams L by the polygon mirrors that rotate. This reflection irradiates each color photoconductor 11Y, M, C, K while deflecting each laser beam L in the main scanning direction which is the axial direction of the photoconductor. As a result, the photoconductors 11Y, 11M, 11C, and 11K of the respective colors are optically scanned in the dark and carry electrostatic latent images for Y, M, C, and K.

  FIG. 2 is an enlarged configuration diagram showing the toner image forming unit 1Y for Y of the four toner image forming units 1Y, 1M, 1C, and 1K together with a part of the transfer unit 100 serving as transfer means. The other toner image forming units (1M, C, K) have the same configuration as that for Y except that the colors of the toners to be used are different from each other. .

  In FIG. 1, a Y toner image forming unit 1Y includes a process unit 10Y and a developing device 20Y. In addition to the photoreceptor 11Y, the process unit 10Y includes a brush roller 12Y for applying a lubricant, a swingable counter blade 13Y for performing a cleaning process, a charge removal lamp 14Y for performing a charge removal process, and the like. Yes. Further, a charging roller 15Y for uniformly charging the photoconductor 11Y and a roller cleaning device 16Y for cleaning the surface of the charging roller 15Y are also provided.

  In the process unit 10Y, a charging roller 15Y to which an AC charging bias is applied by a power source (not shown) is disposed so as to contact the photoreceptor 11Y. Then, the surface of the photoconductor 11Y is uniformly charged while being rotated by the driving means (not shown) so that the surface thereof is moved in the direction opposite to the surface movement of the photoconductor 11Y. When the surface of the photoreceptor 11Y thus uniformly charged is scanned with the laser light L modulated and deflected by the optical writing unit (6 in FIG. 1), an electrostatic latent image is formed on the surface. It is formed.

  The developing device 20Y has a developing roll 22Y disposed so as to partially expose the opening of the developing case 21Y. Further, it also includes a first transport screw 23Y, a second transport screw 24Y, a developing doctor 25Y, a toner concentration sensor (hereinafter referred to as T sensor) 26Y, a powder pump 27Y, and the like.

  The developer case 21Y contains a developer containing a magnetic carrier and a negatively chargeable Y toner. The developer is frictionally charged while being agitated and conveyed by the first conveying screw 23Y and the second conveying screw 24Y, and is then carried on the surface of the developing roll 22Y as a developer carrying member. Then, after the layer thickness is regulated by the developing doctor 25Y, the layer is conveyed to a developing area facing the photoconductor 11Y, where Y toner is attached to the electrostatic latent image on the photoconductor 11Y. This adhesion forms a Y toner image on the photoreceptor 11Y. The developer that has consumed Y toner by development is returned to the developing case 21Y as the surface of the developing roll 22Y (developing sleeve) rotates. On the other hand, the developed Y toner image is transferred to a transfer paper P that is conveyed by a paper conveyance belt 101 described later. The developing roll 22Y includes a developing sleeve made of a non-magnetic pipe that is rotationally driven by a driving unit (not shown), and a magnet roller (not shown) that is included so as not to rotate. The developer is attracted and carried on the surface of the developing sleeve by the magnetic force generated by the magnet roller.

  The T sensor 26Y composed of a magnetic permeability sensor is attached to the bottom plate of the developing case 21Y, and outputs a voltage having a value corresponding to the magnetic permeability of the developer conveyed by the first conveying screw 23Y. Since the magnetic permeability of the developer shows a good correlation with the toner concentration of the developer, the T sensor 26Y outputs a voltage corresponding to the Y toner concentration. This output voltage value is sent to a control unit (not shown). This control unit includes storage means such as an RMA, in which the V Vref for Y, which is the target value of the output voltage from the T sensor 26Y, and the output voltage from the T sensor mounted in another developing device. Data on Vtref for M, C, and K, which are target values, is stored. For the developing device 20Y, the value of the output voltage from the T sensor 26Y is compared with the V Vref for Y, and the powder pump 27Y connected to a Y toner cartridge (not shown) is driven for a time corresponding to the comparison result. As a result, the Y toner in the Y toner cartridge is supplied into the developing device 20Y. By controlling the driving of the powder pump 27Y (toner replenishment control) in this way, an appropriate amount of Y toner is replenished to the developer whose Y toner density has decreased with development, and development in the developing device 20Y is performed. The Y toner concentration of the agent is maintained within a predetermined range. Similar toner replenishment control is performed for other developing devices.

  As described above, the toner image forming portions 1Y, 1M, 1C, and 1K shown in FIG. 1 are visible to the photoconductors 11Y, 11M, 1C, and 1K in cooperation with the optical writing unit 2. A toner image as an image is formed. Therefore, in this printer, a toner image is formed on the surface of the photoreceptors 11Y, 11M, 11C, and 11K that moves endlessly by the combination of the toner image forming units 1Y, 1M, 1C, and 1K and the optical writing unit 2. Function as image forming means.

  Two paper feed cassettes 3 and 4 are disposed at the bottom of the printer body. These paper feed cassettes 3 and 4 accommodate a plurality of transfer papers P in a stack of transfer papers, and press the paper feed rollers 3a and 4a against the uppermost transfer paper P. Then, the sheet feeding rollers 3a and 4a are rotated at a predetermined timing to send the transfer sheet P to the sheet feeding path. A registration roller pair 5 is disposed at the end of the paper feed path, and the transferred transfer paper P is synchronized with the Y toner image formed on the photoreceptor 11Y of the Y toner image forming unit 1Y. At the timing to obtain, it sends out toward the transfer unit 100 described later.

  FIG. 3 is an enlarged configuration diagram illustrating a main configuration of the transfer unit 100. In the figure, a transfer unit 100 includes a paper transport belt 101 as an endless belt member, an entrance roller 102, an electrostatic adsorption roller 103, four transfer bias rollers 104Y, 104M, 104C, 104K, four transport support rollers 105Y, M, C, K, separation roller 106 and the like are included. Further, it also includes a drive roller 107, a belt cleaning device 108, a pressing roller 109, a tension roller 110, a lower roller 111, an inlet bracket 112, a swing bracket 113, an outlet bracket 114, a cam 115, and the like.

  The paper transport belt 101 is an endless belt member made of PVDF (polyvinylidene fluoride) or the like. And it is made to endlessly move counterclockwise in the figure by the driving roller 107 which is driven to rotate counterclockwise in the figure by a driving means (not shown) while being stretched by a plurality of rollers.

  The entrance roller 102, the four transfer bias rollers 104Y, M, C, and K, the four transport support rollers 105Y, M, C, and K, the separation roller 106, the drive roller 107, the tension roller 110, and the lower roller 111 are all included. It is in contact with the back surface (loop inner surface) of the paper transport belt 101. Among these rollers, the rollers other than the four transfer bias rollers 104Y, 104M, 104C, 104K function as tension rollers that tension the belt while supporting the paper conveying belt 101 on the back surface. Of these stretching rollers, the entrance roller 102 disposed on the rightmost side in the drawing is configured to sandwich the paper transport belt 101 between the entrance roller 102 and the electrostatic adsorption roller 103 disposed in the vicinity thereof. . The electrostatic attraction roller 103 is applied with an electrostatic attraction bias, and the transfer sheet P fed from the above-described registration roller pair 5 by applying an electric charge to the belt front surface (loop outer surface). Is electrostatically adsorbed to the front surface of the belt.

  The four transfer bias rollers 104Y, 104M, 104C, and 104K are rollers in which a metal core is covered with an elastic body such as a sponge, and are pressed toward the photoreceptors 11Y, 11M, 11C, and 11K, respectively. The paper conveying belt 101 is sandwiched. By this pressing, transfer nips for Y, M, C, and K are formed in which the photoreceptors 11Y, M, C, and K and the paper transport belt 101 are in contact with each other with a predetermined length in the belt moving direction. Further, a transfer bias that is controlled at a constant current by a transfer bias power source is applied to the cores of the transfer bias rollers 104Y, 104M, 104C, and 104K. As a result, a transfer charge is applied to the back surface of the paper conveyance belt 101 via the transfer bias rollers 104Y, 104M, 104C, and 104K, and between the paper conveyance belt 101 and the photoconductors 11Y, 11M, 11C, and 11K at each transfer nip. A transfer electric field is formed. In this printer, the transfer bias rollers 104Y, 104M, 104C, and 104K are provided as transfer bias members. However, a brush, a blade, or the like may be provided instead of the rollers.

