JP2008286968A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus for positioning an exposure unit to an apparatus main body side with simple structure. <P>SOLUTION: The image forming apparatus is equipped with a main body side member 11 fixed on the apparatus main body 10a, an exposure unit 40 supported by the main body side member 11, a main body side energizing means 41 energizing the exposure unit 40 to the main body side member 11, and a cartridge 200 having an image carrier 20 and inserted in/removed from the main body side member 11. The main body side member 11 has main body side abutting parts 11A and 11cK abutting on the exposure unit 40, and the exposure unit 40 has exposure unit side abutting parts 40dK and 40eK abutting on the main body side member 11, then the exposure unit is positioned by bringing the main body side abutting parts 11A and 11cK respectively into contact with the exposure unit side abutting parts 40dK and 40eK. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus including an exposure unit that is disposed close to an image carrier.

  2. Description of the Related Art Conventionally, there is an image forming apparatus in which an exposure device is urged by a spring in a direction away from the photosensitive drum and the photosensitive drum is brought close to the urging force of the spring by a cam during image formation (see Patent Document 1).

Further, there is an image forming apparatus in which a lever for mounting the photosensitive unit and a mechanism for moving the exposure unit are interlocked and the exposure unit is retracted in accordance with the operation of the lever (see Patent Document 2).
Japanese Patent No. 3618610 Japanese Patent No. 3631042

  However, the positioning of the conventional exposure unit is configured by fitting a hole or the like provided on the exposure unit side with a shaft or the like provided in a cartridge containing a photosensitive member. Usually, the writable width of the exposure unit is set with a certain margin with respect to the image width actually formed on the paper. This is because the writing position and the paper position are positioned in the apparatus so as to intersect each other. Also, in positioning in the writing direction, in the positioning of the shaft and hole, a fine gap is generated due to the intersection of the shaft diameter and the hole diameter, and the exposure unit fluctuates between them, affecting the latent image on the surface of the photoreceptor. This causes image defects. Therefore, it is preferable that the exposure unit be positioned on the apparatus main body side in the same manner as the sheet positioning, rather than on the photosensitive member.

  SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming apparatus that solves the above-described problems and performs positioning of an exposure unit with respect to the apparatus main body with a simple structure.

  The present invention is an image forming apparatus that solves the above-described problems, a main body side member fixed to the main body of the apparatus, an exposure unit supported by the main body side member, and biasing the exposure unit to the main body side member. A main body side urging means; and a cartridge having an image carrier and detachable from the main body side member, wherein the main body side member has a main body side abutting portion that abuts on the exposure unit, The exposure unit has an exposure unit side contact portion that contacts the main body side member, and is positioned by the contact between the main body side contact portion and the exposure unit side contact portion. Therefore, like the paper, the exposure unit is positioned with respect to the apparatus main body, and there is no need to provide an extra writing width.

  The exposure unit side contact portion includes a longitudinal side surface of the exposure unit, and the main body side contact portion includes an inner surface of the main body side member. Therefore, the occurrence of image defects can be suppressed without causing fine fluctuations.

  The exposure unit side contact portion includes a convex portion formed on a side surface in the longitudinal direction of the exposure unit, and the main body side contact portion includes a hole portion formed in the main body side member. Therefore, there is no displacement with respect to the surface, and the occurrence of image defects can be further suppressed without causing minute fluctuations.

  Further, the main body side urging means urges the exposure unit obliquely so as to press the exposure unit to the back side and the side with respect to the cartridge insertion direction. Therefore, it is possible to reduce the size and cost of the apparatus.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing main components constituting an image forming apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing a configuration of a control unit 100 of the image forming apparatus, and FIG. 3 is a yellow diagram of the image forming apparatus. FIG. 4 is a tandem cartridge portion of the image forming apparatus. In FIG. 1, for each color composed of yellow (Y), magenta (M), cyan (C), and black (K), the same component is given Y, M, C, and K representing each color. The same number is used. Of these, FIG. 3 shows the structure of black (K).

  First, the image forming apparatus will be described with reference to FIGS.

