JP2013246399A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve safety of a mechanism for supplying a voltage to a cartridge detachably attachable to a chassis of an image forming apparatus that forms an image on a recording medium with a developer by means of an electrophotographic system.SOLUTION: When a process cartridge is inserted inside of a body frame 123, a supply terminal of the process cartridge is abutted to a cartridge-side contact 133. As the process cartridge is further inserted, completing the attachment, a rod-like part 131 is swung to cause a power supply-side contact 135 to be abutted to an output terminal 121 (B). This causes a voltage output from the output terminal 121 to be applied to the supply terminal, and image-forming is enabled. In contrast, when the process cartridge is detached, the rod-like part 131 is swung to a direction opposite to the direction at the time of attaching the process cartridge by energizing force of a tension coil spring 137 so that the power supply-side contact 135 is separated from the output terminal 121 (A).

Description

  The present invention relates to an image forming apparatus that forms an image with a developer on a recording medium by an electrophotographic method, and more particularly, to a configuration for supplying a voltage to a cartridge that can be attached to and detached from a housing of the image forming apparatus. The present invention relates to an image forming apparatus.

  In an image forming apparatus that forms an image of a developer on a recording medium by an electrophotographic method, each part such as a charger for charging a photoreceptor and a developing roller for developing an electrostatic latent image formed on the photoreceptor, It is necessary to apply a high voltage. Further, in this type of image forming apparatus, a cartridge that holds the above-mentioned photoconductor, charger, developing roller, etc. integrally or individually is configured to be detachable from the casing of the image forming apparatus, and the cartridge that has reached the end of its life Can be replaced.

  For this reason, various configurations have been proposed for supplying the high voltage from a high voltage power source provided inside the housing to the cartridge that can be attached to and detached from the housing. For example, it is proposed that an annular electrode urged in the cartridge direction by a coil spring is provided on the side of the cartridge attachment / detachment path, and the high voltage is supplied by bringing the electrode into contact with the electrode on the cartridge side. (For example, refer to Patent Document 1). In that case, by mounting the cartridge while pushing the annular electrode to the side, the annular electrode is pressed against the electrode of the mounted cartridge.

JP 2011-64925 A

  However, if the annular electrode to which a high voltage is applied is exposed in the cartridge attachment / detachment path, there is a risk of electric shock if the user accidentally touches the electrode. Therefore, in this type of image forming apparatus, when the cover of the casing is opened for attaching and detaching the cartridge, voltage application to the annular electrode may be interrupted by software processing.

  However, even if voltage application is interrupted by such software processing, a certain amount of voltage is applied to the annular electrode immediately after the processing is performed. Considering the case where the software processing is delayed for some reason, it is necessary to improve the safety.

  Accordingly, the present invention improves the safety of a mechanism for supplying a voltage to a cartridge that can be attached to and detached from the housing of an image forming apparatus in an image forming apparatus that forms an image of a developer on a recording medium by an electrophotographic method. It was made for the purpose.

  The image forming apparatus of the present invention made to achieve the above object includes an image forming unit that forms an image by a developer on a recording medium by an electrophotographic method, a housing that houses the image forming unit therein, A cartridge that forms at least a part of the image forming unit, is configured to be detachable from the casing, and includes a supply terminal to which a voltage is supplied when the casing is mounted, and is provided inside the casing. A high-voltage power source that outputs a voltage to be supplied to the supply terminal from an output terminal, and when the cartridge moves in accordance with the attachment / detachment of the cartridge to / from the case, and the cartridge is detached from the case Includes a conductive member that does not contact either the supply terminal or the output terminal, and that contacts both the supply terminal and the output terminal when the cartridge is mounted in the housing, and makes the both conductive. It is characterized in that was.

  In the image forming apparatus of the present invention configured as described above, when the cartridge is mounted in the casing, the conductive member moves in the casing according to the mounting, and the supply terminal of the cartridge and the output terminal of the high-voltage power source Both are brought into contact and made conductive. For this reason, when the high voltage power supply outputs the voltage to be supplied to the supply terminal from the output terminal, the voltage is supplied to the supply terminal of the cartridge, and the voltage is provided in the cartridge as a part of the image forming unit. By supplying the toner to a developing roller or the like, an image of the developer can be formed on the recording medium by an electrophotographic method.

  Further, when the cartridge is detached from the casing, the conductive member moves within the casing in accordance with the separation, and does not come in contact with either the supply terminal or the output terminal. For this reason, even if the user accidentally touches the conductive member after the cartridge is detached from the housing, the conductive member is not in contact with the output terminal, so that safety can be ensured.

  In the present invention, the supply terminal is provided at a tip portion of the cartridge with respect to the mounting direction of the cartridge, and the output terminal is provided at a tip portion of the high-voltage power source with respect to the mounting direction of the cartridge, The conductive member is provided at a rod-like portion configured in a rod shape that swings about an axis perpendicular to the mounting and detaching direction of the cartridge, and at one end of the rod-like portion, while contacting the supply terminal when the cartridge is mounted. A cartridge-side contact that swings the rod-shaped portion around the shaft by being pressed by the supply terminal and the other end of the rod-shaped portion are provided, and the output is generated by the rocking of the rod-shaped portion when the cartridge is mounted. A power-side contact that contacts the terminal, and by applying an urging force to the rod-shaped portion, Is the Jo portion and when the cartridge mounting is swung in the opposite direction, a biasing member for isolating the power supply side contact from the output terminal may be provided.

  In this case, when the cartridge is mounted, the supply terminal provided at the distal end with respect to the mounting direction of the cartridge presses the cartridge side contact, thereby swinging the rod-shaped portion. Then, the power supply side contact comes into contact with the output terminal provided at the tip of the high voltage power supply with respect to the mounting direction of the cartridge, and the supply terminal and the output terminal are electrically connected to enable image formation.

  On the other hand, when the cartridge is detached, the bar-like portion swings in the direction opposite to that when the cartridge is mounted by the urging force of the urging member, and the power supply side contact is isolated from the output terminal. For this reason, since the conductive member composed of the rod-shaped portion, the cartridge side contact, and the power source side contact is electrically isolated from the output terminal, safety can be ensured as described above. In this case, since the output terminal is provided at the tip of the high voltage power supply with respect to the mounting direction of the cartridge, that is, on the back side when viewed from the user, the user can be prevented from directly touching the output terminal. Can be further improved. Further, in this case, the image forming apparatus can be favorably downsized to the side with respect to the mounting / demounting direction of the cartridge, and the manufacturing cost can be reduced because the configuration is simple.

  In the present invention, the cartridge has a recess on a surface facing the high-voltage power source, the supply terminal is provided in the recess, and the output terminal faces the cartridge of the high-voltage power source. The conductive member is formed in a bar shape perpendicular to the mounting / removing direction of the cartridge, and is set in advance while being pushed in the mounting direction tip of the cartridge and moving in the mounting direction when the cartridge is mounted. A power supply side contact that moves in the direction of the high-voltage power supply along the path, and a rod shape that is orthogonal to the mounting and dismounting direction of the cartridge, and the movement of the power supply side contact is transmitted via a conductive link, When the cartridge is mounted, the cartridge enters the recess while moving in the mounting direction along a preset path, and after the insertion, the cartridge engages with the recess. A cartridge-side contact that further enters the recess while moving in the mounting direction and moves the power-side contact via the link, and when the cartridge is completely mounted, the power-side contact and the cartridge By moving the side contact, the power source side contact comes into contact with the output terminal and the cartridge side contact comes into contact with the supply terminal, and by applying a biasing force to the power source side contact or the cartridge side contact, When the cartridge is detached, the power supply side contact and the cartridge side contact are moved in a direction opposite to that when the cartridge is mounted, and an urging member for separating the power supply side contact from the output terminal is further provided. May be.

  In this case, when the cartridge is mounted, the power supply side contact is moved in the direction of the high voltage power supply along a preset path while being pressed in the mounting direction tip of the cartridge and moved in the mounting direction. Further, the movement is transmitted through the conductive link, so that the cartridge-side contact enters the concave portion of the cartridge while moving in the mounting direction, and after the invasion, the cartridge contacts by the engagement with the concave portion. It further enters the recess while moving in the mounting direction. The movement of the cartridge side contact after the intrusion is transmitted to the power source side contact via the link, and when the cartridge is completely mounted, the power source side contact contacts the output terminal and the cartridge side contact contacts the supply terminal. For this reason, the supply terminal and the output terminal are electrically connected to enable image formation.

  On the other hand, when the cartridge is detached, the biasing member applies a biasing force to the power source side contact or the cartridge side contact, thereby moving the power source side contact and the cartridge side contact in the direction opposite to that when the cartridge is mounted. Is isolated from the output terminal. For this reason, since the conductive member including the link, the cartridge side contact, and the power source side contact is electrically isolated from the output terminal, safety can be ensured as described above. Further, in this case, the power supply side contact contacts the output terminal by moving in the high voltage power supply direction. For this reason, it is possible to provide the output terminal at a position far away from the cartridge attachment / detachment path. In this case, it is possible to better suppress the user's direct contact with the output terminal and further improve safety. Can do.

  In the present invention, a main body frame provided between the mounting position of the cartridge and the high-voltage power supply and fixed to the housing, and provided between the main body frame and the mounting position of the cartridge. When the cartridge is mounted, the cartridge is pressed at the tip of the cartridge in the mounting direction and moves in the housing from the reference position in the mounting direction. When the cartridge is detached, the cartridge is urged by the urging member to return to the reference position. A movable member, wherein the supply terminal is provided on a surface of the cartridge facing the body frame, the output terminal is provided on a surface of the high-voltage power source facing the cartridge, and the conductive member The member moves together with the moving member in the direction of attaching / detaching the cartridge and is biased in the direction of the high-voltage power source, and when the cartridge is completely attached A power-side contact that is pressed against the output terminal opposite to the output terminal, and supported by the main body frame and biased toward the cartridge, and when the moving member is at the reference position, The cartridge side contact is held outside the cartridge attachment / detachment path, and when the cartridge is completely loaded, the latch by the moving member is released and pressed against the supply terminal of the cartridge; There may be provided a conduction portion that conducts the power supply side contact and the cartridge side contact while allowing movement.

  In this case, when the cartridge is mounted, the moving member is pressed by the tip of the cartridge in the mounting direction and moves in the housing from the reference position in the mounting direction. Then, when the mounting of the cartridge is completed, the power supply side contact faces the output terminal and is pressed against the output terminal. Further, the cartridge side contact is locked to the moving member when the moving member is at the reference position and is held outside the cartridge attaching / detaching path, but when the cartridge is completely mounted, the locking by the moving member is released. And pressed against the supply terminal of the cartridge. The conducting portion conducts the power supply side contact and the cartridge side contact while allowing the movement of the moving member, so that the supply terminal and the output terminal are conducted to form an image.

  On the other hand, when the cartridge is detached, it is urged by the urging member, and the moving member returns to the reference position. Then, the power supply side contact that moves in the direction of attaching and detaching the cartridge together with the moving member is isolated from the output terminal. For this reason, since the conductive member including the conduction portion, the cartridge side contact, and the power source side contact is electrically isolated from the output terminal, safety can be ensured as described above. Further, in this case, when the moving member returns to the reference position, the cartridge-side contact is locked by the moving member and is held outside the cartridge attaching / detaching path, so that safety can be further improved. . The conductive portion may be a component common to the biasing member or may be a separate component.

1 is a central sectional view schematically showing a configuration of an image forming apparatus to which the present invention is applied. FIG. 2 is a perspective view schematically illustrating the entire configuration of the image forming apparatus. FIG. 3 is a schematic diagram illustrating a mechanism for energizing a cartridge of the image forming apparatus. It is a schematic diagram showing the structure and operation | movement of the electricity supply mechanism in detail. It is a schematic diagram showing the structure and operation | movement of the modification of the electricity supply mechanism in detail. It is a schematic diagram showing the structure and operation | movement of the contact vicinity of the electricity supply mechanism in detail. It is a schematic diagram showing the structure and operation | movement of the further modification of the said electricity supply mechanism in detail.

[Entire configuration of image forming apparatus]
Next, embodiments of the present invention will be described with reference to the drawings. In the following description, when distinguishing each component for each color, subscripts of B (black), Y (yellow), M (magenta), and C (cyan) are added to the reference numerals of the respective parts. If not distinguished, the subscript is omitted.

  FIG. 1 is a central sectional view schematically showing the configuration of an image forming apparatus 1 to which the present invention is applied. As shown in FIG. 1, the image forming apparatus 1 includes a paper feeding unit 3, an image forming unit 5, a transport mechanism 7, a fixing unit 9, and a housing 2 that forms an appearance design surface of the image forming apparatus 1. A belt cleaning mechanism 20 and a high voltage power supply substrate 110 are provided. The paper feeding unit 3 is provided at the lowermost part of the image forming apparatus 1 and includes a tray 17 that accommodates a sheet (paper, OHP sheet, etc.) 15 as an example of a recording medium, and a pickup roller 19. The sheets 15 accommodated in the tray 17 are taken out one by one by a pickup roller 19 and are sent to the transport mechanism 7 via the transport roller 11 and the registration roller 12.

  The transport mechanism 7 transports the sheet 15 and is installed above the paper feed unit 3 in the image forming apparatus 1. The transport mechanism 7 includes a driving roller 31, a driven roller 32, and a belt 34, and the belt 34 is bridged between the driving roller 31 and the driven roller 32. When the drive roller 31 rotates, the surface of the belt 34 facing the photosensitive drums 41B, 41Y, 41M, and 41C moves from the right direction to the left direction in FIG. As a result, the sheet 15 sent from the registration roller 12 is conveyed downward of the image forming unit 5.

  The belt 34 is provided with four transfer rollers 33B, 33Y, 33M, and 33C corresponding to the four photosensitive drums 41B, 41Y, 41M, and 41C. Each transfer roller 33 is disposed at a position facing each of the photosensitive drums 41B, 41Y, 41M, and 41C with the belt 34 interposed therebetween.

  The image forming unit 5 includes four process cartridges 40B, 40Y, 40M, and 40C (an example of a cartridge) and four exposure devices 49B, 49Y, 49M, and 49C. The process cartridges 40B, 40Y, 40M, and 40C are arranged in a line in the conveyance direction of the sheet 15 (left and right direction in FIG. 1). In the following description, for the sake of convenience, the arrangement direction of the process cartridges 40 is the front-rear direction (the process cartridge 40B side is the front), the right side when viewed from the front is the right, and the left side is the left.

  Each process cartridge 40 has the same structure, and a photosensitive drum 41, a developing roller 45 that supplies frictionally charged toner (for example, positively charged non-magnetic one-component toner) to the surface of the photosensitive drum 41, and the photosensitive drum It has a structure including a charger 50 for uniformly charging 41. Each exposure device 49B, 49Y, 49M, 49C has, for example, a plurality of light emitting elements (for example, LEDs and organic EL) arranged in a line along the rotation axis direction of the photosensitive drums 41B, 41Y, 41M, 41C. By emitting light in accordance with image data input from the outside, a function of forming an electrostatic latent image on the surface of each photosensitive drum 41B, 41Y, 41M, 41C is achieved.

  A series of image forming processes performed by the image forming apparatus 1 configured as described above will be briefly described. When the image forming apparatus 1 receives image data, the image forming apparatus 1 starts a printing process. As a result, the surfaces of the photosensitive drums 41B, 41Y, 41M, and 41C are uniformly positively charged by the chargers 50B, 50Y, 50M, and 50C as they rotate. Then, the photosensitive drums 41B, 41Y, 41M, and 41C are exposed by the exposure devices 49B, 49Y, 49M, and 49C according to the received image data. As a result, a predetermined electrostatic latent image corresponding to the image data is formed on the surface of each photoconductive drum 41B, 41Y, 41M, 41C. That is, the exposed portion of the surface of the uniformly positively charged photosensitive drums 41B, 41Y, 41M, and 41C has a reduced potential.

  Next, by the rotation of the developing roller 45, the toner carried on the developing roller 45 and positively charged is supplied to the electrostatic latent images formed on the surfaces of the photosensitive drums 41B, 41Y, 41M, and 41C. The As a result, the electrostatic latent images on the photoconductive drums 41B, 41Y, 41M, and 41C are visualized, and toner images by reversal development are carried on the surfaces of the photoconductive drums 41B, 41Y, 41M, and 41C. The

  In addition, a process for conveying the sheet 15 is performed in parallel with the process for forming the toner image. That is, as the pickup roller 19 rotates, the sheets 15 are sent one by one from the tray 17 to the paper transport path Y. The sheet 15 sent to the paper conveyance path Y is conveyed to a transfer position (a point where the photosensitive drum 41 and the transfer roller 33 face each other) by the conveyance roller 11 and the belt 34.

  Then, when passing through this transfer position, the toner images (developer images) of the respective colors carried on the surface of the photosensitive drums 41 are sequentially applied to the surface of the sheet 15 by the transfer bias applied to the transfer rollers 33. Are superimposed and transferred. Thus, a color toner image (developer image) is formed on the sheet 15. Thereafter, when the toner image passes through the fixing unit 9 provided behind the belt 34, the transferred toner image (developer image) is thermally fixed, and the sheet 15 is discharged onto the discharge tray 60.

  Each process cartridge 40 needs to be replaced when the toner is consumed, for example. Therefore, in the present embodiment, as indicated by thick arrows in FIG. 1, each cartridge 40 is configured to be detachable from the housing 2 individually in the vertical direction. More specifically, as shown in FIG. 2, the housing 2 includes a main body 2A that holds the transport mechanism 7 and each process cartridge 40, and a lid 2B that is provided on the upper surface of the main body 2A so as to be opened and closed. It is configured. Then, by opening the lid 2B, the process cartridges 40B, 40Y, 40M, and 40C mounted in the main body 2A along the conveying direction of the sheet 15 are exposed upward, and the process cartridges 40 are vertically moved. It becomes detachable.

[Configuration of power supply mechanism to cartridge]
As described above, it is necessary to apply a high voltage exceeding at least 100 V (more specifically, 200 V or more) to each part of the process cartridge 40. For example, in the scorotron charger 50, a voltage of 7 kV may be applied to the charging wire and 700 V may be applied to the grid. By doing so, the surface of the photosensitive drum 41 can be charged to about 700V. In this case, a voltage of about 200 to 500 V is applied to the developing roller 45 in order to supply toner to the surface of the photosensitive drum 41 whose potential has been lowered to about 100 V by exposure.

  Therefore, in the present embodiment, as shown in FIGS. 1 and 2, the housing 2 (more specifically, the main body 2 </ b> A) is located laterally (on the right) from the attachment / detachment path of each process cartridge 40. A high voltage power supply substrate 110 is provided. In addition, mold transformers 120B, 120Y, 120M, and 120C (an example of a high-voltage power supply) that output the high voltage are respectively provided at positions opposite to the mounting positions of the process cartridges 40B, 40Y, 40M, and 40C on the high-voltage power supply substrate 110. Is provided. The mold transformer 120 is for boosting a DC voltage of about 24 V created by the high-voltage power supply substrate 110 to a charging voltage of several thousand V and supplying it to the process cartridge 40.

  Hereinafter, a power supply mechanism from the mold transformer 120 to the process cartridge 40 will be described. This energization mechanism is similarly configured for each of the process cartridges 40B, 40Y, 40M, and 40C. FIG. 3 is a schematic diagram illustrating the configuration of the energization mechanism from the front side of the image forming apparatus 1. FIG. 4 is a schematic diagram showing the main part of the energization mechanism in detail. In FIG. 3, only a part of the process cartridge 40 is shown. As shown in FIG. 3, a supply terminal 51 to which a voltage to be applied to the charger 50 (or the developing roller 45) is supplied to the side surface of the process cartridge 40 that faces the high-voltage power supply substrate 110. It is provided at a position facing downward when mounted. An output terminal 121 that outputs a voltage to be supplied to the supply terminal 51 is provided below the mold transformer 120. When the process cartridge 40 is mounted on the housing 2, the supply terminal 51 and the output terminal 121 are electrically connected via the conductive member 130 as shown in FIG.