  Of the four transfer bias rollers 104Y, 104M, 104C, and 104K, three for Y, M, and C are supported by the swing bracket 113 via bearing members (not shown). The swing bracket 113 has two bracket side plates opposed to each other at a predetermined distance and a side plate coupling portion (not shown) that connects the bracket side plates, and the paper transport belt 101 is interposed between the two bracket side plates. It is located. And it is supported by the 2nd support body which is not illustrated so that rocking is possible centering on the rocking shaft 113c.

  Of the four transport support rollers 105Y, 105M, 105C, and 105K, three for Y, M, and C are also supported by the swing bracket 113. Below the swing bracket 113 in the figure, a cam 115 that is driven to rotate about a rotating shaft 115a by a driving means (not shown) is disposed. When this rotation is stopped at a position where the cam surface abuts against the swing bracket 113, the swing bracket 113 is rotated counterclockwise in the figure around the swing shaft 113c. Then, the paper transport belt 101 is pressed by the three transport support rollers 105Y, 105M, and 105C and comes into contact with the photoreceptors 11Y, 11M, and 11C. Thereby, transfer nips for Y, M, and C are formed. On the other hand, when the cam 115 is stopped at a position where the cam surface does not abut against the swing bracket 113, the swing bracket 113 is rotated clockwise around the swing shaft 113c. Then, the Y, M, and C transport support rollers 150Y, M, and C move to a position where the front surface of the paper transport belt 101 is not pressed against the photoreceptors 11Y, 11M, and 11C. The transfer nip for C is not formed. As described above, the transfer unit 100 forms the transfer nip for Y, M, and C by bringing the paper conveying belt 101 into contact with the photosensitive members 11Y, M, and C by the swing of the swing bracket 113 that is the first support. Or the paper conveying belt 101 is separated from the photoconductors 11Y, 11M, and 11C.

  The entrance roller 102, the electrostatic attraction roller 103, and the lower roller 111 are supported by the entrance bracket 112 via bearing members (not shown). The inlet bracket 112 is configured to be swingable about the axis of the lower roller 111. The aforementioned swing bracket 113 has a guide hole 113b in the vicinity of the left end in the figure, and a pin 112a extending from the inlet bracket 112 is movably positioned inside the guide hole 113b. When the cam 115 swings counterclockwise in the figure, the pin 112 in the guide hole 113b is pushed up. Then, the inlet bracket 112 is linked to the swing of the swing bracket 113 and is swung counterclockwise in the figure around the axis of the lower roller 111, and the entrance roller 102, the electrostatic adsorption roller 103, and The lower roller 111 is pushed up. Further, when the swinging bracket 113 is swung clockwise in the figure, the inlet bracket 112 is linked to it and swings clockwise in the figure, and the entrance roller 102, the electrostatic adsorption roller 103 and the lower roller 111 are moved. Move down. By the movement of the entrance roller 102, the electrostatic adsorption roller 103, and the lower roller 111 accompanying the swing of the swing bracket 113, the paper transport surface by the paper transport belt 101 is maintained in a straight line.

  In the monochrome mode in which only the black toner image is formed on the transfer paper P, the transfer unit 100 swings the swing bracket 113 clockwise in the drawing to move the paper transport belt 101 to the Y, M, and C photoconductors. 11Y, M, C. As a result, the K toner image can be transferred from the K photoconductor 11K onto the transfer paper without imposing an extra load on the paper transport belt 101 and its drive system.

  Of the four transfer bias rollers 104Y, 104M, 104C, and 104K, the K transfer bias roller 104K is supported by the outlet bracket 114 via a bearing member (not shown).

