JP2017215567A - Exposure device, image forming unit, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus excellent in operability.SOLUTION: An exposure device comprises a first member, a second member, a first urging member, and a head unit. The first member includes a first contact part. The second member is attached to the first member to be reversely displaceable along a first direction, and includes a second contact part provided to be contactable with the first contact part. The first urging member urges the second member in the first direction so that the first contact part and the second contact part are engaged with each other. The head unit includes a plurality of light emitting elements that are attached to the second member and arranged side by side along a second direction substantially orthogonal to the first direction.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an exposure apparatus, an image forming unit, and an image forming apparatus.

  The present applicant has already proposed an image forming apparatus in which a cover that can be opened and closed is provided to a main body unit that accommodates a process unit including a photosensitive drum and the like, and an LED head is attached inside the cover.

JP 2001-209220 A

  By the way, in the image forming apparatus as in Patent Document 1, it is desired to smoothly open and close the cover.

  Therefore, it is desirable to provide an image forming apparatus with excellent operability, and an exposure apparatus and an image forming unit suitable for mounting such an image forming apparatus.

  An exposure apparatus as an embodiment of the present invention includes a first member, a second member, a first urging member, and a head unit. The first member includes a first contact portion. The second member is attached to the first member so as to be reversibly displaceable along the first direction, and is provided so as to be able to contact the first contact portion. Is included. The first biasing member biases the second member in the first direction so that the first contact portion and the second contact portion engage with each other. The head unit includes a plurality of light emitting elements attached to the second member and arranged along a second direction substantially orthogonal to the first direction.

  An image forming unit according to an embodiment of the present invention includes the above exposure apparatus and an image forming unit that forms an image using a developer.

  An image forming apparatus according to an embodiment of the present invention holds the exposure apparatus, an image forming unit that forms an image using a developer, a main body unit that holds the image forming unit, and an exposure device. And a housing having a lid portion that can be opened and closed with respect to the main body portion.

  In the exposure apparatus and the image forming unit as one embodiment of the present invention, the second member is urged by the first urging member, so that the second member is held without wobbling with respect to the first member. It has become. Further, the second member can be displaced with respect to the first member when an urging force exceeding the urging force of the first urging member is applied in a direction opposite to the first direction. ing. Therefore, when the exposure apparatus and the image forming unit are used in the image forming apparatus as an embodiment of the present invention, for example, when the lid portion is opened and closed, the image forming portion housed in the main body portion and held by the lid portion Interference with the exposed exposure apparatus is avoided.

  According to the exposure apparatus, the image forming unit, and the image forming apparatus as an embodiment of the present disclosure, excellent operability can be obtained.

1 is a schematic diagram illustrating an overall configuration example of an image forming apparatus according to a first embodiment of the present invention. FIG. 2 is a perspective view illustrating an appearance of the image forming apparatus illustrated in FIG. 1 in a fully closed state. FIG. 2 is a perspective view illustrating an appearance of the image forming apparatus illustrated in FIG. 1 in a fully opened state. FIG. 2 is a front view illustrating an appearance of the image forming apparatus illustrated in FIG. 1 in a fully opened state. FIG. 2 is a perspective view illustrating an appearance of the image forming apparatus illustrated in FIG. 1 in a transition state. FIG. 2 is a perspective view illustrating an appearance of the image forming apparatus illustrated in FIG. 1 in a state where an image forming unit is taken out from a main body unit. FIG. 6 is another perspective view showing the appearance of the image forming apparatus shown in FIG. 1 in a state where the image forming unit is taken out from the main body. FIG. 2 is a perspective view showing an appearance of an exposure apparatus attached to a lid portion in the image forming apparatus shown in FIG. 1. FIG. 2 is a first sectional view showing a sectional structure of the exposure apparatus shown in FIG. 1. FIG. 3 is a second sectional view showing a sectional structure of the exposure apparatus shown in FIG. 1. FIG. 4 is a third sectional view showing the sectional structure of the exposure apparatus shown in FIG. 1. FIG. 6 is a fourth sectional view showing the sectional structure of the exposure apparatus shown in FIG. 1. FIG. 2 is a schematic diagram illustrating an internal configuration of an image forming unit in the image forming unit illustrated in FIG. 1. FIG. 12 is an explanatory diagram for explaining the positioning operation of the exposure head with respect to the photosensitive drum shown in FIG. 11. FIG. 2 is a schematic diagram for explaining a retracting operation of the image forming unit illustrated in FIG. 1. FIG. 10 is another schematic diagram for explaining the retreat operation of the image forming unit illustrated in FIG. 1. FIG. 3 is a schematic diagram for explaining an engagement operation between a drive gear and a photosensitive drum gear in the image forming apparatus shown in FIG. 1. FIG. 6 is a perspective view illustrating an appearance of an image forming apparatus according to a second embodiment of the present invention. FIG. 17 is a schematic diagram illustrating an example of an overall configuration inside the image forming apparatus illustrated in FIG. 16. FIG. 18 is a perspective view illustrating an overall configuration example of a lid and an exposure device of the image forming apparatus illustrated in FIG. 17. It is a perspective view which expands and represents the principal part of the exposure apparatus shown in FIG. It is a front view which expands and represents the principal part of the exposure apparatus shown in FIG. FIG. 20 is an enlarged front view illustrating one embodiment of the torsion spring illustrated in FIG. 19. FIG. 20 is an enlarged front view showing another embodiment of the torsion spring shown in FIG. 19. FIG. 20 is an enlarged perspective view illustrating another embodiment of the torsion spring illustrated in FIG. 19. It is an enlarged view for demonstrating operation | movement of the principal part of the exposure apparatus shown in FIG. It is another enlarged view for demonstrating operation | movement of the principal part of the exposure apparatus shown in FIG. FIG. 17 is a front view illustrating a state in which the lid of the image forming apparatus illustrated in FIG. 16 is opened. FIG. 17 is a front view illustrating a state in which the image forming unit is taken out from the main body in the image forming apparatus illustrated in FIG. 16. FIG. 17 is a front view illustrating a state in which the image forming unit is mounted on the main body in the image forming apparatus illustrated in FIG. 16.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description is an example of the present invention, and the present invention is not limited to the following embodiment. Further, the present invention is not limited to the arrangement, dimensions, dimensional ratios, and the like of the components shown in the drawings. The description will be made in the following order.
1. 1st Embodiment (exposure apparatus etc. in which the member holding a head unit is urged in one direction)
1.1 Overall Configuration of Image Forming Apparatus 1.2 Detailed Configuration of Image Forming Unit 1.3 Functions and Effects Second embodiment (exposure apparatus or the like in which a member holding the head unit is urged in both directions)
2.1 Overall Configuration of Image Forming Apparatus 2.2 Detailed Configuration of Image Forming Unit 2.3 Action and Effect 3. Modified example

<1. First Embodiment>
[1.1 Overall Configuration of Image Forming Apparatus PT1]
FIG. 1 schematically shows an overall configuration example of an image forming apparatus PT1 according to the first embodiment of the present invention. This image forming apparatus PT1 corresponds to a specific example of the “image forming apparatus” of the present invention. For example, an image (for example, a color image) is printed on a medium PM to be printed such as paper or film using an electrophotographic method. ). The image forming apparatus PT1 includes a medium supply unit 1, a transport unit 2, an image forming unit 3, a transfer unit 4, a fixing unit 5, a discharge unit 6, a control unit 7, a driving unit 8, and a cleaning unit 9 inside a housing 100. Is provided. The housing 100 includes a main body 101 and a lid 102 that can be opened and closed with respect to the main body 101. The control unit 7 controls the operations of the medium supply unit 1, the conveyance unit 2, the image forming unit 3, the transfer unit 4, the fixing unit 5, the discharge unit 6, and the drive unit 8.

  In this specification, a path through which the medium PM is transported is referred to as a transport path. In the transport path, a direction toward the medium supply unit 1 or a position closer to the medium supply unit 1 when viewed from an arbitrary component is referred to as upstream. In the transport path, a direction opposite to the direction toward the medium supply unit 1 when viewed from any component or a position further away from the medium supply unit 1 is referred to as downstream. A direction in which the medium PM travels (that is, a direction from upstream to downstream) in the transport path is referred to as a transport direction F. A direction (for example, the X-axis direction in FIG. 1) that is parallel to the medium PM being conveyed on the conveyance path and orthogonal to the conveyance direction F is referred to as a width direction. The dimension in the conveyance direction F is called a length, and the dimension in the width direction is called a width.

(Media supply unit 1)
The medium supply unit 1 supplies the medium PM to the transport unit 2 one by one. The medium supply unit 1 includes, for example, a cassette 1A, a pickup roller 1B, and a feed roller 1C. A plurality of media PM are stored in the cassette 1A in a stacked state. For example, the cassette 1A is detachably attached to the lower part of the image forming apparatus. The pickup roller 1 </ b> B and the feed roller 1 </ b> C function to sequentially feed the medium PM stored in the cassette 1 </ b> A to the conveyance path that reaches the conveyance unit 2. The pickup roller 1 </ b> B and the feed roller 1 </ b> C rotate under the control of the control unit 7 in the direction in which the medium PM is fed out toward the downstream transport unit 2. The pickup roller 1B is disposed at a position where it can come into contact with the upper surface of the uppermost medium PM. The feed roller 1C is disposed downstream of the pickup roller 1B.

(Transport unit 2)
The transport unit 2 transports the medium PM from the medium supply unit 1 to the transfer unit 4 while restricting skew feeding. The transport unit 2 includes, for example, two pairs of registration rollers 2A and 2B.

(Image forming unit 3)
The image forming unit 3 forms a toner image on the medium PM transported from the transport unit 2. For example, as shown in FIG. 1, four image forming units 3Y, 3M, 3C, and 3K are mounted on the image forming apparatus PT1. The image forming units 3Y, 3M, 3C, and 3K form toner images (images) of the respective colors using the corresponding toners of the respective colors, that is, yellow toner, magenta toner, cyan toner, and black toner. In the image forming apparatus PT1, for example, the image forming unit 3Y, the image forming unit 3M, the image forming unit 3C, and the image forming unit 3K are arranged in this order along the transport direction F. In this specification, when the four image forming units 3Y, 3M, 3C, and 3K are not distinguished, they may be collectively referred to as an image forming unit 3. The image forming unit 3 includes an exposure device LD and an image forming unit ID that forms an image using toner. Here, the image forming unit 3 corresponds to a specific example of “image forming unit” of the present invention, and the toner corresponds to a specific example of “developer” of the present invention. Details of the image forming unit 3 will be described later.

(Transfer unit 4 and cleaning unit 9)
The transfer unit 4 is also called a transfer belt unit. The transfer unit 4 is opposed to the transfer belt 4A, a drive roller 4B that drives the transfer belt 4A, an idle roller 4C that is driven by the drive roller 4B, and the photosensitive drum 32 (described later) across the transfer belt 4A. A transfer roller 4D. Each of the driving roller 4B and the idle roller 4C is a substantially cylindrical member that can rotate around a rotation shaft portion extending in the width direction W. The transfer unit 4 conveys the medium PM conveyed from the conveyance unit 2 along the conveyance direction F, and sequentially forms toner images formed in the image forming units 3Y, 3M, 3C, and 3K on the surface of the medium PM. This is a mechanism for transcription.

  The transfer belt 4A is an endless elastic belt made of a resin material such as polyimide resin. The transfer belt 4A is stretched (strung) by a drive roller 4B and an idle roller 4C. The drive roller 4B is rotationally driven in the direction in which the medium PM is conveyed in the conveyance direction F based on the control of the control unit 7, and circulates and rotates the transfer belt 4A. The drive roller 4B is disposed upstream of the image forming units 3Y, 3M, 3C, and 3K. The idle roller 4C adjusts the tension applied to the transfer belt 4A by the urging force of the urging member. The idle roller 4C rotates in the same direction as the drive roller 4B, and is disposed downstream of the image forming units 3Y, 3M, 3C, and 3K. The cleaning unit 9 is provided, for example, below the transfer unit 4 and collects waste toner remaining on the surface of the transfer belt 4A without being transferred to the surface of the medium PM, and cleaning the transfer belt 4A.

  The transfer roller 4D rotates in the direction opposite to that of the photosensitive drum 32 to convey the medium PM along the conveyance direction F, and the toner image formed in each of the image forming units 3Y, 3M, 3C, and 3K to the medium PM. It is a member for electrostatically transferring onto the top. The transfer roller 4D is made of, for example, a foaming semiconductive elastic rubber material.

(Fixing unit 5)
The fixing unit 5 is a member for fixing the toner image onto the medium PM by applying heat and pressure to the toner image transferred onto the medium PM that has passed through the transfer unit 4. The fixing unit 5 includes, for example, an upper roller 5A and a lower roller 5B.

  Each of the upper roller 5A and the lower roller 5B includes a heat source that is a heater such as a halogen lamp, and functions as a heating roller that applies heat to the toner image on the medium PM. The upper roller 5 </ b> A is controlled to rotate in the direction in which the medium PM is transported in the transport direction F under the control of the control unit 7. The heat sources in the upper roller 5A and the lower roller 5B are supplied with a bias voltage controlled by the control unit 7, and control the surface temperatures of the upper roller 5A and the lower roller 5B. The lower roller 5B is disposed to face the upper roller 5A so that a pressure contact portion is formed between the lower roller 5A and functions as a pressure roller that applies pressure to the toner image on the medium PM. To do. The lower roller 5B may have a surface layer made of an elastic material.

(Discharge unit 6)
The discharge unit 6 discharges the medium PM on which the toner image is fixed by the fixing unit 5 to the outside. The discharge unit 6 includes, for example, transport rollers 6A and 6B. The transport rollers 6A and 6B are configured to discharge the medium PM to the outside through the transport path and store it on the external stacker 100A. The transport rollers 6 </ b> A and 6 </ b> B are configured to rotate in a direction in which the medium PM is transported in the transport direction F under the control of the control unit 7.

(Driver 8)
The drive unit 8 includes a motor that serves as a drive source for the image forming apparatus PT1, and supplies power for rotating the photosensitive drum 32 (described later) via, for example, a drive gear.

  2 is a perspective view showing the appearance of the image forming apparatus PT1 shown in FIG. 1, and shows a state in which the lid 102 is completely closed with respect to the main body 101 (hereinafter referred to as a fully closed state). In the image forming apparatus PT1, the image is formed in the fully closed state shown in FIG. Note that the image forming apparatus PT1 may be provided with a lock mechanism for maintaining the fully closed state.

  3A and 3B show the appearance of the image forming apparatus PT1 in a state where the lid portion 102 is completely opened with respect to the main body portion 101 (hereinafter referred to as a fully opened state). 3A is a perspective view, and FIG. 3B is a front view seen in the + X direction. In FIG. 3A, the front side plate 101A (see FIG. 2) is omitted so that the inside of the main body 101 can be visually recognized.

  4 is a perspective view illustrating a state (hereinafter referred to as a transition state) between the fully closed state (FIG. 2) and the fully open state (FIGS. 3A and 3B) in the image forming apparatus PT1. In FIG. 4, as in FIG. 3A, the front side plate 101 </ b> A (see FIG. 2) is omitted so that the inside of the main body 101 can be visually recognized.

  As shown in FIGS. 3A, 3B, and 4, the lid portion 102 includes a rectangular upper plate 102S that extends along the XY plane in the fully closed state, and four side plates that stand along the outer edge of the upper plate 102S. 102A to 102D. For example, four exposure apparatuses LD standing in the −Z direction are attached to the inner surface of the upper plate 102S. Further, the side plate 102B is provided with a handle 102T used for opening and closing the lid 102. A pair of hinges 103A and 103B are attached to the side plate 102D at a position facing the side plate 102B provided with the handle 102T, and can be opened and closed by this.

  On the other hand, the main body unit 101 holds four image forming unit IDs, and has a rectangular bottom plate 101S extending along the XY plane and four side plates 101A to 101D erected along the outer edge of the bottom plate 101S. And have. As shown in FIGS. 5A and 5B, the four image forming unit IDs can be taken out from the main body unit 101. The side plate 101B is provided with notches K (KY, KM, KC, KK) as a specific example of the “guide portion” of the present invention. The notches K (KY, KM, KC, KK) are respectively engaged with the convex portions P1 provided at one end in the X-axis direction of the housing 30 of each image forming unit ID, and along the extending direction of the notches K (KY, KM, KC, KK). Each of the convex portions P1 is guided. The side plate 101D facing the side plate 101B has a groove U (UY, UM, UC, UK) and a hole V (VY, VM, VC, VK) as other specific examples of the “guide portion” of the present invention. Is provided. The grooves U (UY, UM, UC, UK) are respectively engaged with the convex portions P2 provided at the other end in the X-axis direction of the housing 30 of each image forming unit ID, and along the extending direction thereof. Each of the convex portions P2 is guided. Each of the holes V (VY, VM, VC, VK) is associated with a convex portion P3 provided at a location different from the convex portion P2 at the other end in the X-axis direction of the housing 30 of each image forming unit ID. It comes to match. The notches K (KY, KM, KC, KK) and the grooves U (UY, UM, UC, UK) extend in an oblique direction intersecting both the X-axis direction and the Z-axis direction in the YZ plane.

  In this specification, the exposure apparatuses LD corresponding to the image forming units 3Y, 3M, 3C, and 3K are referred to as exposure apparatuses LDY, LDM, LDC, and LDK, respectively. Similarly, image forming unit IDs corresponding to the image forming units 3Y, 3M, 3C, and 3K are set as image forming units IDY, IDM, IDC, and IDK, respectively.

[1.2 Detailed Configuration of Image Forming Unit 3]
Next, a detailed configuration of the image forming unit 3 will be described.

(Configuration of exposure apparatus LD)
First, the configuration of the exposure apparatus LD will be described with reference to FIGS. FIG. 6 is a perspective view showing a state in which four exposure apparatuses LD are attached to the lid 102. 7 to 9 are cross-sectional views in the arrow direction along the lines VII-VII, VIII-VIII, and IX-IX shown in FIG. 6, respectively. FIG. 10 is a cross-sectional view in the arrow direction along the line XX shown in FIG.

  The exposure apparatuses LDY, LDM, LDC, and LDK have substantially the same structure. Therefore, here, it will be described simply as exposure apparatus LD. The exposure apparatus LD includes a first member 10, a second member 20, a torsion spring 40, and a head unit 50.

  The first member 10 includes a flat plate portion 11 fixed to the upper plate 102 </ b> S of the lid portion 102, a pair of upright portions 12 erected at both ends of the flat plate portion 11 in the X-axis direction, and one upright portion 12. The contact part 13 and the control part 14 which were provided in are included. Further, a shaft 15 extending in the X-axis direction is attached to the first member 10 so as to connect the pair of standing portions 12. Here, the first member 10 is a specific example corresponding to the “first member” of the present invention, and the contact portion 13 is a specific example corresponding to the “first contact portion” of the present invention. The shaft 15 is a specific example corresponding to the “shaft” of the present invention.

  The second member 20 is attached to the first member 10 so as to be reversibly displaceable along the Y-axis direction, and includes a contact portion 21 provided so as to be able to contact the contact portion 13. More specifically, the second member 20 is attached to the first member 10 so as to be swingable about the shaft 15. The contact part 21 is sandwiched between the contact part 13 and the restriction part 14 in the first member 10 in the Y-axis direction. The dimension of the contact part 21 in the Y-axis direction is smaller than the distance between the contact part 13 and the restriction part 14. For this reason, the second member 20 is movable in the Y-axis direction by the gap between the contact portion 21 and the contact portion 13 and the restricting portion 14. Here, in the state in which the external force is not applied to the second member 20, the abutting portion 21 abuts the edge 211 facing the abutting portion 13 against the abutting portion 13 by the biasing force of the torsion spring 40. (See FIG. 10). For this reason, for example, when the lid 102 is opened and closed, the behavior of the second member 20 swinging relative to the first member 10 and the lid 102 is suppressed. When an external force is applied to the second member 20 in the −Y direction, the edge 211 is separated from the contact portion 13 when the external force exceeds the urging force of the torsion spring 40. However, when the end edge 212 (FIG. 10) of the abutting portion 21 facing the restricting portion 14 abuts on the restricting portion 14, no further displacement occurs. The second member 20 includes a grip portion 22 that grips an end portion 42 (described later) of the torsion spring 40. Here, the second member 20 is a specific example corresponding to the “second member” of the present invention, and the contact portion 21 is a specific example corresponding to the “second contact portion” of the present invention. . The Y-axis direction is a specific example corresponding to the “first direction” of the present invention.

  The torsion spring 40 elastically urges the second member 20 in the + Y direction so that the abutting portion 13 and the abutting portion 21 are in contact with each other, and is the “first urging member” of the present invention. It is one specific example corresponding to. The torsion spring 40 includes, for example, an end 41 that contacts the inner surface of the upper plate 102S, an end 42 that is gripped by the gripping portion 22, and a winding portion 43 that is wound around the shaft 15 (FIG. 9). Including.

  The head unit 50 includes an exposure head 51 including a plurality of light emitting elements (for example, LEDs: Light Emitting Diodes) arranged in the X-axis direction, and a head holder 52 that holds the exposure head 51. The head unit 50 further includes a pair of coil springs 53A and 53B. The pair of coil springs 53A and 53B are urging members that urge the exposure head 51 away from the head holder 52 along the Z-axis direction, and are a specific example of the “second urging member” of the present invention. Corresponding to Further, both ends in the X-axis direction of the exposure head 51 and both ends in the X-axis direction of the head holder 52 are locked so as to be relatively movable in the Z-axis direction at the locking portions 56A and 56B. In this way, the exposure head 51 is held by the head holder 52 so as to be reversibly displaceable (elastically) along the Z-axis direction. Therefore, when the exposure apparatus LD faces the image forming unit ID in the fully closed state, even if there is a slight tilt error such as a manufacturing error, the tilt error is absorbed by the pair of coil springs 53A and 53B. As a result, the distance between the exposure head 51 and the photosensitive drum 32 is optimized, and an appropriate exposure operation is possible. Further, a pair of openings 51H are provided at both ends in the X-axis direction on the lower surface of the exposure head 51 (the surface that faces the photosensitive drum 32) (see FIGS. 3A and 3B). The pair of openings 51H are fitted with a pair of posts 30T (described later) in the image forming portion ID in the fully closed state, and are a specific example corresponding to the “first fitting portion” of the present invention. . The X-axis direction is a specific example corresponding to the “second direction” of the present invention.

  The head holder 52 of the head unit 50 is held by the second member 20 so as to be reversibly displaceable along the X-axis direction. The head holder 52 has elongated holes 54A and 54B extending in the X-axis direction and penetrating in the Y-axis direction. On the other hand, the second member 20 has pins 23A and 23B extending in the Y-axis direction, for example, in the vicinity of the end away from the shaft 15. The pin 23A and the pin 23B are inserted into the elongated hole 54A and the elongated hole 54B, respectively, so that the head holder 52 can be reversibly displaced along the X-axis direction with respect to the second member 20. Here, the exposure apparatus LD is further provided with a coil spring 16. As shown in FIG. 8, one end of the coil spring 16 is locked to the hook portion 25 of the second member 20, and the other end of the coil spring 16 is locked to the hook portion 55 of the head holder 52. The coil spring 16 elastically biases the second member 20 and the head holder 52 so as to attract each other along the X-axis direction. Therefore, the head holder 52 is biased in the direction of the arrow Y52 by the biasing force of the coil spring 16 in a state where the external force in the + X direction is not applied, and is the position closest to the −X direction with respect to the second member 20. Exists. In this state, as shown in FIG. 8, the pins 23A and 23B are in contact with the right inner surface of the long holes 54A and 54B. When an external force in the + X direction is applied to the head holder 52, the head holder 52 moves in the + X direction with respect to the second member 20 when the external force exceeds the urging force of the coil spring 16. However, when the pins 23A and 23B are in contact with the left inner surfaces of the long holes 54A and 54B, no further displacement occurs (see FIG. 8). Thus, since the head holder 52 is held by the second member 20 so as to be reversibly displaceable along the X-axis direction, for example, when the lid portion 102 is opened and closed, the exposure head 51 is attached to the main body portion 101, for example. A collision with the upper end of the side plate 101D can be easily avoided. The coil spring 16 is a specific example corresponding to the “third urging member” of the present invention.

(Configuration of image forming unit ID)
FIG. 11 shows the internal configuration of the image forming unit ID (IDY, IDM, IDC, IDK) in the image forming unit 3. FIG. 11 also shows some components of the transfer unit 4 (transfer roller 4D and transfer belt 4A). The image forming unit ID includes a housing 30, a toner storage chamber 31 </ b> A that occupies a part of the housing 30, and an image forming chamber 31 </ b> B that is located below the toner storage chamber 31 </ b> A in the housing 30. The toner storage chamber 31A is a space for storing toner, and has an opening 31K in the lower part thereof. Toner is supplied to the image forming chamber 31B through the opening 31K. In the image forming chamber 31B, a photosensitive drum 32, a charging roller 33, a developing roller 35, a supply roller 36, a waste toner conveying spiral 38, and the like are accommodated. The photosensitive drum 32 is a specific example corresponding to the “image carrier” of the present invention.

  A pair of posts 30T are provided at both ends in the X-axis direction of the housing 30 so as to protrude upward (in the + Z direction), for example. The pair of posts 30T is inserted into and fitted into the pair of openings 51H in the fully closed state, and is a specific example corresponding to the “second fitting portion” and the “projection” of the present invention (FIG. 12). 12 shows a state in which the exposure head 51 descends in the −Z direction from the upper side with respect to the housing 30, and the post 30T and the opening 51H are in the same position in the XY plane. Represents. The right side of FIG. 12 shows a state where the exposure head 51 is further displaced in the −Z direction and the post 30T and the opening 51H are fitted. In this image forming unit 3, the post 30 </ b> T and the opening 51 </ b> H are provided so that they can be fitted, so that, for example, when the lid 102 is closed, the alignment between the photosensitive drum 32 and the exposure head 51 is easy and accurate. Can be implemented. Here, the tip of the post 30T may include an inclined surface. This is because the alignment between the post 30T and the opening 51H is further facilitated, and the alignment between the photosensitive drum 32 and the exposure head 51 is promptly performed.

  In the present embodiment, the post 30T as the “second fitting portion” is provided in the housing 30 and the opening 51H as the “first fitting portion” is provided in the exposure head 51. An opening may be provided in the housing 30 and a post may be provided in the exposure head 51. Further, the image forming unit ID shown in FIG. 11 has a housing 30 in which the toner storage chamber 31A and the image formation chamber 31B are integrated, but the toner storage chamber 31A and the image formation chamber 31B are separated. The body may be configured to be detachable from each other.

  The photosensitive drum 32 is a cylindrical member capable of carrying an electrostatic latent image on the surface (surface layer portion), and is configured using a photosensitive member (for example, an organic photosensitive member). Specifically, the photosensitive drum 32 has a conductive support and a photosensitive layer (photoconductive layer) covering the outer periphery (surface) thereof. The conductive support is made of, for example, a metal pipe made of aluminum. The photoconductive layer has, for example, a structure in which a charge generation layer and a charge transport layer are sequentially stacked. The photosensitive drum 32 is controlled by the control unit 7, and the driving force transmitted from the driving unit 8 causes the medium PM to be conveyed in the conveyance direction F (direction of the arrow Y <b> 32) with a predetermined circumference around the shaft 32 </ b> J. It is designed to rotate at a speed.

  The charging roller 33 is a member (charging member) that charges the surface layer portion (photosensitive layer) of the photosensitive drum 32, and is disposed so as to be in contact with the surface of the photosensitive drum 32. The charging roller 33 has, for example, a metal shaft and a semiconductive rubber layer (for example, a semiconductive epichlorohydrin rubber layer) covering the outer periphery (surface) thereof. The charging roller 33 is controlled by the control unit 7 to rotate in the same direction as the photosensitive drum 32, for example.

  The exposure head 51 is an exposure device that forms an electrostatic latent image on the surface layer portion (photosensitive layer) of the photosensitive drum 32 by exposing the surface layer portion (photosensitive layer) of the photosensitive drum 32. The exposure head 51 has a plurality of light emitting elements arranged in the X-axis direction with respect to one photosensitive drum 32. Each light emitting element includes, for example, a light source such as an LED that emits irradiation light, and a lens array that forms an image of the irradiation light on the surface of the photosensitive drum 32.

  The developing roller 35 is a member that carries toner for developing an electrostatic latent image on the surface thereof, and is disposed so as to be in contact with the surface (circumferential surface) of the photosensitive drum 32. The developing roller 35 has, for example, a metal shaft and a semiconductive urethane rubber layer covering the outer periphery (surface). The developing roller 35 is controlled by the control unit 7 and rotates at a predetermined peripheral speed in the opposite direction to the photosensitive drum 32.

  The supply roller 36 is a member (supply member) for supplying toner to the developing roller 35 and is disposed in contact with the surface (circumferential surface) of the developing roller 35. The supply roller 36 has, for example, a metal shaft and a foamable silicone rubber layer covering the outer periphery (surface) thereof. The supply roller 36 is controlled by the control unit to rotate in the direction opposite to the developing roller 35.

  The waste toner conveying spiral 38 is, for example, a member in which spiral blades are erected around the shaft, and are rotated under the control of the control unit. The waste toner conveyance spiral 38 functions to convey the toner scraped off by the cleaning blade in the + X direction, for example, by rotating.

[1.3 Action and effect]
(A. Basic operation)
In the image forming apparatus PT1, the toner image is transferred to the medium PM as follows.

  First, when print image data and a print command are input to the control unit 7 from an external device such as a PC with respect to the image forming apparatus PT1 in the fully closed state (FIG. 2) and in the activated state, In response to the print command, the print image data printing operation is started.

  For example, as shown in FIG. 1, the medium PM stored in the cassette 1A is picked up one by one from the uppermost portion by the pickup roller 1B, and is fed to the downstream conveyance unit 2 while the skew is corrected by the feed roller 1C. . Next, the medium PM is conveyed to the image forming unit 3 by the two pairs of registration rollers 2A and 2B. In the image forming unit 3, the toner image is transferred onto the medium PM as follows.

  In the image forming unit 3, a toner image of each color is formed by the following electrophotographic process in accordance with a print command from the control unit 7. Specifically, the control unit 7 puts the toner stored in the toner storage chamber 31A into the image forming chamber 31B and rotates the photosensitive drum 32 at a constant speed in the direction of arrow R32. Accordingly, the charging roller 33, the developing roller 35, and the supply roller 36 also start rotating in a predetermined direction.

  On the other hand, the control unit 7 applies a predetermined voltage to the charging roller 33 for each color to uniformly charge the surface of the photosensitive drum 32 for each color. Next, the control unit 7 activates the exposure head 51, irradiates each color photosensitive drum 32 with light corresponding to the color component of the print image based on the image signal, and forms an electrostatic latent image on the surface of each color photosensitive drum 32. Form each one.

  The toner is supplied to the developing roller 35 via the supply roller 36 and is carried on the surface of the developing roller 35. The developing roller 35 attaches toner to the electrostatic latent image formed on the photosensitive drum 32 to form a toner image. Further, a predetermined voltage is applied to the transfer roller 4D in the transfer unit 4, and an electric field is generated between the photosensitive drum 32 and the transfer roller 4D. In this state, when the medium PM travels between the photosensitive drum 32 and the transfer roller 4D, the toner image formed on the photosensitive drum 32 is transferred onto the medium PM.

  Thereafter, the toner image IMG on the medium PM is fixed on the medium PM by applying heat and pressure in the fixing unit 5. Finally, the medium PM on which the toner image IMG is fixed by the discharge unit 6 is discharged to the stacker 100A outside the image forming apparatus PT1.

(B. About the mounting operation of the exposure head 51)
In the image forming apparatus PT1, the exposure apparatus LD is attached to and detached from the image forming unit ID by opening and closing the lid 102. That is, for example, by performing a closing operation for shifting from the fully open state (FIGS. 3A and 3B) with the lid 102 opened to the fully closed state (FIG. 2) through the transition state (FIG. 4), the photosensitive drum in the image forming unit ID The alignment of the exposure head 51 with respect to 32 is performed.

  During the closing operation, for example, the end of the head holder 52 is guided by a guide groove G (see FIGS. 3A and 5A) provided near the upper end of the side plate 101D, and the exposure head 51 is moved from above the photosensitive drum 32. approach. As described above, since the head holder 52 is held by the second member 20 so as to be reversibly displaceable along the X-axis direction, it is possible to easily avoid the exposure head 51 from colliding with the upper end of the side plate 101D. . Finally, the post 30T is inserted into the opening 51H and the two are fitted together, whereby the positioning of the exposure head 51 with respect to the photosensitive drum 32 is completed (FIG. 12).

  During the printing operation, the convex portions P1 to P3 are locked at the deepest portions of the notch K, the groove U, and the recess V, respectively. For example, as illustrated in FIG. 13, the image forming unit ID is held in the main body unit 101 in a state where the convex portion P1 is in contact with the deepest portion K1 of the notch K. However, when performing a printing operation using only a part of the four image forming units 3 such as single color printing or two color printing, it is not used to avoid transfer from the unused image forming unit 3 to the medium PM. It is necessary to retract the image forming unit 3 from the transfer unit 4 by a predetermined amount. Specifically, as shown in FIG. 13, the convex portion P1 extends along the extending direction of the notch K from the position P0 in contact with the deepest portion K1 of the notch K to the position PP indicated by the broken line. The unused image forming unit 3 is retracted so as to move obliquely upward to the left (in the direction of the white arrow Y17). At this time, as shown in FIG. 14, among the image forming units 3 that are not used, the image forming unit ID is changed from the position ID0 indicated by the solid line (left figure in FIG. 14) to the position ID1 indicated by the broken line (right figure in FIG. 14). ) On the other hand, the exposure apparatus LD shifts the exposure head 51 upward by compressing the coil springs 53A and 53B, and changes only the angle θ with the shaft 15 as the rotation axis in the direction of the arrow 18 without changing the position of the shaft 15. Rotate. The rotation in the direction of the arrow 18 is an operation that resists the biasing force of the torsion spring 40. Thus, since the position of the shaft 15 in the exposure apparatus LD does not change, the first member 10 and the lid portion 102 to which the first member 10 is fixed need not be displaced. Therefore, the retracting operation of the image forming unit 3 that is not used can be performed with the lid portion 102 closed. This is because in the exposure apparatus LD, the second member 20 that indirectly holds the exposure head 51 is provided so as to be swingable about the shaft 15 with respect to the first member 10 fixed to the lid portion 102. is there.

  The reason why the notch K and the groove U are inclined not in the vertical direction (Z-axis direction) but in the medium traveling direction from the Z-axis direction is as follows. As described above, the photosensitive drum 32 rotates in the direction in which the medium PM is transported in the transport direction F by the driving force transmitted from the drive unit 8. Specifically, as shown in FIG. 15, the drive gear 81 interlocked with the motor shaft of the drive unit 8 and the gear 32G interlocked with the shaft 32J of the photosensitive drum 32 are engaged with each other. The rotational force is transmitted to the photosensitive drum 32 through the gear 32G. When the gear 32G and the drive gear 81 are engaged with each other, the rotation center 32C and the rotation center 81C are arranged in the vertical direction (Z-axis direction). Since the motor of the drive unit 8 is a member that is a drive source for other parts other than the photosensitive drum 32, the motor is basically continuously rotated at a constant speed during energization. Here, when the image forming unit 3 that has not been used so far is moved from the retracted position to the used position for printing, the gear 32G approaches the drive gear 81 and engages. At this time, the rotating drive gear 81 is viewed from a direction Y82 orthogonal to the direction Y81 of the pressure angle (for example, 20 °) or a direction that is slightly smaller than 90 ° with respect to the direction Y81 of the pressure angle. It is desirable to make the gear 32G approach and engage. This is because a force to move the gear 32G in the pressure angle direction Y81 of the drive gear 81 acts on the gear 32G. For example, when the gear 32G approaches the drive gear 81 from a direction larger than 90 ° with respect to the direction Y81 of the pressure angle of the drive gear 81, the gear 32G is rattled or bounced by the drive force of the drive gear 81. There is a risk. For this reason, the notch K and the groove U are inclined, and the direction Y82 perpendicular to the pressure angle direction Y81 of the drive gear 81 or the pressure angle direction Y81 is about 10 ° smaller than 90 °. The gear 32G is brought closer to the drive gear 81 from an angled direction.

(C. Effects of the image forming apparatus PT1)
Thus, in the present embodiment, the second member 20 is attached to the first member 10 so as to be swingable about the shaft 15. Therefore, in the state where the external force is not applied to the second member 20, the contact portion 21 is in contact with the contact portion 13 at the edge 211 facing the contact portion 13 by the biasing force of the torsion spring 40. For this reason, for example, when the lid 102 is opened and closed, the behavior of the second member 20 swinging relative to the first member 10 and the lid 102 is suppressed. Therefore, when the lid 102 is opened and closed, interference between the image forming unit ID accommodated in the main body 101 and the exposure apparatus LD held on the lid 102 can be avoided, and damage to them can be prevented. Further, when an external force exceeding the urging force of the torsion spring 40 is applied to the second member 20 in the −Y direction, the second member 20 rotates around the shaft 15. For this reason, the exposure apparatus LD can cope with the retreat operation of the image forming unit ID. Therefore, according to the exposure apparatus LD of the present embodiment, and the image forming unit 3 and the image forming apparatus including the exposure apparatus LD, the opening / closing operation of the lid 102 and the retracting operation of the unused image forming unit ID can be smoothly performed. And excellent operability can be obtained.

<2. Second Embodiment>
[2.1 Overall Configuration of Image Forming Apparatus PT2]
The overall configuration of the image forming apparatus PT2 according to the second embodiment of the present invention will be described below with reference to FIG. FIG. 16 is a perspective view illustrating an appearance of the image forming apparatus PT2, and FIG. 17 is a schematic diagram illustrating an internal configuration example of the image forming apparatus PT2. The image forming apparatus PT2 corresponds to a specific example of the “image forming apparatus” of the present invention. For example, an image (for example, a color image) is printed on a medium PM to be printed, such as paper or film, using an electrophotographic method. It is a printer which forms. The image forming apparatus PT2 includes a housing 200 having a main body portion 201 and a lid portion 202. The lid portion 202 is attached to the main body portion 201 so as to be openable and closable. Specifically, for example, the rotating shaft 202J (see FIG. 18 described later) is rotated reversibly as indicated by an arrow Y202 (see FIG. 16). Inside the housing 200, similarly to the image forming apparatus PT1, the medium supply unit 1, the conveyance unit 2, the image forming unit 3, the transfer unit 4, the fixing unit 5, the discharge unit 6, the control unit 7, the driving unit 8, and the cleaning are provided. Part 9 is provided. In the present embodiment, components that are substantially the same as those described in the first embodiment are given the same reference numerals, and descriptions thereof are omitted as appropriate.

[2.2 Detailed Configuration of Image Forming Unit 3]
Next, a detailed configuration of the image forming unit 3 will be described.

(Configuration of cover top assembly 60)
First, the configuration of the cover top assembly 60 will be described with reference to FIGS. 18 to 21C. FIG. 18 is a perspective view showing a cover top assembly 60 including a plurality of exposure apparatuses LD2. FIG. 18 shows a state in which four exposure apparatuses LD2 are attached to the inner surface 202S of the lid 202 as an example, but the number of exposure apparatuses LD2 is not limited to this. FIG. 19 is an enlarged perspective view showing a main part of the exposure apparatus LD2. FIG. 20 is an enlarged view of the main part of the exposure apparatus LD2, viewed from the front.

  Each of the four exposure devices LD2 includes a pair of head frames 61L and 61R attached to the inner surface 202S, a head holder 62, an exposure head 63, a torsion spring 64, and a shaft 65. The exposure head 63 includes a plurality of light emitting elements (for example, LEDs) arranged in the X-axis direction, for example, and is held by a head holder 62.

  The head frames 61L and 61R are fixed to both ends of the inner surface 202S of the lid portion 202 in the width direction (X-axis direction), and hold the head holder 62 in a rotatable manner. Specifically, the head frames 61L and 61R are respectively provided with shafts 65 extending in the X-axis direction. The head holder 62 is held by head frames 61L and 61R so as to be rotatable in both the −R62 direction and the + R62 direction around the shaft 65 (see FIG. 20 and the like). Here, the −R62 direction is a specific example corresponding to the “first rotation direction” of the present invention, and the + R62 direction is a specific example corresponding to the “second rotation direction” of the present invention. The torsion spring 64 is a specific example corresponding to the “biasing member” of the present invention, and is a member that elastically biases the head holder 62 in both the −R62 direction and the + R62 direction.

  Each of the head frames 61L and 61R is provided with a rib 66 that protrudes toward the head holder 62. One rib 66 may be provided corresponding to only one of the head frame 61L and the head frame 61R. Further, the rib 66 may be provided on the inner surface 202S of the lid portion 202. That is, the rib 66 may be fixed directly or indirectly to the head frames 61L and 61R. Here, the head frames 61L and 61R are one specific example corresponding to the “first member” of the present invention, and the head holder 62 is one specific example corresponding to the “second member” of the present invention. 65 is a specific example corresponding to the “shaft” of the present invention.

  In the exposure apparatus LD2, the head holder 62 is, for example, a direction (Z-axis direction) orthogonal to the inner surface 202S of the lid 202 by the urging force of the torsion spring 64 in a state where no external force is applied to the head holder 62. (See FIG. 20 and the like). For this reason, for example, when the lid 202 is opened and closed, the behavior of the head holder 62 swinging with respect to the head frames 61L and 61R and the lid 202 is suppressed.

  The torsion spring 64 includes, for example, as shown in FIGS. 21A to 21C, a pair of end portions 641 and 642, and a winding portion 643 provided between them and wound. FIG. 21A is an enlarged front view showing one form of the torsion spring 64 shown in FIG. 19, and shows the torsion spring in a state where no external force is applied to the torsion spring 64. On the other hand, FIGS. 21B and 21C correspond to the state shown in FIG. 20, and the external force −F1 is applied to the end portion 641 and the external force −F2 is applied to the end portion 642. It is the front view and perspective view showing the torsion spring 64 of the state which was in the state. In the state shown in FIGS. 21B and 21C, an urging force + F1 opposite to the external force −F1 is generated at the end portion 641, and an urging force + F2 opposite to the external force −F2 is generated at the end portion 642. In FIG. 20, the end portion 641 and the end portion 642 are provided so as to face each other with the rib 66 interposed therebetween, for example, and are in contact with the locking portion 621 and the locking portion 622 respectively provided on the head holder 62. . Further, in the exposure apparatus LD2, the winding portion 643 is wound so as to surround the shaft 65. With such a configuration, as described above, the head holder 62 is orthogonal to, for example, the inner surface 202 </ b> S of the lid 202 by the urging force of the torsion spring 64 in a state where no external force is applied to the head holder 62. It is held in a state extending in the direction (Z-axis direction) (see FIG. 20 and the like). The state shown in FIG. 20 is a reference state.

  Here, for example, as shown in FIG. 22A, when the external force FF1 in the -Y direction is applied to the head holder 62, the head holder 62 rotates in the direction of the arrow -R62 around the shaft 65 from the reference state. The external force FF1 is a specific example corresponding to the “first external force” of the present invention, and is greater than both the urging force + F1 and the urging force + F2 shown in FIGS. 21B and 21C. At this time, the end portion 642 comes into contact with the rib 66 and the end portion 641 is locked to the locking portion 621. On the other hand, as shown in FIG. 22B, when the external force FF2 in the + Y direction is applied to the head holder 62, the head holder 62 rotates about the shaft 65 in the direction of the arrow + R62. The external force FF2 is a specific example corresponding to the “second external force” of the present invention, and is assumed to be larger than both the urging force + F1 and the urging force + F2 shown in FIGS. 21B and 21C. At this time, the end portion 641 comes into contact with the rib 66 and the end portion 642 is locked to the locking portion 622. When the external force FF1 and the external force FF2 are respectively removed, the head holder 62 returns to the reference state shown in FIG. 20 by the urging force of the torsion spring 64.

  The exposure head 63 is preferably held by the head holder 62 so as to be reversibly displaceable (elastically) along the Z-axis direction via, for example, a coil spring. This is because when the exposure apparatus LD faces the image forming unit ID in the fully closed state, even if there is a slight tilt error such as a manufacturing error, the tilt error is absorbed by the coil spring or the like. As a result, the distance between the exposure head 51 and the photosensitive drum 32 is optimized, and an appropriate exposure operation is possible.

[2.3 Functions and effects]
(A. Basic operation)
The basic operation of the image forming apparatus PT2 is substantially the same as that of the image forming apparatus PT1 in the first embodiment.

(B. About the attaching / detaching operation of the image forming unit ID)
In the image forming apparatus PT2, for example, as shown in FIGS. 23A to 23C, the image forming unit ID is attached to and detached from the main body unit 201 in the open state in which the lid unit 202 is opened.

  For example, when the image forming unit ID is taken out from the main body unit 201, first, the casing 200 is opened from the closed state (the lid unit 202 is closed) shown in FIG. The state is shifted to an open state (a state in which the lid portion 202 rotates around the rotation shaft portion 202J and jumps upward). At this stage, the head holder 62 in each exposure apparatus LD2 is in the reference state shown in FIG.

  Next, as illustrated in FIG. 23B, the image forming unit ID housed in the main body unit 201 is lifted obliquely upward, that is, for example, in the direction indicated by the white arrow. At this time, the image forming unit ID may interfere with each exposure apparatus LD2, but in this case, the head holder 62 held rotatably with respect to the head frames 61L and 61R rotates around the shaft 65. Damage to the exposure head 63 and the like is avoided. In FIG. 23B, the head holder 62M of the exposure apparatus LD2 corresponding to the image forming unit 3M interferes with the image forming unit ID, and the head holder 62M rotates in the −R62 direction as shown in FIG. 22A. Show. Thus, the impact at the time of interference is relieved by the rotation of the head holder 62M. When the external force is not applied, the head holder 62M returns to the reference state shown in FIG. 20 by the urging force of the torsion spring 64.

  On the other hand, when the image forming unit ID is accommodated inside the main body unit 201, in the open state shown in FIG. 23A, for example, the image forming unit ID is moved obliquely downward as shown in FIG. Proceed in the direction indicated. At this time, the image forming unit ID may interfere with each exposure apparatus LD2, but in this case, the head holder 62 held rotatably with respect to the head frames 61L and 61R rotates around the shaft 65. Again, damage to the exposure head 63 and the like is avoided. FIG. 23C shows a state in which the head holder 62K of the exposure apparatus LD2 corresponding to the image forming unit 3K interferes with the image forming unit ID, and the head holder 62K rotates in the + R62 direction as shown in FIG. 22B. ing. Thus, the impact at the time of interference is relieved by the rotation of the head holder 62K. The head holder 62K returns to the reference state shown in FIG. 20 by the urging force of the torsion spring 64 when no external force is applied.

(C. Effects of the image forming apparatus PT2)
As described above, in the present embodiment, the head holder 62 is attached to the head frames 61L and 61R so as to be swingable about the shaft 65. Therefore, the head holder 62 is elastically held by the urging force of the torsion spring 64. For this reason, for example, when the lid 202 is opened and closed, the behavior of the head holder 62 swinging with respect to the head frames 61L and 61R and the lid 202 is suppressed. Therefore, during the opening / closing operation of the lid 202, interference between the image forming unit ID accommodated in the main body 201 and the exposure apparatus LD2 held by the lid 202 can be avoided, and damage thereof can be prevented.

  Further, when an external force exceeding the urging force of the torsion spring 64 is applied to the head holder 62 in the + Y direction or the −Y direction, the head holder 62 rotates about the shaft 65. For this reason, the exposure apparatus LD2 can cope with the attaching / detaching operation of the image forming unit ID. That is, even when the exposure apparatus LD2 interferes with the image forming unit ID during the attaching / detaching operation of the image forming unit ID, it is possible to reduce the impact at the time of interference and avoid damage. Therefore, according to the exposure apparatus LD2 of the present embodiment, and the image forming unit 3 and the image forming apparatus including the exposure apparatus LD2, the opening / closing operation of the lid 102 and the attaching / detaching operation of the unused image forming unit ID are performed smoothly. And excellent operability can be obtained.

<3. Modification>
While the present invention has been described with reference to the embodiment, the present invention is not limited to the above embodiment, and various modifications can be made. For example, in the above-described embodiment, an image forming apparatus that forms a color image has been described. However, the present invention is not limited to this. For example, an image forming apparatus that forms a monochrome image by transferring only a black toner image. There may be. In the above embodiment, the primary transfer type (direct transfer type) image forming apparatus has been described. However, the present invention can also be applied to a secondary transfer type.

  In the above-described embodiment and the like, an LED head using a light emitting diode as a light source is used as the exposure device. However, for example, an exposure device using a laser element or the like as a light source may be used.

  Furthermore, in the above-described embodiment and the like, an image forming apparatus having a printing function has been described as a specific example of the “image forming apparatus” in the present invention, but the present invention is not limited to this. That is, in addition to such a printing function, for example, the present invention can also be applied to an image forming apparatus that functions as a multifunction peripheral having a scanning function and a fax function.

  DESCRIPTION OF SYMBOLS 1 ... Medium supply part, 1A ... Cassette, 1B ... Pick-up roller, 1C ... Feed roller, 2 ... Conveyance part, 2A, 2B ... Registration roller pair, 3 (3Y, 3M, 3C, 3K) ... Image forming unit, 4 ... Transfer section, 4A ... transfer belt, 4B ... drive roller, 4C ... idle roller, 4D ... transfer roller, 5 ... fixing section, 6 ... discharge section, 7 ... control section, 8 ... drive section, 9 ... cleaning section, 10 ... 1st member, 11 ... Flat plate part, 12 ... Standing part, 13 ... Abutting part, 14 ... Restricting part, 15 ... Shaft, 16 ... Coil spring, 17 ... Arrow, 20 ... Second member, 21 ... Abutting part 22 ... gripping part, 23A, 23B ... pin, 25 ... hook part, 30 ... housing, 31A ... toner storage chamber, 31B ... image forming chamber, 32 ... photosensitive drum, 33 ... charging roller, 35 ... developing roller, 36 ... Supply roller, 38 ... Waste toner Feed spiral, 40 ... Torsion spring, 41, 42 ... End, 43 ... Winding part, 50 ... Head unit, 51 ... Exposure head, 52 ... Head holder, 53A, 53B ... Coil spring, 54A, 54B ... Long hole, 55 ... Hook part, 100 ... Housing, 101 ... Main body part, 102 ... Lid part, LD ... Exposure apparatus, ID ... Image forming part, P1-P3 ... Convex part, PM ... Medium, 60 ... Cover top assembly, 61L, 61R: head frame, 62: head holder, 621, 622 ... locking portion, 63: exposure head, 64 ... torsion spring, 641, 642 ... end, 643 ... winding part, 65 ... shaft, 66 ... rib, 200 ... casing, 201 ... main body, 202 ... lid, 202J ... rotating shaft, 202S ... inner surface.

Claims (19)

A first member including a first contact portion;
The second member includes a second contact part that is attached to the first member so as to be reversibly displaceable along a first direction and that can be contacted with the first contact part. And members of
A first urging member that urges the second member in the first direction so that the first abutting portion and the second abutting portion abut on each other;
An exposure apparatus comprising: a head unit including a plurality of light emitting elements attached to the second member and arranged along a second direction substantially orthogonal to the first direction. A shaft extending in the second direction;
The exposure apparatus according to claim 1, wherein the second member is attached to the first member so as to be swingable about the shaft. The exposure apparatus according to claim 2, wherein the first biasing member is a torsion spring including a winding portion provided so as to surround the periphery of the shaft. The head unit is
A head member;
A holding member that holds the head member in a reversibly displaceable manner along a third direction orthogonal to both the first direction and the second direction;
The exposure apparatus according to claim 1, further comprising: a second urging member that urges the head member to move away from the holding member along the third direction. The head unit is held by the second member so as to be reversibly displaceable along the second direction,
The exposure apparatus according to claim 1, further comprising a third urging member that urges the second member and the head unit to attract each other along the second direction. An exposure apparatus according to any one of claims 1 to 5,
And an image forming unit that forms an image using a developer. The head unit includes a first fitting portion,
The image forming unit includes:
An image carrier that is disposed opposite to the plurality of light emitting elements and carries a latent image formed by exposure of the plurality of light emitting elements on a surface;
The image carrier is held so as to be fitted with the first fitting portion by moving along a third direction orthogonal to both the first direction and the second direction. The image forming unit according to claim 6, further comprising: a holding body including a second fitting portion. The first fitting portion is a first opening and the second fitting portion is a protrusion provided to be inserted into or inserted into the first opening,
The image forming according to claim 7, wherein the second fitting portion is a second opening, and the first fitting portion is a protrusion that is inserted into or insertable into the second opening. unit. The image forming unit according to claim 8, wherein the protrusion has a tip including an inclined surface. An exposure apparatus according to any one of claims 1 to 5,
An image forming unit that forms an image using a developer;
An image forming apparatus comprising: a main body that holds the image forming unit; and a housing that holds the exposure apparatus and has a lid that can be opened and closed with respect to the main body. The image forming unit has an engaging unit,
The body portion has a guide portion that engages and guides the engagement portion,
The image forming apparatus according to claim 10, wherein the guide portion extends in an oblique direction intersecting the first direction in a plane orthogonal to the second direction. The engaging portions are convex portions provided at both ends in the second direction in the image forming portion,
The image forming apparatus according to claim 11, wherein the guide portion is a notch, a groove, or a hole that engages with the convex portion. A first member;
A shaft extending in a second direction;
A second member attached to the first member so as to be reversibly rotatable about the shaft in both a first rotation direction and a second rotation direction opposite to the first rotation direction; ,
A biasing member that biases the second member in both the first rotation direction and the second rotation direction;
And an exposure head including a plurality of light emitting elements attached to the second member and arranged along the second direction. The urging member includes a first end portion, a second end portion, and a winding portion that connects the first end portion and the second end portion and surrounds the periphery of the shaft. The exposure apparatus according to claim 13, wherein the exposure apparatus is a spring. A rib fixed directly or indirectly to the first member;
The exposure apparatus according to claim 14, wherein the first end and the second end are opposed to each other with the rib interposed therebetween. The second member includes a first locking portion and a second locking portion,
When a first external force in the first rotation direction is applied to the second member, the first end is locked to the first locking portion, and the second end is Abutting against the rib,
When a second external force in the second rotational direction is applied to the second member, the second end is locked to the second locking portion, and the first end is The exposure apparatus according to claim 15, which comes into contact with the rib. An exposure apparatus according to any one of claims 13 to 16,
And an image forming unit that forms an image using a developer. An exposure apparatus according to any one of claims 13 to 16,
An image forming unit that forms an image using a developer;
An image forming apparatus comprising: a main body that holds the image forming unit; and a housing that holds the exposure apparatus and has a lid that can be opened and closed with respect to the main body. The image forming apparatus according to claim 18, wherein the first member is attached to the lid portion.

Images