  As shown in FIG. 4, a body frame 123 that supports the process cartridge 40 is provided inside the housing 2, and a part of the conductive member 130 is attached to a shaft 125 that is provided in the body frame 123 in the front-rear direction. The rod-shaped part 131 which comprises is attached. The conductive member 130 includes the rod-shaped portion 131 and cartridge side contacts 133 and power source side contacts 135 provided at both ends thereof. The conductive member 130 is made of a conductive material such as metal, and can swing around the shaft 125. Has been. The main body frame 123 is positioned and fixed with respect to the housing 2 between the mounting position of the process cartridge 40 and the mold transformer 120.

  The cartridge side contact 133 is an annular electrode that can come into contact with the supply terminal 51 when the process cartridge 40 is mounted, and the power supply side contact 135 is an annular electrode provided at a position facing the output terminal 121. Further, the rod-shaped portion 131 is biased in the direction in which the end portion on the power source side contact 135 side is separated from the output terminal 121 by a tension coil spring 137 (an example of a biasing member).

[Effect of this embodiment]
For this reason, when the process cartridge 40 is not attached, the power-side contact 135 is isolated from the output terminal 121 by the urging force of the tension coil spring 137 as shown in FIG. As the urging member, a plate spring, a compression coil spring, rubber or the like may be used in addition to the tension coil spring.

  From this state, when the process cartridge 40 is inserted inside the main body frame 123, the supply terminal 51 comes into contact with the cartridge side contact 133, and when the process cartridge 40 is further inserted and the mounting is completed, FIG. The conductive member 130 swings to the position shown. That is, when the supply terminal 51 presses the cartridge side contact 133, the rod-like portion 131 is swung, and the power supply side contact 135 is brought into contact with the output terminal 121. As a result, the voltage output from the output terminal 121 is applied to the supply terminal 51, and image formation using the process cartridge 40 becomes possible.

  On the other hand, when the process cartridge 40 is detached, the rod-shaped portion 131 swings in the opposite direction to that when the process cartridge 40 is mounted due to the urging force of the tension coil spring 137, and the power-side contact 135 is output as shown in FIG. Isolate from the terminal 121. For this reason, since the conductive member 130 including the rod-shaped portion 131, the cartridge side contact 133, and the power source side contact 135 is electrically isolated from the output terminal 121, the safety of the image forming apparatus 1 can be ensured as follows. it can. That is, even if the user accidentally touches the conductive member 130 after the process cartridge 40 is detached from the housing 2, the conductive member 130 is not in contact with the output terminal 121, so that safety can be ensured. it can.

  In this embodiment, the output terminal 121 is provided on the lower side of the mold transformer 120, that is, on the back side when viewed from the user in the mounting direction of the process cartridge 40, so that the user directly touches the output terminal 121. Can be suppressed, and safety can be further improved. Further, in the present embodiment using the conductive member 130, the image forming apparatus 1 can be favorably downsized in the side (left and right direction) with respect to the attaching / detaching direction of the process cartridge 40, and the manufacturing cost is reduced because the configuration is simple. be able to.

[Other Embodiments of the Present Invention]
In addition, this invention is not limited to the said embodiment at all, It can implement with a various form in the range which does not deviate from the summary of this invention. For example, in the above-described embodiment, the present invention is applied to the configuration in which the charging voltage is applied to the process cartridge 40. However, the present invention may be applied to a configuration in which a developing voltage or a transfer voltage is applied. Moreover, the form of a conductive member can consider various forms as follows besides the said embodiment.

  FIG. 5 is a schematic diagram illustrating in detail the configuration and operation of a modification of the energization mechanism. In this embodiment, the process cartridge 40 has a recess 53 on the surface facing the mold transformer 120, and the supply terminal 51 is provided on the inner wall of the recess 53 in the rear end side in the cartridge insertion direction. The output terminal 121 of the mold transformer 120 is provided on the surface of the mold transformer 120 facing the process cartridge 40. The conductive member 230 includes a link 231, a cartridge side contact 233, and a power supply side contact 235 that are made of a conductive material such as metal.

  That is, the main body frame 223 is formed with an elliptical guide hole 225 having a major axis divided into halves with the strings facing the mold transformer 120 side. The cartridge side contact 233 and the power supply side contact 235 move along the guide hole 225 when at least one of the pins 234 and 236 penetrating the cartridge side contact 233 and the power supply side contact 235 engages with the guide hole 225. The guide hole 225 has a length so that the front end of the process cartridge 40 in the insertion direction faces the output terminal 121 and the power contact 235 contacts the output terminal 121 when the pin 236 moves to the front end in the insertion direction. Designed.

