JP2006030420A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent such a failure that a supporting frame which is not loaded to the normal position of an image forming apparatus main body is erroneously detected, regarding an image forming apparatus where the supporting frame for supporting a photoreceptor drum is attached/detached to/from the image forming apparatus main body in the axial direction of the photoreceptor drum. <P>SOLUTION: A hook 70 is rotatably supported by the supporting frame 66 for a process cartridge 11, and a locking piece 74B for locking the hook part 70A of the hook 70 and a micro switch 68 having a lever 68A which is depressed by the hook part 70A locked by the locking piece 74B are arranged in the loading part 19 of the printer main body 18. Besides, the process cartridge 11 is energized by a compression coil spring 82 in a direction of ejecting the cartridge 11 from the loading part 19, then, the process cartridge 11 is positioned in the normal position of the loading part 19. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus in which a cartridge including a photosensitive drum is detachable from a main body of the image forming apparatus.

  In image forming apparatuses such as printers and copiers that use electrophotography, the photosensitive drum can be replaced by attaching or detaching a process cartridge containing a photosensitive drum that is a consumable item to the main body of the image forming apparatus. It is said. As a configuration for mounting the process cartridge on the image forming apparatus main body, a configuration in which a cover provided on the upper part of the image forming apparatus main body is opened and inserted from above, and a cover provided on a side surface of the image forming apparatus main body are provided. A general configuration is such that it is opened and inserted in the axial direction of the photosensitive drum.

  Here, in the configuration in which the process cartridge is inserted in the axial direction of the photosensitive drum and attached to the image forming apparatus main body, the attachment of the process cartridge to the image forming apparatus main body is detected by various methods. For example, a micro switch (see, for example, Patent Document 1) whose switch is operated by a process cartridge mounted on the image forming apparatus main body or a photosensor that senses an actuator moved by the process cartridge mounted on the image forming apparatus main body. This is detected by checking the continuity of the drawer connector that is fitted when the process cartridge is mounted on the image forming apparatus main body.

  However, a fitting tolerance is provided between the process cartridge and the image forming apparatus main body. Further, there is a tolerance in the stroke of the switch for turning on the micro switch and the stroke of the actuator detected by the photosensor, and the drawer connector is conductive even if it is not completely fitted.

For this reason, even if the process cartridge is deviated from the normal position of the image forming apparatus main body by several millimeters, it may be erroneously detected that the process cartridge is mounted on the image forming apparatus main body by a detecting means such as a microswitch. If the photosensitive drum is exposed in this state, the laser irradiation position may be out of the effective image forming area of the photosensitive drum.
JP-A-8-238769

  The present invention has been made in consideration of the above facts, and in an image forming apparatus in which a support frame for supporting the photosensitive drum is detachable from the main body of the image forming apparatus in the axial direction of the photosensitive drum. It is possible to prevent erroneous detection of a support frame that is not mounted in the normal position.

  The image forming apparatus according to claim 1 supports a photosensitive drum that carries a toner image and transfers it to a transfer medium, and supports the photosensitive drum, and is detachable from an image forming apparatus main body in an axial direction of the photosensitive drum. A support frame, locking means provided in the support frame or the image forming apparatus main body, and a normal position of the image forming apparatus main body provided in the image forming apparatus main body or the support frame. And a detecting means for detecting the locking means locked to the locked means provided on the image forming apparatus main body or the support frame. It is characterized by having.

  In the image forming apparatus according to the first aspect, the photosensitive drum carries the toner image and transfers it onto the transfer medium. The photosensitive drum is supported by a support frame, and the support frame can be attached to and detached from the image forming apparatus main body in the axial direction of the photosensitive drum. As a result, the photosensitive drum, which is a consumable item, can be replaced, and the paper transport jam can be easily handled.

  Here, the image forming apparatus main body or the support frame is provided with a locking means such as a hook, and when the support frame is attached to the normal position of the image forming apparatus main body, the locking means is The device is locked in a locked means such as a locking hole provided in the apparatus main body. The image forming apparatus main body or the support frame is provided with detection means, and this detection means detects the locking means locked to the locked means.

  That is, unless the support frame is mounted at the normal position of the image forming apparatus main body, the detection means does not detect the locking means. Therefore, the support frame that is not mounted at the normal position of the image forming apparatus main body is erroneously detected by the detection means. Will not be detected. In addition, the photosensitive drum and the support frame can be reliably positioned at the normal positions of the image forming apparatus main body.

  An image forming apparatus according to claim 2 is the image forming apparatus according to claim 1, wherein an exposure unit that exposes the photosensitive drum to form an electrostatic latent image on the photosensitive drum, and the detection A first cheat circuit that does not supply power to the exposure means unless the means detects the locking means locked to the locked means.

  In the image forming apparatus according to the second aspect, the exposure unit exposes the photosensitive drum to form an electrostatic latent image on the photosensitive drum. Here, if the locking means is not locked to the locked means and is not detected by the detection means, the first cheat circuit does not supply power to the exposure means.

  For this reason, the exposure unit does not expose the photosensitive drum positioned at a position deviated from the normal position of the image forming apparatus main body, and the exposure position can be prevented from being deviated from the effective image forming area of the photosensitive drum. .

  The image forming apparatus according to claim 3 is the image forming apparatus according to claim 1 or 2, wherein a high voltage generating unit that generates a high voltage to charge or neutralize the photosensitive drum, and the detection unit. And a second cheat circuit that does not supply power to the high voltage generating means unless the locking means locked to the locked means is detected.

  In the image forming apparatus according to the third aspect, the high voltage generating means generates a high voltage to charge or remove the charge from the photosensitive drum. Here, if the locking means is not locked to the locked means and is not detected by the detecting means, the second cheat circuit does not supply power to the high voltage generating means.

  For this reason, when the terminal of the high voltage generating unit is exposed in a state where the support frame is not attached to the regular position of the image forming apparatus main body, the operator touches the exposed terminal of the high voltage generating unit. But there is no fear of electric shock.

  The image forming apparatus according to claim 4 is the image forming apparatus according to any one of claims 1 to 3, wherein the detection unit and the locked unit are provided in the image forming apparatus main body, The detecting means is arranged on the back side of the locked means to prevent an operator from touching the detecting means.

  In the image forming apparatus according to claim 4, the locked means is provided in the main body of the image forming apparatus, and the detection means is provided on the back side of the locked means of the main body of the image forming apparatus. The erroneous detection of the support frame due to the operator touching the detection means is prevented. As a result, it is possible to prevent the exposure unit and the high voltage generation unit from being operated in a state where the support frame is not attached to the image forming main body, and the operator can receive light from the exposure unit or the high voltage generation unit. It is possible to prevent an electric shock from being applied to a high voltage.

  An image forming apparatus according to a fifth aspect is the image forming apparatus according to any one of the first to fourth aspects, wherein the support frame is urged in a direction to be pulled out from the main body of the image forming apparatus. It has a frame urging means for locking the locking means to the locked means.

  In the image forming apparatus according to the fifth aspect, the frame urging means urges the support frame in a direction to be extracted from the image forming apparatus, and the locking means is locked to the locked means. As a result, the photosensitive drum and the support frame are reliably positioned at the normal positions of the image forming apparatus main body.

  The image forming apparatus according to claim 6 is the image forming apparatus according to claim 5, wherein the frame urging unit is rotatably provided on the main body of the image forming apparatus, and the rotation shaft of the photosensitive drum. And a connecting member that is rotated by a drive source of the main body of the image forming apparatus to rotate the photosensitive drum, and a connecting member urging unit that urges the connecting member in the extracting direction. Features.

  In the image forming apparatus according to claim 6, the connecting member connected to the rotation shaft of the photosensitive drum is rotatably provided in the image forming apparatus main body, and is rotated by a drive source of the image forming apparatus main body. Thus, the photosensitive drum is rotated. Here, the connecting member is urged in the direction of pulling out the support frame from the image forming apparatus main body by the connecting member urging means. As a result, the photosensitive drum connected to the connecting member and the support frame that supports the photosensitive drum are urged in the direction to be extracted from the image forming apparatus main body, and the locking means is locked to the locked means.

  The image forming apparatus according to claim 7 is the image forming apparatus according to claim 5, wherein the frame urging unit includes a helical gear on a drum side attached to a rotation shaft of the photosensitive drum, The image forming apparatus main body is rotatably provided and connected to the drum side helical gear, and is rotated by a driving source of the image forming apparatus main body to rotate the photosensitive drum, and the drum side helical And a main body side helical gear that applies a thrust force to the toothed gear in the extracting direction.

  In the image forming apparatus according to the seventh aspect, the helical gear on the drum side is attached to the rotating shaft of the photosensitive drum. Further, the main body side helical gear connected to the drum side helical gear is rotatably provided in the image forming apparatus main body, and the main body side helical gear is driven by a drive source of the image forming apparatus main body. The photosensitive drum is rotated by being driven to rotate.

  Here, the helical gear on the main body side rotates by meshing with the helical gear on the drum side, so that a thrust force in the direction of extracting the support frame from the main body of the image forming apparatus is applied to the helical gear on the drum side. To do. As a result, the photosensitive drum and the support frame are urged in the direction of extraction from the main body of the image forming apparatus, and the locking unit is locked to the locked unit.

  An image forming apparatus according to an eighth aspect is the image forming apparatus according to any one of the fifth to seventh aspects, wherein the locked means is provided in the main body of the image forming apparatus. The locking means is a hook rotatably supported by the support frame and provided with a locking projection to be locked to the locking plate material. A hook urging means for urging the locking member toward the locking member; and a locking surface of the locking projection locked by the locking plate material; and a locking surface from a pivot center of the hook The angle with the straight line extending to the contact point with the locking plate is 90 ° or less.

  The image forming apparatus according to claim 8, when the support frame is attached to the image forming apparatus main body, the support frame is urged in a direction to be pulled out from the image forming apparatus main body by the frame urging means, and is rotatable to the support frame. The hook supported by the hook is biased by the hook biasing means toward the locking plate provided on the image forming apparatus main body, and the locking surface of the locking protrusion provided on the hook is locked. It is locked to the plate material. As a result, the support frame is positioned at the normal position of the image forming apparatus main body.

  Here, when the urging force of the frame urging means is large, the hook rotates against the urging force of the hook urging means by a reaction force that acts on the engaging surface of the engaging protrusion from the engaging plate material. There is a risk that it will come off from the locking plate.

  For this reason, the angle between the locking surface of the locking projection and the straight line extending to the contact point between the locking surface and the locking plate is 90 ° or less, and the direction of the reaction force is the same as this straight line. By doing so, the reaction force is prevented from acting on the lock release side in the rotation direction of the hook with respect to the lock surface.

  Since the present invention is configured as described above, in the image forming apparatus in which the support frame for supporting the photosensitive drum is detachable from the image forming apparatus main body in the axial direction of the photosensitive drum, the image forming apparatus main body is mounted at a normal position. It is possible to prevent erroneous detection of a support frame that is not. Further, it is possible to prevent erroneous detection of the support frame due to the operator touching the detection means by mistake, and further, it is possible to prevent the hook from being detached from the locking plate by the urging force of the frame urging means.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a monochrome laser beam printer (hereinafter referred to as a printer) 10 forms a toner image on a photosensitive drum 12 and transfers the toner image onto a sheet P conveyed from the photosensitive drum 12. The unit 14 is provided. A plurality of paper feed cassettes 16 are provided below the image forming unit 14 so as to be inserted into and removed from the printer main body 18.

  Sheets P are stacked on the sheet feeding cassette 16, and a pickup roll 20 is provided at the downstream end of the sheet feeding cassette 16 in the transport direction. The pickup roll 20 abuts on the uppermost sheet P and is rotationally driven to feed the sheet P from the sheet feeding cassette 16 to the downstream side in the transport direction one by one.

  Then, the conveyance path L on the downstream side of the pickup roll 20 extends upward, and then is folded back and extends in the horizontal direction to reach the image forming unit 14. A plurality of transport rolls 22 are disposed along the transport path L. Further, a manual feed tray 24 for feeding paper P from the outside of the printer main body 18 is disposed facing the vertical conveyance path L1 of the conveyance path L, and is disposed at the downstream end of the manual feed tray 24 in the conveyance direction. A pickup roll 26 is provided for feeding the paper P set on the manual feed tray 24 to the vertical conveyance path L1.

  A transport belt 28 that holds the paper P and transports it in the horizontal direction is disposed in the horizontal transport path L2 of the transport path L. The photosensitive drum 12 is disposed so as to face the upper surface of the conveying belt 28, and a transfer roll 30 disposed on the back side of the conveying belt 28 presses the upper surface of the conveying belt 28 against the photosensitive drum 12.

  Around the photosensitive drum 12, there are a charging charger 32 for cleaning, a cleaning blade 34, a charging charger 36, a developing roller 38, a charge eliminating charger 40, and a transfer roller 30 in order in the rotational direction (counterclockwise direction in the figure). It is arranged.

  The charging charger 32 for cleaning charges the photosensitive surface after transfer, and reduces the electrostatic adsorption force between the toner remaining without being transferred to the paper P and the photosensitive drum 12. Then, the cleaning blade 34 scrapes off the untransferred residual toner on the photosensitive drum 12. A waste toner box 42 is provided on the right side of the photosensitive drum 12, and the toner scraped off from the photosensitive drum 12 by the cleaning blade 34 is collected in the waste toner box 42.

  Further, the charging charger 36 uniformly charges the photosensitive drum 12. An optical scanning device 44 is disposed above the photosensitive drum 12. The optical scanning device 44 scans the charged surface of the photosensitive drum 12 with laser light and causes the photosensitive drum 12 to electrostatic latent. Form an image.

  The developing roller 38 develops the electrostatic latent image on the photosensitive drum 12 with toner. The developing device 46 provided with the developing roller 38 is provided with a stirring screw 48 rotatably. 48 is rotated and the toner in the developing device 46 is supplied to the developing roll 38 while being agitated. A toner cartridge 50 is disposed on the left side of the developing unit 46 in the drawing. The toner cartridge 50 is provided with a toner tank 52 filled with toner and a screw auger 54. When the screw auger 54 is driven to rotate, a developer is supplied from the toner tank 52 via a toner supply path (not shown). Toner is supplied into 46.

  The neutralization charger 40 neutralizes the surface of the photosensitive drum 12 on which the toner image is formed, and the transfer roll 30 transfers the toner image from the photosensitive drum 12 to the paper P. The sheet P on which the toner image is transferred is conveyed in the horizontal direction by the conveying belt 28 and enters a fixing device 56 disposed in the horizontal direction of the conveying belt 28. In the fixing device 56, the pressure roll 60 is pressed against the heat roll 58, and when the paper P is nipped and conveyed by the heat roll 58 and the pressure roll 60, the toner is melted. Fix on the paper P. Then, the sheet P sent out from the fixing device 56 is discharged to a discharge tray 64 by a discharge roll 62.

  Here, the photosensitive drum 12, the cleaning charger 32, the cleaning blade 34, the charging charger 36, the charge removal charger 40, and the toner box 42 are accommodated in a support frame 66 that rotatably supports the photosensitive drum 12. This unit is called a process cartridge 11.

  As shown in FIG. 2, the process cartridge 11 can be attached to and detached from the printer main body 18 in the axial direction of the photosensitive drum 12. A mounting portion 19 to which the photosensitive drum 12 of the printer main body 18 is mounted is provided with a micro switch 68 that detects the presence or absence of the process cartridge 11. The process cartridge 11 is an actuator that presses a lever 68 A of the micro switch 68. A hook 70 is provided.

  As shown in FIG. 3, a hook 70 is rotatably supported at an end of the upper surface of the support frame 66 on the near side in the attaching / detaching direction. One end of the hook 70 in the longitudinal direction is supported by the support frame 66, and an upward hook portion 70A is formed at the other end in the longitudinal direction. Further, a compression coil spring 72 is provided between the hook 70 and the support frame 66, and the hook 70 is biased upward by the compression coil spring 72. The hook 70 is stopped from rotating by the urging force of the compression coil spring 72 at a horizontal position by a stopper (not shown).

  On the other hand, the micro switch 68 is attached to a support member 74 provided on the front side of the attaching portion 19 in the attaching / detaching direction. As shown in FIGS. 2 and 3, the support member 74 is an L-shaped plate, and the microswitch 68 is attached to the side wall 74A with the lever 68A facing downward. Further, as shown in FIG. 3A, the locking piece 74B extending in the horizontal direction from the lower end portion of the side wall 74A is disposed at a height that makes contact with the hook portion 70A. The surface of the hook portion 70A that comes into contact with the locking piece 74B is tapered. As shown in FIG. 3B, the process cartridge 11 is inserted into the mounting portion 19, and the hook portion 70A is connected to the locking piece 74B. When abutting, the hook 70 is pushed down against the urging force of the compression coil spring 72 and passes under the locking piece 74B.

  Here, as shown in FIG. 3C, a locking hole 74C is formed in the locking piece 74B, and when the hook portion 70A moves below the locking hole 74C, the hook 70 is moved. Is lifted by the urging force of the compression coil spring 72, and the hook portion 70A is inserted into the locking hole 74C.

  The micro switch 68 is disposed above the locking hole 74C, and the lever 68A is pushed up by the hook portion 70A inserted into the locking hole 74C so that the switch is turned on. .

  In addition, a grip portion 71 that protrudes in a direction orthogonal to the longitudinal direction of the hook 70 is provided at one end portion in the longitudinal direction of the hook 70, and the hook 70 is engaged by pushing the grip portion 71 clockwise in the drawing. The locking with the stop piece 74B can be released.

  The rotating shaft 12A of the photosensitive drum 12 protrudes to the back side of the support frame 66, and a coupling 76 is attached to a portion protruding from the support frame 66 of the rotating shaft 12A. A rotating shaft 78 that is driven to rotate by a driving source provided in the printer main body 18 is provided on an extension line of the rotating shaft 12A of the photosensitive drum 12 of the mounting portion 19. The rotating shaft 78 includes a cup. A ring 80 is slidably mounted. The coupling 80 is pressed against the coupling 76 by a compression coil spring 82. Further, the contact surfaces of the couplings 76 and 80 are formed with convex and concave shapes that can be engaged.

  As a result, the rotating shaft 12A of the photosensitive drum 12 and the rotating shaft 78 of the printer main body 18 are connected, so that the photosensitive drum 12 can be rotated by rotationally driving the rotating shaft 78.

  Further, since the process cartridge 11 is urged by the compression coil spring 82 in the direction of pulling out from the printer main body 18 (in the direction of arrow A in the figure), the hook portion 70A always has the hole wall 74C ′ of the locking hole 74C. Pressed against. Therefore, the process cartridge 11 is always positioned at the same position in the mounting portion 19.

  Here, the position where the process cartridge 11 is positioned by the hook 70 or the like is the normal position of the process cartridge 11. However, when the process cartridge 11 is out of the normal position as shown in FIG. 70 does not contact the lever 68A of the micro switch 68, and the hook 70 pushes up the lever 68A of the micro switch 68 only when the process cartridge 11 is positioned at the normal position as shown in FIG. Switch 68 is turned on.

  That is, the micro switch 68 cannot be turned on in a state where the process cartridge 11 is not mounted at the normal position of the mounting portion 19. Further, the micro switch 68 is provided on the back side of the locking piece 74B so that a user, a serviceman or the like cannot directly touch the micro switch 68.

  Therefore, it can be reliably prevented that the process cartridge 11 is erroneously detected as being attached to the attachment portion 19 even though the process cartridge 11 is not attached to the regular position of the attachment portion 19.

  As shown in FIG. 2, a side surface 18A of the printer body 18 to which the process cartridge 11, the developing device 46, and the like are attached and detached includes a cover (not shown) that opens and closes the side surface 18A, and an interface that detects opening and closing of the cover. A lock switch (not shown) is provided. This interlock switch is connected to a cheat circuit. That is, when the cover is closed and the interlock switch is turned on, the cleaning charging charger 32, the charging charger 36, the high voltage generating circuit 84 (see FIG. 3) for generating a high voltage in the charge eliminating charger 40, and the optical scanning device 44. The power is supplied to (see FIGS. 1 and 3), and the printing operation becomes possible. On the other hand, when the cover is opened and the interlock switch is turned off, the power supply to the high voltage generation circuit 84 and the optical scanning device 44 is cut off, and generation of a high voltage and emission of laser light become impossible.

