JPH06106814A - Image forming device - Google Patents

Abstract

PURPOSE:To provide an image forming device which is free from any interference with an electric charge part by a line head when a cover for a main device system is opened and can determine the tip position of the line head positively against the surface of an image bearer when the cover is closed. CONSTITUTION:This image forming device is equipped with a line head 19 held in a freely rotatable manner on the inner surface of a cover 3 provided in a freely operating way using one end of a main device system 1 as a rotary supporting point. In addition, the device consists of an energization means 24 for energizing the line head 19 the rotary supporting point side and a stopper 25 which restricts the rotation. Further, a guide part 22 which positions the line head 19 against an image bearer 11 when the cover 3 is closed to the main device system 1 side is provided on the main device system 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus for forming an electrostatic latent image on the surface of an image carrier by a self-scanning type line head.

[0002]

2. Description of the Related Art Conventionally, in an image forming apparatus, at least a charging section, an exposing section, a developing section and a transferring section are arranged in that order as a process unit around a rotating image carrier. As the exposure section, a self-scanning line head is known in which a large number of light emitting elements such as edge emitting EL elements and LEDs are arranged in a line, and the image carrier is charged by the charging section.
An electrostatic latent image is formed by irradiating the charged portion with light from a line head, a visible image is formed by toner in the developing unit, and then the visible image is transferred onto a sheet conveyed by the transfer unit. It is composed.

On the other hand, the main body of the image forming apparatus has an upper surface opened for jam processing, maintenance, etc.
The top surface of the main body is generally closed by an openable / closable cover having a rotation fulcrum. In this case, the image carrier and the process unit can be easily taken out when the cover is opened. The line head described above is attached to the inner surface of the cover by screws.

[0004]

However, in the above-mentioned conventional image forming apparatus, when the cover is opened to perform jam processing or the like, the tip of the line head moves in an arc along with the pivoting movement of the cover. