IMAGE FORMING APPARATUS HAVING OPTICAL PRINT HEAD

• US 20180364613A1
• Filed: 06/06/2018
• Published: 12/20/2018
• Est. Priority Date: 06/16/2017
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Momoka, Toshiki, Iwai, Hitoshi, Hosoi, Shinichiro, Ishidate, Takehiro
• Granted Patent: US 10,642,182 B2
• Time in Patent Office: Days
• CPC Class Codes: G03G 15/04036 Details of illuminating systems, e.g. lamps, reflectors lamp housings for copying cameras, reflex exposure lighting G03B27/542
• CPC Class Codes: G03G 21/1647 Mechanical connection means
• CPC Class Codes: G03G 21/1666 for the exposure unit
• CPC Class Codes: G03G 2221/1654 Locks and means for positioning or alignment

Abstract

A resin holding member is supported by a one link member and another link member at positions further outside from both ends of a lens array and both ends of a circuit board in a rotational axis direction of a photosensitive drum, but further inside from an abutting pin and another abutting pin. Force in the opposite direction from the gravitational direction is applied to a portion of the holding member between the link members in a state where the abutting pins are abutting a drum unit. Accordingly, warping of the holding member is suppressed.

Claims

1. An image forming apparatus having a drum unit rotatably supporting a photosensitive drum, where the lower side of the photosensitive drum is exposed by a plurality of lights from a side lower than a rotational axis of the photosensitive drum in the vertical direction, the image forming apparatus comprising:

a holding member configured to hold

a circuit board having a plurality of light-emitting elements configured to emit light to expose the photosensitive drum, and

a lens configured to collect the light on the surface of the photosensitive drum,

and configured to reciprocally move between an exposure position where the light-emitting elements expose the photosensitive drum, and a retracted position further retracted from the drum unit than the exposure position;

a first moving member configured to support one end side in the longitudinal direction of the holding member in a direction opposite to the gravitational direction, at a side further downstream from the lens and the circuit board in a direction from an other end of the holding member in the longitudinal direction of the holding member toward the one end of the holding member in the longitudinal direction, and to cause the one end side to move in the direction of reciprocal movement by moving in the direction of reciprocal movement while supporting the holding member;

a second moving member configured to support the other end side in the longitudinal direction of the holding member in a direction opposite to the gravitational direction, at a side further downstream from the lens and the circuit board in a direction from one end of the holding member in the longitudinal direction toward the other end of the holding member in the longitudinal direction, and to cause the other end side to move in the direction of reciprocal movement by moving in the direction of reciprocal movement while supporting the holding member;

a first abutting portion that is provided to the holding member at a side further downstream from the first moving member in a direction from the other end of the holding member in the longitudinal direction toward the one end of the holding member in the longitudinal direction, and that is configured to protrude from the holding member further toward the drum unit side than a light emission face of the lens and abut one end side of the drum unit in the longitudinal direction; and

a second abutting portion that is provided to the holding member at a side further downstream from the second moving member in a direction from the one end of the holding member in the longitudinal direction toward the other end of the holding member in the longitudinal direction, and that is configured to protrude from the holding member further toward the drum unit side than a light emission face of the lens and abut another end side of the drum unit in the longitudinal direction,

wherein force in the direction opposite to the gravitational direction is applied to a portion between the first moving member and the second moving member, regarding the holding member that has been moved from the retracted position toward the exposure position by the first moving member and the second moving member, with the first abutting portion and second abutting portion abutting the drum unit.

2. The image forming apparatus according to claim 1,

wherein the holding member is a resin molded article.

3. The image forming apparatus according to claim 1, further comprising:

a sliding portion configured to move by sliding in the longitudinal direction,

wherein one end side of the first moving member in the longitudinal direction of the first moving member is pivotably attached to one end side of the holding member in the longitudinal direction of the holding member, and the other end side of the first moving member in the longitudinal direction of the first moving member is pivotably attached to one end side of the sliding portion in the longitudinal direction of the sliding portion,

wherein the other end side of the second moving member in the longitudinal direction of the second moving member is pivotably attached to the other end side of the holding member in the longitudinal direction of the holding member, and the other end side of the second moving member in the longitudinal direction of the second moving member is pivotably attached to the other end side of the sliding portion in the longitudinal direction of the sliding portion,

and wherein the first moving member and the second moving member pivot as to the sliding portion, in conjunction with the sliding movement of the sliding portion, and move the holding member in the direction of reciprocal movement in conjunction with this pivoting.

4. An image forming apparatus having a drum unit rotatably supporting a photosensitive drum, where the lower side of the photosensitive drum is exposed by a plurality of lights from a side lower than a rotational axis of the photosensitive drum in the vertical direction, the image forming apparatus comprising:

a holding member configured to hold

a circuit board having a plurality of light-emitting elements configured to emit light to expose the photosensitive drum, and

a lens configured to collect the light on the surface of the photosensitive drum,

and configured to reciprocally move between an exposure position where the light-emitting elements expose the photosensitive drum, and a retracted position further retracted from the drum unit than the exposure position;

a sliding portion configured to move by sliding in the longitudinal direction of the holding member;

a first spring that is provided to the holding member at a side further downstream from the lens and the circuit board in a direction from an other end of the holding member in the longitudinal direction toward the one end of the holding member in the longitudinal direction, and is configured to impart biasing force to the holding member to bias the holding member in a direction opposite to the gravitational direction;

a second spring that is provided to the holding member at a side further downstream from the lens and the circuit board in a direction from the other end of the holding member in the longitudinal direction toward the one end of the holding member in the longitudinal direction, and is configured to impart biasing force to the holding member to bias the holding member in the direction opposite to the gravitational direction;

a first link portion of which one end side is in contact with the first spring and the other end side is pivotably connected to one end side of the sliding portion in the longitudinal direction, and that is configured to pivot in conjunction with sliding movement of the sliding portion and to deform the first spring in conjunction with the pivoting;

a second link portion of which one end side is in contact with the second spring and the other end side is pivotably connected to the other end side of the sliding portion in the longitudinal direction, and that is configured to pivot in conjunction with sliding movement of the sliding portion and to deform the second spring in conjunction with the pivoting;

a first abutting portion that is provided to the holding member at a side further downstream from the first link portion in a direction from the other end of the holding member in the longitudinal direction toward the one end of the holding member in the longitudinal direction, and that is configured to protrude from the holding member further toward the drum unit side than a light emission face of the lens and abut one end side of the drum unit in the longitudinal direction; and

a second abutting portion that is provided to the holding member at a side further downstream from the second link portion in a direction from the one end of the holding member in the longitudinal direction toward the other end of the holding member in the longitudinal direction, and that is configured to protrude from the holding member further toward the drum unit side than a light emission face of the lens and abut another end side of the drum unit in the longitudinal direction,

wherein force in the direction opposite to the gravitational direction is applied to a portion between the first spring and the second spring, regarding the holding member that has been moved from the retracted position toward the exposure position in conjunction with the first moving member and the second moving member pivoting, with the first abutting portion and second abutting portion abutting the drum unit.

5. The image forming apparatus according to claim 4, further comprising:

a third link portion that is pivotably connected between one end side of the first link portion in the longitudinal direction of the first link portion and the other end side of the first link portion in the longitudinal direction, and that is configured to be pivotably connected to a portion fixed to the main body of the image forming apparatus, to assist pivoting of the first link portion and pivoting of the second link portion.

6. The image forming apparatus according to claim 4,

wherein the holding member is a resin molded article.

7. The image forming apparatus according to claim 4, further comprising:

a first moving portion that is provided to one end side of the first link portion in the longitudinal direction of the first link portion, and that is configured to deform the first spring in conjunction with pivoting of the first link portion; and

a second moving portion that is provided to one end side of the second link portion in the longitudinal direction of the second link portion, and that is configured to deform the second spring in conjunction with pivoting of the second link portion,

wherein the first moving portion and the second moving portion move toward the drum unit in conjunction with sliding movement of the sliding portion, and biasing force is imparted to the holding member by deformation of the first spring and the second spring.

8. The image forming apparatus according to claim 7,

wherein the first link portion is connected to the sliding portion and the holding member with the first moving portion being situated at the downstream side of the connection portion of the first link portion and the sliding portion, in the direction of sliding movement, and the second link portion is connected to the sliding portion and the holding member with the second moving portion being situated at the downstream side of the connection portion of the second link portion and the sliding portion, in the direction of sliding movement.

9. The image forming apparatus according to claim 8,

wherein the first link portion is connected to the sliding portion and the holding member with the first moving portion being situated closer to the drum unit than the connection portion of the first link portion and the sliding portion, in the direction of reciprocal movement, and the second link portion is connected to the sliding portion and the holding member with the second moving portion being situated closer to the drum unit than the connection portion of the second link portion and the sliding portion, in the direction of reciprocal movement.

10. The image forming apparatus according to claim 4, further comprising:

a guide portion configured to abut an end portion of the holding member in the longitudinal direction, at a side further downstream from the holding member in the direction of sliding movement of the sliding portion, and guide the holding member toward the exposure position, to move the holding member from the retracted position toward the exposure position in conjunction with pivoting of the first link portion and the second link portion.

11. The image forming apparatus according to claim 7, further comprising:

a pair of first attaching portions that is formed on one end side of the holding member in the longitudinal direction of the holding member, and that is configured to be attached with one end side and the other end side of the first spring in the longitudinal direction of the first spring; and

a pair of second attaching portions that is formed on the other end side of the holding member in the longitudinal direction of the holding member, and that is configured to be attached with one end side and the other end side of the second spring in the longitudinal direction of the second spring,

wherein the first link portion is rotatably connected to the sliding portion and the holding member, with the first moving portion abutting the first spring attached to the pair of first attaching portions between the one end side of the first spring in the longitudinal direction of the first spring and the other side of the first spring in the longitudinal direction of the first spring, from a side opposite to the side at which the photosensitive drum is disposed,

wherein the second link portion is rotatably connected to the sliding portion and the holding member, with the second moving portion abutting the second spring attached to the pair of second attaching portions between the one end side of the second spring in the longitudinal direction of the second spring and the other side of the second spring in the longitudinal direction of the second spring, from a side opposite to the side at which the photosensitive drum is disposed,

and wherein the sliding portion is moved by sliding in a state where the holding member is in contact with the drum unit, the first moving portion that moves toward the drum unit in conjunction with the sliding movement of the sliding portion stretches the first spring, the second moving portion that moves toward the drum unit in conjunction with the sliding movement of the sliding portion stretches the second spring, and the restoring forces of the stretched first spring and second spring act on the holding member, thereby imparting biasing force to the holding member.

12. The image forming apparatus according to claim 7,

wherein one first attaching portion of the pair of first attaching portions is disposed closer to one end side of the holding member in the longitudinal direction of the holding member as compared to the other first attaching portion, and one first attaching portion of the pair of first attaching portions is disposed closer to the side where the photosensitive drum is disposed as compared to the other first attaching portion,

wherein one second attaching portion of the pair of second attaching portions is disposed closer to one end side of the holding member in the longitudinal direction of the holding member as compared to the other second attaching portion, and one attaching portion of the pair of second attaching portions is disposed closer to the side where the photosensitive drum is disposed as compared to the other second attaching portion,

and wherein the holding member is biased by the first spring and the second spring in a direction from the one end side to the other end side of the first spring in the longitudinal direction of the first spring, by the first moving portion and the second moving portion each moving toward the drum unit in conjunction with the sliding movement of the sliding portion and deforming the first spring and the second spring in a direction of stretching the first spring and the second spring.

13. The image forming apparatus according to claim 7,

wherein one end side of the first spring in the longitudinal direction of the first spring is attached to the holding member and the other end side of the first spring in the longitudinal direction of the first spring is attached to the first moving portion at a position closer to the photosensitive drum than the connection portion of the one end side and the holding member,

wherein one end side of the second spring in the longitudinal direction of the second spring is attached to the holding member and the other end side of the second spring in the longitudinal direction of the first spring is attached to the second moving portion at a position closer to the photosensitive drum than the connection portion of the one end side and the holding member,

and wherein the sliding portion is moved by sliding in a state where the holding member is in contact with the drum unit, the first moving portion that moves toward the drum unit in conjunction with the sliding movement stretches the first spring and the second moving portion that moves toward the drum unit in conjunction with the sliding movement stretches the second spring, and the biasing force is imparted to the holding member by the restoring forces of the stretched first spring and the stretched second spring acting on the holding member.

14. The image forming apparatus according to claim 7,

wherein one end side of the first spring in the longitudinal direction of the first spring comes into contact with the first moving portion, and the other end of the first spring in the longitudinal direction of the first spring is connected to the holding member at a position closer to the photosensitive drum than the portion where the one end side and the first moving portion come into contact,

wherein one end side of the second spring in the longitudinal direction of the second spring comes into contact with the second moving portion, and the other end of the second spring in the longitudinal direction of the second spring is connected to the holding member at a position closer to the photosensitive drum than the portion where the one end side and the second moving portion come into contact,

and wherein the sliding portion is moved by sliding in a state where the holding member is in contact with the drum unit, the first moving portion that moves toward the drum unit in conjunction with the sliding movement of the sliding portion compresses the first spring and the second moving portion that moves toward the drum unit in conjunction with the sliding movement of the sliding portion compresses the second spring, and the biasing force is imparted to the holding member by the restoring forces of the compressed first spring and the compressed second spring acting on the holding member.

15. The image forming apparatus according to claim 11,

wherein the first spring and the second spring are coil-shaped springs.

16. The image forming apparatus according to claim 7,

wherein the first moving portion formed at one end side of the first link portion in the longitudinal direction of the first link portion is a protrusion protruding in a pivoting axis direction of the first link portion that pivots as to the holding member,

and wherein the second moving portion formed at one end side of the second link portion in the longitudinal direction of the second link portion is a protrusion protruding in a pivoting axis direction of the second link portion that pivots as to the holding member.