  In this embodiment, as shown in FIG. 3, in addition to the cheat circuit connected to the interlock switch described above, a cheat circuit 86 in which the optical scanning device 44 and the high voltage generation circuit 84 are connected to the micro switch 68 is provided. Provided. That is, when the process cartridge 11 is mounted at the normal position of the mounting portion 19 and the micro switch 68 is turned on, power is supplied to the optical scanning device 44 and the high voltage generation circuit 84, and conversely, the process cartridge 11 is mounted on the mounting portion 19. When the micro switch 68 is turned off, the power supply to the optical scanning device 44 and the high voltage generation circuit 84 is cut off.

  As a result, the optical scanning device 44 does not expose the photosensitive drum 12 out of the normal position of the printer main body 18, and it is possible to prevent the exposure position from deviating from the effective image forming area of the photosensitive drum 12.

  Further, even if it is not detected that the cover is open due to a malfunction of the interlock switch, for example, the optical scanning device 44, the high voltage generation circuit, and the like as long as the process cartridge 11 is not mounted at the normal position of the mounting portion 19 84 becomes inoperable. For this reason, a user or serviceman who attaches or removes the process cartridge 11 to / from the mounting unit 19 receives the laser beam emitted from the optical scanning device 44, and a user or serviceman or the like receives a terminal of the high voltage generation circuit 84. It is possible to reliably prevent an electric shock from being touched.

  Next, the shape of the hook portion 70A of the hook 70 will be described.

  As shown in FIG. 4, the hook 70 is rotatably supported at one end in the longitudinal direction by the support frame 66, and the hook portion 70 </ b> A is a protrusion protruding toward the locking piece 74 </ b> B at the other end in the longitudinal direction. Is formed. The hook portion 70A has a trapezoidal shape, and a locking surface 70B that is locked to the hole wall 74C ′ of the locking hole 74C is inclined toward one end in the longitudinal direction.

  Here, when the urging force of the compression coil spring 82 that urges the process cartridge 11 in the direction in which the process cartridge 11 is pulled out from the mounting portion 19 is large, the reaction force acting on the locking surface 70B from the hole wall 74C ′ causes the hook 70 to move to the compression coil spring 72. There is a risk that the hook portion 70A may come out of the locking hole 74C by rotating against the urging force. For this reason, an angle α between the straight line X (shown by a chain line in the figure) extending from the rotation center 70C of the hook 70 to the contact point P between the locking surface 70B and the hole wall 74C ′ and the locking surface 70B, By making the direction of the reaction force the same as that of the straight line X at 90 ° or less, the reaction force is prevented from acting on the locking release side in the rotation direction of the hook 70 with respect to the locking surface 70B. .

  Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted.

  As shown in FIG. 5A, in the process cartridge 100, the rotating shaft 12A of the photosensitive drum 12 protrudes to the back side of the support frame 66, and a portion protruding from the support frame 66 of the rotating shaft 12A A helical gear 102 is attached. A rotation shaft 104 that is rotated by a drive source provided in the printer main body 18 is provided at the innermost portion of the mounting portion 19, and a helical gear 106 is attached to the rotation shaft 104. . As shown in FIG. 5B, the process cartridge 100 is mounted on the mounting portion 19, the helical gear 106 is connected to the helical gear 102, and the rotary shaft 104 is driven to rotate, so that the photoconductor. The drum 12 is rotated.

  Here, as shown in FIG. 5C, when the helical gear 106 meshes with the helical gear 102 and rotates, a thrust force Q acts on the helical gear 102. This thrust force Q However, the tooth directions and rotation directions of the helical gears 102 and 106 are set so that the process cartridge 100 acts in the direction in which the process cartridge 100 comes out of the mounting portion 19 (the direction of arrow A in the figure). For this reason, when the rotation shaft 104 is driven to rotate, the photosensitive drum 12 is rotated and the process cartridge 100 is urged in the direction of being detached from the mounting portion 19. Accordingly, since the hook portion 70A is always pressed against the hole wall 74C ′ of the locking hole 74C, the process cartridge 100 is always positioned at the same position in the mounting portion 19.

  In the present embodiment, a photo sensor 108 is provided instead of the micro switch 68 of the first embodiment. The photo sensor 108 is attached to the side wall 74A of the support member 74, and detects the hook portion 70A locked to the locked member 74B.

