JP6950563B2 - Image forming device and image reading device - Google Patents

Description

The present invention relates to an image forming apparatus and an image reading apparatus.

In an image forming apparatus using an electrophotographic method, an electrostatic latent image is formed by irradiating the surface of an image carrier (for example, a photoconductor drum) with light from an exposure head (optical head), and the electrostatic latent image is developed. And transfer to the medium.

The exposure head is held by a head holder provided in the image forming apparatus. In order to position the exposure head with respect to the image carrier, a spring is provided between the exposure head and the head holder to urge the exposure head toward the image carrier (for example, Patent Document 1).

JP-A-2009-73041 (see FIG. 1)

Here, the exposure head may be configured to swing with respect to the head holder. Therefore, it is desired that the spring does not come off from the exposure head when the exposure head is swung. It is also desired to improve the assembly efficiency of the exposure head.

The present invention has been made to solve the above problems, and an object of the present invention is to prevent the spring from coming off from the exposure head or the reading head, and to improve the assembly efficiency.

The image forming apparatus of the present invention includes an image carrier, a swingable exposure head for exposing the image carrier, and a spring for urging the exposure head toward the image carrier. The exposure head has a base portion that comes into contact with the spring, and a protrusion portion that projects from the base portion to the side opposite to the image carrier, is formed smaller than the inner dimension of the spring, and is inserted into the inner peripheral side of the spring. The protrusion has a recess at the base on the base side that can be engaged with the spring. When the exposure head is in a position to expose the image carrier, the spring does not engage the recess, and when the exposure head swings from the position where the image carrier is exposed, the spring engages the recess.
The image forming apparatus of the present invention also includes an image carrier, a swingable exposure head for exposing the image carrier, and a spring for urging the exposure head toward the image carrier. The exposure head has a base portion that comes into contact with the spring, and a protrusion portion that projects from the base portion to the side opposite to the image carrier, is formed smaller than the inner dimension of the spring, and is inserted into the inner peripheral side of the spring. The protrusion has a recess at the base on the base side that can be engaged with the spring. The exposure head has a long shape in one direction and can swing around a swing axis in the longitudinal direction of the exposure head. The recess is formed on the swinging side of the exposure head in the protrusion. The exposure head can swing about the swing axis by a first angle in the first direction, and can swing by a second angle in a second direction opposite to the first direction. be. The first angle is smaller than the second angle. The recess is formed only on the first direction side of the protrusion.

The image reading device of the present invention includes a support base for holding the reading target object, a swingable reading head that receives light of the reading target object, and a spring that urges the reading head toward the support base. The reading head has a base portion that comes into contact with the spring, and a protrusion portion that projects from the base portion to the side opposite to the support base, is formed smaller than the inner dimension of the spring, and is inserted into the inner peripheral side of the spring. The protrusion has a recess at the base on the base side that can be engaged with the spring. When the reading head is in a position to receive the light of the object to be read, the spring does not engage with the recess, and when the reading head swings from the position of receiving the light of the object to be read, the spring engages with the recess.

In the present invention, a recess that can be engaged with the spring is provided at the base of the protrusion of the exposure head. Therefore, when the exposure head is swung, the spring engages with the concave portion of the protrusion, whereby the spring is prevented from coming off from the exposure head. Thereby, the assembly efficiency can be improved.

It is a figure which shows the whole structure of the image forming apparatus of 1st Embodiment. It is sectional drawing which shows the LED head of 1st Embodiment. It is sectional drawing which shows the LED head and the head holder of 1st Embodiment. It is a perspective view which shows the LED head of 1st Embodiment. It is a perspective view which shows the state in the process of attaching the spring holder to the frame of the LED head of 1st Embodiment. It is a perspective view which shows the state which attached the spring holder to the frame of the LED head of 1st Embodiment. It is a perspective view which shows the spring holder of 1st Embodiment. It is a perspective view which shows the post of 1st Embodiment. It is sectional drawing which shows the post of 1st Embodiment. It is a schematic diagram which shows the post and the spring of 1st Embodiment. It is sectional drawing of the LED head in the line segment XI-XI of FIG. It is sectional drawing which shows the state which the LED head of 1st Embodiment oscillated in a 1st direction. It is sectional drawing which shows the state which the LED head of 1st Embodiment oscillated in a 2nd direction. It is sectional drawing which shows the other structural example of the post of 1st Embodiment. It is sectional drawing which shows the post of the 1st modification of 1st Embodiment. It is sectional drawing which shows the post of the 2nd modification of 1st Embodiment. It is sectional drawing which shows the post of the 3rd modification of 1st Embodiment. It is sectional drawing which shows the post of the 4th modification of 1st Embodiment. It is an example cross-sectional view which shows the post of the 5th modification of 1st Embodiment. It is sectional drawing which shows the post of the 6th modification of 1st Embodiment. It is sectional drawing which shows the post of the 7th modification of 1st Embodiment. It is a perspective view which shows the whole structure of the image reading apparatus which has the reading head which applied the optical head of 1st Embodiment and each modification.

The first embodiment.
<Structure of image forming apparatus>
FIG. 1 is a diagram showing an overall configuration of an image forming apparatus 1 according to the first embodiment of the present invention. The image forming apparatus 1 shown in FIG. 1 forms an image by using an electrophotographic method, and is, for example, a color printer. The image forming apparatus 1 has process units (image forming units) 11Bk, 11Y, 11M, 11C for forming images of black (Bk), yellow (Y), magenta (M), and cyan (C).

A paper feeding mechanism for supplying paper (recording medium) to the process units 11Bk, 11Y, 11M, and 11C is provided below the image forming apparatus 1. The paper feeding mechanism includes a paper cassette 22 for storing paper, a hopping roller 23 for feeding out the paper stored in the paper cassette 22 one by one, and a transport roller pair for transporting the paper fed by the hopping roller 23 to the transport belt 21. It has 24 and.

The process units 11Bk, 11Y, 11M, and 11C are arranged from the upstream side to the downstream side (here, from the right side to the left side) along the paper transport path. As the recording medium, in addition to paper, OHP sheets, envelopes, copy paper, special paper and the like can be used.

The process units 11Bk, 11Y, 11M, and 11C uniformly charge the surfaces of the cylindrical photoconductor drums 12Bk, 12Y, 12M, 12C as image carriers and the photoconductor drums 12Bk, 12Y, 12M, 12C, respectively. Toner image by adhering toner (developer) of each color to the electrostatic latent image formed on the surface of the charging rollers 13Bk, 13Y, 13M, 13C and the photoconductor drums 12Bk, 12Y, 12M, 12C as charging members. A developing roller 14Bk, 14Y, 14M, 14C as a developing agent carrier for forming (developer image) is provided.

Further, the toner supply rollers 15Bk, 15Y, 15M, 15C and the developing rollers 14Bk as supply members for supplying toner to the developing rollers 14Bk, 14Y, 14M, 14C so as to come into contact with the developing rollers 14Bk, 14Y, 14M, 14C. , 14Y, 14M, 14C are arranged with developing blades 16Bk, 16Y, 16M, 16C that regulate the thickness of the toner layer formed on the surface of the toner layer. Further, toner cartridges 17Bk, 17Y, 17M, 17C as a developer accommodating portion for supplying toner are attached to the upper side of the toner supply rollers 15Bk, 15Y, 15M, 15C.

Further, on the upper side of the process units 11Bk, 11Y, 11M, 11C, LED heads 10Bk, 10Y, 10M, 10C as exposure heads (optical heads) face the photoconductor drums 12Bk, 12Y, 12M, 12C, respectively. Is located in. The LED heads 10Bk, 10Y, 10M, and 10C expose the surfaces of the photoconductor drums 12Bk, 12Y, 12M, and 12C to form an electrostatic latent image based on the image data of each color.

A transfer unit is arranged below the process units 11Bk, 11Y, 11M, and 11C. The transfer unit includes a transport belt 21 as a transport member that adsorbs paper and travels, a drive roller 21a that drives the transport belt 21, a tension roller 21b that applies tension to the transport belt 21, and photoconductor drums 12Bk, 12Y. , 12M, 12C have transfer rollers 20k, 20Y, 20M, 20C as transfer members arranged to face each other via a transfer belt 21. The transfer rollers 20k, 20Y, 20M, 20C charge the paper with the polarity opposite to that of the toner, and transfer the toner images of each color formed on the photoconductor drums 12Bk, 12Y, 12M, 12C to the paper.

A fixing device (fixing device) 25 is arranged on the downstream side (left side in the drawing) of the photoconductor drums 12Bk, 12Y, 12M, and 12C along the paper transport direction. The fixing device 25 includes a fixing roller 25a and a pressure roller 25b that apply heat and pressure to the toner image transferred to the paper to fix it on the paper, and a temperature sensor 25c that detects the surface temperature of the fixing roller 25a.

A discharge mechanism for discharging paper is provided further downstream of the fixing device 25. The discharge mechanism has discharge rollers 26 and 27 that convey the paper discharged from the fixing device 25 and discharge it from the discharge port. On the upper surface of the image forming apparatus 1, a stacker portion 29 on which the paper discharged by the discharge roller pairs 26 and 27 is placed is provided.

The image forming apparatus 1 has a housing 1A for accommodating these components and an openable and closable top cover 1B that covers the upper part of the housing 1A. The LED heads 10Bk, 10Y, 10M, and 10C are supported from above by the top cover.

In the above configuration, the direction of the rotation axis of each of the photoconductor drums 12Bk, 12Y, 12M, 12C of the process units 11Y, 11M, 11C, 11K is the X direction. Further, the moving direction of the paper when passing through the process units 11Y, 11M, 11C, 11K is set to the Y direction (more specifically, the + Y direction). Further, the direction orthogonal to both the X direction and the Y direction is defined as the Z direction. Here, the Z direction is the vertical direction, the upper direction is the + Z direction, and the lower direction is the −Z direction.

Since the process units 11Bk, 11Y, 11M, and 11C have a common configuration, they will be described as "process unit 11". Further, since the LED heads 10Bk, 10Y, 10M, and 10C have a common configuration, they will be described as "LED head 10".

Similarly, the photoconductor drums 12Bk, 12Y, 12M, 12C will be described as the "photoreceptor drum 12", and the charging rollers 13Bk, 13Y, 13M, 13C will be described as the "charging roller 13". The developing rollers 14Bk, 14Y, 14M, 14C are described as "developing rollers 14", and the toner supply rollers 15Bk, 15Y, 15M, 15C are described as "toner supply rollers 15". The developing blades 16Bk, 16Y, 16M, 16C are described as "developing blade 16", and the toner cartridges 17Bk, 17Y, 17M, 17C are described as "toner cartridge 19".

<LED head configuration>
Next, the configurations of the LED heads 10Bk, 10Y, 10M, and 10C as the exposure head will be described. FIG. 2 is a cross-sectional view of the LED head 10 on a plane parallel to the YZ plane. As shown in FIG. 2, the LED head 10 is illustrated for controlling an LED array chip 61 having LEDs (light emitting diodes) as a plurality of light emitting elements arranged to face the photoconductor drum 12 and the LED array chip 61. The board 6 is provided with a driver IC that does not.

The light emitting direction of each LED of the LED array chip 61 is the −Z direction. The LEDs are arranged in a row in the X direction (that is, the axial direction of the photoconductor drum 12). Therefore, the X direction is also referred to as a main scanning direction, and the Y direction is also referred to as a sub-scanning direction. The substrate 6 is made of, for example, a glass epoxy resin.

The LED head 10 also includes a lens array 2 as an optical system (lens) between the substrate 6 and the photoconductor drum 12. The lens array 2 is also referred to as, for example, a Selfock (registered trademark) lens array. The lens array 2 has a plurality of rod lenses (condensing lenses) that form an image of light emitted from each LED of the LED array chip 61 on the surface 12a of the photoconductor drum 12. The plurality of rod lenses of the lens array 2 are arranged in one row (or a plurality of rows) in the X direction with the optical axis direction as the Z direction.

The LED head 10 also has a frame 3 as a support member that supports the substrate 6 and the lens array 2. The frame 3 is an elongated member that is long in the X direction, and is formed of, for example, an aluminum die-cast molded body. The frame 3 has two wall portions 31 and 32 facing in the Y direction and a bottom portion 30 facing the photoconductor drum 12.

Of the two wall portions 31, 32, the first wall portion 31 is located on the downstream side in the rotation direction (clockwise in FIG. 2) of the photoconductor drum 12, and the second wall portion 32 is the photoconductor drum 12. It is located upstream in the direction of rotation. However, the positional relationship between the wall portions 31 and 32 may be reversed.

An opening 30a into which the lens array 2 is inserted is formed in the bottom portion 30 of the frame 3. The lens array 2 is inserted into the opening 30a with the optical axis direction of each rod lens oriented in the Z direction. The lens array 2 is positioned in the Z direction so that the distance Lo between the incident end surface 2b and the LED array chip 61 is the optimum distance due to the characteristics of the lens array 2, and is fixed to the frame 3 with an adhesive or the like. .. The gap between the lens array 2 and the opening 30a is sealed by, for example, a sealing material (not shown).

Inside the wall portions 31 and 32 of the frame 3 in the Y direction, substrate contact portions 33 and 34 that abut on the lower surface (-Z side surface) of the substrate 6 are formed, respectively. Above the substrate 6 (in the + Z direction), a pressing member 7 that presses the substrate 6 against the substrate contact portions 33 and 34 is arranged.

The pressing member 7 is, for example, a plastic plate-shaped member. Protruding pieces 71 and 72 protruding outward in the Y direction are formed at both ends of the pressing member 7 in the Y direction. Further, on the lower surface (the surface on the −Z side) of the pressing member 7, pressing portions 73 and 74 for pressing the upper surface (the surface on the + Z side) of the substrate 6 are projected, respectively.

The protruding pieces 71, 72 of the pressing member 7 are fitted into the slits 38, 39 formed in the wall portion 31 of the frame 3. The projecting pieces 71 and 72 have a slightly upwardly curved shape before being fitted into the slits 38 and 39. When the projecting pieces 71 and 72 are fitted into the slits 38 and 39, the projecting pieces 71 and 72 are elastically deformed, and the pressing portions 73 and 74 of the pressing member 7 press the substrate 6 downward by the elastic force. As a result, the substrate 6 is held in a state of being pressed against the substrate contact portions 33 and 34.

A plurality of projecting pieces 71 and 72 and slits 38 and 39 are arranged in the X direction (longitudinal direction of the LED head 10). As a result, the pressing member 7 can press the substrate 6 with an even force in the X direction.

In order to accurately converge (image) the light emitted from each lens element of the lens array 2 on the surface 12a of the photoconductor drum 12, the distance from the surface of the LED array chip 61 to the incident end surface 2b of the lens array 2 It is necessary to adjust the distance Li so that Lo and the distance Li from the exit end surface 2a of the lens array 2 to the surface 12a of the photoconductor drum 12 are substantially the same (Lo≈Li).

Therefore, a pair of springs 100 (FIG. 3) for urging the LED head 10 toward the photoconductor drum 12 are arranged at both ends of the LED head 10 in the longitudinal direction (that is, the X direction). The axial direction of the spring 100 is the Z direction, and the LED head 10 is urged in the direction indicated by the arrow F1 in FIG.

FIG. 3 is a cross-sectional view showing the LED head 10 and the head holder 8. As described above, the LED head 10 is held by the head holder 8 provided in the image forming apparatus 1. The head holder 8 is located above the LED head 10 (in the + Z direction) and is supported by the top cover 1B (FIG. 1).

The head holder 8 has two support portions 81 that support the LED head 10 from both sides in the X direction, and a connecting portion 80 that connects them. The two support portions 81 extend downward (in the − direction) from both ends of the connecting portion 80 in the X direction. A head accommodating portion 82, which is a region for accommodating the LED head 10, is formed between the two support portions 81.

Guide grooves 83 are formed on the opposite sides of the two support portions 81, respectively. The guide groove 83 extends in the Z direction (vertical direction), has a width in the Y direction, and has a depth in the X direction.

Both ends 37 of the frame 3 of the LED head 10 in the X direction are provided with claws 35 protruding outward in the X direction. Each claw portion 35 is inserted into the guide groove 83 of the head holder 8. The width of the claw portion 35 (that is, the dimension in the Y direction) is slightly narrower than the width of the guide groove 83. By inserting the claw portion 35 into the guide groove 83, the LED head 10 is movably supported in the Z direction.

As shown in FIG. 3, the LED head 10 can swing around the claw portion 35 in a state where each claw portion 35 is located at the lower end of each guide groove 83. That is, the LED head 10 can swing around the swing shaft (claw portion 35) in the X direction. A metal plate (not shown) is arranged on the inner surface of the guide groove 83, and the LED head 10 is grounded through the metal plate.

Two springs 100 are arranged between the head holder 8 and the LED head 10 to urge the LED head 10 toward the photoconductor drum 12 (that is, in the −Z direction). These springs 100 are arranged near both ends of the LED head 10 in the X direction. The spring 100 is, for example, a cylindrical compression coil spring. The number of springs 100 is not limited to two and may be arbitrary.

The head holder 8 is provided with two posts 85 for holding each spring 100. The post 85 is inserted on the inner peripheral side of the spring 100. It is desirable that the length of the post 85 in the Z direction is shorter than 1/2 of the length of the spring 100 in the Z direction.

The LED head 10 is provided with two posts (projections) 5 for holding each spring 100. The post 5 is inserted on the inner peripheral side of the spring 100. It is desirable that the length of the post 5 in the Z direction is shorter than 1/2 of the length of the spring 100 in the Z direction.

Each post 5 of the LED head 10 and each post 85 of the head holder 8 are coaxial with each other. In other words, the central axis C of the post 5 (see FIG. 8) and the central axis of the post 85 coincide with each other. As a result, one post 5 and one post 85 can hold one spring 100 from both sides in the Z direction.

FIG. 4 is a perspective view showing the LED head 10. The LED head 10 has the above-mentioned frame 3 and spring holders 4 attached to two places of the frame 3. The spring holder 4 is a member having the above-mentioned post 5, and is made of, for example, a resin. The spring holder 4 is arranged near both ends of the frame 3 in the X direction, for example. However, depending on the number of springs 100, the frame 3 may be provided at three or more locations.

A connector 300 is provided at one end of the frame 3 in the X direction. A flexible cable for supplying a drive signal and electric power from the outside to the substrate 6 is connected to the connector 300.

FIG. 5 is a perspective view showing a state in which the spring holder 4 is being attached to the frame 3 of the LED head 10. As shown in FIG. 5, the spring holder 4 is attached to the mounting hole 36 formed in the second wall portion 32 of the frame 3. The mounting hole 36 is a notch connected to the upper end of the second wall portion 32. The shape of the mounting hole 36 is rectangular here, but is not limited thereto.

In the first wall portion 31, a slit 31a is formed at a position facing the mounting hole 36 of the second wall portion 32 in the Y direction. The slit 31a is a portion to which the tip end portion 45 (described later) of the spring holder 4 fits. Further, in the second wall portion 32, fitting holes 32a are formed on both sides of the mounting holes 36 in the X direction. The fitting hole 32a is a portion to which the protruding end portion 43a (described later) of the spring holder 4 is fitted.