  When transferring a full-color image onto the transfer paper P, the transfer unit 100 brings the paper transport belt 101 into contact with all the photoreceptors 11Y, 11M, 11C, 11K, and transfer nips for Y, M, C, and K. Form. The transfer paper P sent out from the registration roller pair 5 is sandwiched between the electrostatic adsorption roller 103 and the paper transport belt 101. Then, the toner passes through the transfer nips for Y, M, C, and K sequentially while being attracted to the front surface of the paper transport belt 101. As a result, the Y, M, C, and K toner images on the photoconductors 11Y, 11M, 11C, and 11K are superimposed on the transfer paper P at the transfer nip, and the transfer paper is subjected to the effects of the transfer electric field and nip pressure. The image is superimposed on P and transferred. A full-color image is formed on the transfer paper P by this superposition transfer.

  The transfer paper P on which the full-color image is formed approaches the belt stretching position by the separation roller 106 as the paper conveying belt 101 moves endlessly. At this belt stretching position, the separation roller 106 stretches the paper transport belt 101 at a steep wrapping angle that substantially reverses the endless movement direction of the paper transport belt 101. The transfer paper P adsorbed on the paper transport belt 101 cannot follow such a sudden change in the moving direction of the belt and is separated from the paper transport belt 101. Then, it is delivered to the fixing unit (8 in FIG. 1).

  The tension roller 110 is biased toward the paper transport belt 101 by a spring, thereby applying a predetermined tension to the paper transport belt 101. The pressing roller 109 is pressed against the front surface of the belt extension portion between the tension roller 110 and the driving roller 67. By this pressing, the paper conveying belt 101 is greatly depressed and curved between the driving roller 67 and the tension roller 110 into the loop. Since the paper conveyance belt 101 is greatly curved in this way, a larger portion of the paper conveyance belt 101 around the drive roller 67 is secured. The belt cleaning device 108 is in contact with the front surface of the winding portion. On the front surface of the paper conveying belt 101 that has transferred the transfer paper P to the fixing unit at the position where the separation roller 106 is stretched, the dirt toner transferred from the photoreceptors 11Y, 11M, 11C, and 11K is transferred. It is attached. The belt cleaning device 108 is for removing the dirty toner from the paper transport belt 101.

  In FIG. 1 described above, the fixing unit 8 includes a pressure roller 8a, an endless fixing belt 8b, a heating roller 8c, a driving roller 8d, and the like. The fixing belt 8b is endlessly moved clockwise in the drawing by a driving roller 8d that is rotated by a driving unit (not shown) while being stretched by a heating roller 8c and a driving roller 8d. The heating roller 8c includes a heat source such as a halogen lamp, and thereby heats the paper transport belt 8b from the back surface. On the other hand, the pressure roller 8a is rotated so as to move the surface in the same manner as the belt at the contact portion while contacting the fixing belt 8b that is moved endlessly to form a fixing nip. The transfer paper P transferred from the paper conveying belt 101 of the transfer unit 100 to the fixing unit 8 is sandwiched between the fixing nips in such a posture that the image transfer surface is in contact with the fixing belt 8b. Then, it passes through the fixing unit 8 while the full color image is fixed on the image transfer surface by heating or pressing.

  The transfer paper P that has passed through the fixing unit 8 passes through a pair of conveyance rollers, a reversing guide plate, and the like, and is further discharged through a pair of conveyance rollers toward a stack portion provided on the upper surface of the printer housing.

  In FIG. 2 described above, the surface of the photoreceptor 11Y after passing through the transfer nip for Y is coated with a predetermined amount of lubricant by the brush roller 12Y and then cleaned by the counter blade 13Y. Then, the static electricity is removed by the light emitted from the static elimination lamp 14Y to prepare for the formation of the next electrostatic latent image.

  A small amount of toner that could not be completely removed remains on the surface of the photoreceptor 11Y cleaned by the counter blade 13Y. The cleaning residual toner remaining in this way is cleaned by the roller cleaning device 16Y.