1 is a diagram schematically illustrating a monochrome laser printer according to a first embodiment of the present invention. 1 is a perspective view showing a process cartridge of a monochrome laser printer according to a first embodiment of the present invention. (A)-(C) is a figure which shows the attachment or detachment mechanism of the process cartridge and printer main body of the monochrome laser printer of 1st Embodiment of this invention. It is a figure which shows the shape of the hook of the process cartridge of the monochrome laser printer of 1st Embodiment of this invention. (A)-(C) is a figure which shows the attachment or detachment mechanism of the process cartridge and printer main body of the monochrome laser printer of 2nd Embodiment of this invention.

Explanation of symbols

10 Monochrome laser printer (image forming device)
12 Photosensitive drum 18 Printer body (image forming apparatus body)
32 Charging charger for cleaning (high voltage generating means)
36 Charging charger (high voltage generating means)
40 Charger (high voltage generator)
44 Optical scanning device (exposure means)
66 Support frame 68 Micro switch (detection means)
70 hook (locking means)
70A hook part (protrusion for locking)
70B Locking surface 72 Compression coil spring (hook biasing means)
74B Locking piece (locking plate)
78 Rotating shaft 80 Coupling (connecting member)
82 Compression coil spring (frame biasing means)
86 Cheat circuit (first cheat circuit, second cheat circuit)
102 helical gear (drum side helical gear)
106 Helical gear (helical gear on the main body side)
108 Photosensor (detection means)
P paper (recording medium)
Q Thrust force X Straight line α Angle

Claims (8)

A photosensitive drum carrying a toner image and transferring it to a transfer medium;
A support frame that supports the photosensitive drum and is detachably attached to an image forming apparatus main body in an axial direction of the photosensitive drum;
Locking means provided on the support frame or the image forming apparatus main body;
Locked means provided on the image forming apparatus main body or the support frame and locked by the locking means when the support frame is mounted at a normal position of the image forming apparatus main body.
A detecting unit that is provided on the image forming apparatus main body or the support frame and detects the locking unit locked to the locked unit;
An image forming apparatus comprising: Exposure means for exposing the photosensitive drum to form an electrostatic latent image on the photosensitive drum;
A first cheat circuit that does not supply power to the exposure means unless the detection means detects the locking means locked to the locked means;
The image forming apparatus according to claim 1, further comprising: High voltage generating means for generating a high voltage to charge or charge the photosensitive drum;
A second cheat circuit that does not supply power to the high-voltage generating means unless the detecting means detects the locking means locked to the locked means;
The image forming apparatus according to claim 1, further comprising:   The detection means and the locked means are provided in the image forming apparatus main body, and the detection means is disposed on the back side of the locked means to prevent an operator from touching the detection means. The image forming apparatus according to any one of claims 1 to 3.   5. The frame urging means for urging the support frame in a direction in which the support frame is pulled out from the main body of the image forming apparatus and for locking the locking means to the locked means. The image forming apparatus according to claim 1. The frame biasing means is
A connecting member rotatably provided in the image forming apparatus main body and connected to a rotation shaft of the photosensitive drum, and rotated by a driving source of the image forming apparatus main body to rotate the photosensitive drum;
Connecting member urging means for urging the connecting member in the direction in which it is extracted;
The image forming apparatus according to claim 5, further comprising: The frame biasing means is
A helical gear on the drum side attached to the rotating shaft of the photosensitive drum;
The image forming apparatus main body is rotatably provided and connected to the drum side helical gear, and is rotated by a driving source of the image forming apparatus main body to rotate the photosensitive drum, and the drum side helical A helical gear on the main body side that imparts a thrust force in the extraction direction to the tooth gear;
The image forming apparatus according to claim 5, further comprising: The locked means is a locking plate provided in the image forming apparatus main body,
The locking means is a hook that is rotatably supported by the support frame and is provided with a locking projection that is locked to the locking plate.
Hook urging means for urging the hook toward the locking member;
A locking surface of the locking projection that is locked to the locking plate material, and a straight line that extends from the pivot center of the hook to a contact point between the locking surface and the locking plate material. The image forming apparatus according to claim 5, wherein the angle is 90 ° or less.

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