FIG. 6 is a perspective view showing the spring holder 4. The spring holder 4 has a plate-shaped base portion (base portion) 41 parallel to the XY plane, and a side plate portion 42 extending downward (−Z direction) from the + Y direction end portion of the base portion 41.

The upper surface (+ Z side surface) of the base portion 41 is parallel to the XY surface. This surface is referred to as a reference surface 41a. The reference surface 41a of the base portion 41 is a portion where the end portion of the spring 100 abuts. The above-mentioned post 5 is formed so as to project in the + Z direction at substantially the center of the reference surface 41a. The side plate portion 42 is a member that abuts on the outer surface of the second wall portion 32 of the frame 3 when the spring holder 4 is attached to the frame 3.

Beam-shaped portions 44 are formed on both sides of the base portion 41 in the X direction. The two beam-shaped portions 44 are inclined so that the distance between the two beam-shaped portions 44 in the X direction decreases as the beam-shaped portion 44 advances in the −Y direction. The distance between the end portions 44a of the two beam-shaped portions 44 in the + Y direction in the X direction is wider than the width of the mounting holes 36 in the X direction. Further, the tip portion 45 of the base portion 41 in the −Y direction is a portion that fits into the slit 31a of the first wall portion 31.

Arms 43 projecting on both sides in the X direction are formed at both ends of the side plate portion 42 in the + Z direction (that is, the upper end portion) and in the X direction. Each arm portion 43 is formed with a protruding end portion 43a projecting in the −Y direction.

FIG. 6 is a perspective view showing a state in which the spring holder 4 is attached to the frame 3. The base portion 41 of the spring holder 4 is pushed into the mounting hole 36 of the second wall portion 32 in the −Y direction. The spring holder 4 slides in the −Y direction, and the beam-shaped portions 44 on both sides of the base portion 41 are elastically deformed inward in the X direction accordingly.

As the spring holder 4 slides in the −Y direction, the beam-shaped portion 44 elastically deforms inward in the X direction, passes through the mounting hole 36, and returns to the state before deformation. As a result, the distance between the end portions 44a of the beam-shaped portion 44 in the X direction is widened to come into contact with the inner surface of the second wall portion 32, and the spring holder 4 is prevented from falling out of the mounting hole 36.

In this state, the tip 45 of the spring holder 4 fits into the slit 31a of the first wall 31. Further, the protruding end portion 43a of the arm portion 43 of the spring holder 4 is fitted into the fitting hole 32a of the second wall portion 32. As a result, the spring holder 4 is positioned with respect to the frame 3.

The attachment structure of the spring holder 4 to the frame 3 is not limited to the structure described here.

With the spring holder 4 attached to the frame 3 in this way, the base portion 41 is located between the first wall portion 31 and the second wall portion 32. Further, the post 5 formed on the base portion 41 is formed between the first wall portion 31 and the second wall portion 32 (for example, between the first wall portion 31 and the second wall portion 32 in the Y direction). Located in the center position).

FIG. 7 is a perspective view showing the spring holder 4. The post 5 is formed so as to project upward (that is, in the + Z direction) from the reference surface 41a of the base portion 41 of the spring holder 4. In the post 5, the portion of the base portion 41 connected to the reference surface 41a is referred to as a root portion.

Here, the post 5 is formed integrally with the spring holder 4. However, the post 5 may be formed separately from the spring holder 4 and fixed to the spring holder 4 by adhesion or the like. Further, the post 5 may be provided on the pressing member 7 instead of the spring holder 4.

FIG. 8 is an enlarged perspective view of the post 5. The post 5 has a first portion 51, a second portion 52, a third portion 53, and a fourth portion 54 extending radially and evenly in the circumferential direction about a central axis C extending in the Z direction. .. The first portion 51 and the second portion 52 face each other in the Y direction, and the third portion 53 and the fourth portion 54 face each other in the X direction.

The post 5 has the first to fourth portions 54 here, and the cross-sectional shape in the plane parallel to the XY plane is cross-shaped. However, the post 5 is not limited to such a shape, and a plurality of portions may extend radially around the central axis C. Further, it may have a cylindrical shape or a prismatic shape (for example, a triangular prismatic shape, a square prismatic shape, etc.).

Each portion 51, 52, 53, 54 of the post 5 has outer peripheral surfaces 51a, 52a, 53a, 54a, respectively. The distances from the central axis C to the outer peripheral surfaces 51a, 52a, 53a, 54a are the same as each other. The upper surfaces 50 of the portions 51, 52, 53, 54 are flush with each other. In FIG. 8, a tapered surface is provided on the upper side of the outer peripheral surfaces 51a, 52a, 53a, 54a, but the tapered surface does not necessarily have to be provided.

FIG. 9 is a schematic view showing a cross-sectional shape of the post 5 in a plane parallel to the YZ plane. The post 5 has a notch 51b as a recess at the root of the first portion 51. The notch portion 51b is a portion retracted to the inner peripheral side of the outer peripheral surface 51a of the first portion 51. A convex portion 51c is formed on the upper side of the notch portion 51b so as to protrude in the outer peripheral direction from the notch portion 51b. The convex portion 51c includes the outer peripheral surface 51a.

The distance from the outer peripheral surface 51a of the first portion 51 to the outer peripheral surface 52a of the second portion 52 (that is, the maximum outer dimension of the post 5) is defined as L1. Further, the distance from the notch portion 51b of the first portion 51 to the outer peripheral surface 52a of the second portion 52 is defined as L2. The distance L1 is larger than the distance L2.

The height from the reference surface 41a to the upper surface 50 of the post 5 is defined as H1. Further, the height of the notch portion 51b of the first portion 51 (that is, the height from the reference surface 41a to the upper end of the notch portion 51b) is defined as H2. The height H1 is larger than the height H2.

The depth of the notch 51b (the amount of retreat in the Y direction with respect to the outer peripheral surface 51a) indicated by reference numeral E in FIG. 9 is set so that the recess 15b does not reach the center of the post 5 (central axis C). This is because when the spring 100 is removed from the post 5 in a state where the spring 100 is not curved (a state in which the LED head 10 is not swung as described later), it is easier to remove the spring 100 if the recess 15b is not too deep. ..

FIG. 10 is a schematic view showing a state in which the spring 100 is attached to the post 5. The spring 100 is a wire wound in a spiral shape. Let φ be the outer diameter (referred to as the wire diameter) of the wire rod of the spring 100. Further, each wound portion of the spring 100 is referred to as a first roll 101, a second roll 102, a third roll 103, a fourth roll 104, and a fifth roll 105 in order from the reference surface 41a side. Note that FIG. 10 shows the first roll 101 to the fifth roll 105 of the spring 100, which is a part of the spring 100.

The inner diameter D (that is, the inner dimension) of the spring 100 is larger than the above distance (maximum outer diameter dimension) L1 (that is, D> L1) of the post 5. Therefore, the post 5 is inserted inside the spring 100. Further, when the spring 100 is pulled up in the + Z direction, it can be pulled out without being caught by the post 5.

Further, the height from the reference surface 41a to the upper surface of the third roll 103 of the spring 100 is defined as Hs. The height Hs is larger than the heights H1 and H2 shown in FIG.

<Action>
Next, the operation of the first embodiment will be described. FIG. 11 is a cross-sectional view of the LED head 10 at the mounting position of the spring holder 4 (indicated by the line segment XI-XI in FIG. 4). In the state shown in FIG. 11, the LED head 10 is at a position where the LED array chip 61 faces the photoconductor drum 12 (that is, a position where the photoconductor drum 12 is exposed). This position is used as the reference position.

At the mounting position of the spring holder 4, a mounting hole 36 is formed in the second wall portion 32 of the wall portions 31 and 32 of the frame 3. Therefore, at the mounting position of the spring holder 4, the first wall portion 31 of the frame 3 is higher than the second wall portion 32.

When attaching the LED head 10 to the head holder 8 (FIG. 3), first attach the spring 100 to the post 85 of the head holder 8. Then, the LED head 10 is inserted into the head accommodating portion 82 of the head holder 8 while inserting the claw portion 35 of the LED head 10 into the guide groove 83 of the head holder 8.

After that, the post 5 of the LED head 10 is inserted into the spring 100 attached to the post 85 of the head holder 8. At this time, the LED head 10 is centered on the reference position (the position facing the photoconductor drum 12) in the first direction indicated by the arrow R1 in FIG. 11 or in the second direction indicated by the arrow R2 in FIG. Swing. The LED head 10 swings around a swing shaft defined by the claw portion 35 (FIG. 2).

By swinging the LED head 10 in this way, the post 5 can be easily inserted into the spring 100. Further, when connecting the terminal of the flexible cable to the connector 300 (FIG. 4) of the LED head 10, the LED head 10 is swung to facilitate the connection work.

FIG. 12 is a cross-sectional view taken along the line segment XI-XI of FIG. 4, showing a state in which the LED head 10 is swung in the first direction (the direction indicated by the arrow R1 in FIG. 11). FIG. 13 is a cross-sectional view taken along the line segment XI-XI of FIG. 4, showing a state in which the LED head 10 is swung in the second direction (the direction indicated by the arrow R2 in FIG. 11). For convenience of illustration, FIGS. 12 and 13 show the direction of the LED head 10 in the same direction as when it is in the reference position (FIG. 11).

As shown in FIG. 12, when the LED head 10 is swung in the first direction (the direction indicated by the arrow R1 in FIG. 11), the spring 100 is curved so as to fall toward the first wall portion 31 of the frame 3. .. When the swing angle of the LED head 10 becomes large, the spring 100 comes into contact with the upper surface (indicated by reference numeral 3A) of the first wall portion 31 of the frame 3. The swing angle of the LED head 10 at this time is referred to as a first angle.

As shown in FIG. 13, when the LED head 10 is swung in the second direction (the direction indicated by the arrow R2 in FIG. 11), the spring 100 is curved so as to fall toward the second wall portion 32 of the frame 3. .. At the mounting position of the spring holder 4, the second wall portion 32 of the frame 3 is lower than the first wall portion 31, so that the LED head 10 is swung to a second angle larger than the first angle. Can be done.

Therefore, when the LED head 10 is swung in the first direction as shown in FIG. 12, a force acts on the spring 100 as shown by an arrow F with the contact portion 3A as a fulcrum, and the spring 100 May come off post 5.

Therefore, in the present embodiment, in the post 5, a notch portion 51b (FIG. 9) as a recess is provided at the root portion of the first portion 51 facing the first wall portion 31. At least the first winding 101 and the second winding 102 of the spring 100 are pushed into the notch 51b as the spring 100 bends.

Since the convex portion 51c (FIG. 9) including the outer peripheral surface 51a projects in the outer peripheral direction on the upper side of the notch portion 51b of the post 5, at least the first winding 101 and the second winding 102 of the spring 100 are notched portions. It is in a state of being engaged with 51b. This prevents the spring 100 from coming off the post 5.

The “engagement” refers to a state in which the spring 100 does not disengage from the post 5 even if it is moved in the direction of the central axis C of the post 5 (here, the Z direction).

Next, the relationship between the dimensions of each part of the post 5 will be described. As described above, the distance L1 (that is, the maximum outer diameter of the post 5) from the outer peripheral surface 51a of the first portion 51 to the outer peripheral surface 52a of the second portion 52 is from the notch 51b of the first portion 51. The distance L2 to the outer peripheral surface 52a of the second portion 52 is larger than the distance L2, and is smaller than the inner diameter D of the spring 100. That is, D> L1> L2 holds. As a result, the post 5 can be inserted into the inner peripheral side of the spring 100.

Further, the height H2 of the notch portion 51b of the first portion 51 is larger than twice the wire diameter φ of the spring 100. That is, H2> 2 × φ is established. As a result, at least the first winding 101 and the second winding 102 of the spring 100 can penetrate into the notch 51b of the post 5. Therefore, it is possible to effectively prevent the spring 100 from coming off from the post 5.

Further, the spring 100 engages with the notch 51b of the post 5 when it is curved, but engages with the notch 51b of the post 5 when it is not curved (for example, during the exposure operation of the LED head 10). It doesn't fit. Therefore, when the spring 100 is pulled up from the post 5 in the + Z direction, it can be easily removed without being interfered with by the convex portion 51c of the post 5.

Further, in the present embodiment, the height H1 from the reference surface 41a to the upper surface 50 of the post 5, the height Hs from the reference surface 41a to the upper surface of the third roll 103 of the spring 100, and the wire diameter φ of the spring 100 Is particularly effective when H1 <Hs-2φ is satisfied (FIG. 14).

That is, when H1 ≧ Hs-2φ is satisfied (FIG. 10), when the spring 100 is curved toward the first portion 51 of the post 5, as shown by the arrow A in FIG. 12, the spring 100 3 The winding 103 is in a state of being applied to the second portion 52 of the post 5, and the spring 100 is less likely to come off by that amount.

