JP6187137B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus.

  2. Description of the Related Art Conventionally, an image forming apparatus of a type that exposes a photoreceptor surface with an LED is known.

  For example, in Patent Document 1, four exposure units close to the upper side of the photosensitive drum are separated upward, and a transfer unit that is pressed against the lower side of the photosensitive drum is separated downward, and in this state, the drum unit and the developing unit are separated. An image forming apparatus is disclosed that pulls out the image in the front direction of the main body.

JP 2001-166555 A

  The present invention avoids interference between the detachable body and the exposure device with a simple structure.

An image forming apparatus according to claim 1 is provided.
A housing,
An image holding body that is arranged in the housing and forms an image on the surface to hold the image;
A detachable body that mounts the image holding body and is detachable from the housing;
An exposure device that is provided separately from the detachable body and exposes the surface of the image carrier;
It is located between the detachable body and the exposure device, extends along the direction of detachment of the detachable body with respect to the housing, and a specific part of the detachable body comes into contact with the attachment / detachment to thereby reduce the distance between the detachable body and the exposure device. Keep the contact surface of the shape away from the specific part when the attachment of the detachable body is completed,
A positioning member that is provided in the exposure device, contacts the detachable body with the attachment of the detachable body, and moves the exposure device in a direction away from the detachable body to position the exposure device;
It is provided with.

An image forming apparatus according to a second aspect further includes the image forming apparatus according to the first aspect.
A guide member is provided that guides the attachment / detachment of the attachment / detachment body to / from the housing and makes the specific part contact the contact surface within an error range of the guide.

An image forming apparatus according to a third aspect further includes the image forming apparatus according to the first or second aspect.
When the detachable body is inserted into the casing, the specific part contacts the specific part to the contact surface when the specific part comes into contact, and a guiding slope inclined from the contact surface is provided.

  According to the image forming apparatus of the first aspect, it is possible to avoid interference between the detachable body and the exposure device with a simple structure as compared with the case where the contact surface is not provided.

  According to the image forming apparatus of the second aspect, it is possible to achieve both ease of attachment / detachment and reliability of avoiding interference.

  According to the image forming apparatus of the third aspect, it is easy to insert the detachable body as compared with the case where the guiding slope is not provided.

1 is a schematic configuration diagram of a printer corresponding to an embodiment of an image forming apparatus. FIG. 2 is a perspective view illustrating a main part of an image forming process unit illustrated in FIG. 1. It is a figure of the insertion state of photoconductor module PM which showed the structure which guides attachment or detachment of photoconductor module PM. FIG. 3 is a diagram illustrating a structure for guiding attachment / detachment of the photoreceptor module PM, in a state where the photoreceptor module PM is extracted. It is the figure which showed a mode that interference was prevented by the abutting surface. It is a figure which shows the state at the time of the insertion start of a photoconductor module. FIG. 3 is an overall view showing a positional relationship between a photosensitive drum and LPH when a photosensitive module is mounted in a printer. FIG. 4 is an enlarged view of the rear side showing a positional relationship between the photosensitive drum and LPH when the photosensitive module is mounted in the printer. FIG. 4 is an enlarged view of the front side showing the positional relationship between the photosensitive drum and LPH when the photosensitive module is mounted in the printer.

  An embodiment of an image forming apparatus of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic configuration diagram of a printer corresponding to an embodiment of an image forming apparatus.

  A printer 1 shown in FIG. 1 is a so-called tandem color printer, and includes an image forming process unit 10 that forms an image corresponding to image data of each color, a control unit 30 that controls the operation of the entire printer 1, and each unit. And a main power source 35 for supplying electric power to the power source. The image forming process unit 10, the control unit 30, and the main power source 35 are incorporated in a housing 42.

  The casing 42 has a plastic cover part that mainly forms the appearance of the printer 1 and a frame part that mainly serves as a framework of the printer 1 and holds the entire structure of the printer 1. . A part of the casing 42 can be opened and closed. When this part is opened by a user operation or the like, an opening for exposing the inside of the printer 1 is formed on the front side (front side) in FIG. A part of the image forming process unit 10 is detachable from the housing 42 through the opening for convenience of maintenance and the like. A specific example of the detachable portion will be described in detail later.

  The image forming process unit 10 includes four image forming units 11Y, 11M, 11C, and 11K (hereinafter collectively referred to simply as “image forming units 11”) arranged in parallel at regular intervals. It has been. Each image forming unit 11 includes a photosensitive drum 12 on which an electrostatic latent image or a toner image is formed, a charger 13 for charging the surface of the photosensitive drum 12, and the surface of the photosensitive drum 12 as image data. An LED print head (LPH) 14 that performs exposure on the basis, a developing device 15 that develops an electrostatic latent image formed on the photosensitive drum 12, and a cleaner 16 that cleans the surface of the photosensitive drum 12 after transfer. Yes. Note that the photosensitive drum 12 in the present embodiment includes a rotation shaft not shown in FIG. 1, and the axial direction from the front side (front side in the figure) to the rear side (back side in the figure) of the printer 1. It is arranged to face.

  The photoconductive drum 12 corresponds to an example of an image carrier according to the present invention, and the LPH 14 corresponds to an example of an exposure unit according to the present invention.

  Here, in each image forming unit 11, the photosensitive drum 12, the charger 13, and the cleaner 16 are an integrated module (hereinafter referred to as a photosensitive module PM). The photoconductor module PM is detachable from the housing 42 of the printer 1 and is exchanged according to the life of the photoconductor drum 12 or the like. The photoreceptor module PM may be a module of only the photoreceptor drum 12 that does not include the charger 13 and the cleaner 16, or a module in which the developing device 15 is further integrated in addition to the charger 13 and the cleaner 16. It may be adopted. That is, as long as the photoconductor drum 12 is included, the photoconductor module PM can be combined with any component, but in the present embodiment, the photoconductor module PM and the LPH 14 are configured separately. It is said. This photoreceptor module PM corresponds to an example of the detachable body referred to in the present invention.

  Each image forming unit 11 has the same configuration except for the toner stored in the developing device 15. Each image forming unit 11 forms yellow (Y), magenta (M), cyan (C), and black (K) toner images. The toner of each color is supplied from the toner cartridges 17Y, 17M, 17C, and 17K corresponding to each image forming unit 11 to the developing device 15 of each image forming unit 11 via a supply path (not shown).

  Further, the image forming process unit 10 performs intermediate transfer on the intermediate transfer belt 20 onto which the color toner images formed on the photosensitive drums 12 of the image forming units 11 are transferred, and the color toner images on the image forming units 11. A primary transfer roll 21 that is sequentially transferred to the belt 20, a secondary transfer roll 22 that collectively transfers the superimposed toner image transferred onto the intermediate transfer belt 20 onto a sheet as a recording material, and an image that is secondarily transferred onto the sheet. And a fixing device 45 for fixing the toner image.

  In the printer 1, the image forming process unit 10 performs an image forming operation based on various control signals supplied from the control unit 30. For example, image data is input to the control unit 30 from an external device such as a personal computer or an image reading device. The image data is subjected to image processing by the control unit 30 and is connected to each image forming unit via an interface (not shown). 11 is supplied. For example, in the black (K) image forming unit 11K, the photosensitive drum 12 is charged to a predetermined potential by the charger 13 while rotating in the direction of arrow A, and the image transmitted from the control unit 30 is transmitted. Exposure is performed by the LPH 14 that emits light based on data representing a black component image in the data. As a result, an electrostatic latent image related to a black (K) color image is formed on the photosensitive drum 12. The electrostatic latent image formed on the photosensitive drum 12 is developed by the developing device 15, and a black (K) toner image is formed on the photosensitive drum 12. Similarly, yellow (Y), magenta (M), and cyan (C) toner images are formed in the image forming units 11Y, 11M, and 11C of other colors, respectively.

  The respective color toner images formed by the respective image forming units 11 are sequentially electrostatically attracted by the primary transfer roll 21 onto the intermediate transfer belt 20 moving in the direction of arrow B to form a composite toner image in which the respective color toners are superimposed. Is done. The synthetic toner image on the intermediate transfer belt 20 is conveyed to a region (secondary transfer portion T) where the secondary transfer roll 22 is disposed as the intermediate transfer belt 20 moves. Further, the sheet is supplied from the sheet holding unit 40 to the secondary transfer unit T in accordance with the conveyance timing of the synthetic toner image by the intermediate transfer belt 20. The composite toner image is collectively electrostatically transferred onto the conveyed paper by the transfer electric field formed by the secondary transfer roll 22 in the secondary transfer portion T.

  Thereafter, the sheet on which the synthetic toner image has been electrostatically transferred is peeled off from the intermediate transfer belt 20 and conveyed to the fixing device 45. The synthesized toner image on the paper conveyed to the fixing device 45 is fixed on the paper by the fixing device 45 by a fixing process using heat and pressure. Then, the sheet on which the fixed image is formed is conveyed to the paper discharge stacking unit 41 provided in the discharge unit of the printer 1.

  On the other hand, toner (transfer residual toner) adhering to the intermediate transfer belt 20 after the secondary transfer is removed from the surface of the intermediate transfer belt 20 by the belt cleaner 25 after the completion of the secondary transfer to prepare for the next image forming cycle. In this way, image formation by the printer 1 is repeatedly executed for the number of printed sheets.

  Next, the detail regarding attachment / detachment of the attachment / detachment body mentioned above is demonstrated.

  FIG. 2 is a perspective view showing a main part of the image forming process section 10 shown in FIG.

  In FIG. 2, four photoconductor modules PM are shown, and these photoconductor modules PM are arranged close to other components. For this reason, it is required to safely guide the photoconductor module PM so that it does not interfere with other components when the photoconductor module PM is attached or detached (that is, hit or get caught). .

  3 and 4 are diagrams showing a structure for guiding the mounting and removal of the photoreceptor module PM. FIG. 3 shows a state when the photoreceptor module PM is inserted, and FIG. 4 shows the structure of the photoreceptor module PM. The extracted state is shown.

  In the printer 1 of the present embodiment, a guide rail 44_1 and a guide piece 44_2 are provided on the frame portion 43 of the housing in order to guide the attachment / detachment of the photoconductor module PM. An overhang portion 51 provided at the lower portion of the photoreceptor module PM is fitted into the guide rail 44_1 and moves along the guide rail 44_1. In addition, the protrusion 52 provided on the upper part of the photosensitive module PM is caught by the guide piece 44_2, and the inclination of the photosensitive module PM is suppressed. The guide rail 44_1 and the guide piece 44_2 correspond to an example of a guide member according to the present invention. The guide of the photoreceptor module PM by the guide rail 44_1 and the guide piece 44_2 is accompanied by a certain amount of backlash (that is, a guide error), and the presence of the backlash facilitates the insertion of the photoreceptor module PM. On the other hand, the presence of such backlash may cause interference with elements that are close to the photoconductor module PM, such as the LPH 14 shown in FIG. For this reason, the printer 1 of the present embodiment is provided with an abutting surface 44_3 between the LPH 14 and the photoreceptor module PM, and interference is prevented as described below.

  FIG. 5 is a diagram showing how interference is prevented by the abutting surface.

  The photoreceptor module PM is provided with an abutting portion 53 on the side surface on the LPH 14 side, and the abutting portion 53 abuts against the abutting surface 44_3. Regardless, the distance between the photosensitive drum 12 and the LPH 14 of the photosensitive module PM is maintained. For this reason, both the ease of insertion due to the presence of play and the certainty of preventing interference between the LPH 14 and the photoreceptor module PM are achieved. The abutting surface 44_3 corresponds to an example of a contact surface referred to in the present invention, and the abutting portion 53 corresponds to an example of a specific portion referred to in the present invention.

  The abutting portion 53 is provided on the front side in the insertion direction of the photoconductor module PM and comes into contact with the abutting surface 44_3 immediately after the insertion of the photoconductor module PM, and then the photoconductor module PM is pushed in. Accordingly, the abutting portion 53 enters the printer 1 while rubbing against the abutting surface 44_3. Further, the abutting portion 53 moves while rubbing against the abutting surface 44_3 even when the photoreceptor module PM is extracted. That is, the contact between the abutting portion 53 and the abutting surface 44_3 is maintained over the entire process of attaching and detaching the photoconductor module PM, and interference is prevented throughout the attachment and detachment.

  FIG. 6 is a diagram illustrating a state at the start of insertion of the photoconductor module PM.

  A tapered surface 44_4 connected to the abutting surface 44_3 is provided on the entrance side (that is, the front side of the printer 1) of the abutting surface 44_3 (see FIG. 4). The tapered surface 44_4 is an inclined surface that is inclined with respect to the abutting surface 44_3 so as to spread outward from the abutting surface 44_3 (that is, in a direction away from the abutting portion 53 of the photoreceptor module PM). It has a role to guide the abutting portion 53 to the abutting surface 44_3 at the start of insertion. The presence of such a tapered surface 44_4 facilitates the insertion of the photoreceptor module PM. The tapered surface 44_4 corresponds to an example of a guiding slope according to the present invention.

  Incidentally, the contact between the abutting surface 44_3 and the abutting portion 53 as shown in FIG. 5 is highly accurate in preventing interference between the LPH 14 and the photoreceptor module PM, but the photoreceptor module PM is mounted in the printer 1. This is insufficient to realize the relative positional accuracy required between the photosensitive drum 12 and the LPH 14. Therefore, in the present embodiment, interference avoidance at the time of attachment / detachment and high positional accuracy are realized by the structure described below.

  FIGS. 7 to 9 are views showing the positional relationship between the photosensitive drum and the LPH when the photosensitive module is mounted in the printer, FIG. 7 is an overall view, and FIG. 8 is an enlarged view of the rear side. 9 is an enlarged view of the front side.

  7 to 9, the right side is the rear side that is the back side of FIG. 1, and the left side is the front side that is the front side of FIG. 1.

  The LPH 14 is provided with datums 141 and 142 on the front side and the rear side, respectively. On the other hand, LPH receiving surfaces 54 and 55 are provided on the outer surface of the bearing of the photosensitive drum 12. When the photoconductor module PM is inserted into the printer 1 to the end, as shown in FIGS. 7 to 9, the datums 141 and 142 provided on the front side and the rear side of the LPH 14 are incorporated in the LPH 14. The spring 143 comes into contact with the LPH receiving surfaces 54 and 55 provided on the front side and the rear side of the photoreceptor module PM. As described above, this is a simple method in which the specific portion of the LPH 14 is in contact with the specific surface of the photoconductor module PM. However, the distance between the LPH 14 and the photoconductor drum 12 is a distance suitable for exposure. The relative positioning is performed with high accuracy.

  Immediately before the positioning, the abutting surface 44_3 and the abutting portion 53 are shaped such that the abutting surface 44_3 escapes so as to avoid contact, and the photosensitive drum 12 avoids interference during attachment and detachment. And LPH14 is positioned accurately.

  DESCRIPTION OF SYMBOLS 1 ... Printer, 11 ... Image forming unit, 12 ... Photoconductor drum, PM ... Photoconductor module, 51 ... Overhang part, 52 ... Protruding part, 53 ... Abutting part, 54, 55 ... LPH receiving surface, 14 ... LED print head (LPH), 141, 142 ... datum, 42 ... housing, 43 ... frame portion, 44_1 ... guide rail, 44_2 ... guide piece, 44_3 ... butting Surface, 44_4 ... Tapered surface

Claims (3)

A housing,
An image carrier that is disposed in the housing and has an image formed on a surface thereof to hold the image;
A detachable body that mounts the image holding body and is detachable from the housing;
An exposure device that is provided separately from the detachable body and exposes the surface of the image carrier;
The detachable body and the exposure device are positioned between the detachable body and the exposure device, extend in a direction in which the detachable body is attached to or detached from the housing, and a specific part of the detachable body comes into contact with the attachment / detachment. A contact surface that is shaped to be separated from the specific part when the attachment of the detachable body is completed,
A positioning member that is provided in the exposure device, contacts the detachable body with the attachment of the detachable body, and moves the exposure device in a direction away from the detachable body to position the exposure device;
An image forming apparatus comprising:   The image forming apparatus according to claim 1, further comprising: a guide member that guides attachment / detachment of the attachment / detachment body with respect to the housing and causes the specific portion to contact the contact surface within an error range of the guide.   2. A guide slope inclined from the contact surface, wherein the specific portion comes into contact with the contact surface when the specific portion contacts when the detachable body is inserted into the housing. 2. The image forming apparatus according to 2.

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