  In this embodiment, a printer 10 is taken as an example of the image forming apparatus. The printer 10 includes image forming units 15Y, 15M, 15C, and 15K as an example of the cartridge 15, an intermediate transfer belt 70 as an example of an intermediate transfer member, a primary transfer unit 60, backup rollers 65Y, 65M, and the like in the apparatus main body 10a. 65C and 65K, a secondary transfer unit 80, a fixing unit 90, a display unit 95 which is a liquid crystal panel as a means for notifying a user, and a control unit 100 which controls these units and controls the operation as a printer. is doing. The cartridge 15 includes at least the photoconductor 20, and the charging unit 30, the exposure unit 40, the developing unit 50, and the like may be selected and placed in combination.

  The image forming units 15Y, 15M, 15C, and 15K have a function of forming latent images and toner images on the photoconductors 20Y, 20M, 20C, and 20K. These four image forming portions 15Y, 15M, 15C, and 15K are arranged in a row in a predetermined direction. Here, the photoconductor 20Y of the image forming unit 15Y is farthest from the secondary transfer unit C1 on the upstream side in the rotation direction of the intermediate transfer belt 70 among the four photoconductors 20Y, 20M, 20C, and 20K. The photoconductor 20K of the forming unit 15K is closest to the secondary transfer unit C1 on the upstream side in the rotation direction of the intermediate transfer belt 70 among the four photoconductors.

  Since the image forming units 15Y, 15M, 15C, and 15K have the same configuration, the image forming unit 15K out of the four image forming units 15Y, 15M, 15C, and 15K will be described below as an example. . As shown in FIG. 3, the image forming unit 15K includes a charging unit 30K, an exposure unit 40K, a developing unit 50K, and a photoconductor cleaning unit 75K along the rotation direction of the photoconductor 20K.

  The photoreceptor 20K has a cylindrical base material (specifically, an aluminum material) and a photosensitive layer formed on the outer peripheral surface thereof, and carries a latent image on the surface of the photosensitive layer. The photosensitive body 20K is rotatably supported at both ends in the axial direction by the printer main body, and in the present embodiment, it rotates clockwise as indicated by the arrows in FIG.

  The charging unit 30K is a device for charging the photoconductor 20K. As shown in FIG. 3, the charging unit 30K opposes the photosensitive member 20K and charges the photosensitive member 20K. The charging unit 30K contacts the charging roller 31K and cleans the surface of the charging roller 31K. And a cleaning roller 35K. When a charging bias in which a DC voltage and an AC voltage are superimposed is supplied from the charging bias supply unit 121 (FIG. 2) to the charging roller 31K, a discharge occurs between the charging roller 31K and the photoconductor 20K. As a result, the photoconductor 20K is charged.

  The charging roller 31K has a configuration in which a conductive paint is applied to the surface of a metal shaft. Further, the charging roller 31K is attached with a tape (not shown) that contacts the photoconductor 20K at both ends in the axial direction. Since the outer diameter of the tape is larger than the outer diameter of the central portion of the charging roller 31K, a gap is formed between the central portion and the photoconductor 20K. For this reason, the charging roller 31K charges the photoreceptor 20K by a so-called non-contact charging method.

  The exposure unit 40K is a device that forms a latent image on the photosensitive member 20K charged by irradiating a laser. The exposure unit 40K includes, for example, a semiconductor laser, a polygon mirror, an F-θ lens, and the like, and is modulated based on an image signal input from a host computer (not shown) such as a personal computer or a word processor. Is irradiated onto the charged photoconductor 20K.

  The black developing unit 50K is an apparatus for visualizing a latent image formed on the photoreceptor 20K as a black toner image using black (K) toner, which is an example of a developer, in the developing unit A1. As shown in FIG. 3, the black developing unit 50K includes a toner containing portion 51K for containing black toner, and a developing roller 52K for carrying the black toner and developing a latent image on the photoreceptor 20K. , A supply roller 53K for supplying the toner in the toner container 51K to the developing roller 52K, and a regulating blade for charging the black toner carried on the developing roller 52K (in this embodiment, the toner is negatively charged). (Not shown).

  The developing roller 52K faces the photoconductor 20K with a gap. When a developing bias in which a DC voltage and an AC voltage are superimposed is supplied from the developing bias supply unit 122 (FIG. 2) to the developing roller 52K, An electric field is formed between the developing roller 52K and the photoconductor 20K, and the latent image on the photoconductor 20K is developed.