On the other hand, as shown in FIG. 14, when H1 <Hs-2φ is satisfied, when the spring 100 is curved toward the first portion 51 of the post 5, the spring 100 is shown by an arrow B. The third roll 103 does not cover the second portion 52 of the post 5, and the spring 100 is easily disengaged by that amount.

Therefore, when H1 <Hs-2φ is satisfied as shown in FIG. 14, the effect of preventing the spring 100 from coming off by the notch 51b of the first portion 51 of the post 5 is particularly large.

<Operation of image forming device>
Next, the image forming operation of the image forming apparatus 1 will be described with reference to FIGS. 1 and 2. When the image forming operation is started, the hopping roller 23 rotates, and the paper contained in the paper cassette 22 is sent out to the transport path one by one. Further, the transfer roller pair 24 rotates at a predetermined timing to transfer the paper sent to the transfer path to the transfer belt 21. The transport belt 21 travels in the direction indicated by the arrow e by the rotation of the drive roller 21a, and sucks and holds the paper for transport.

On the other hand, in the process units 11Bk, 11Y, 11M and 11C, the surfaces of the photoconductor drums 12Bk, 12Y, 12M and 12C are uniformly charged by the charging rollers 13Bk, 13Y, 13M and 13C, respectively.

Further, the LED heads 10Bk, 10Y, 10M, and 10C irradiate light according to the image data for each color. As shown in FIG. 2, in each LED head 10, the light emitted from the LED array chip 61 on the substrate 6 is incident on the incident end surface 2b of the lens array 2 and further emitted from the emitted end surface 2a of the lens array 2. , Converges on the surface 12a of the photoconductor drum 12. As a result, an electrostatic latent image is formed on the photosensitive layer on the surface 12a of the photoconductor drum 12.

Returning to FIG. 1, the electrostatic latent image formed on each surface of the photoconductor drums 12Bk, 12Y, 12M, and 12C is developed with toner by the developing rollers 14Bk, 14Y, 14M, and 14C to obtain a toner image. Further, as the transport belt 21 travels, the paper passes between the process units 11Bk, 11Y, 11M, 11C and the transfer rollers 20k, 20Y, 20M, 20C, and at that time, the photoconductor drums 12Bk, 12Y, 12M. , The toner images formed on the surfaces of 12C are sequentially transferred to the paper on the transport belt 21.

The paper on which the toner image is transferred is sent to the fixing device 25. In the fixing device 25, the toner image is heated and pressurized by the fixing roller 25a and the pressure roller 25b, and the toner image is melted and fixed on the paper. The paper on which the toner image is fixed is discharged to the outside of the image forming apparatus 1 by the ejection roller pairs 26 and 27, and is loaded on the stacker portion 29 provided on the upper part of the image forming apparatus 1.

<Effect of embodiment>
As described above, in the image forming apparatus 1 of the present invention, the photoconductor drum 12 (image carrier), the LED head 10 (exposure head) for exposing the photoconductor drum 12, and the LED head 10 are mounted on the photoconductor drum 12. It has a spring 100 that urges the image carrier. The LED head 10 projects from the base portion 41 (base portion) and the base portion 41 to the side opposite to the photoconductor drum 12 (-Z side), is formed smaller than the inner dimension (inner diameter D) of the spring 100, and is formed to be smaller than the inner dimension (inner diameter D) of the spring 100. It has a post 5 (protrusion) to be inserted on the inner peripheral side of the. The post 5 has a notch 51b (recess) that can be engaged with the spring 100 at the root portion on the base portion 41 side.

With this configuration, when the spring 100 is curved due to the swing of the LED head 10, the spring 100 engages with the notch 51b of the post 5 of the LED head 10, and the spring 100 comes from the post 5. Can be prevented from coming off. This facilitates the assembly of the LED head 10, the head holder 8 and the spring 100, and can improve the assembly efficiency of the image forming apparatus 1.

Further, when the spring 100 is curved, the spring 100 engages with the notch portion 51b, but when the spring 100 is not curved, the spring 100 does not engage with the notch portion 51b. Therefore, the spring 100 can be easily removed from the post 5.

Further, since the notch portion 51b is formed at the base portion of the post 5, it is possible to realize a configuration in which the spring 100 enters the notch portion 51b when the spring 100 is curved, with a simple configuration.

Further, the LED head 10 can swing about a swing shaft extending in the X direction, and a notch 51b is provided on the swing side (−Y side in FIG. 9) of the LED head 10 at the post 5. ing. Therefore, it is possible to effectively prevent the spring 100 from coming off from the post 5 when the LED head 10 swings.

Further, the LED head 10 can swing by a first angle in the first direction with respect to the position facing the photoconductor drum 12, and a second angle larger than the first angle in the second direction. It can swing by an angle, and the notch 51b of the post 5 is formed on the first direction side. Therefore, it is possible to prevent the spring 100 from coming off from the post 5 with the minimum configuration.

Modification example.
A modified example of the first embodiment will be described below. FIG. 15 is a cross-sectional view of a plane parallel to the YZ plane for explaining the first modification. In the first modification, a hole 51d is formed in a portion of the base portion 41 located below the notch portion 51b of the post 5A. The notch 51b and the hole 51d are integrated with each other to form a cavity. At least the first roll of the spring 100 can enter the cavity. This configuration also prevents the spring 100 from coming off the post 5.

In this case, it is desirable that the height H4 from the bottom of the hole 51d to the upper end of the notch 51b is at least twice the wire diameter φ of the spring 100. This is because at least the first and second windings of the spring 100 can be effectively prevented from coming off of the spring 100 by entering the cavity portion formed by the notch portion 51b and the hole 51d. Other configurations are the same as in the first embodiment.

FIG. 16 is a cross-sectional view of a plane parallel to the YZ plane for explaining a second modification. In the second modification, the base portion 41 is formed with a hole 51e similar to the hole 51d in the first modification, but the hole 51e penetrates the base portion 41 in the Z direction. The notch 51b and the hole 51e are integrated with each other to form a cavity. At least the first roll of the spring 100 can enter the cavity. This configuration also prevents the spring 100 from coming off the post 5. Since the hole 51e is a through hole, there is an advantage that it is easy to manufacture.

In this case, it is desirable that the height H5 from the bottom of the hole 51e (that is, the bottom of the base 41) to the upper end of the notch 51b is at least twice the wire diameter φ of the spring 100. This is because at least the first and second windings of the spring 100 can be effectively prevented from coming off of the spring 100 by entering the cavity portion formed by the notch portion 51b and the hole 51e. Other configurations are the same as in the first embodiment.

FIG. 16 is a cross-sectional view of a plane parallel to the YZ plane for explaining a third modification. In the third modification, notches 51b and 52b as recesses are formed on both sides of the post 5 in the Y direction. That is, notches 51b and 52b are formed at the roots of the first portion 51 and the second portion 52 of the post 5.

In the third modification, since the notches 51b and 52b are formed on both sides of the post 5 in the Y direction, the LED head 10 is in the first direction (indicated by the arrow R1 in FIG. 11) and the second direction. It is possible to prevent the spring 100 from coming off from the post 5 in any case (indicated by the arrow R2 in FIG. 11). Other configurations are the same as in the first embodiment.

FIG. 18 is a perspective view for explaining a fourth modification. In the fourth modification, notches 51b, 52b, and 53b as recesses are formed at a total of three locations on both sides of the post 5 in the Y direction and one side in the X direction. That is, notches 51b, 52b, and 35b are formed at the roots of the first portion 51, the second portion 52, and the third portion 53 of the post 5.

In the fourth modification, since the notches 51b, 52b, and 53b are formed at the three positions of the post 5, the LED head 10 is in the first direction (indicated by the arrow R1 in FIG. 11) and the second direction. The spring 100 can be prevented from coming off from the post 5 in any case (indicated by the arrow R2 in FIG. 11) or in the case of swinging to one side in the X direction for some reason. Other configurations are the same as in the first embodiment.

FIG. 19 is a perspective view for explaining a fifth modification. In the fifth modification, notches 51b, 52b, 53b, 54b as recesses are formed at a total of four locations on both sides of the post 5 in the Y direction and both sides in the X direction. That is, notches 51b, 52b, 53b, 54b are formed at the roots of the first portion 51, the second portion 52, the third portion 53, and the fourth portion 54 of the post 5.

In the fifth modification, since the notches 51b, 52b, 53b, and 54b are formed at the four positions of the post 5, the LED head 10 is in the first direction (indicated by the arrow R1 in FIG. 11) and the second. It is possible to prevent the spring 100 from coming off from the post 5 even if it swings in any of the directions (indicated by the arrow R2 in FIG. 11) or in any side in the X direction for some reason. can. Other configurations are the same as in the first embodiment.

FIG. 20 is a perspective view for explaining a sixth modification. In the sixth modification, a cylindrical post 5A is used instead of the post 5 described in the first embodiment. The post 5A has a cylindrical outer peripheral surface 56a centered on the central axis C in the Z direction. Further, at the root portion of the post 5A, a notched portion 56b as a recess is formed by notching the outer peripheral surface 56a in a flat surface.

The notch 56 of the post 5A is formed in a portion facing the first wall 31 (FIG. 9), similarly to the notch 51b of the post 5 of the first embodiment. The dimensions H1, H2, L1, L2, E of the notch 56b described in the first embodiment can be applied to the notch 56b of the post 5A. Even with such a configuration, it is possible to prevent the spring 100 from coming off the post 5A. Other configurations are the same as in the first embodiment.

Further, the first to fifth modifications shown in FIGS. 15 to 19 may be applied to the cylindrical post 5A.

FIG. 21 is a perspective view for explaining a seventh modification. In the seventh modification, the triangular prism-shaped post 5B is used instead of the post 5 described in the first embodiment. The post 5B has three sides 58a parallel to the Z direction. Further, at the root portion of the post 5B, a notched portion 58b as a recess is formed by notching a portion including the ridge line 58c between the two side surfaces 58a in a plane.

The notch 56 of the post 5A is formed in a portion facing the first wall 31 (FIG. 9), similarly to the notch 51b of the post 5 of the first embodiment. The dimensions H1, H2, L1, L2, E of the notch 56b described in the first embodiment can be applied to the notch 58b of the post 5B. Even with such a configuration, it is possible to prevent the spring 100 from coming off the post 5A. Other configurations are the same as in the first embodiment.

Further, the first to fifth modifications shown in FIGS. 15 to 19 may be applied to the triangular columnar post 5B. Further, as the shape of the post 5B, a polygonal prism shape (for example, a square prism shape) other than the triangular prism shape may be adopted.

In the above-described first embodiment and each modification, a color printer (FIG. 1) has been described as an example of the image forming apparatus. However, the image forming apparatus of the present invention is not limited to a color printer, and may be, for example, a monochromatic (monochrome) printer. Further, the image forming apparatus of the present invention is not limited to a printer, and may be, for example, a copying machine, a facsimile machine, a multifunction device, or the like.

<Configuration of image reader>
Next, an image reading device 9 including a reading head 90 (FIG. 15) having a light receiving head to which the optical heads of the first embodiment and the respective modifications are applied will be described.

FIG. 22 is a perspective view showing the image reading device 9. The image reading device 9 is, for example, a flatbed type image scanner. The image reading device 9 includes a housing 92, a document base (support base) 93 provided on the upper surface of the housing 92, and a reading head 90 (contact image sensor) as an optical head arranged below the document base 93. A head) and a lid 94 that covers the upper side of the platen 93 are provided. The platen 93 is made of a material such as glass that transmits visible light, and a scanning document (object to be read) is placed on the surface thereof.

The reading head 90 replaces the LED array chip 61 (FIG. 2) in the LED head 10 described above with a light receiving element. The reading head 90 is configured in the same manner as the LED head 10 except that the LED array chip 61 (light emitting element) is replaced with a light receiving element chip (light receiving element).

That is, the reading head 90 can swing like the LED head 10 (FIGS. 2 and 3), and is urged toward the platen 93 by a spring. Further, the reading head 90 has a base portion that comes into contact with the spring and a protrusion that protrudes from this base portion to the side opposite to the platen 93 and is inserted into the inner peripheral side of the spring, similarly to the LED head 10 (FIGS. 9 and 10). It has a part (for example, a post). Further, the protrusion has a recess (notch) that can be engaged with the spring at the base portion on the base side.

A pair of guides 95 are provided along the platen 93 in order to guide the reading head 90 in the sub-scanning direction (Y direction). Further, the reading head 90 is connected to a drive belt 96, and the drive belt 96 is connected to a stepping motor 97. Further, the reading head 90 is connected to the control circuit 91 via a flexible flat cable 98.

The basic operation of the image reading device 9 is as follows. When the scanned document is placed on the platen 93 and a switch such as a scan button is pressed, a light source (not shown) attached to the scanning head 90 lights up to illuminate the scanned document. The reading head 90 captures the light reflected on the surface of the scanned document while moving in the Y direction by the drive belt 96 driven by the stepping motor 97. The reading head 90 converts the received optical signal into an electric signal.

Since the reading head 90 has the same characteristics as the LED head described in the first embodiment and each modification, it is possible to prevent the spring 100 from coming off and improve the assembly efficiency.

Instead of moving the scanning head 90 as described above, the scanning head is conveyed by an ADF (Automatic Document Feeder) so as to pass through a predetermined scanning position on the platen 93, and is stopped at the scanning position. The image of the scanned document may be scanned at 90.

Although the preferred embodiments of the present invention have been specifically described above, the present invention is not limited to the above embodiments, and various improvements or modifications are made without departing from the gist of the present invention. be able to.

1 image forming device, 2 lens array, 3 frame, 4 spring holder, 5 post, 6 substrate, 7 pressing member, 8 head holder, 9 image reader, 10, 10Bk, 10Y, 10M, 10C LED head (exposure head, Optical head), 11,11Bk, 11Y, 11M, 11C Process unit (image forming unit), 12,12Bk, 12Y, 12M, 12C Photoreceptor drum (image carrier), 13,13Bk, 13Y, 13M, 13C Charging roller (Charging member), 14, 14Bk, 14Y, 14M, 14C developing roller (developer carrier), 15, 15Bk, 15Y, 15M, 15C supply roller (supply member), 16, 16Bk, 16Y, 16M, 16C developing blade (Developer control member), 17,17Bk, 17Y, 17M, 17C toner cartridge (developer container), 20,20Bk, 20Y, 20M, 20C transfer roller (transfer member), 21 transport belt, 22 paper cassette (medium) Accommodating part), 25 Fixing device, 30 Bottom part, 31 First wall part, 31a Holding hole, 32 Second wall part, 32a Positioning hole, 33, 34 Board contact part, 35 Claw part, 36 Insertion hole, 38 , 39 Slit, 41 Base, 41a Reference plane, 50 Top surface, 51 First part, 52 Second part, 53 Third part, 54 Fourth part, 51a, 52a, 53a, 54a, Outer surface, 51b, 52b, 53b, 54b Notch (recess), 60 reading head, 61 LED array chip, 71,72 protruding part, 73,74 pressing part, 80 connecting part, 81 support part, 82 head accommodating part, 83 guide Groove, 85 post (protrusion), 90 reading head, 100 spring, 101 1st roll, 102 2nd roll, 103 3rd roll, 104 4th roll, 105 5th roll, 300 connector.

Claims (15)

Image carrier and
A swingable exposure head that exposes the image carrier,
A spring for urging the exposure head toward the image carrier is provided.
The exposure head
The base that comes into contact with the spring and
It has a protrusion that protrudes from the base to the side opposite to the image carrier, is formed smaller than the inner dimension of the spring, and is inserted into the inner peripheral side of the spring.
The protrusion has a recess that can be engaged with the spring at the base portion on the base side.
When the exposure head is in a position to expose the image carrier, the spring does not engage the recess.
An image forming apparatus characterized in that when the exposure head swings from a position where the image carrier is exposed, the spring engages with the recess. Image carrier and
A swingable exposure head that exposes the image carrier,
With a spring that urges the exposure head toward the image carrier
With
The exposure head
The base that comes into contact with the spring and
A protrusion that projects from the base to the side opposite to the image carrier, is formed smaller than the inner dimension of the spring, and is inserted into the inner peripheral side of the spring.
Have,
The protrusion has a recess that can be engaged with the spring at the base portion on the base side.
The exposure head has a long shape in one direction and can swing around a swing axis in the longitudinal direction of the exposure head.
The recess is formed on the swinging side of the exposure head in the protrusion.
The exposure head can swing about the swing axis by a first angle in a first direction, and swings by a second angle in a second direction opposite to the first direction. Movable,
The first angle is smaller than the second angle,
An image forming apparatus characterized in that the recess is formed only on the first direction side of the protrusion. The image forming apparatus according to claim 2 , further comprising a member that comes into contact with the spring when the exposure head swings in the first direction by the first angle. The base has a hole that connects to the recess.
The image forming apparatus according to any one of claims 1 to 3 , wherein the spring can be engaged with the hollow portion formed by integrally forming the concave portion and the hole. The image forming apparatus according to claim 4 , wherein the hole penetrates the base portion. The image forming apparatus according to any one of claims 1 to 5 , wherein the recess is a notch formed in the protrusion. The image forming apparatus according to any one of claims 1 to 6 , wherein the dimension of the recess in the protruding direction of the protrusion is at least twice the wire diameter of the spring. In the projecting direction of the protrusion, the height H1 of the protrusion, the distance Hs from the base to the third roll of the spring, and the wire diameter φ of the spring are
H1 <Hs- (φ / 2)
The image forming apparatus according to any one of claims 1 to 7 , wherein the image forming apparatus is characterized in that. The image forming apparatus according to any one of claims 1 to 8 , wherein the recess has a dimension that does not reach the center of the protrusion. The image forming apparatus according to any one of claims 1 to 9 , wherein the protruding portion has a cross section having a cross section orthogonal to the protruding direction of the protruding portion. The image forming apparatus according to any one of claims 1 to 9 , wherein the protrusion has a cylindrical shape. The image forming apparatus according to any one of claims 1 to 9 , wherein the protrusion has a prismatic shape. Further provided with a head holder for holding the exposure head,
The image forming apparatus according to any one of claims 1 to 12 , wherein the spring is provided between the exposure head and the head holder. The exposure head has a pair of wall portions and has a pair of wall portions.
The image forming apparatus according to any one of claims 1 to 13 , wherein a spring holder including the base portion is attached to one of the pair of wall portions. A support for holding the object to be read and
A swingable reading head that receives light from the object to be read,
A spring for urging the reading head toward the support is provided.
The reading head
The base that comes into contact with the spring and
It has a protrusion that protrudes from the base to the side opposite to the support, is formed smaller than the inner dimension of the spring, and is inserted into the inner peripheral side of the spring.
The protrusions on the root portion of the base side, possess the spring engageable with the recess,
When the reading head is in a position to receive light of the object to be read, the spring does not engage with the recess.
An image reading device characterized in that when the reading head swings from a position where it receives light from the object to be read, the spring engages with the recess.

Images