  Further, the cartridge side contact 233 and the power source side contact 235 are each formed in a rod shape and connected by a link 231, and the posture is maintained in the left-right direction orthogonal to the insertion direction of the process cartridge 40. Further, the length of the link 231 is designed so that when either one of the cartridge side contact 233 or the power source side contact 235 is located at the end of the guide hole 225, the other is located at the center of the guide hole 225. . Furthermore, a tension coil spring 237 (an example of an urging member) that urges the cartridge side contact 233 toward the upstream side in the insertion direction of the process cartridge 40 acts on the cartridge side contact 233.

  Therefore, when the process cartridge 40 is not mounted, as shown in FIG. 5A, the cartridge-side contact 233 is positioned at the upstream end of the guide cartridge 225 in the insertion direction of the process cartridge 40, and the power-side contact 235 is Located in the center of the guide hole 225. The power supply side contact 235 is designed to have a length that projects from the inner wall surface of the main body frame 223 to the attachment / detachment path of the process cartridge 40 at this time. Further, the cartridge side contact 233 is designed to have a length that does not protrude into the attachment / detachment path of the process cartridge 40 at this time.

  Therefore, when the process cartridge 40 is mounted, the power-side contact 235 moves in the direction of the mold transformer 120 along the guide hole 225 while being moved in the insertion direction by being pressed by the tip of the process cartridge 40 in the insertion direction. Further, when the movement is transmitted through the link 231, the cartridge side contact 233 moves in the direction of the process cartridge 40 along the guide hole 225 while moving in the insertion direction. The cartridge-side contact 233 is designed to have a length that enters the recess 53 of the process cartridge 40 during this movement. After the entry, the cartridge-side contact 233 moves in the insertion direction by engaging with the recess 53. Invade further.

  Then, the movement of the cartridge side contact 233 after this intrusion is transmitted to the power supply side contact 235 via the link 231. When the mounting of the process cartridge 40 is completed, as shown in FIG. 5B, the power supply side contact 235 comes into contact with the output terminal 121 and the cartridge side contact 233 comes into contact with the supply terminal 51. Therefore, the supply terminal 51 and the output terminal 121 are electrically connected to enable image formation. At this time, the cartridge-side contact 233 is pressed against the supply terminal 51 by the urging force from the tension coil spring 237, so that energization between the two is performed more satisfactorily.

  On the other hand, when the process cartridge 40 is detached, the tension coil spring 237 applies the urging force, thereby moving the power source side contact 235 and the cartridge side contact 233 in the opposite direction to that when the process cartridge 40 is mounted, as shown in FIG. Return to the state. Then, the power supply side contact 235 is isolated from the output terminal 121, and the conductive member 230 composed of the link 231, the cartridge side contact 233, and the power supply side contact 235 is electrically isolated from the output terminal 121. Safety can be ensured.

  In the present embodiment, the power supply side contact point 235 contacts the output terminal 121 by moving in the direction of the mold transformer 120. For this reason, the output terminal 121 can also be provided at a position far away from the attachment / detachment path of the process cartridge 40. In this case, the user can be more effectively prevented from directly touching the output terminal 121, thereby improving safety. This can be further improved. Furthermore, in this embodiment, the lengths of the cartridge side contact 233 and the power source side contact 235 can be designed according to the model of the image forming apparatus 1, and can be applied even when the installation space for the conductive member 230 is small.

  In the present embodiment, the cartridge side contact 233 and the power supply side contact 235 do not need to be conductive as a whole. For example, the power supply side contact 235 is a contact portion between the conduction portion with the link 231 and the output terminal 121. The outer surface except for and may be coated with an insulating material. Further, in the present embodiment, a mechanism in which the cartridge side contact 233 and the power supply side contact 235 each configured in a bar shape move in parallel in a state in which the posture is maintained in the left-right direction orthogonal to the insertion direction of the process cartridge 40 is, A parallel link mechanism or the like may be used. Further, the energization mechanism for supplying power to each process cartridge 40 does not necessarily have to be the same for each color. For example, as shown in FIG. 6, the position of the conduction portion 239 in the cartridge side contact 233 and the supply terminal 51 in the recess 53. May be provided so as to be different for each color.

  FIG. 6A shows the position of the conducting portion 239C in the cartridge side contact 233C for cyan and the position of the supply terminal 51C in the recess 53C. As shown in FIG. 6A, when the cartridge side contact 233C enters the recess 53C as described above, the conducting portion 239C contacts the supply terminal 51C and applies the voltage. FIG. 6B shows the position of the conduction part 239M in the cartridge side contact 233M with respect to magenta and the position of the supply terminal 51M in the recess 53M. As shown in FIG. 6B, when the cartridge side contact 233M enters the recess 53M as described above, the conduction portion 239M contacts the supply terminal 51M and applies the voltage.

  On the other hand, when the process cartridge 40C and the process cartridge 40M are installed in a reversed manner, as shown in FIG. 6C, the conducting portion 239C of the cartridge side contact 233C does not contact the supply terminal 51M. Similarly, as shown in FIG. 6D, the conducting portion 239M of the cartridge side contact 233M does not contact the supply terminal 51C. For this reason, if the conduction | electrical_connection part 239 and the supply terminal 51 are comprised as mentioned above, it can suppress that a voltage is applied with respect to the process cartridge 40 with which the incorrect position was mounted | worn. In the present embodiment, the forms of the link 231 and the guide hole 225 can be variously changed, and the movement paths of the cartridge side contact 233 and the power supply side contact 235 may be different from each other.