Next, a characteristic configuration of the printer will be described.
FIG. 4 is a partial perspective view showing the front end of the printer. In the figure, a housing 201 is a resin case containing each device of the printer. An opening / closing door 201a is attached to an end portion on the front side of the housing 201 so as to be rotatable about a rotation axis, and the opening of the housing 201 is opened and closed by the rotation. When the opening / closing door 201a is opened and the opening of the housing 201 is wide open, the side surface on one end side in the belt width direction of the transfer unit 100 is exposed to the outside through the opening. The transfer unit 100 is held in the housing 201 so as to be slidable in the belt width direction. The operator can pull out the transfer unit 100 from the housing 201 by grasping and pulling the one side of the transfer unit 100 exposed to the outside through the opening. Hereinafter, in the transfer unit 100, the side exposed through the opening with the open / close door 201 a opened (one end side in the belt width direction) is referred to as the front side, and the opposite side (the other end side in the belt width direction) is referred to as the back side. Will be explained.

  FIG. 5 is a perspective view showing the transfer unit 100 in a state of being pulled out from the housing 201. The transfer unit 100 includes a second support 150 that connects a first support side plate 150a and a second support side plate 150b facing each other at a predetermined distance by a bottom plate or the like. Between the first support side plate 150a and the second support side plate 150b in the second support 150, the above-mentioned three brackets (112, 113, 114), the paper transport belt 101, and various rollers are held. In the swing bracket (113) described above, the first bracket side plate 113a on the front side, which is one end side in the belt width direction, is supported by the first support side plate 150a of the second support 150 so as to be swingable. . Further, the second bracket side plate 113b on the back side, which is the other end side in the belt width direction, is swingably supported by the second support side plate 150b of the second support 150. A through hole Sa is provided in the first support side plate 150 a of the second support 150. Further, the second support side plate 150b is provided with a through hole Sb.

  When the printer is shipped from the factory, as shown in FIG. 6, the first fixing pin 210 having a rod-like tip end is formed in the through hole (Sa) of the first support side plate 150 a of the second support 150. Inserted into. The rear end of the first fixing pin 210 is shaped to be folded back toward the front end side, and a claw is provided at the end. The claw is inserted into a claw receiving hole (not shown) of the first support side plate 150a and hooked on the inner surface of the side plate, thereby preventing the first fixing pin 210 from coming off from the through hole (Sa) of the first support side plate 150a. The first fixing pin 210 passed through the through hole (Sa) of the first support side plate 150a makes its tip end contact the upper end of the first bracket side plate 113a of the swing bracket. When the first bracket side plate 113a tries to swing, the upper end of the first bracket side plate 113a is caught by the first fixing pin 210. As a result, the swing of the swing bracket as the first support is prevented at one end side (front side).

  When the printer is shipped from the factory, as shown in FIG. 7, the second fixing pin 211 having a rod-like tip end is formed in the through hole (second support side plate 150 b of the second support 150). Inserted into Sb). The rear end of the second fixing pin 211 is also shaped to be folded back toward the front end side, and a claw is provided at the end. The claw is inserted into a claw receiving hole (not shown) of the second support side plate 150b and hooked on the inner surface of the side plate, thereby preventing the second fixing pin 211 from coming off from the through hole (Sb) of the second support side plate 150b. The second fixing pin 211 passed through the through hole (Sb) of the second support side plate 150b makes its tip end contact the upper end of the second bracket side plate 113b of the swing bracket. When the second bracket side plate 113b tries to swing, the upper end of the second bracket side plate 113b is caught by the second fixing pin 211. As a result, the swinging of the swinging bracket is prevented even at the other end (side).

  As described above, the printer includes the first fixing pin 210 as the first engaging member that can be engaged with the through hole Sa of the first supporting side plate 150a that is one end portion of the second supporting member 150 in the belt width direction, and the other. It has the 2nd fixing pin 211 which is a 2nd engaging member which can engage with the through-hole Sb of the 2nd support side plate 150b which is one end part. Then, by engaging these fixing pins with the first support side plate 150a and the second support side plate 150b, which are both ends of the second support 150, the swinging of the swinging bracket accompanying the vibration during transportation is reduced to the belt. Stop at both ends in the width direction.

  Prior to the initial operation of the printer, the end user opens the door 201a of the housing 201 to expose the front side surface of the transfer unit 100 as shown in FIG. Then, the first fixing pin 210 is pulled out from the first support side plate 150 a of the second support 150. At this time, by pinching and deforming the rear end side of the first fixing pin 210, the above-mentioned claw hooked on the inner surface of the first support side plate 150a is retracted from the inner surface, and the claw is pulled out from the claw receiving hole. When the first fixing pin 210 is pulled out in this way, the transfer unit 100 is pulled out from the housing 201. Then, the second fixing pin 211 is pulled out from the second support side plate 150 b of the second support 150. Thus, when the swing bracket of the transfer unit 100 can swing at both ends in the belt width direction, the transfer unit 100 is set in the housing 201 and the initial operation is performed.

  The example in which the fixing pin inserted into the through hole of the support side plate of the second support 150 is abutted against the upper end of the bracket side plate of the swing bracket to prevent the swing bracket from swinging will be described. It may be as follows. In other words, the fixing pins are sequentially inserted into the through holes provided in the support side plate of the second support and the through holes provided in the bracket side plate of the swing bracket.

Next, a modified apparatus of the printer according to the embodiment will be described.
FIG. 8 is a perspective view showing the transfer unit 100 in the modified apparatus. Also in this modified apparatus, a through hole is provided in the first support side plate 150 a of the second support 150. The second support side plate 150b of the second support 150 is also provided with a through hole. And the position of these through-holes is the position which mutually opposes linearly.

  In this modified apparatus, as the fixing pin 212 which is a rod-shaped engaging member, a pin longer than the width of the paper conveying belt 101 is used as shown in the figure. Then, the fixing pins 212 are sequentially passed through the two through holes described above from the front side of the transfer unit 100, and the first support side plate 150a and the substitute support side plate which are both ends of the second support in the belt width direction. The fixing pins 212 are engaged with 150b, respectively. The first bracket side plate 113a and the second bracket side plate 113b of the swinging bracket to be swung are brought into contact with the fixed pin 212 engaged in this way, thereby swinging the swinging bracket in the belt width direction. Stop at both ends.

  In such a configuration, even if the opening / closing door 201a is arranged in such a layout that only the front side surface of the transfer unit 100 is exposed as shown in FIG. 4, the fixing pin 212 is inserted and removed from the front side. 212 can be engaged with or removed from both the first support side plate 150a and the second support side plate 150b. Thus, the fixing pin 212 can be engaged with or removed from both the first support side plate 150a and the second support side plate 150b without pulling out the transfer unit 100 from the housing 201.

  As shown in FIG. 8, the fixing pin 212 that has passed through the through hole of the first support side plate 150a of the second support 150 passes through the inner side of the loop of the paper conveying belt 101 supported by the swing bracket, and then 2 It reaches the through hole of the second support side plate 150b of the support 150. Thus, by passing the fixing pin 212 inside the loop of the paper conveyance belt 101, contact between the fixing pin 212 and the front surface of the paper conveyance belt 101 is avoided. Thereby, the damage by the contact with the fixing pin 212 of the front surface where the scratch on the surface greatly deteriorates the transferability can be avoided.

  As the fixing pin 212, a pin whose tip is tapered is used. Thereby, as shown in FIG. 9, the front-end | tip of the fixing pin 212 can be easily passed through the through-hole of a support side board (150a, b). In the figure, the conical shape is shown as the tapered tip portion of the fixing pin 212. However, when the fixing pin 212 is passed inside the belt loop as in the modified device, the conical shape is not used. It is desirable to use a kadomatsu shape that is obliquely cut from one end side to the other end side in the diameter direction. This is for the reason explained below. That is, when the fixing pin 212 is passed inside the belt loop, in addition to smoothly passing the tip of the pin through the through hole of the support side plate, it is desirable to guide it to the inside of the loop instead of the outside of the loop. When the tip of the fixing pin 212 has a Kadomatsu shape, as shown in FIG. 10, if the sharpest top is made lower in the direction of gravity, the top is naturally positioned at the level inside the loop in the height direction. Let Thereby, the fixing pin 212 can be smoothly passed inside the loop.

  FIG. 11 is an enlarged partial perspective view showing a part of the transfer unit 100. In the figure, a guide member 116 is bridged between the first bracket side plate 113a and the second bracket side plate 113b of the swing bracket 113. A semi-cylindrical guide groove 116a is provided on the upper surface of the guide member 116 so as to extend in the side plate facing direction (belt width direction). The distal end of the fixing pin 212 that penetrates the through hole of the first support side plate 150a of the second support 150 enters the guide groove 116a from one end side in the length direction. Then, while the play in the diametrical direction is regulated by the guide groove 116a, the guide groove 116a advances in the length direction and is guided to the through hole of the second support side plate 150b on the opposite side. Thereby, the front end side of the fixing pin 212 that has penetrated the through hole of the first support side plate 150a is smoothly guided to the through hole of the second support side plate 150b inside the belt loop.

  The upper end of the first bracket side plate 113a or the second bracket 113b of the swing bracket is abutted against the fixing pin 212 that is passed through the through hole of the first support side plate 150a and the through hole of the second support side plate 150b. Although an example in which the oscillation of the motor is prevented has been described, the following may be employed. That is, the first bracket side plate 113a and the second bracket side plate 113b are also provided with through holes, and the fixing pins 212 are sequentially passed through the through holes of the four plates.

  As described above, in the printer according to the embodiment, the engagement member is engaged with the first support side plate 150a that is one end portion in the belt width direction of at least one of the second support 150 and the swing bracket 113 that is the first support. A first fixing pin 210 as a first engaging member, and a second engaging member engaged with the second supporting side plate 150b which is the other end portion in the belt width direction of at least one of the second supporting member 150 and the swinging bracket 113. Two of the second fixing pins 211 as a joint member are used. In such a configuration, the attaching / detaching operation of the first fixing pin 210 for preventing the swing of the first bracket side plate 113a which is the front end of the swing bracket 113, and the back end of the swing bracket 113 are performed. The attachment / detachment operation of the second fixing pin 211 for preventing the swing of the second bracket side plate 113b can be performed separately.

  Further, in the modified apparatus, a rod-like member that is longer than the width of the paper conveying belt 101 that is a belt member is used as the fixing pin 212 that is an engaging member. A through hole is provided in each of the first support side plate 150a that is one end of the second support 150 in the belt width direction and the second support side plate 150b that is the other end of the second support in the belt width direction. The fixing pins 212 are sequentially passed through these through holes, and the first support side plate 150a and the second support side plate which are at least both ends of the second support 150 and the swing bracket in the belt width direction of the second support 150. The fixing pins 212 are respectively engaged with 150b. In this configuration, as described above, the fixing pin 212 can be engaged with or removed from both the first support side plate 150a and the second support side plate 150b without pulling out the transfer unit 100 from the housing 201. it can.

  Further, in the modified apparatus, the fixing pin 212 is passed inside the loop of the paper transport belt 101. In such a configuration, it is possible to avoid scratching the front surface of the belt by bringing the fixing pin 212 set in the transfer unit 100 into contact with the front surface of the paper conveying belt 101.

  Moreover, in the modified apparatus, since the tip of the fixing pin 212 is tapered, the fixing pin 212 can be smoothly passed through the through hole.

  Further, in the modified device, when the tip of the fixing pin 212 is formed in a Kadomatsu shape that is obliquely cut from one end side to the other end side in the diameter direction, as described above, the fixing pin 212 After passing through the through hole of the first support side plate 150a, the tip can be smoothly passed inside the loop of the paper conveying belt 101. Thereby, the setability of the fixing pin 212 can be improved.

  In the modified apparatus, the tip of the fixing pin 212 that is passed through the through hole provided in the first support side plate 150 a that is one end of the second support 150 in the belt width direction is used as the second support 150. The transfer unit 100 is provided with a guide member for guiding toward a through hole provided in the second support side plate 150b, which is the other end in the belt width direction. In such a configuration, as described above, the fixing pin 212 is guided toward the through hole of the second support side plate 150b by the guide member, and the fixing pin 212 that does not easily enter the through hole is repeatedly inserted and removed. Thus, the setability of the fixing pin 212 can be improved.

1 is a schematic configuration diagram illustrating a printer according to an embodiment. FIG. 3 is an enlarged configuration diagram illustrating a Y toner image forming unit together with a part of a transfer unit among four toner image forming units in the printer. FIG. 3 is an enlarged configuration diagram illustrating a main configuration of the transfer unit. The fragmentary perspective view which shows the edge part of the front side of the printer. The perspective view which shows the same transfer unit of the state pulled out from the inside of a housing | casing. The perspective view which shows the same transfer unit of the state which set the 1st fixing pin. The perspective view which shows the same transfer unit of the state which set the 1st fixing pin and the 2nd fixing pin. The perspective view which shows the transfer unit in a modification apparatus. The side view which shows an example of the front-end | tip shape of the fixing pin in the modification apparatus. Explanatory drawing which shows the behavior of the fixing pin which made the front-end | tip part the Kadomatsu shape. FIG. 7 is an enlarged partial perspective view showing a part of a transfer unit 100 in the modified apparatus.

Explanation of symbols

  11Y, M, C, K: photoconductor (image carrier), 100: transfer unit (transfer means), 101: paper transport belt (belt member), 102: inlet roller (stretch member), 105Y, M, C , K: conveying support roller (stretching member), 106: separation roller (stretching member), 107: driving roller (stretching member), 110: tension roller (stretching member), 111: lower roller (stretching member) ), 113: swing bracket (first support), 113a: first bracket side plate (one end of the first support), 113b: second bracket side plate (the other end of the first support), 113c: swing Driving shaft 116: guide member 150: second support 150a: first support side plate (one end of the second support), 150b: second support side plate (the other end of the second support), 210: First fixing pin (first engaging member), 21 : Second locking pin (second engagement member) 212: securing pin (engaging member)

Claims (7)

While endlessly moving a plurality of image carriers carrying toner images and a surface of an endless belt member stretched by a plurality of stretch members so as to sequentially enter the contact positions with the plurality of image carriers. Transfer means for transferring a toner image on each image carrier at each contact position on the surface of the belt member or a transfer sheet held by the belt member. The first support that is supported at both ends in the width direction is swung around the swing shaft, whereby the surface of the belt member is brought into contact with or separated from all or part of the image carrier, and A second support that supports the first support at both ends in the belt width direction so as to be swingable about the swing shaft; and an engagement that is engageable with at least one of the first support By engaging the members, vibration during transportation In the image forming apparatus constituting a transcription unit so as to prevent swinging of the first support associated with,
An image forming apparatus, wherein the engaging member is engaged with both ends in the belt width direction of at least one of the second support and the first support. The image forming apparatus according to claim 1.
As the engagement member, a first engagement member that engages with one end portion in the belt width direction of at least one of the second support and the first support, and at least one of the second support and the first support An image forming apparatus comprising: a second engaging member that engages with the other end of the belt in the belt width direction. The image forming apparatus according to claim 1.
As the engagement member, a rod-like member longer than the width of the belt member is used, and one end portion of the second support body in the belt width direction and the other end portion of the second support body in the belt width direction are used. Each of the through holes is provided, and the rod-like engaging members are sequentially passed through the through holes, and at least both ends of the second support in the belt width direction of the first support and the second support. An image forming apparatus, wherein the engaging members are engaged with each other. The image forming apparatus according to claim 3.
An image forming apparatus characterized in that the rod-shaped engaging member is passed through the inside of the loop of the belt member. The image forming apparatus according to claim 4.
An image forming apparatus characterized in that the tip of the rod-shaped engaging member is tapered. The image forming apparatus according to claim 5.
An image forming apparatus characterized in that the rod-shaped engaging member has a distal end cut obliquely from one end side to the other end side in the diameter direction. The image forming apparatus according to any one of claims 3 to 6,
A front end portion of the rod-shaped engaging member that is passed through a through hole provided at one end portion in the belt width direction of the second support member is passed through the other end portion in the belt width direction of the second support member. An image forming apparatus characterized in that a guide member for guiding toward a hole is provided in the transfer means.

Images