  The intermediate transfer belt 70 transfers toner images (toners) of different colors carried on the four photoconductors 20Y, 20M, 20C, and 20K to a medium (paper, film, cloth, etc.) and forms an image on the medium. In this state, the toner image is moved by rotating in the direction indicated by the arrow in FIG. The intermediate transfer belt 70 is in contact with the photoconductors 20Y, 20M, 20C, and 20K provided along the rotation direction of the intermediate transfer belt 70, and the intermediate transfer belt 70 and the photoconductors 20Y, 20M, and 20C. , 20K are formed with primary transfer portions B1, B2, B3, B4 to which the toner image on the photoreceptor is transferred to the intermediate transfer belt 70.

  The primary transfer unit 60 cooperates with the backup rollers 65Y, 65M, 65C, and 65K to transfer the toner images formed on the photoreceptors 20Y, 20M, 20C, and 20K to the intermediate transfer belt 70 (hereinafter also referred to as primary transfer). ). The primary transfer unit 60 is in contact with the intermediate transfer belt 70 and supplies a primary transfer bias, which is a transfer voltage, to the intermediate transfer belt 70 via the primary transfer unit 60 of the voltage supply unit 123.

  Here, the primary transfer bias is a voltage for directing the toner on the photoreceptors 20Y, 20M, 20C, and 20K to the intermediate transfer belt 70 at the primary transfer portions B1, B2, B3, and B4. The primary transfer bias is a voltage having a polarity opposite to the charged polarity (negative polarity) of the toner on the photoconductors 20Y, 20M, 20C, and 20K. When the primary transfer bias is supplied to the intermediate transfer belt 70, an electric field is formed between the photoreceptors 20Y, 20M, 20C, and 20K and the intermediate transfer belt 70 in the primary transfer portions B1, B2, B3, and B4. The

  The backup rollers 65Y, 65M, 65C, and 65K are in contact with the photoreceptors 20Y, 20M, 20C, and 20K of the four image forming units 15Y, 15M, 15C, and 15K via the intermediate transfer belt 70, respectively. Then, the backup rollers 65Y, 65M, 65C, and 65K come into contact with the photoreceptors 20Y, 20M, 20C, and 20K through the intermediate transfer belt 70, and as described above, in the primary transfer portions B1, B2, B3, and B4. When an electric field is formed between the photoconductors 20Y, 20M, 20C, and 20K and the intermediate transfer belt 70, the primary transfer portions B1, B2, B3, and B4 are arranged on the photoconductors 20Y, 20M, 20C, and 20K. The toner images are sequentially primary transferred onto the intermediate transfer belt 70. As a result, a full color toner image is formed on the intermediate transfer belt 70.

  The photoconductor cleaning unit 75K is a device for removing and collecting the toner remaining on the photoconductor 20K after the toner image is transferred onto the intermediate transfer belt 70 by the primary transfer unit 60. The photoconductor cleaning unit 75K includes a photoconductor cleaning blade 76K. The leading end of the photosensitive member cleaning blade 76K contacts the surface of the photosensitive member 20K, and removes the toner image (toner) left on the photosensitive member 20K without being transferred to the intermediate transfer belt 70.

  The secondary transfer unit 80 is a device for transferring a single color toner image or a full color toner image formed on the intermediate transfer belt 70 to a medium (hereinafter also referred to as secondary transfer). The secondary transfer unit 80 includes a secondary transfer roller 82 as an example of a secondary transfer member that can be brought into contact with and separated from the intermediate transfer belt 70. A toner that has moved to the secondary transfer portion C1 as the intermediate transfer belt 70 rotates. This is for transferring an image (toner) to a medium. Specifically, when the secondary transfer bias is supplied to the secondary transfer roller 82 from the secondary transfer bias supply unit 124 (FIG. 2), the intermediate transfer belt 70 and the secondary transfer roller 82 are transferred to the secondary transfer unit C1. Between the toner image and the toner image on the intermediate transfer belt 70 is secondarily transferred to the medium.

  The fixing unit 90 is a device that heats and presses a single-color toner image or a full-color toner image transferred onto a medium and fuses it to the medium to form a permanent image. The fixing unit 90 includes a fixing roller 90a and a pressure roller 90b. The fixing roller 90a is for heating the toner image on the medium and fusing the toner image to the medium. The pressure roller 90b is for pressing the toner image on the medium in cooperation with the fixing roller 90a.