  In the present embodiment, instead of changing the position of the conductive portion 239 of the cartridge side contact 233 for each color, the length of the cartridge side contact 233 itself may be changed for each color. Furthermore, the same configuration can also be applied to the embodiment. For example, if the positions of the rod-shaped portion 131, the supply terminal 51, and the output terminal 121 are changed for each color of the process cartridge 40, it is possible to suppress the voltage from being applied to the process cartridge 40 mounted at an incorrect position. can do.

  Next, FIG. 7 is a schematic diagram illustrating in detail the configuration and operation of a further modification of the energization mechanism. In the present embodiment, the following moving member 331 is provided on the surface of the main body frame 323 on the process cartridge 40 side. That is, the moving member 331 is provided between the main body frame 323 and the mounting position of the process cartridge 40, and the reference position shown in FIGS. 7 (A) and 7 (B) and the positions shown in FIGS. 7 (C) and 7 (D). It is configured to be slidable between the mounting completion positions.

  When the process cartridge 40 is mounted, the moving member 331 is pressed from the reference position shown in FIGS. 7A and 7B to the front end in the mounting direction of the process cartridge 40 and moves in the mounting direction in the mounting direction. . When the mounting of the process cartridge 40 is completed, the moving member 331 reaches the mounting completion position shown in FIGS. Further, when the process cartridge 40 is detached, the moving member 331 is urged by the tension coil spring 337 (an example of the urging member and the conducting portion) and returns to the reference position shown in FIGS.

  Here, the supply terminal 51 of the process cartridge 40 is provided on the surface facing the main body frame 323 of the process cartridge 40, and the output terminal 121 of the mold transformer 120 is disposed on the surface facing the process cartridge 40 of the mold transformer 120. Is provided. Further, a hole 324 is formed at a position facing the output terminal 121 of the main body frame 323 so that the output terminal 121 is exposed to the mounting position of the process cartridge 40.

  When the moving member 331 moves to the mounting completion position, the tip thereof faces the hole 324, and a concave portion 325 that is recessed from the main body frame 323 side is formed at the tip. Further, a concave portion 327 that is recessed from the process cartridge 40 side is formed at a position of the main body frame 323 that faces the supply terminal 51 when the moving member 331 moves to the mounting completion position. The concave portion 327 is provided with a cartridge side contact 333 which is configured as a compression coil spring as a whole and whose tip on the process cartridge 40 side is configured as an annular contact. Further, the concave portion 325 is provided with a power supply side contact 335 configured as a compression coil spring as a whole and having a tip on the mold transformer 120 side configured as an annular contact.

  In addition, metal plates 338 and 339 (an example of a conductive portion) are attached to the surfaces of the moving member 331 and the main body frame 323 that face each other, and the metal members 338 and 339 are moved from the reference position. It is in constant contact while moving to the mounting completion position. The cartridge side contact 333 and the power source side contact 335 are electrically connected through the contact between the metal plates 338 and 339 and the tension coil spring 337 described above. Further, when the moving member 331 is at the reference position, the cartridge side contact 333 is locked to the proximal end portion of the moving member 331 and is restricted from projecting toward the process cartridge 40.

  In the present embodiment configured as described above, when the moving member 331 moves to the mounting completion position when the process cartridge 40 is mounted, the power supply side contact 335 faces the hole 324 and projects through the hole 324 to output. The terminal 121 is press-contacted. Further, the cartridge-side contact 333 is released from being locked by the moving member 331 and is brought into pressure contact with the supply terminal 51 of the process cartridge 40. As described above, since the power supply side contact 335 and the cartridge side contact 333 are electrically connected, the supply terminal 51 and the output terminal 121 are electrically connected to enable image formation as described above.

  On the other hand, when the process cartridge 40 is detached, it is biased by the tension coil spring 337 and the moving member 331 returns to the reference position. Then, the power-side contact 335 that moves in the direction in which the process cartridge 40 is attached and detached together with the moving member 331 is pushed by the edge of the hole 324 and contracts, and is isolated from the output terminal 121. Further, the cartridge-side contact 333 is also pressed by the proximal end portion of the moving member 331 and contracts, and retracts from the attachment / detachment path of the process cartridge 40.

  For this reason, the conductive member 330 including the metal plates 338 and 339, the cartridge side contact 333, and the power source side contact 335 is electrically isolated from the output terminal 121, so that safety is ensured as in the above embodiments. can do. Further, in this embodiment, when the moving member 331 returns to the reference position, the cartridge-side contact 333 is locked by the moving member 331 and is held outside the attachment / detachment path of the process cartridge 40, so that safety is further improved. Can be improved. In addition, the conduction | electrical_connection part may be comprised only by the tension coil spring 337, may be comprised only by the metal plates 338 and 339, and may be comprised by the other member. Further, the cartridge side contact 333 and the power source side contact 335 may be leaf spring contacts.

