JP6119698B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having an exposure unit that exposes a photoreceptor.

  2. Description of the Related Art Conventionally, as an image forming apparatus, an LED head that exposes a photosensitive member is retracted from the photosensitive member in conjunction with opening of a cover (see Patent Document 1). Specifically, in this technique, an arm having a cam surface is provided on the cover, and when the cover is opened, the LED head is pushed upward by the cam surface, thereby retracting the LED head from the photosensitive member. .

JP 2001-209220 A

  However, in the above configuration, since the LED head is pushed up by the cam surface, there is a problem that it is difficult to increase the moving amount for retracting the LED head.

  Accordingly, an object of the present invention is to provide an image forming apparatus capable of increasing the amount of movement for retracting the LED head (exposure unit).

In order to solve the above problems, an image forming apparatus according to the present invention includes a housing, a cover rotatably connected to the housing, capable of opening and closing the opening of the housing, and an exposure unit that exposes a photoconductor. And a unit guide part that is provided in the housing and guides the exposure unit between an exposure position for exposing the photoconductor and a retracted position that is farther from the photoconductor than the exposure position, and the cover An interlocking mechanism for moving the exposure unit between the exposure position and the retracted position in conjunction with opening and closing of the.
The interlocking mechanism has a link connected to the exposure unit and the cover.

  According to this configuration, since the exposure unit is retracted from the photosensitive member using the link, the amount of movement for retracting the exposure unit can be increased.

  Further, in the above-described configuration, the housing includes a pair of side plates that cover both end portions in the rotation axis direction of the photoconductor, and the rotation axis of the cover is parallel to the rotation axis of the photoconductor, The unit guide portion may be provided on the pair of side plates and guide both end portions of the exposure unit in the rotation axis direction.

  According to this, since both end portions in the rotation axis direction of the exposure unit are guided by the unit guide portion, the exposure unit can be favorably moved between the exposure position and the retracted position.

  Moreover, in the above-described configuration, the connecting portion between the cover and the link can be disposed closer to the distal end portion of the cover than the connecting portion between the cover and the housing.

  In the configuration described above, the connecting portion between the exposure unit and the link may overlap the unit guide portion when viewed from the direction of the rotation axis of the photoconductor.

  By arranging the connecting portion so as to overlap the unit guide portion in this way, the connecting portion of the exposure unit can be guided by the unit guide portion, so that the exposure unit can be favorably moved between the exposure position and the retracted position. Can be made.

  In the configuration described above, a holding portion that holds the exposure unit at the retracted position may be provided at an end portion of the unit guide portion that is far from the photoconductor.

  By holding the exposure unit in the retracted position by the holding unit in this way, the cover can be held open via the link, so that the cover can be kept open without being supported by the user. .

  Further, in the above-described configuration, the unit guide part may have a restricting part that restricts the movement of the exposure unit to the side farther from the photoconductor at the end farther from the photoconductor.

  According to this, since the movement of the exposure unit to the side far from the photosensitive member is restricted by the restricting portion, it is possible to prevent the exposure unit from coming off the casing.

  Further, in the above-described configuration, the casing includes a photosensitive member positioning unit that positions the photosensitive member, and the unit guide unit includes a unit positioning unit that positions the exposure unit with respect to the photosensitive member. It may be.

  According to this, since the exposure unit is positioned by the unit positioning portion of the unit guide portion provided in the casing with respect to the photosensitive member positioned with respect to the casing, the exposure unit is accurately positioned with respect to the photosensitive body. It can be positioned well.

  Further, in the above-described configuration, the exposure unit may include a positioned portion that contacts the unit positioning portion, and further includes a biasing member that biases the positioned portion toward the unit positioning portion. Good.

  According to this, since the positioned portion can be satisfactorily brought into contact with the unit positioning portion by the biasing force of the biasing member, the exposure unit can be positioned more favorably with respect to the photoreceptor. Further, the urging member can be used as a holding member for holding the cover in a closed state.

  In the above-described configuration, the unit positioning portion and the positioned portion may be in contact with each other in the optical axis direction of light emitted from the exposure unit and in the circumferential direction of the photoconductor.

  According to this, since the exposure unit can be positioned in the optical axis direction and the circumferential direction of the photosensitive member (sub-scanning direction), the focal position and the sub-scanning position are defined, and good exposure characteristics can be obtained.

  Further, in the above-described configuration, the connection portion between the cover and the link of the exposure unit may be disposed at a position closer to the center portion than the end portion in the rotation axis direction of the photoconductor.

  According to this, since there is no connecting portion at the end in the rotation axis direction of the cover and the exposure unit, a member such as a harness can be arranged in the space where the end is free.

  Further, in the above-described configuration, in the case of including an LED control board connected to the exposure unit via a first harness and a main board connected to the LED control board via a second harness, The main board may be arranged on one end side of the casing in the rotation axis direction, and the LED control board may be arranged on one end side of the cover in the rotation axis direction.

  According to this, since the LED control board and the main body board can be arranged on one end side (the same side) in the rotation axis direction, the length of the second harness connecting the LED control board and the main body board is shortened. Can do. Moreover, since the LED control board can be disposed near the exposure unit by providing the LED control board on the cover, the length of the first harness can be shortened.

  In the above-described configuration, the first harness may be connected to one end of the exposure unit in the rotation axis direction.

  According to this, compared with the structure which connects a 1st harness to the other end part of an exposure unit, for example, the length of a 1st harness can be shortened.

  In the above-described configuration, the photoconductor may be detachable from the housing when the exposure unit is in the retracted position.

  According to this, it is possible to prevent the photoconductor from interfering with the exposure unit when the photoconductor is attached to and detached from the housing.

  According to the present invention, the amount of movement for retracting the exposure unit can be increased.

1 is a diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is a perspective view which shows the structure around an LED unit. It is the figure (a) which shows the LED unit in an exposure position, and the structure of the circumference | surroundings, and the figure (b) which expands and shows the LED unit vicinity of Fig.3 (a). It is a figure which shows the LED unit in a retracted position, and the structure around it. It is a figure which shows the state which removed the process cartridge from the main body housing | casing.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of the printer 1 as an example of the image forming apparatus will be described, and then the characteristic part of the present invention will be described in detail.

  In the following description, the direction will be described with reference to the user when using the printer 1. That is, in FIG. 1, the right side is “front side”, the left side is “rear side”, the front side in the vertical direction on the paper is “left side”, and the back side in the vertical direction on the paper is “right side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

  As shown in FIG. 1, the printer 1 includes a main body housing 2 as an example of a housing, a feeder unit 3 for feeding paper P, and an image forming unit 4 for forming an image on the paper P. It is mainly equipped with.

  The main body housing 2 has an opening 2A (see also FIG. 5) for attaching and detaching a process cartridge 6 to be described later on the front upper portion thereof. The opening 2 </ b> A is opened and closed by a cover 21.

  The cover 21 is a substantially flat member, and is disposed so as to cover the opening 2A. The cover 21 is rotatably connected to the main body housing 2 via a main body connecting portion 21A provided at the rear end portion.

  In addition, the main body housing 2 has a pair of left and right resin side plates 23 that cover the image forming unit 4 (photosensitive drum 81 and the like) from the left and right directions.

  The feeder unit 3 includes a paper feed tray 31 that is detachably attached to the lower portion of the main body housing 2, and a paper feed mechanism 32 that feeds the paper P in the paper feed tray 31 toward the image forming unit 4. ing.

  The image forming unit 4 includes an LED unit 5 as an example of an exposure unit, a process cartridge 6, and a fixing device 7.

  The LED unit 5 is a member that exposes the surface of a photosensitive drum 81 to be described later, and is disposed in the vicinity of the photosensitive drum 81. The detailed structure of the LED unit 5 will be described later.

  The process cartridge 6 is detachable from the main body housing 2 and includes a drum cartridge 8 and a developing cartridge 9. The developing cartridge 9 can be attached to and detached from the drum cartridge 8.

  The drum cartridge 8 mainly includes a photosensitive drum 81 as an example of a photosensitive member, a charger 82, and a transfer roller 83. The developing cartridge 9 mainly includes a developing roller 91, a supply roller 92, and a toner storage portion 93.

  In the process cartridge 6, the surface of the rotating photosensitive drum 81 is uniformly charged by the charger 82 and then exposed to light from the LED unit 5. Thereby, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 81.

  Next, after the toner in the developing cartridge 9 is supplied to the developing roller 91 by the supply roller 92, the toner on the developing roller 91 is supplied to the electrostatic latent image on the photosensitive drum 81, and the toner is transferred onto the surface of the photosensitive drum 81. An image is formed. Thereafter, the paper P is conveyed between the photosensitive drum 81 and the transfer roller 83, whereby the toner image carried on the surface of the photosensitive drum 81 is transferred onto the paper P.

  The fixing device 7 includes a heating roller 71 and a pressure roller 72 that is disposed to face the heating roller 71 and presses the heating roller 71. In the fixing device 7 configured as described above, the toner transferred onto the paper P is thermally fixed while the paper P passes between the heating roller 71 and the pressure roller 72.

  The paper P thermally fixed by the fixing device 7 is conveyed to a paper discharge roller R disposed on the downstream side of the fixing device 7, and is sent out from the paper discharge roller R onto the paper discharge tray 2B.

Next, the structure around the LED unit 5 which is a characteristic part of the present invention will be described in detail.
As shown in FIG. 2, the LED unit 5 is connected to the cover 21 via one link 100, and the left and right side portions are guided by a pair of left and right unit guide portions 200, thereby interlocking with opening and closing of the cover 21. Thus, it is movable between an exposure position (position in FIG. 3) for exposing the photosensitive drum 81 and a retracted position (position in FIG. 4) farther from the photosensitive drum 81 than the exposure position.

  Each unit guide 200 has a symmetrical structure, and is provided on each of the left and right side plates 23. In FIG. 2, the side plate 23 is illustrated in a simplified manner for the sake of convenience, so the right unit guide portion 200 appears to be separated from the side plate 23, but actually, the side plate 23 is formed by resin molding. A unit guide portion 200 that is formed and protrudes inward in the left-right direction is integrally formed.

  As shown in FIG. 3A, the unit guide 200 has a guide groove 210 that extends obliquely upward and rearward from the photosensitive drum 81. The guide groove 210 includes a pair of guide surfaces 211 and 212 that guide the LED unit 5, an upper end surface 213 that connects the upper ends of the guide surfaces 211 and 212, and a lower end surface 214 that connects the lower ends of the guide surfaces 211 and 212. And have. That is, the guide groove 210 is a groove in which both the end portion on the side far from the photosensitive drum 81 and the end portion on the side close to the photosensitive drum 81 are closed. The left and right bottom surfaces of the guide grooves 210 are constituted by the side plates 23. Moreover, the upper end surface 213 is an example of a restricting portion.

  The guide surfaces 211 and 212 are disposed so as to sandwich a later-described positioned portion 52 </ b> B of the LED unit 5, and are disposed in parallel to each other so as to extend along the substantially radial direction of the photosensitive drum 81. The upper end surface 213 is formed in an arc shape in a sectional view along an outer peripheral surface of an end portion of a connecting shaft portion 52 </ b> C described later of the LED unit 5.

  The lower end surface 214 extends substantially horizontally forward from the lower end of the lower guide surface 212 to the lower end of the upper guide surface 211, and is configured to be inclined with respect to the moving direction of the LED unit 5. ing. The lower end surface 214 and the lower portion of the upper guide surface 211 function as a unit positioning unit that positions the LED unit 5 with respect to the photosensitive drum 81.

  In other words, the unit guide part 200 includes a pair of guide walls 201 and 202 extending in the moving direction of the LED unit 5, an arc-shaped upper connecting wall 203 that connects the upper ends of the guide walls 201 and 202, and the moving direction. And a lower connection wall 204 that extends obliquely and connects the lower ends of the guide walls 201 and 202 to each other. And the 1st hole 201A for arrange | positioning the holding spring 220 as an example of a holding | maintenance part is formed in the upper end part of the upper side guide wall 201. As shown in FIG.

  Further, a second hole 201B for arranging a positioning spring 230 as an example of an urging member is formed at the lower end of the upper guide wall 201.

  Returning to FIG. 2, the LED unit 5 includes a long LED head 51 extending in the left-right direction and a resin support frame 52 that supports the LED head 51.

  The LED head 51 includes a resin holding case 51A, a plurality of light emitting elements (LED array) (not shown) arranged in the left-right direction (the axial direction of the photosensitive drum 81), and light from the light emitting elements on the surface of the photosensitive drum 81. And a lens array 51B that forms an image at the same magnification. The LED head 51 exposes the surface of the photosensitive drum 81 by blinking each light emitting element according to image data.

  The support frame 52 has a base portion 52A having a width substantially the same as the width of the LED head 51 in the left-right direction, and a pair of left and right positioned members that protrude outward from the left and right side surfaces of the base portion 52A and engage with the unit guide portions 200 It has a portion 52B and a connecting shaft portion 52C that is provided on the upper portion of the base portion 52A and is rotatably supported by the link 100.

  The connecting shaft portion 52C is a substantially columnar member extending in the left-right direction, and is fixed to the upper end of the base portion 52A in a state where the center portion thereof is rotatably supported by a head side connecting portion 120 described later of the link 100. Has been. Both end portions of the connecting shaft portion 52C protrude outward from the lateral side surface of the positioned portion 52B, enter the unit guide portion 200 together with the positioned portion 52B, and are guided by the unit guide portion 200. .

  When the LED unit 5 moves to the retracted position, the connecting shaft portion 52C engages with the holding spring 220 and is held by the holding spring 220 (see FIG. 4). More specifically, the connecting shaft portion 52 </ b> C is urged toward the upper end surface 213 by the holding spring 220. Thereby, the LED unit 5 is held at the retracted position. Here, the holding spring 220 is a leaf spring bent in a substantially U shape in cross section, and its corner is engaged with the connecting shaft portion 52C.

  As shown in FIG. 3B, the positioned portion 52B includes a pair of guided surfaces B1 and B2 guided by the guide surfaces 211 and 212 of the guide groove 210, and upper ends of the guided surfaces B1 and B2. , A lower end surface B4 extending substantially horizontally forward from the lower guided surface B2 and in surface contact with the lower end surface 214 of the guide groove 210, and a front end and an upper guided surface B1 of the lower end surface B4. And a connecting surface B5 having a V-shaped cross-sectional view that connects the lower end of each. 3A and 3B, the positioned portion 52B is hatched in order to emphasize and illustrate the positioned portion 52B.

  The connecting surface B5 is disposed with a space from the lower end surface 214 of the guide groove 210 and the upper guide surface 211. The upper end surface B3 is formed in a shape along the peripheral surface of the connecting shaft portion 52C.

  The upper guided surface B <b> 1 is formed with a recess B <b> 11 that engages with the positioning spring 230. The positioning spring 230 is a substantially V-shaped leaf spring in cross-section, and its corner is engaged with the recess B11, so that the positioned portion 52B is placed on the photosensitive drum 81 side, that is, the lower end surface 214 of the guide groove 210. It is energizing towards.

  As shown in FIG. 2, the link 100 includes a main body 110 having a width substantially the same as the horizontal width of the LED head 51, and a head extending toward the LED unit 5 from the horizontal central portion of the lower end surface of the main body 110. The side connection part 120 and the cover side connection part 130 extended toward the cover 21 from the center part in the left-right direction of the upper end surface of the main body part 110 are provided. A harness holding portion 111 that holds a first harness 410 that connects a board (not shown) in the LED unit 5 and an LED control board 310 (to be described later) to the right of the connecting portions 120 and 130 of the main body 110 is formed. ing. The harness holding part 111 is formed in a groove shape having a wall surface in the left-right direction of the first harness 410.

  The head-side connecting portion 120 has a shaft support hole 121 that rotatably supports the connecting shaft portion 52C, and a tip portion of the shaft-side connecting portion 120 is formed in the center in the left-right direction of the support frame 52 (base portion 52A). Arranged in A1. The head side connecting portion 120 and the connecting shaft portion 52C overlap with the unit guide portion 200 when viewed from the left-right direction (the rotation axis direction of the photosensitive drum 81).

  The cover-side connecting portion 130 is rotatably supported at its tip by a pair of left and right support walls 21B (only one on the left is shown) provided on the cover 21. Each support wall 21B is disposed closer to the tip 21C side of the cover 21 than the main body connecting portion 21A (the end side opposite to the main body connecting portion 21A, see FIG. 1). Note that one main body connecting portion 21A is provided at each of the right end portion and the left end portion of the rear end portion of the cover 21.

  Here, in the present embodiment, an interlock mechanism that moves the LED unit 5 between the exposure position and the retracted position in conjunction with opening and closing of the cover 21 includes one link 100, each support wall 21B, and a connecting shaft portion. 52C. In the present embodiment, the rotation axes of the cover 21, the link 100, and the LED unit 5 are parallel to the rotation axis of the photosensitive drum 81.

  An LED control board 310 for controlling each light emitting element in the LED head 51 is provided on the right side (one end side in the rotation axis direction) of the cover 21 with respect to the cover side connecting portion 130. Then, from the LED control board 310 arranged on the right side of the cover side connecting part 130 in this way, the first harness 410 described above passes through the harness holding part 111 of the link 100 and the right side (head side) of the LED unit 5. It extends toward the right side of the connecting portion 120 and is connected to a substrate (not shown) in the LED unit 5. Further, the LED control board 310 overlaps with the cover side connecting portion 130 when viewed from the left-right direction (see also FIG. 3).

  The right side plate 23 is provided with a main body substrate 320 connected to the LED control substrate 310 via the second harness 420. As shown in FIG. 5, each side plate 23 is formed with a guide groove 23 </ b> A for guiding the process cartridge 6 to the mounting position in the main body housing 2.

  The guide groove 23A is a groove whose upper end portion is opened upward and only the lower end portion 23B is closed. The lower end portion 23B is in contact with a bearing of the photosensitive drum 81, thereby positioning the photosensitive drum 81. It functions as a department. A spring that biases the bearing of the photosensitive drum 81 and the like toward the lower end 23B may be provided as appropriate.

Next, the movement of the LED unit 5 when the process cartridge 6 is attached to and detached from the main body housing 2 will be described in detail.
When removing the process cartridge 6 from the main body housing 2, the user first opens the cover 21. At this time, as shown in FIGS. 3 and 4, the LED unit 5 connected to the cover 21 via the link 100 moves from the exposure position to the retracted position with a large movement amount in conjunction with the opening of the cover 21. . As a result, as shown in FIG. 5, the LED unit 5 is retracted larger than the movement locus (the range indicated by the broken line) when the process cartridge 6 is attached and detached, so that the process cartridge 6 does not interfere with the LED unit 5. It becomes possible to attach and detach.

  When the LED unit 5 is moved to the retracted position, the connecting shaft portion 52C of the LED unit 5 engages with the holding spring 220, so that the LED unit 5 is held at the retracted position by the holding spring 220. At this time, the holding spring 220 holds the cover 21 in an open state via the LED unit 5 and the link 100.

  Therefore, after the user opens the cover 21, the user can release his / her hand from the cover 21, so that the subsequent work is easy. After opening the cover 21, the user removes the process cartridge 6 along the guide groove 23A.

  When attaching the process cartridge 6 to the main body housing 2, the user puts a part of the process cartridge 6 in the guide groove 23 </ b> A, and then puts the process cartridge 6 in the main body housing 2. It abuts against the lower end 23B of the guide groove 23A. Thereby, the photosensitive drum 81 and the like are positioned with respect to the side plate 23.

  Thereafter, the user closes the cover 21. As a result, the LED unit 5 moves from the retracted position toward the exposure position. When the LED unit 5 moves to the vicinity of the exposure position, as shown in FIG. 3B, the positioning spring 230 engages with the concave portion B11 of the positioned portion 52B, so that the positioned portion 52B is moved by the positioning spring 230. It is biased toward the lower end surface 214 of the guide groove 210.

  When the positioned portion 52B comes into contact with the lower end surface 214 of the guide groove 210, the positioned portion 52B approaches the guide surface 211 on the upper side of the guide groove 210 by the lower end surface 214 inclined with respect to the moving direction of the LED unit 5. And abut. Accordingly, the positioned portion 52B and the guide groove 210 come into contact with each other in the optical axis direction of the light emitted from the LED unit 5 and in the circumferential direction (sub-scanning direction) of the photosensitive drum 81. It is positioned with respect to the photosensitive drum 81 in the optical axis direction and the sub-scanning direction.

  At this time, even if a small force is applied to the cover 21 in the opening direction, the cover 21 is held closed by the positioning spring 230.

According to the above, the following effects can be obtained in the present embodiment.
Since the LED unit 5 is retracted from the photosensitive drum 81 using the link 100, the amount of movement for retracting the LED unit 5 can be increased as compared with the conventional structure in which the LED head is moved on the cam surface. .

  Since both end portions in the left-right direction of the LED unit 5 are guided by the unit guide portion 200, the LED unit 5 can be favorably moved between the exposure position and the retracted position.

  Since the connecting shaft portion 52C of the LED unit 5 is arranged so as to overlap the unit guide portion 200 when viewed from the left-right direction, the connecting shaft portion 52C of the LED unit 5 can be guided by the unit guide portion 200, and the LED unit 5 It can be favorably moved between the exposure position and the retracted position.

  By holding the LED unit 5 in the retracted position by the holding spring 220, the cover 21 can also be held in an open state via the link 100. Therefore, the cover 21 can be kept open even if the user does not support it. Can do.

  Since the upper end portion of the guide groove 210 of the unit guide portion 200 is closed by the upper end surface 213, the upper end surface 213 of the guide groove 210 restricts the LED unit 5 from moving beyond the retracted position, and the main body housing 2 Can be prevented from coming off.

  Since the LED unit 5 is positioned with respect to the photosensitive drum 81 positioned with respect to the main body housing 2 by the unit guide portion 200 provided in the main body housing 2, the LED unit 5 is positioned with respect to the photosensitive drum 81. Positioning can be performed with high accuracy.

  Since the portion 52B to be positioned can be satisfactorily brought into contact with the lower end surface 214 and the guide surface 211 of the guide groove 210 by the biasing force of the positioning spring 230, the LED unit 5 can be satisfactorily positioned with respect to the photosensitive drum 81. Can do. Further, the positioning spring 230 can be used as a holding member for holding the cover 21 in a closed state.

  Since the LED unit 5 can be positioned in the optical axis direction and the sub-scanning direction, the focal position and the sub-scanning position are defined, and good exposure characteristics can be obtained.

  The head side connecting portion 120 and the cover side connecting portion 130 are provided at the center in the left-right direction of the cover 21 and the LED unit 5, that is, the connecting portion is provided at the ends of the cover 21 and the LED unit 5 in the left-right direction. Since there is not, members, such as LED control board 310 and the 1st harness 410, can be arranged in the space where the end was vacant.

  Since the LED control board 310 and the main board 320 are disposed on the same side (right side) in the left-right direction, the length of the second harness 420 that connects the LED control board 310 and the main board 320 can be shortened. In addition, since the LED control board 310 is provided on the cover 21, the LED control board 310 can be disposed near the LED unit 5, and the length of the first harness 410 can be shortened.

  Since the first harness 410 extending from the LED control board 310 disposed on the right side of the cover 21 is connected to the right end of the LED unit 5, for example, the first harness is connected to the left end of the LED unit. Compared to the configuration, the length of the first harness 410 can be shortened.

  When the LED unit 5 is in the retracted position, the process cartridge 6 can be attached to and detached from the main body housing 2, so that when the process cartridge 6 is attached to and detached from the main body housing 2, the process cartridge 6 Interference with the LED unit 5 can be suppressed.

  In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.

  In the said embodiment, although the head side connection part 120 and the cover side connection part 130 were arrange | positioned in the left-right direction center part in the cover 21 or the LED unit 5, this invention is not limited to this, Each connection part is, for example, You may arrange | position at the edge part of the left-right direction of a cover or an LED unit, and may be arrange | positioned in the position shifted | deviated slightly to the left-right direction outer side rather than the center part.

  In the above embodiment, the photosensitive drum 81 is exemplified as the photosensitive member, but the present invention is not limited to this, and may be, for example, a belt-shaped photosensitive member.

  In the above-described embodiment, the unit guide unit 200 has the configuration having the guide groove 210. However, the present invention is not limited to this, and may be configured in a protruding rail shape. In this case, the restricting portion may be provided as a wall (for example, a wall protruding from the rail) provided at the end of the rail on the side far from the photosensitive member.

  In the above embodiment, the holding spring 220 and the positioning spring 230 made of a plate spring are exemplified as the holding portion and the urging member. However, the present invention is not limited to this, and other springs such as a wire spring, It may be an engaging protrusion or the like that is formed as a part of the unit guide and engages the LED unit.

  In the above embodiment, the present invention is applied to the printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.

DESCRIPTION OF SYMBOLS 1 Printer 2 Main body housing | casing 2A Opening 5 LED unit 21 Cover 81 Photosensitive drum 100 Link 200 Unit guide part

Claims (13)

A housing,
A cover rotatably connected to the housing and capable of opening and closing the opening of the housing;
An exposure unit for exposing the photoreceptor;
A unit guide part provided in the housing for guiding the exposure unit between an exposure position for exposing the photosensitive member and a retracted position farther from the photosensitive member than the exposure position;
An interlocking mechanism for moving the exposure unit between the exposure position and the retracted position in conjunction with opening and closing of the cover,
The interlocking mechanism includes a link connected to the front Symbol exposure unit and said cover,
The image forming apparatus according to claim 1, wherein the unit guide portion includes a restricting portion that restricts movement of the exposure unit to the side farther from the photoconductor at an end portion farther from the photoconductor. The housing has a photosensitive member positioning unit for positioning the photosensitive member,
The image forming apparatus according to claim 1 , wherein the unit guide unit includes a unit positioning unit that positions the exposure unit with respect to the photoreceptor. The exposure unit has a positioned part that contacts the unit positioning part,
The image forming apparatus according to claim 2 , further comprising an urging member that urges the positioned portion toward the unit positioning portion. The image forming apparatus according to claim 3 , wherein the unit positioning unit and the positioned unit are in contact with each other in an optical axis direction of light emitted from the exposure unit and in a circumferential direction of the photosensitive member.   5. The holding portion for holding the exposure unit at the retracted position is provided at an end of the unit guide portion on the side far from the photosensitive member. 6. The image forming apparatus described in the item. A housing,
A cover rotatably connected to the housing and capable of opening and closing the opening of the housing;
An exposure unit for exposing the photoreceptor;
A unit guide part provided in the housing for guiding the exposure unit between an exposure position for exposing the photosensitive member and a retracted position farther from the photosensitive member than the exposure position;
An interlocking mechanism for moving the exposure unit between the exposure position and the retracted position in conjunction with opening and closing of the cover,
The interlocking mechanism includes a link connected to the front Symbol exposure unit and said cover,
A holding portion that holds the exposure unit at the retracted position is provided at an end portion of the unit guide portion that is far from the photoconductor.
The image forming apparatus according to claim 1, wherein the holding unit includes an urging member that engages with the exposure unit and holds the exposure unit at the retracted position when the exposure unit moves to the retracted position. The housing includes a pair of side plates that cover both ends of the photosensitive member in the rotation axis direction,
The rotation axis of the cover is parallel to the rotation axis of the photoconductor,
7. The unit according to claim 1 , wherein the unit guide portion is provided on the pair of side plates and guides both end portions of the exposure unit in the rotation axis direction. 8. Image forming apparatus. 8. The connection portion between the cover and the link is disposed closer to the distal end side of the cover than the connection portion between the cover and the housing . 2. The image forming apparatus according to item 1 . Connection portion between the link and the exposure unit, the viewed from the rotation axis direction of the photosensitive member, an image as claimed in any one of claims 8, characterized in that overlaps the unit guide section Forming equipment.   10. The connecting portion between the cover and the link of the exposure unit is disposed at a position closer to the center portion than the end portion in the rotation axis direction of the photoconductor. The image forming apparatus according to claim 1. An LED control board connected to the exposure unit via a first harness;
A main body board connected to the LED control board via a second harness,
The said main body board | substrate is arrange | positioned at the one end side of the said housing | casing in the said rotating shaft direction, The said LED control board is arrange | positioned at the one end side of the said cover in the said rotating shaft direction. Image forming apparatus.   The image forming apparatus according to claim 11, wherein the first harness is connected to one end of the exposure unit in the rotation axis direction.   The image forming apparatus according to claim 1, wherein the photoconductor is detachable from the housing when the exposure unit is in the retracted position. .

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