  A medium transport path 13 for transporting the medium in the paper feed tray 92 to the paper discharge tray 98 is formed from the lower part to the upper part of the printer 10. The medium transport path 13 is composed of a large number of guide members. Each medium has a function of conveying a medium on the medium conveyance path 13. A plurality of rollers such as a paper feed roller 94a, a registration roller 94b, and a paper discharge roller 94c are arranged.

  As shown in FIG. 2, the control unit 100 includes a main controller 101 and a unit controller 102. An image signal and a control signal are input to the main controller 101, and in response to a command based on the image signal and the control signal. A unit controller 102 controls each of the units and forms an image.

  Next, the color image forming operation of the printer 10 configured as described above will be described with reference to other components.

  First, when an image signal and a control signal from a host computer (not shown) are input to the main controller 101 of the printer 10 via the interface (I / F) 112, the unit controller 102 based on a command from the main controller 101. Under the control, the photoconductors 20Y, 20M, 20C, and 20K, the developing rollers 52Y, 52M, 52C, and 52K provided in the developing units 50Y, 50M, 50C, and 50K, the intermediate transfer belt 70, and the like rotate.

  The photoreceptors 20Y, 20M, 20C, and 20K are sequentially charged at the charging position by the charging units 30Y, 30M, 30C, and 30K (specifically, the charging rollers 31Y, 31M, 31C, and 31K to which a charging bias is supplied) while rotating. Is done. The charged regions of the photoconductors 20Y, 20M, 20C, and 20K reach the exposure position as the photoconductors 20Y, 20M, 20C, and 20K rotate, and yellow Y and magenta are obtained by the exposure units 40Y, 40M, 40C, and 40K. A latent image corresponding to the image information of M, cyan C, and black K is formed in the area.

  The latent images formed on the photoconductors 20Y, 20M, 20C, and 20K reach the developing units A1, A2, A3, and A4 as the photoconductors 20Y, 20M, 20C, and 20K rotate, and develop units 50Y, 50M, and It is developed as a toner image by 50C and 50K (specifically, developing rollers 52Y, 52M, 52C and 52K). As a result, monochromatic toner images are formed on the photoreceptors 20Y, 20M, 20C, and 20K. In developing, a developing bias is supplied to the developing rollers 52Y, 52M, 52C, and 52K.

  The monochromatic toner images formed on the photoconductors 20Y, 20M, 20C, and 20K reach the primary transfer units B1, B2, B3, and B4 as the photoconductors 20Y, 20M, 20C, and 20K rotate, and the primary transfer unit. 60 and the backup rollers 65Y, 65M, 65C, 65K are primarily transferred to the intermediate transfer belt 70. At this time, a primary transfer bias is supplied to the intermediate transfer belt 70. As a result, the four color toner images formed on the respective photoconductors 20Y, 20M, 20C, and 20K are primarily transferred so as to sequentially overlap the intermediate transfer belt 70, and a full color toner image is formed on the intermediate transfer belt 70. It is formed.

  The full-color toner image formed on the intermediate transfer belt 70 reaches the secondary transfer portion C1 as the intermediate transfer belt 70 rotates, and is secondarily transferred to the medium by the secondary transfer roller 82 of the secondary transfer unit 80. The The medium sandwiches the medium conveyed from the paper feed tray 92 to the secondary transfer portion C1 via the paper feed roller 94a and the registration roller 94b, and a secondary transfer bias is supplied to the secondary transfer roller 82. Is done.

  When the medium on which the full-color toner image is secondarily transferred is conveyed into the fixing unit 90, the medium passes between the fixing roller 90a and the pressure roller 90b while being sandwiched between the fixing roller 90a and the pressure roller 90b. To do. At this time, the fixing roller 90a and the pressure roller 90b heat and press the full color toner image on the medium, so that the full color toner image is fused to the medium. The medium on which the full-color toner image is fused is conveyed to the paper discharge tray 98 via the paper discharge roller 94c.

  On the other hand, the toner remaining on the photoconductors 20Y, 20M, 20C, and 20K without being primarily transferred to the intermediate transfer belt 70 at the primary transfer portions B1, B2, B3, and B4 is the photoconductor cleaning blades 76Y, 76M, and 76C. Removed by 76K.

  Next, the configuration of the control unit 100 will be described with reference to FIG. The main controller 101 of the control unit 100 is connected to a host computer via an interface 112 and includes an image memory 113 for storing image signals input from the host computer.

  The unit controller 102 includes units (photoconductors 20Y, 20M, 20C, and 20K, charging units 30Y, 30M, 30C, and 30K, exposure units 40Y, 40M, 40C, and 40K, developing units 50Y, 50M, 50C, and 50K). The primary transfer unit 60, the intermediate transfer belt 70, the photoreceptor cleaning units 75Y, 75M, 75C, and 75K, the secondary transfer unit 80, the fixing unit 90, and the display unit 95). By receiving the signal, each unit is controlled based on the signal input from the main controller 101 while detecting the state of each unit.

  Next, the exposure unit of this embodiment will be described. 5 shows a black exposure unit 40K, FIG. 6 shows the exposure units 40Y, 40M, 40C, and 40K attached to the cartridge guide member 11, and FIG. 7 shows one exposure unit 40 as viewed from above. FIG. 8 is an enlarged view of the first convex portion when the exposure unit 40 is mounted, and FIG. 9 is an enlarged view of the second convex portion when the exposure unit 40 is mounted. Here, since the configuration of the exposure units 40Y, 40M, 40C, and 40K is the same, the following description will be made by taking the exposure unit 40K of the four exposure units 40Y, 40M, 40C, and 40K as an example.

  In the drawing, 40aK is a line head, 40bK is a base, 40cK is a photosensitive member side contact portion, 40dK is a contact surface as an example of an exposure unit side contact portion, and 40eK is a first as an example of an exposure unit side contact portion. A convex part, 40 fK, is a second convex part as an example of the exposure unit side contact part.

  The exposure unit 40K has a line head 40aK along the upper longitudinal direction of the bowl-shaped base 40bK. Further, on both outer sides in the longitudinal direction of the line head 40aK, there is provided a photoreceptor side abutting portion 40cK for positioning with respect to the photoreceptor 20K of the cartridge 15K. The contact surface 40dK in the longitudinal direction of the base portion 40bK includes, for example, a first convex portion 40eK including, for example, two convex portions disposed on the back side of the cartridge guide member 11 described later, and one convex portion disposed on the near side. A second convex portion 40fK.

  The cartridge guide member 11 as an example of the main body side member is a member fixed to the apparatus main body 10a, and has a first hole portion 11aK as an example of a hole portion on the inner surface 11A on the back side and a hole portion on the near side. As an example, it has the 2nd hole 11bK. The first convex portion 40eK of the exposure unit 40K is inserted into the first hole portion 11aK, and the second convex portion 40fK of the exposure unit 40K is inserted into the second hole portion 11bK. In this way, the exposure unit 40K is positioned by contacting the cartridge guide member 11 at the contact surfaces 40dK at both ends.

  Next, positioning will be described in detail. As shown in FIG. 7, the cartridge guide member 11 and the exposure unit 40K are connected by a main body side biasing spring 41K as an example of a main body side biasing means disposed obliquely. The urging force of the urging spring 41K causes the exposure unit 40K to be pressed in an oblique direction that is the direction of the arrow X and against the longitudinal inner surface 11A in the longitudinal direction that is a contact surface with the cartridge guide member 11 as the exposure unit support. It abuts against and is positioned.

  As shown in FIG. 8, the first convex portion 40eK inserted into the first hole portion 11aK is abutted against the first abutting surface 11cK that is the inner surface of the first hole portion 11aK and positioned. Furthermore, as shown in FIG. 9, the second convex portion 40eK inserted into the second hole portion 11bK is abutted against the second abutting surface 11dK, which is the inner surface of the second hole portion 11bK, and positioned. In addition, the 1st hole part 11aK and the 2nd hole part 11bK are long holes, and the 1st convex part 40eK and the 2nd convex part 40fK can move the inside of a long hole.

  As described above, the cartridge guide member 11 fixed to the apparatus main body 10a, the exposure unit 40K supported by the cartridge guide member 11, and the main body side biasing spring for biasing the exposure unit 40K to the cartridge guide member 11. 41K and a cartridge 200 having the image carrier 20 and removable from the cartridge guide member 11, and the cartridge guide member 11 has a longitudinal inner surface 11A in contact with the exposure unit 40K and a first protrusion. The exposure unit 40 has a contact surface 11cK and a second contact surface 11dK. The exposure unit 40 has a contact surface 40dK that contacts the cartridge guide member 11, a first protrusion 40eK, and a second protrusion 40fK. Side inner surface 11A, first hole 11aK and second hole 11bK, first abutting surface 11cK and second protrusion The surface 11dK, the contact surface 40dK, the first convex portion 40eK, and the second convex portion 40fK are positioned by contacting each other. 11, it is not necessary to provide an extra writing width.

  Further, the exposure unit side contact portion includes the side surface 40dK of the exposure unit 40, and the main body side contact portion includes the inner surface 11A of the cartridge guide member 11. Therefore, the occurrence of image defects can be suppressed without causing minute fluctuations.

  Further, the exposure unit side contact portion includes convex portions 40eK and 40fK formed on the side surface in the longitudinal direction of the exposure unit 40, and the main body side contact portion is a first hole portion 11aK formed in the cartridge guide member 11. Since the second hole 11bK is provided, there is no displacement with respect to the surface, and the occurrence of image defects can be further suppressed without causing minute fluctuations.

  Further, the main body side biasing spring 41K biases the exposure unit 40K obliquely so as to move to the back side and the side with respect to the insertion direction of the cartridge 15K. Thus, the apparatus can be reduced to a small size and the cost can be reduced.

  Next, a mechanism for moving the exposure unit as shown in FIGS. 10 to 20 will be described. Here, since the configurations of the cartridges 200Y, 200M, 200C, and 200K and the exposure units 40Y, 40M, 40C, and 40K are the same, the four cartridges 200Y, 200M, 200C, and 200K and the exposure units 40Y and 40M are described below. , 40C, 40K, etc., the cartridge 200K and the exposure unit 40K will be described as examples.

  FIG. 10 is a diagram illustrating attachment and detachment of the cartridge 200K. In this embodiment, a tandem type printer 10 to which the cartridge 200K can be attached and detached is applied. The printer 10 has a door 10b that opens and closes when the cartridge 200K is replaced in the apparatus main body 10a. By opening the door 10b, the cartridge 200K can be inserted into and removed from the cartridge guide member 11. Further, the cartridge 200K is obtained by placing the photosensitive member 20K and the like on the cartridge housing 21K.

  FIG. 11 is a perspective view of the cartridge guide member 11 and the cartridge 200K as seen from above, and FIG. 12 is a perspective view of the cartridge guide member 11 and the cartridge 200K as seen from below.

  As shown in FIGS. 11 and 12, the cartridge guide member 11 supports an exposure unit 40K, and the cartridge 200K is mounted above the exposure unit 40K. Further, the cartridge guide member 11 has a hole portion 11eK and a support portion 11fK for installing an exposure unit push-up lever 12K of an exposure unit moving mechanism 110 described later.

  13 to 20 show the operation of the exposure unit moving mechanism 110. 13 to 16 show the state before the cartridge 200K is mounted, and FIGS. 17 to 20 show the state after the cartridge 200K is mounted.

  First, the configuration of the exposure unit moving mechanism 110 will be described with reference to FIGS. 15 and 19. The exposure unit moving mechanism 110 includes an exposure unit push-up lever 12K as an example of a lever, an exposure unit pressurizing spring 13K as an example of a cartridge side biasing means, a spring receiving member 14K, a hole 11eK of the cartridge guide member 11, and a lever. It has a support portion 11fK, an opening portion 11gK, and step portions 21aK and 21bK of the cartridge housing 21K. Note that the stepped portions 21aK and 21bK are configured by slopes. Further, the stepped portions 21aK and 21bK are not limited to two, and a plurality of stepped portions 21aK and 21bK may be provided.

  The exposure unit push-up lever 12K has a fulcrum 12aK supported by a lever support portion 11fK, a cartridge contact portion 12bK provided on one end side, and a spring receiving portion 12cK on the other end side contacted with the exposure unit 40K. It is inserted into the hole 14aK of the spring receiving member 14K and is connected to the spring receiving member 14K via the exposure unit pressurizing spring 13K.

  The exposure unit pressurizing spring 13K is provided between and connected to the exposure unit push-up lever 12K and the spring receiving member 14K. The spring receiving member 14K supports the exposure unit 40K from below and from the side.

  The hole 11eK of the cartridge guide member 11 is provided below the exposure unit 40K, and the exposure unit pressurizing spring 13K and the spring receiving member 14K are inserted therethrough. The lever support portion 11fK is a portion that pivotally supports the exposure unit push-up lever 12K. The opening portion 11gK is a portion where the cartridge contact portion 12bK of the exposure unit push-up lever 12K contacts the step portions 21aK and 21bK of the cartridge housing 21K.

  Next, the operation of the exposure unit moving mechanism 110 will be described.

  First, a state before the cartridge 200K is mounted will be described. FIG. 13 is a view of the cartridge 200K before mounting from the left side in FIG. 10, FIG. 14 is a view of the cartridge 200K before mounting from the right side in FIG. 10, and FIG. FIG. 16 shows a view of section BB of FIG.

  As shown in FIGS. 13 and 14, when the cartridge 200K is in the removed state before being mounted, the cartridge 200K is not in contact with the exposure unit moving mechanism 110 of the cartridge guide member 11, and the exposure unit 40K is retracted. Yes.

  At this time, as shown in FIG. 15 and FIG. 16, the exposure unit push-up lever 12K is pressed downward by the other weight of the exposure unit 40K, the spring receiving member 14K, and the exposure unit pressurizing spring 13K. The cartridge contact portion 12bK on one side rotates upward about a fulcrum supported by the lever support portion 11fK.

  Next, a state after the cartridge 200K is mounted will be described. 17 is a view of the mounted cartridge 200K as viewed from the left side in FIG. 10, FIG. 18 is a view of the mounted cartridge 200K as viewed from the right side in FIG. 10, and FIG. 19 is a cross-sectional view of FIG. FIG. 20 shows a view of the section DD of FIG.

  As shown in FIGS. 17 and 18, when the cartridge 200K is mounted, the back side step portion 21aK and the front side step portion 21bK of the cartridge housing 21K are synchronized with the cartridge of the exposure unit push-up lever 12K at a predetermined position. It contacts the part 12bK. At this time, as shown in FIGS. 19 and 20, the exposure unit push-up lever 12K presses the cartridge contact portion 12bK on one end side and falls downward, and the spring receiving portion 12cK on the other end side centers on the lever support portion 11fK. Turn upward. Then, an urging force is applied to the exposure unit pressurizing spring 13K, and the spring receiving member 14K and the exposure unit 40K are pressed upward. The pressed exposure unit 40K moves while being applied with an urging force while being in contact with the inner surface 11A in the longitudinal direction shown in FIG. 7, and the first hole portion 11aK and the second hole shown in FIGS. The first abutting surface 11cK and the second abutting surface 11dK in the elongated hole, which is the portion 11bK, and the first convex portion 40dK and the second convex portion 40eK move to move the photosensitive member side abutting portion. 40cK is positioned in contact with the cartridge housing 21K.

  In this way, the cartridge guide member 11 fixed to the apparatus main body 10a, the exposure unit 40K supported by the cartridge guide member 11, and the photosensitive member 20K, and the cartridge 200K that can be inserted into and removed from the cartridge guide member 11 are provided. The exposure unit 40K is moved to the cartridge 200K side by the mounting operation of the cartridge 200K and is moved to the cartridge guide member 11 side by the removal operation of the cartridge 200K. In addition, the size of the apparatus can be reduced, and the exposure unit 40K can be moved to the cartridge 200K only by the operation of inserting the cartridge 200K, so that no special operation by the user is required and the operability is excellent. .

  Further, an exposure unit pressurizing spring 13K that biases the exposure unit 40K toward the cartridge 200K side, and a fulcrum supported by the cartridge guide member 11, on the one hand, abuts on the cartridge 200K when mounted, and on the other hand, the exposure unit And an exposure unit push-up lever 12K coupled to the exposure unit 40K via the pressurizing spring 13K. Therefore, the exposure unit 40K can be moved to the cartridge 200K side with a simple structure. .

  The cartridge 200K is characterized by having step portions 21aK and 21bK that press one of the exposure unit push-up levers 12K in synchronization with the mounting operation of the cartridge 200K. Therefore, the exposure unit 40K is accurately moved to the cartridge 200K side. It becomes possible to make it.

  Further, the step portions 21aK and 21bK are arranged at least at two different locations and are characterized by pressing one of the levers 12K in synchronization with each other, so that the force for moving the exposure unit 40K to the cartridge 200K side is increased. Can do.

  Furthermore, the present invention is an image forming apparatus provided with an exposure unit moving mechanism 110 that solves the above-described problems, and includes an exposure unit 40, a cartridge 200, an intermediate transfer body 70 to which an image formed by the cartridge 200 is transferred, Since it has a primary transfer portion B that transfers to the intermediate transfer body 70 and a secondary transfer portion C that transfers the image on the intermediate transfer body 70 to a medium, it is possible to reduce costs and reduce the size of the apparatus. Since the exposure unit 40 can be urged toward the cartridge 200 only by inserting the cartridge 200, no special operation by the user is required and the operability is excellent.

It is a figure which shows the printer of this embodiment. It is the figure which showed the structure of the control unit of this embodiment. 2 is a diagram illustrating an image forming unit of the image forming apparatus according to the present exemplary embodiment. FIG. FIG. 4 is an enlarged view of the vicinity of four image forming units of the present embodiment. It is a perspective view of the exposure unit of this embodiment. It is a perspective view of the member for cartridge guides of this embodiment. It is a figure which shows the exposure unit attached to the member for cartridge guides of this embodiment. It is the figure which looked at the exposure unit attachment part from the back side (left side of FIG. 7). It is the figure which looked at the exposure unit attachment part from the near side (right side of FIG. 7). FIG. 3 is a perspective view when a cartridge is attached to the printer of the present embodiment. It is the perspective view which looked at the state which attached the cartridge to the member for cartridge guides of this embodiment from the upper direction. It is the perspective view which looked at the state which attached the cartridge to the member for cartridge guides of this embodiment from the bottom. It is a figure which shows the state before mounting | wearing with the cartridge guide member of this embodiment. It is a figure which shows the state before mounting | wearing with the cartridge guide member of this embodiment. It is a figure which shows the cross section AA of FIG. It is a figure which shows the cross section BB of FIG. It is a figure which shows the state after mounting a cartridge in the member for cartridge guides of this embodiment. It is a figure which shows the state after mounting a cartridge in the member for cartridge guides of this embodiment. It is a figure which shows the cross section CC of FIG. It is a figure which shows the cross section DD of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Printer, 11 ... Cartridge guide member (main body side member), 12Y, 12M, 12C, 12K ... Exposure unit push-up lever (lever), 13Y, 13M, 13C, 13K ... Exposure unit pressurizing spring (cartridge side bias) Means), 15Y, 15M, 15C, 15K ... cartridge, 20Y, 20M, 20C, 20K ... photoconductor (image carrier), 30Y, 30M, 30C, 30K ... charging unit, 40Y, 40M, 40C, 40K ... exposure unit , 41Y, 41M, 41C, 41K ... spring (main body side biasing means), 50Y, 50M, 50C, 50K ... developing unit, 52Y, 52M, 52C, 52K ... developing roller (developer carrier), 60 ... primary transfer Unit: 70 ... Intermediate transfer belt, 80 ... Secondary transfer unit, 90 ... Fixing unit, 10 ... control unit

Claims (4)

  A main body side member fixed to the apparatus main body, an exposure unit supported by the main body side member, a main body side biasing means for biasing the exposure unit to the main body side member, and an image carrier, A cartridge that can be inserted into and removed from the main body side member, the main body side member having a main body side abutting portion that abuts on the exposure unit, and the exposure unit that is in contact with the main body side member. An image forming apparatus, comprising: a contact portion, wherein the main body side contact portion and the exposure unit side contact portion are in contact with each other.   The image forming apparatus according to claim 1, wherein the exposure unit side contact portion includes a longitudinal side surface of the exposure unit, and the main body side contact portion includes an inner surface of the main body side member.   The exposure unit side contact portion includes a convex portion formed on a side surface in the longitudinal direction of the exposure unit, and the main body side contact portion includes a hole formed in the main body side member. The image forming apparatus according to claim 1.   4. The body-side biasing unit biases the exposure unit obliquely so as to press the exposure unit inward and sideward with respect to the cartridge insertion direction. An image forming apparatus according to claim 1.

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