  Furthermore, needless to say, the conductive member may have other forms than those described in the above embodiments. In addition, the conductive member may be provided for a so-called drawer that can be attached to and detached from the individual process cartridges 40 instead of providing conductive members.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Housing 5 ... Image forming part 40 ... Process cartridge 41 ... Photosensitive drum 45 ... Developing roller 50 ... Charger 51 ... Supply terminal 53 ... Concave 110 ... High voltage power supply board 120 ... Mold transformer 121 ... Output Terminals 123, 223, 323 ... Body frame 125 ... Shafts 130, 230, 330 ... Conductive member 131 ... Rod-like parts 133, 233, 333 ... Cartridge side contacts 135, 235, 335 ... Power supply side contacts 137, 237, 337 ... Tensile coil springs 225 ... guide hole 231 ... link 331 ... moving members 338, 339 ... metal plate

Claims (4)

An image forming unit for forming an image by a developer on a recording medium by an electrophotographic method;
A housing that houses the image forming unit therein;
A cartridge comprising at least a part of the image forming unit, configured to be detachable from the casing, and provided with a supply terminal to which a voltage is supplied when mounted on the casing;
A high-voltage power supply that is provided inside the housing and outputs a voltage to be supplied to the supply terminal from an output terminal;
The cartridge moves in the housing in accordance with the attachment / detachment of the cartridge to / from the housing, and when the cartridge is detached from the housing, it does not come in contact with either the supply terminal or the output terminal, and the cartridge A conductive member that comes into contact with both the supply terminal and the output terminal when connected to the housing and makes both conductive;
An image forming apparatus comprising: The supply terminal is provided at a tip portion of the cartridge with respect to the mounting direction of the cartridge,
The output terminal is provided at a tip portion of the high-voltage power supply with respect to the mounting direction of the cartridge,
The conductive member is
A rod-shaped portion configured in a rod shape that swings around an axis orthogonal to the mounting and detaching direction of the cartridge;
A cartridge-side contact that is provided at one end of the rod-shaped portion and swings the rod-shaped portion around the axis by being pressed against the supply terminal while being in contact with the supply terminal when the cartridge is mounted;
A power-side contact that is provided at the other end of the rod-shaped portion and contacts the output terminal by swinging of the rod-shaped portion when the cartridge is mounted;
In addition,
By applying a biasing force to the rod-shaped portion, when the cartridge is detached, a biasing member that swings the rod-shaped portion in a direction opposite to that when the cartridge is mounted and isolates the power supply side contact from the output terminal,
The image forming apparatus according to claim 1, further comprising an image forming apparatus. The cartridge has a recess on a surface facing the high-voltage power source,
The supply terminal is provided in the recess;
The output terminal is provided on a surface of the high-voltage power supply facing the cartridge;
The conductive member is
It is configured in a rod shape orthogonal to the mounting / removal direction of the cartridge, and when the cartridge is mounted, it is pushed in the mounting direction tip and moved in the mounting direction while moving in the high-voltage power supply direction along a preset path. A moving power supply side contact,
It is configured in a bar shape orthogonal to the mounting / removal direction of the cartridge, and the movement of the power supply side contact is transmitted through a conductive link, so that when the cartridge is mounted, the cartridge moves in the mounting direction along a preset path. The cartridge side that moves into the recess while moving, and then further enters the recess while moving in the mounting direction by engagement with the recess, and moves the power supply side contact through the link. Contacts,
When the mounting of the cartridge is completed, the power supply side contact contacts the output terminal and the cartridge side contact contacts the supply terminal due to the movement of the power supply side contact and the cartridge side contact,
By applying a biasing force to the power supply side contact or the cartridge side contact, when the cartridge is detached, the power supply side contact and the cartridge side contact are moved in a direction opposite to that when the cartridge is mounted, and the power supply side contact is moved. An urging member for separating from the output terminal;
The image forming apparatus according to claim 1, further comprising: A main body frame provided between the mounting position of the cartridge and the high-voltage power supply, and fixed to the housing;
It is provided between the main body frame and the mounting position of the cartridge. When the cartridge is mounted, it is pressed by the tip of the cartridge in the mounting direction and moves from the reference position in the housing in the mounting direction, and the cartridge is detached. A moving member that is sometimes urged by the urging member to return to the reference position;
Further comprising
The supply terminal is provided on a surface of the cartridge facing the body frame;
The output terminal is provided on a surface of the high-voltage power supply facing the cartridge;
The conductive member is
A power-side contact that moves in the direction of attaching and detaching the cartridge integrally with the moving member and is biased in the direction of the high-voltage power supply, and is pressed against the output terminal opposite to the output terminal when the cartridge is completely installed;
The cartridge is supported by the main body frame and biased toward the cartridge. When the moving member is at the reference position, the moving member is locked by the moving member and is held outside the cartridge attaching / detaching path, and the cartridge is completely mounted. Sometimes, the cartridge side contact that is unlocked by the moving member and pressed against the supply terminal of the cartridge,
A conducting portion for conducting the power supply side contact and the cartridge side contact while allowing movement of the moving member;
The image forming apparatus according to claim 1, further comprising: