JP7094499B2 - Image forming device - Google Patents

Description

The present invention relates to an image forming apparatus including a photoconductor drum exposed by an exposure head having a plurality of light emitting portions and a method for manufacturing the same.

Conventionally, as an image forming apparatus, a photoconductor drum, an LED head for exposing the photoconductor drum, a spacer provided between the photoconductor drum and the LED head, and an eccentric cam provided between the spacer and the LED head have been used. Is known (see Patent Document 1). In this technique, the focal position of the LED head is adjusted by rotating the eccentric cam.

Japanese Unexamined Patent Publication No. 2002-361931

However, in the prior art, there is a problem that the adjustment work becomes complicated because the eccentric cam must be rotated to adjust the focal position while measuring the focal position of the LED head.

Therefore, an object of the present invention is to facilitate adjustment of the focal position of the LED head (exposure head).

In order to solve the above problems, the image forming apparatus according to the present invention includes a drum unit provided with a cylindrical photoconductor drum, a plurality of light emitting units arranged in the direction of the rotation axis of the photoconductor drum, and light from the light emitting unit. It is provided with an exposure head including an optical member for forming an image on the surface of the photoconductor drum, and a frame for supporting the light emitting portion and the optical member.
The exposure head includes a reference surface formed on the frame and facing the rotation axis side, a contact member that abuts on the drum unit, and a spacer sandwiched between the reference surface and the contact member. ..

According to this configuration, even if the focal position of the exposure head with respect to the reference surface is not an appropriate position due to a manufacturing error of the frame or the contact member, the exposure head is inserted between the reference surface of the frame and the contact member. The focal position can be accurately defined simply by selecting the type and number of spacers. Then, the spacer can be easily selected based on the information, for example, once the focal position of the exposure head with respect to the reference plane is acquired, so that the conventional focal position can be measured many times. It is easier to adjust the focal position than the required technique.

Further, in the method for manufacturing an image forming apparatus according to the present invention, a drum unit including a photoconductor drum, a plurality of light emitting units arranged in the direction of the rotation axis of the photoconductor drum, and light from the light emitting unit are used as the photoconductor drum. An exposure head including an optical member for forming an image on the surface of the frame and a frame for supporting the light emitting portion and the optical member, and the exposure head is a reference surface located on the drum unit side of the frame. A method for manufacturing an image forming apparatus, comprising a contact member having a facing surface facing the reference surface and a contact surface contacting the drum unit, and a spacer sandwiched between the reference surface and the facing surface. be.
In this manufacturing method, a spacer is used based on the acquisition step of acquiring the focal position of the exposure head with respect to the reference surface, the length in the optical axis direction from the facing surface to the contact surface, and the focal position and the length. It is provided with a selection step of selecting the above and an assembly step of assembling the selected spacer between the reference surface and the facing surface.

According to this manufacturing method, even if the focal position of the exposure head with respect to the reference surface is not an appropriate position due to a manufacturing error of the frame or the contact member, information is acquired in the acquisition process and the spacer is acquired in the selection process. Since the focal position can be accurately defined only by selecting the type and the number, the adjustment of the focal position becomes easy.

According to the present invention, the focal position of the exposure head can be easily adjusted.

It is a figure which shows the schematic structure of the color printer which concerns on one Embodiment of this invention. It is a figure which shows the color printer with the top cover open. It is a figure which shows the exposure head and a drum unit located in a retracted position. It is a figure which shows the exposure head and the drum unit located at the exposure position. It is a perspective view which shows by disassembling the interval adjusting member. It is sectional drawing which shows the structure in the vicinity of a resin spring. It is a perspective view which shows the rotation support member. It is a figure which shows the relationship between a rotation support member, a drum frame and the like. It is a figure (a)-(c) which shows the information (dimension) necessary for the method of selecting a spacer.

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

Further, in the following description, the direction will be described with reference to the user who uses the color printer 1. That is, the left side in FIG. 1 is "front", the right side is "rear", the back side is "left", and the front side is "right". Further, the upper side in FIG. 1 is referred to as "upper" and the lower side is referred to as "lower".

As shown in FIG. 1, the color printer 1 mainly includes a main body housing 10, a top cover 11, a paper feeding unit 20 and an image forming unit 30 provided in the main body housing 10.

The top cover 11 is arranged on the upper part of the main body housing 10, is rotatably provided with respect to the main body housing 10 around the rear rotation shaft 11A, and is formed on the upper part of the main body housing 10. The opening 10A is opened and closed. Specifically, the top cover 11 can be moved to a closed position (position in FIG. 1) for closing the opening 10A and an open position (position in FIG. 2) for opening the opening 10A.

The paper feed unit 20 is provided in the lower part of the main body housing 10, and mainly includes a paper feed tray 21 for accommodating the paper P and a paper supply mechanism 22 for supplying the paper P from the paper feed tray 21 to the image forming unit 30. Preparing for. The paper P in the paper feed tray 21 is separated one by one by the paper supply mechanism 22 and supplied to the image forming unit 30.

The image forming unit 30 is mainly composed of four exposure heads 40, four process cartridge PCs, a transfer unit 70, and a fixing unit 80.

The exposure head 40 has a plurality of LEDs at its tip and is held by the top cover 11 (details, a holder 12 described later) so as to be suspended from the top cover 11 in a state where the top cover 11 is closed. , Which will be described later, are arranged so as to face each other above the photoconductor drum 51. Specifically, the exposure head 40 has an exposure position (position in FIG. 1) for exposing the photoconductor drum 51 by opening and closing the top cover 11 and a retracted position (FIG. 2) farther from the exposure position than the exposure position. It is possible to move to (position). The exposure head 40 exposes the surface of the photoconductor drum 51 by blinking a plurality of LEDs based on image data. The structure of the exposure head 40 will be described in detail later.

Each process cartridge PC is arranged in parallel between the top cover 11 and the paper feed tray 21 along the front-rear direction. Each process cartridge PC is removable through the opening 10A of the main body housing 10 in a state where the top cover 11 is opened (see FIG. 2). The process cartridge PC includes a drum unit 50 and a developing cartridge 60 that can be attached to and detached from the drum unit 50.

The drum unit 50 includes a cylindrical photoconductor drum 51, a charger 52 for charging the photoconductor drum 51, a pressing spring 53 for urging the developing cartridge 60 toward the photoconductor drum 51, a cleaning roller 54, and photosensitivity. It includes a drum frame 55 that supports the body drum 51 and the like. The structure of the photoconductor drum 51 will be described in detail later.

The cleaning roller 54 is a roller that removes foreign matter such as toner remaining on the photoconductor drum 51. The cleaning roller 54 is in contact with the photoconductor drum 51 and can rotate.

The developing cartridge 60 mainly includes a toner accommodating portion 61 for accommodating toner and a developing roller 62 for supplying the toner in the toner accommodating portion 61 to the photoconductor drum 51. The developing roller 62 is movable in the radial direction of the photoconductor drum 51.

Specifically, the developing roller 62 rotates in a state of being urged by the photoconductor drum 51 by the pressing spring 53. At this time, the developing roller 62 moves in the radial direction of the photoconductor drum 51 following the eccentricity of the photoconductor drum 51 and the developing roller 62. As a result, the urging force of the pressing spring 53 acts stably on the contact portion between the photoconductor drum 51 and the developing roller 62, and the toner is supplied to the electrostatic latent image of the photoconductor drum 51.

The transfer unit 70 is provided between the paper feed tray 21 and the process cartridge PC. The transfer unit 70 mainly includes a drive roller 71, a driven roller 72, an endless transfer belt 73 stretched between the drive roller 71 and the driven roller 72, and four transfer rollers 74. The outer surface of the transport belt 73 is in contact with each photoconductor drum 51, and each transfer roller 74 is arranged inside the transport belt 73 so as to sandwich the transport belt 73 with each photoconductor drum 51.

The fixing unit 80 is provided behind the process cartridge PC and the transfer unit 70, and mainly includes a heating roller 81 and a pressure roller 82 that is arranged to face the heating roller 81 and presses the heating roller 81.

In such an image forming unit 30, the surface of the photoconductor drum 51 is uniformly charged by the charger 52 and then exposed by the exposure head 40, so that the surface of the photoconductor drum 51 is static electricity based on image data on the photoconductor drum 51. An electro-latent image is formed. Then, by supplying toner to the photoconductor drum 51 from the developing roller 62, the electrostatic latent image is visualized and a toner image is formed on the photoconductor drum 51.

The toner image formed on each photoconductor drum 51 is sequentially superposed on the paper P transported on the transport belt 73 and transferred by the transfer roller 74. The paper P on which the toner image is transferred is conveyed between the heating roller 81 and the pressure roller 82, so that the toner image is thermally fixed. After that, the paper P is discharged from the inside of the main body housing 10 to the outside by the transport roller 91, and is placed on the paper discharge tray 11B formed on the upper surface of the top cover 11.

Next, the structure around the photoconductor drum 51 and the structure of the exposure head 40 will be described in detail.
As shown in FIG. 3, in the present embodiment, the rotation axis X1 of the photoconductor drum 51 extends in the left-right direction. In the following description, the extending direction of the rotation axis X1, that is, the left-right direction is also simply referred to as "rotation axis direction".

Each end of the photoconductor drum 51 in the direction of the rotation axis is rotatably supported by the rotation support member 500. Each rotation support member 500 arranged on one end side and the other end side of the photoconductor drum 51 is supported by the drum frame 55.

The photoconductor drum 51 includes a cylindrical raw tube 51A and two fitting members 400 that are fitted to the inner peripheral surface of the raw tube 51A. The raw tube 51A is made of a conductive material such as metal. A photosensitive layer is formed on the outer peripheral surface of the raw tube 51A. The outer peripheral surface of the raw tube 51A is also referred to as a surface. The photosensitive layer is formed in a range wider than the exposure range ER of the exposure head 40 at least.

The fitting member 400 is provided on one end side and the other end side of the raw pipe 51A in the direction of the rotation axis, respectively. The fitting member 400 is made of resin. The fitting member 400 can rotate together with the raw pipe 51A by being fitted into the inner peripheral surface of the raw pipe 51A. The fitting member 400 integrally includes a fitting portion 410 located inside the end surface A1 of the raw pipe 51A in the rotation axis direction and an exposed portion 420 located outside the end surface A1 of the raw pipe 51A in the rotation axis direction. Have in.

The fitting portion 410 is formed in a substantially columnar shape. The fitting portion 410 is fitted to the inner peripheral surface of the raw pipe 51A. The fitting portion 410 is arranged outside the exposure range ER of the exposure head 40 in the direction of the rotation axis.

The exposed portion 420 has a supported portion 421 supported by the rotation support member 500, and a flange portion 422 protruding radially outward from the outer peripheral surface of the supported portion 421. The supported portion 421 is formed in a substantially columnar shape. The outer diameter of the supported portion 421 is smaller than the outer diameter of the raw tube 51A.

The flange portion 422 is formed in a substantially disk shape. The flange portion 422 is arranged between the supported portion 421 and the fitting portion 410 in the direction of the rotation axis. The flange portion 422 is in contact with the end surface A1 of the raw pipe 51A. The outer diameter of the flange portion 422 is larger than the outer diameter of the raw pipe 51A.

The fitting member 400 has a through hole 401 penetrating in the direction of the rotation axis. Specifically, the through hole 401 is formed from the inner end surface of the fitting portion 410 in the rotation axis direction to the outer end surface of the exposed portion 420 in the rotation axis direction. Further, the through hole 401 passes through the center of the fitting portion 410 and the exposed portion 420.

One of the two fitting members 400 (on the left side) has an input unit 402 to which a rotational driving force is input. The input portion 402 is formed as a concave portion having a non-circular shape when viewed from the direction of the rotation axis. An advancing / retreating coupling provided in the main body housing 10 can be inserted into the input unit 402. The input unit 402 and the coupling can be engaged with each other in the rotation direction of the photoconductor drum 51. This makes it possible to transmit the rotational driving force from the coupling to the input unit 402.

A metal shaft 610 is provided in the through hole 401 of the fitting member 400 on the other side (right side). The shaft 610 is arranged at the center of rotation of the fitting member 400. The length of the shaft 610 in the rotation axis direction is smaller than the length of the raw tube 51A in the rotation axis direction. Specifically, the length of the shaft 610 in the rotation axis direction is slightly larger than the length of the fitting member 400 in the rotation axis direction. Both ends of the shaft 610 project outward from each end face in the rotation axis direction of the fitting member 400.

A metal earth spring 620 is provided at the inner end of the shaft 610 in the direction of the rotation axis. The earth spring 620 is in contact with the outer peripheral surface of the shaft 610 and is in contact with the inner peripheral surface of the raw pipe 51A. As a result, the shaft 610 is electrically connected to the raw pipe 51A via the earth spring 620. When the photoconductor drum 51 is mounted on the main body housing 10, the shaft 610 conducts with a metal member provided on the main body housing 10 and is connected to a ground potential.

The rotation support member 500 is a member that rotatably supports the outer peripheral surface of the supported portion 421 of the fitting member 400. The rotation support member 500 is configured as a slide bearing made of resin. The rotation support member 500 is located outside the raw tube 51A in the direction of the rotation axis.

The rotation support member 500 has a contact surface 531 that abuts on the exposure head 40. The contact surface 531 is located radially outside the surface of the raw tube 51A. Specifically, the contact surface 531 projects radially outward from the outer peripheral surface of the flange portion 422 of the fitting member 400 toward the exposure head 40. The details of the structure of the rotation support member 500 will be described later.

The exposure head 40 includes a first frame 100 and a second frame 200 as an example of a frame, and an interval adjusting member 300 arranged between the second frame 200 and the drum unit 50. Specifically, the spacing adjusting member 300 is arranged between the second frame 200 and the rotation support member 500 of the drum unit 50.

The first frame 100 and the second frame 200 are made of resin. The first frame 100 integrally has a substantially rectangular parallelepiped base portion 110 that is long in the left-right direction and two extending portions 120 that extend outward in the left-right direction from each end surface of the base portion 110 in the left-right direction. .. The base portion 110 is made of resin and is open in the vertical direction.

In the base portion 110, an LED array 101 and a memory 103 in which information about the focal position is stored are provided. A lens array 102, which is an optical member that forms an image of light from the LED array 101 on the surface of the photoconductor drum 51, is provided in the lower opening of the base portion 110. That is, the base portion 110 supports the LED array 101, the lens array 102, and the memory 103. The lower surface of the lens array 102 is an exit surface that emits light and faces the rotation axis X1 side.

The LED array 101 is a semiconductor element having a plurality of light emitting units arranged in the direction of the rotation axis, and the photoconductor drum 51 is subjected to scanning exposure by sequentially lighting each light emitting unit. In the following description, the direction in which the photoconductor drum 51 is scanned in the rotation axis direction by a plurality of light emitting units arranged in the rotation axis direction is referred to as a main scanning direction. Further, the optical axis direction of the light emitted from the LED array 101 is simply referred to as "optical axis direction". Further, the direction orthogonal to the optical axis direction and the main scanning direction is referred to as a sub-scanning direction. In addition, in this embodiment, since the sub-scanning direction substantially coincides with the front-back direction, it is also appropriately referred to as the front-back direction. Further, in the present embodiment, since the optical axis direction substantially coincides with the vertical direction, it is also appropriately referred to as a vertical direction.

The vertical length of the extending portion 120 is smaller than the vertical length of the base portion 110. The extending portion 120 is located above the left and right end faces of the base portion 110. The lower surface of the extending portion 120 is a supported surface 121 supported by the second frame 200. The supported surface 121 faces the rotation axis X1 side.

The second frame 200 is a resin frame that supports the first frame 100, and is supported in a state of being suspended by a resin holder 12 that is rotatably supported by the top cover 11. The second frame 200 integrally has a substantially rectangular base portion 210 that is long in the left-right direction and two projecting portions 220 that support both ends of the first frame 100 in the rotation axis direction.

The base portion 210 has a first recess 211, a second recess 212, and a hole 213. Two holes 213 are provided at intervals in the left-right direction. Each hole 213 is arranged symmetrically with respect to the center of the base portion 210 in the left-right direction. Each hole 213 penetrates the base portion 210 in the front-rear direction.

The holder 12 has a hook 12A for suspending the base portion 210 at a position corresponding to each hole 213. The tip of each hook 12A projects inward in the front-rear direction and engages with each hole 213.

The first recess 211 is a recess that opens toward the holder 12 side. The first recess 211 is formed one by one on the outer side in the left-right direction with respect to the two holes 213 on the left and right. A compression coil spring SP as an example of the urging member is provided between the bottom surface of the first recess 211 and the holder 12. The compression coil spring SP urges the exposure head 40 toward the photoconductor drum 51.

The second recess 212 is a recess that opens toward one side in the front-rear direction. The second recess 212 is formed one by one on the lateral side in the left-right direction with respect to the left and right first recesses 211. Specifically, the second recess 212 is arranged at a position closer to the end portion than the center in the left-right direction of the base portion 210. The lower wall of the second recess 212 is a support wall 214 that supports the spacing adjusting member 300.

The lower surface of the support wall 214 is a second support surface F2 that supports the interval adjusting member 300 from above in a state where the exposure head 40 is located at the exposure position (position in FIG. 4). The second support surface F2 is arranged at a position farther from the rotation axis X1 than the first support surface F1 described later. The second support surface F2 functions as a reference surface FB as a reference for determining the thickness of the spacer 320, which will be described later. The reference surface FB is located below the support wall 214 (photoreceptor drum 51 side), that is, below the base portion 210, and faces the rotation axis X1 side.

Each protruding portion 220 protrudes from the lower surface of the base portion 210 toward the photoconductor drum 51. Specifically, each protruding portion 220 protrudes in the optical axis direction from the lens array 102. Each protrusion 220 is arranged between the compression coil spring SP and the interval adjusting member 300 in the left-right direction.

Each protrusion 220 has a third recess 223 and a fourth recess 224 that open toward one side in the front-rear direction. Specifically, the third recess 223 and the fourth recess 224 are open toward the rear. The third recess 223 is formed on the upper portion of the protrusion 220. The third recess 223 can accommodate the extension portion 120 of the first frame 100 inside the third recess 223. The lower wall of the third recess 223 is a support wall 221 that supports the extension 120 of the first frame 100. The upper surface of the support wall 221 is a first support surface F1 that supports the extending portion 120 of the first frame 100 from the lower side. The first support surface F1 faces the radial outer side of the photoconductor drum 51. The first support surface F1 is arranged between the photoconductor drum 51 and the first frame 100 in the optical axis direction.

A part of the protrusion 220 is arranged at the same position as the first support surface F1 in the direction of the rotation axis. Specifically, the photoconductor drum 51 side of the protrusion 220 has a tip surface 225 orthogonal to the optical axis direction, and the tip surface 225 overlaps with the first support surface F1 when viewed from the optical axis direction.

The fourth recess 224 is arranged below the third recess 223. The support wall 221 described above is arranged between the third recess 223 and the fourth recess 224. As shown in FIG. 6, the extending portion 120 of the first frame 100 supported by the support wall 221 is attached to the protruding portion 220 by the resin spring 700. The resin spring 700 is attached from the rear to prevent the user from touching it.

The resin spring 700 functions as a pressing member that presses the extending portion 120 of the first frame 100 toward the first support surface F1 and the bottom surface 223A of the third recess 223. Specifically, the resin spring 700 includes a first part 710, a second part 720, a third part 730, a fourth part 740, a fifth part 750, a sixth part 760, and a seventh part 770. It has an eighth part 780 integrally. The first portion 710 penetrates into the fourth recess 224 and is in contact with the lower surface of the support wall 221. The second portion 720 extends upward from one end in the anteroposterior direction of the first portion 710.

The third portion 730 extends from the upper end of the second portion 720 toward the bottom surface 223A of the third recess 223. The fourth site 740 extends obliquely from the other end of the third site 730 in the anteroposterior direction toward the second site 720 side with respect to the third site 730. The fifth site 750 extends diagonally from the end of the fourth site 740 on the second site 720 side toward the third site 730 with respect to the third site 730.

The sixth site 760 extends substantially parallel to the third site 730 from the end of the fifth site 750 on the second site 720 side toward the second site 720 side. The seventh site 770 extends diagonally from the end of the sixth site 760 on the second site 720 side toward the first site 710 with respect to the third site 730. The eighth site 780 extends downward from the lower end of the seventh site 770. Then, the seventh portion 770 contacts the corner portion of the extension portion 120 of the first frame 100 and presses the extension portion 120 toward the first support surface F1 and the bottom surface 223A of the third recess 223. ..

Further, as shown in FIG. 6, the width of the protrusion 220 in the front-rear direction is larger than the width of the lens array 102 in the front-rear direction. The lens array 102 is arranged within the width of the protrusion 220 in the front-rear direction.

As shown in FIG. 5, the interval adjusting member 300 includes one contact member 310 and two spacers 320. The contact member 310 is a member for defining the distance in the optical axis direction from the lens array 102 to the photoconductor drum 51 by contacting the contact surface 531 (see FIG. 3) of the rotation support member 500.

The contact member 310 is made of resin. The abutting member 310 integrally has a substantially triangular main body portion 310A and a boss 310B protruding upward from the main body portion 310A. The width of the main body 310A in the front-rear direction becomes narrower toward the photoconductor drum 51.

The main body portion 310A has a first wall portion 311, a second wall portion 312, and a third wall portion 313. The first wall portion 311 has a facing surface F3 facing the second support surface F2 (reference surface FB) of the second frame 200 in the optical axis direction.

The second wall portion 312 extends diagonally from one end of the first wall portion 311 in the front-rear direction toward the lower side and the other end side in the front-rear direction. The third wall portion 313 extends from the other end of the first wall portion 311 in the front-rear direction toward the lower end and one end side in the front-rear direction, and is connected to the lower end portion of the second wall portion 312. .. The end surface of the lower side (photoreceptor drum 51 side) of the corner portion, which is the connection portion between the second wall portion 312 and the third wall portion 313, is a contact surface F4 that abuts on the contact surface 531 of the rotation support member 500. ing. The contact surface F4 is a curved surface that is convex downward.

The boss 310B projects upward from the facing surface F3. The boss 310B is formed in a substantially columnar shape. The boss 310B is movably supported by the support wall 214 in the vertical direction while being inserted into the through hole 214A formed in the support wall 214. That is, the boss 310B functions as a supported portion supported by the support wall 214. Here, the through hole 214A is formed so as to penetrate the support wall 214 in the vertical direction. As a result, the reference plane FB has an opening facing the rotation axis X1 side.

The boss 310B has a slit 314 extending downward from its upper surface. The slit 314 is formed so as to open upward and to pass through the boss 310B in the left-right direction. As a result, the upper part of the boss 310B has a bifurcated shape divided in the front-rear direction.

Two claws 315 protruding outward in the front-rear direction are formed on the outer peripheral surface of the upper end portion of the boss 310B. The claw 315 is engageable with the upper surface of the support wall 214. Further, the claw 315 is formed so that the height of the boss 310B from the outer peripheral surface gradually decreases toward the upper side. That is, the outer surface of the claw 315 in the front-rear direction is an inclined surface that is located inward in the front-rear direction toward the upper side.

As a result, when the boss 310B is pushed into the through hole 214A of the support wall 214 from below, each claw 315 can enter the through hole 214A while the upper part of the bifurcated shape of the boss 310B is elastically deformed. ing. Further, after each claw 315 passes through the through hole 214A, the upper portion of the bifurcated shape of the boss 310B returns to the original position, so that each claw 315 is satisfactorily engaged with the upper surface of the support wall 214. Is possible.

The spacer 320 is a rectangular plate-shaped member sandwiched between the reference surface FB (second support surface F2) and the facing surface F3 of the contact member 310. The spacer 320 is arranged so as to be orthogonal to the optical axis direction. The thickness (length in the optical axis direction) of each spacer 320 is the same. Here, the length of the spacer 320 in the optical axis direction is preferably, for example, 0.025 mm to 0.2 mm, more preferably 0.05 mm to 0.1 mm.

The length of the spacer 320 in the front-rear direction is smaller than the length of the facing surface F3 in the front-rear direction. Further, the length of the spacer 320 in the left-right direction is smaller than the length of the facing surface F3 in the left-right direction. The spacer 320 has a hole 321 through which the boss 310B penetrates.

As shown in FIG. 3, the interval adjusting member 300 configured as described above is supported in a state of being suspended from the second frame 200 in a state where the exposure head 40 is located at the retracted position. Specifically, the contact member 310 is supported in a suspended state from the second frame 200, and the two spacers 320 are laminated on the contact member 310 in a state of being separated from the second frame 200 in the vertical direction. There is. That is, the distance from the reference surface FB to the facing surface F3 when the exposure head 40 is located at the retracted position is set to a distance that allows the maximum number of spacers 320 that can be assumed to be installed. Here, the maximum number of spacers 320 can be appropriately set in consideration of an error at the time of designing.

Further, as shown in FIG. 4, in a state where the exposure head 40 is located at the exposure position, the two spacers 320 are sandwiched between the reference surface FB and the facing surface F3. Specifically, when the exposure head 40 is moved from the retracted position to the exposure position, the contact member 310 first comes into contact with the contact surface 531 of the rotation support member 500, so that the contact member 310 moves. Is stopped. After that, the second frame 200 moves so as to approach the contact member 310 whose movement has been stopped, and when the reference surface FB comes into contact with the spacer 320, the movement of the second frame 200 is stopped. The exposure head 40 is positioned in the optical axis direction. In this state, the contact surface F4 is arranged at a position closer to the rotation axis X1 than the first support surface F1.

As shown in FIG. 7, the rotation support member 500 is formed of a resin, and has a cylindrical bearing portion 510 and a ring-shaped flange portion 520 projecting radially outward from a substantially central portion in the rotation axis direction of the bearing portion 510. And, an extension portion 530 extending radially outward of the raw pipe 51A (see FIG. 8) from the outer peripheral surface of the flange portion 520, a guide portion 540, a rotation restricting portion 550, and a roller support portion 560 are integrally provided.

As shown in FIG. 8, the bearing portion 510 is a portion that rotatably supports the fitting member 400. The bearing portion 510 has a pressing portion 511 that presses the fitting member 400 toward the lower side (one side in the radial direction of the raw pipe 51A). The pressing portion 511 is a portion between two notches formed at two positions at one end of the bearing portion 510, and is elastically deformable in the radial direction. The pressing portion 511 is a resin spring in which the tip portion 511A is inclined so as to be close to the rotation axis X1 and the fitting member 400 is urged toward the rotation axis X1 by the urging force FR. The pressing portion 511 is located on a straight line L1 that is orthogonal to the rotation axis X1 of the photoconductor drum 51 and passes through the contact surface 531 when viewed from the rotation axis direction.

The extending portion 530 extends from the flange portion 520 toward the upper side, specifically, the contact member 310 of the exposure head 40. The extending portion 530 has the above-mentioned contact surface 531 at the tip thereof. The contact surface 531 is a plane orthogonal to the optical axis direction. The contact surface 531 abuts on the contact member 310 of the exposure head 40 to define the distance in the optical axis direction from the lens array 102 to the photoconductor drum 51.

The guide portion 540 extends from the flange portion 520 in the upper right direction in the drawing, specifically in the direction from the photoconductor drum 51 toward the developing roller 62. The guide portion 540 is adjacent to the downstream side of the extension portion 530 in the rotation direction of the photoconductor drum 51 and is connected to the extension portion 530. The guide portion 540 has a guide groove 541 that supports the shaft 62A of the developing roller 62 so as to be movable in the radial direction of the photoconductor drum 51.

The rotation control unit 550 is adjacent to the downstream side of the guide unit 540 in the rotation direction of the photoconductor drum 51 and is connected to the guide unit 540. The rotation control unit 550 has a first rotation control surface 551 that regulates the position of the rotation support member 500 with respect to the drum frame 55 in the rotation direction of the photoconductor drum 51. The first rotation restricting surface 551 is arranged so as to face the downstream side in the rotation direction of the photoconductor drum 51, and is in contact with the drum frame 55.

The roller support portion 560 is arranged between the extension portion 530 and the rotation restricting portion 550 in the rotation direction of the photoconductor drum 51. The roller support portion 560 is arranged apart from the extension portion 530 and the rotation restricting portion 550 in the rotation direction. The roller support portion 560 is arranged on the side opposite to the rotation restricting portion 550 with the rotation axis X1 interposed therebetween.

The roller support portion 560 has a support hole 561 that rotatably supports the cleaning roller 54. The roller support portion 560 has a second rotation control surface 562 that regulates the position of the rotation support member 500 with respect to the drum frame 55 in the rotation direction of the photoconductor drum 51. The second rotation restricting surface 562 is arranged so as to face the downstream side in the rotation direction of the photoconductor drum 51, and is in contact with the drum frame 55. It is sufficient that at least one of the first rotation restricting surface 551 and the second rotation restricting surface 562 is in contact with the drum frame 55 when the photoconductor drum 51 is rotating.

Further, the second rotation restricting surface 562 is arranged at a position farther from the rotation axis X1 of the photoconductor drum 51 than the contact surface 531. Further, the rotation control surfaces 551 and 562 are formed on both sides of the contact surface 531 and the linear L1 along the radial direction of the photoconductor drum 51 passing through the rotation axis X1 of the photoconductor drum 51 when viewed from the rotation axis direction. It is provided.

Next, a method of manufacturing the color printer 1, specifically, a method of assembling the exposure head 40 will be described in detail. In the method described below, the selection method of the spacers 320 arranged on the left and right sides of the exposure head 40 is particularly important, and this selection method is the same for the left side and the right side. Therefore, in the following, the left side will be described as a representative, and the right side will be omitted.

As shown in FIG. 9A, first, the LED array 101, the lens array 102, and the memory 103 are assembled to the first frame 100. After that, the first frame 100 is set in the inspection device. Next, light is emitted from the LED array 101, and the first distance D1 from the supported surface 121 of the first frame 100 to the focal point FP is measured. Since there are two supported surfaces 121 on the left and right, the first distance D1 is measured on the left side and the right side, respectively. After that, the measured first distance D1 is recorded in the memory 103.

Further, as shown in FIG. 9B, for the second frame 200, for example, the second distance D2 from the reference surface FB on the left side to the first support surface F1 on the left side is measured and acquired (acquisition step). The first support surface F1 is a surface that supports the supported surface 121 of the first frame 100. Therefore, the second distance D2 corresponds to the distance from the reference surface FB to the supported surface 121 when the first frame 100 is assembled to the second frame 200. The acquisition of the second distance D2 is performed on the left side and the right side of the second frame 200, respectively. By recording the measurement result of the first distance D1 in the memory 103, it becomes possible to carry out the measurement of the first distance D1 and the measurement of the second distance D2 in different processes or factories.

After that, the first distance D1 is acquired from the memory 103 of the first frame 100 to be assembled in the second frame 200 (acquisition step). Then, the focal position of the exposure head 40 with respect to the reference plane FB is acquired based on the first distance D1 and the second distance D2 (acquisition step). Specifically, by adding the first distance D1 and the second distance D2, the distance D3 from the reference plane FB to the focal point FP, that is, the focal position of the exposure head 40 with respect to the reference plane FB is calculated and acquired.

Further, as shown in FIG. 9C, for the left contact member 310 attached to the left reference surface FB, the length D4 in the optical axis direction from the facing surface F3 to the contact surface F4 is measured and acquired. (Acquisition process). The same applies to the right side.

Then, the number of spacers 320 is selected based on the distance D3 and the length D4 corresponding to the focal position (selection step). Specifically, the difference between the distance D3 and the length D4 is calculated, and the number of spacers 320 for filling this difference is determined. Here, assuming that the length of the spacer 320 in the optical axis direction is T1, the number N of spacers 320 can be derived by the following equation (1).
N = (D3-D4) / T1 ... (1)

After determining the number of spacers 320, the spacers 320 for the number of spacers 320 are assembled to the boss 310B of the contact member 310, and then the contact member 310 is assembled to the second frame 200. As a result, the spacers 320 for the selected number of sheets are assembled between the reference surface FB and the facing surface F3 (assembly step).

Based on the above, the following effects can be obtained in the present embodiment.
Since the contact surface 531 with which the exposure head 40 abuts is provided on the rotation support member 500 that supports the fitting member 400, which is a member different from the raw tube 51A, foreign matter on the raw tube 51A can be removed from the exposure head 40. It becomes difficult to enter between the rotation support member 500 and the rotation support member 500. Therefore, according to the present embodiment, the distance in the optical axis direction from the lens array 102 to the photoconductor drum 51 can be accurately defined, so that the focal position can be suppressed from shifting.

Since the rotation support member 500 is located outside the raw tube 51A in the rotation axis direction, the contact surface 531 can be kept away from the surface of the raw tube 51A in the rotation axis direction, and foreign matter on the raw tube 51A is on the contact surface. It is possible to further suppress the entry between the 531 and the exposure head 40.

Since the outer diameter of the supported portion 421 of the fitting member 400 is smaller than the outer diameter of the raw pipe 51A, for example, compared with a structure in which the outer diameter of the supported portion is larger than the outer diameter of the raw pipe, it rotates with the supported portion 421. The contact area with the support member 500 can be reduced. Therefore, wear of the supported portion 421 or the rotation support member 500 can be suppressed.

Since the fitting member 400 has a flange portion 422, when the fitting member 400 is fitted into the raw pipe 51A, the flange portion 422 comes into contact with the end surface of the raw pipe 51A, so that the fitting member 400 with respect to the raw pipe 51A Positioning can be easily performed.

Since the contact surface 531 is provided at the tip of the extension portion 530 extending in the radial direction of the raw tube 51A, the contact surface 531 can be brought closer to the contact member 310 of the exposure head 40 by the extension portion 530. Therefore, the amount of protrusion of the contact member 310 protruding from the second frame 200 toward the contact surface 531 can be reduced, so that the shape of the exposure head 40 can be simplified.

By arranging the contact surface 531 radially outside the surface of the raw tube 51A, the contact surface 531 can be moved radially away from the surface of the raw tube 51A, so that foreign matter on the raw tube 51A abuts. It is possible to further suppress the entry between the surface 531 and the exposure head 40.

By making the contact surface 531 a flat surface and the contact surface F4 a curved surface, the contact surface 531 and the contact surface F4 can be brought into line contact with each other. The distance can be defined accurately.

By making the contact surface 531 a plane orthogonal to the optical axis direction, the exposure head 40 can slide and move on the contact surface 531 in the sub-scanning direction orthogonal to the optical axis direction, so that the exposure head 40 can be moved. It is possible to prevent the contact surface 531 from becoming an obstacle when positioning in the sub-scanning direction.

Since both the fitting member 400 and the rotation support member 500 are made of resin, the shapes of the fitting member 400 and the rotation support member 500 can be easily formed. Further, the sliding bearing can be formed by the fitting member 400 and the rotation support member 500.

Since the fitting member 400 is pressed to one side in the radial direction by the pressing portion 511 provided on the rotation support member 500, it is possible to suppress fluctuations in the distance between the focal position of the exposure head 40 and the surface of the photoconductor drum 51. Further, by giving resistance to the rotation of the photoconductor drum 51, it is possible to suppress rotation unevenness.

By arranging the pressing portion 511 on a straight line L1 that is orthogonal to the rotation axis X1 of the photoconductor drum 51 and passes through the contact surface 531 when viewed from the direction of the rotation axis, the direction in which the photoconductor drum 51 is loosened. Since the optical axis directions of the exposure head 40 can be substantially matched, the distance in the optical axis direction from the lens array 102 to the photoconductor drum 51 can be accurately defined.

Since the fitting portion 410 of the fitting member 400 is arranged outside the exposure range ER of the exposure head 40 in the rotation axis direction, it corresponds to the exposure range ER on the photoconductor drum 51 by fitting the fitting member 400. It is possible to prevent the part to be deformed from being deformed.

Since the metal shaft 610 electrically connected to the raw pipe 51A is provided at the center of rotation of the fitting member 400 on the right side, the raw pipe 51A can be conducted to the main body of the apparatus via the shaft 610.

Since the fitting member 400 on the left side is provided with an input unit 402 for inputting the rotational driving force, the rotational driving force can be satisfactorily input to the fitting member 400, and the photoconductor drum 51 can be satisfactorily rotated. Can be done.

Since the left and right rotation support members 500 are supported by the drum frame 55, the photoconductor drum 51 and each rotation support member 500 can be unitized by the drum frame 55.

Since the rotation restricting surfaces 551 and 562 are provided on the rotation support member 500 having the contact surface 531 for positioning the exposure head 40 in the optical axis direction, the rotation support member 500 vibrates in the rotation direction and the focal position shifts. It can be suppressed from being lost.

By arranging the second rotation restricting surface 562 at a position farther from the rotation axis X1 than the contact surface 531, rotation regulation can be performed at a position far from the rotation axis X1, so that rotation regulation can be performed efficiently. Can be done. Further, since the vibration on the contact surface 531 is smaller than the vibration on the second rotation regulation surface 562 (vibration in the rotation direction), the positioning of the exposure head 40 by the contact surface 531 can be kept good.

Since the rotation restricting surfaces 551 and 562 are provided on both sides of the contact surface 531 and the straight line L1 passing through the rotation axis X1, vibration in the rotation direction can be effectively suppressed.

By providing the second rotation restricting surface 562 on the roller support portion 560 that supports the cleaning roller 54, the cleaning roller 54 can be supported by the roller support portion 560 in which vibration in the rotation direction is suppressed, so that the photoconductor drum 51 can be supported. The cleaning roller 54 can be positioned with high accuracy.

Since the guide portion 540 is provided on the rotation support member 500 whose vibration in the rotation direction is suppressed by the rotation control surfaces 551 and 562, the developing roller 62 can be accurately positioned in the rotation direction with respect to the photoconductor drum 51.

Since the spacer 320 is provided between the reference surface FB of the second frame 200 and the contact member 310, the focal position of the exposure head 40 with respect to the reference surface FB is appropriate due to manufacturing errors of the frames 100, 200 and the contact member 310. Even if the position is not the same, the focal position can be accurately defined by appropriately selecting the number of spacers 320.

Since the spacer 320 has a plate shape, an error in the thickness (length in the optical axis direction) of the spacer 320 can be made very small.

Since the thicknesses of the plurality of spacers 320 are all the same, the operator can easily adjust the focal position by simply changing the number of spacers 320 when assembling the exposure head 40.

By making the abutting member 310 movable in the optical axis direction with respect to the second frame 200, when the exposure head 40 is pressed against the photoconductor drum 51, the second frame 200 is made with respect to the abutting member 310. Can move to sandwich the spacer 320 between the reference surface FB and the contact member 310. Therefore, compared to a structure in which the contact member is fixed to the second frame with screws or the like with a spacer sandwiched between the contact member and the second frame, for example, a mounting member such as a screw is not provided. The cost can be reduced.

Since the spacer 320 has a hole 321 through which the boss 310B of the contact member 310 penetrates, it is possible to prevent the spacer 320 from shifting with respect to the contact member 310.

By providing the compression coil spring SP that urges the exposure head 40 toward the photoconductor drum 51, the reference surface FB, the spacer 320, and the contact member 310 can be brought into close contact with each other by the urging force of the compression coil spring SP. Can be specified accurately.

Since the reference surface FB is provided on the second frame 200, which is a separate component from the first frame 100 on which the optical components such as the LED array 101 are provided, the exposure head 40 is pressed against the reference surface FB when pressed against the photoconductor drum 51. It is possible to suppress the applied force from being transmitted to the optical component provided in the first frame 100.

Since the supported surface 121 of the first frame 100 faces the rotation axis X1 side like the light emitting surface of the lens array 102, the position of the focal point FP with respect to the supported surface 121 is accurately measured and acquired. As a result, the focal position with respect to the reference plane FB can be acquired with high accuracy.

By arranging the second support surface F2 at a position farther from the rotation axis X1 than the first support surface F1, the distance adjusting member 300 is arranged from the surface of the exposure head 40 on the photoconductor drum 51 side (the tip surface of the protrusion 220). Since the amount of protrusion can be reduced, it is possible to prevent the interval adjusting member 300 from interfering with other members when the exposure head 40 is moved toward the photoconductor drum 51.

Since the protruding portion 220 arranged at substantially the same position in the rotation axis direction as the first support surface F1 supporting the first frame 100 protrudes toward the photoconductor drum 51 from the lens array 102, the protruding portion 220 causes the lens array. 102 can be well protected.

Since the width of the protrusion 220 in the sub-scanning direction is larger than the width of the lens array 102 in the sub-scanning direction, the wide protrusion 220 can satisfactorily protect the lens array 102.

Since the width of the main body portion 310A of the contact member 310 in the sub-scanning direction becomes narrower toward the photoconductor drum 51, when the exposure head 40 is moved toward the photoconductor drum 51, the contact member 310 is used as another. It is possible to suppress interference with the member.

The present invention is not limited to the above embodiment, and can be used in various forms as illustrated below. In the following description, members having substantially the same structure as those of the above-described embodiment are designated by the same reference numerals, and the description thereof will be omitted.

In the above embodiment, a plurality of spacers 320 having the same thickness are provided between the reference surface FB and the contact member 310, but the present invention is not limited to this, and the space between the reference surface and the contact member 310 is not limited to this. A plurality of spacers having different thicknesses may be provided. Specifically, between the reference surface and the contact member, a first spacer having a length in the optical axis direction as the first length and a second length having a length in the optical axis direction larger than the first length. A second spacer may be provided. According to this, by providing a second spacer having a length in the optical axis direction larger than that of the first spacer between the reference surface and the contact member, it is possible to suppress an extremely large number of spacers. ..

The second length may be an integral multiple of the first length. For example, the first length may be 0.05 mm and the second length may be 0.15 mm. This makes it possible to adjust the range of 0 to 0.35 mm in increments of 0.05 mm by selectively using a maximum of three spacers from the first spacer and the second spacer.
Further, a third spacer having a third length whose length in the optical axis direction is larger than the second length may be further provided. For example, the first length may be 0.05 mm, the second length may be 0.1 mm, and the third length may be 0.25 mm. This makes it possible to adjust the range of 0 to 0.35 mm in increments of 0.05 mm by selectively using a maximum of two spacers from the first spacer, the second spacer, and the third spacer.

In the above embodiment, the memory 103 provided in the exposure head 40 stores the first distance D1 as information regarding the focal position, but the present invention is not limited thereto. For example, the first distance D1 measured in the process of manufacturing the first frame 100 may be stored in an external storage device such as a server in association with the serial number of the first frame 100. In this case, in the process of manufacturing the second frame 200, the first distance D1 corresponding to the serial number of the first frame 100 can be acquired from an external storage device.

Further, when the assembly of the optical component on the first frame 100 and the assembly of the first frame 100 and the spacing adjusting member 300 on the second frame 200 are performed in a continuous process, the first distance D1 and the second distance D2 are performed. Etc. may be measured and obtained respectively.

In the above embodiment, the exposure head 40 has a structure including two frames 100 and 200, but the present invention is not limited to this, and the exposure head may have a structure including one frame. In this case, one frame may be provided with an optical component such as a light emitting portion and an interval adjusting member.

Further, when the exposure head is configured by one frame in this way, the distance D3 from the reference plane FB to the focal point FP, that is, the focal position of the exposure head 40 with respect to the reference plane FB may be measured and acquired.

In the above embodiment, the guide portion 540 movably supports the developing roller 62 that rotates in contact with the photoconductor drum 51, but the separating mechanism that moves the developing roller 62 to a separating position that does not contact the photoconductor drum 51. The guide unit 540 may be configured to movably support the developing roller 62 between the contact position and the separation position.

In the above embodiment, the compression coil spring SP is exemplified as the urging member, but the present invention is not limited to this, and the urging member may be, for example, a leaf spring or a torsion spring.

In the above embodiment, the contact member 310 is brought into contact with the rotation support member 500, but the present invention is not limited to this, and the contact member may be in contact with the drum unit. For example, the contact member may be in contact with the drum frame, or may be in contact with the fitting member or the raw pipe.

In the above embodiment, the fitting member 400 among the parts constituting the photoconductor drum 51 is rotatably supported by the rotation support member 500, but the present invention is not limited thereto. For example, the rotation support member may rotatably support a shaft fixed to the center of the base tube of the photoconductor drum or the fitting member.

In the above embodiment, the substantially columnar boss 310B is exemplified as the supported portion of the abutting member, but the present invention is not limited to this, and the supported portion may be, for example, a rib of a plate-shaped portion. ..

In the above embodiment, the outer diameter of the supported portion 421 is made smaller than the outer diameter of the raw tube 51A, but the present invention is not limited to this, and the outer diameter of the supported portion 421 is, for example, the outer diameter of the raw tube 51A. May be larger than. By setting the outer diameter of the supported portion 421 to a value different from the outer diameter of the raw pipe 51A in this way, a step is formed between the outer peripheral surface of the supported portion 421 and the surface of the raw pipe 51A, for example. Compared to the structure in which the outer peripheral surface of the support portion and the surface of the raw pipe are flush with each other, it is possible to suppress foreign matter on the raw pipe 51A from entering between the supported portion 421 and the rotary support member 500. The outer diameter of the supported portion 421 may be the same as the outer diameter of the raw tube 51A.

The contact surface 531 may be orthogonal to the optical axis of the photoconductor drum 51 toward the rotation axis X1. For example, the contact surface 531 may or may not be parallel to the contact surface of the transport belt 73 (see FIG. 1) with the photoconductor drum 51.

In the above embodiment, the contact surface 531 is a flat surface and the contact surface F4 is a curved surface, but the present invention is not limited to this, and the contact surface may be a curved surface and the contact surface may be a flat surface. Further, the curved surface may be a spherical surface. In this case, the contact surface and the contact surface can be brought into point contact.

The material of each component such as the fitting member and the rotation support member is not limited to the above embodiment, and various materials can be selected and used. Further, the rotation support member may be a rolling bearing or the like instead of a sliding bearing.

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

Further, each element described in the above-described embodiment and modification may be arbitrarily combined and carried out.

1 Color printer 40 Exposure head 50 Drum unit 51 Photoreceptor drum 100 1st frame 101 LED array 102 Lens array 200 2nd frame 310 Contact member 320 Spacer FB reference plane

Claims (9)

A drum unit with a cylindrical photoconductor drum,
A frame that supports a plurality of light emitting portions arranged in the rotation axis direction of the photoconductor drum, an optical member that forms an image of light from the light emitting portion on the surface of the photoconductor drum, and the light emitting portion and the optical member. And, with an exposure head, with,
The exposure head is formed in the frame and has a plate-like shape sandwiched between a reference surface facing the rotation axis side, a contact member capable of contacting the drum unit, and the reference surface and the contact member. With spacers ,
The exposure head can be moved to an exposure position where the contact member and the drum unit are in contact with each other to expose the photoconductor drum and a retracted position where the contact member is separated from the drum unit . An image forming device as a feature. The contact member is supported by the frame in a state of being movable in directions toward and away from the reference surface.
The image forming apparatus according to claim 1, wherein the reference surface, the spacer, and the contact member are in close contact with each other when the exposure head is in the exposure position. A urging member for urging the exposure head toward the photoconductor drum is provided.
The image forming apparatus according to claim 2, wherein the reference surface, the spacer, and the abutting member are brought into close contact with each other by the urging force of the urging member. A plurality of the spacers are provided between the reference surface and the contact member.
The image forming apparatus according to any one of claims 1 to 3, wherein the thicknesses of the plurality of spacers are all the same. A first spacer having a thickness of a first thickness and a second spacer having a thickness larger than the first thickness are provided between the reference surface and the contact member. The image forming apparatus according to any one of claims 1 to 3, wherein the image forming apparatus is characterized by the above. The drum unit has a contact surface that comes into contact with the contact member.
The contact member has a contact surface that abuts on the contact surface.
The one according to any one of claims 1 to 5, wherein one of the contact surface and the contact surface is a curved surface, and the other of the contact surface and the contact surface is a flat surface. Image forming device. The drum unit includes a rotation support member that rotatably supports the photoconductor drum.
The rotation support member is characterized by having a slide bearing that rotatably supports the photoconductor drum, and an extension portion that extends radially outward of the photoconductor drum and abuts on the contact member. The image forming apparatus according to any one of claims 1 to 6. The photoconductor drum includes a cylindrical raw tube and a fitting member fitted to the inner peripheral surface of the raw tube.
The image forming apparatus according to claim 7, wherein the slide bearing rotatably supports the fitting member. The contact member has a facing surface facing the reference surface, and the contact member has a facing surface facing the reference surface.
The image forming apparatus according to any one of claims 1 to 8, wherein the length of the spacer in the rotation axis direction is smaller than the length of the facing surface in the rotation axis direction.

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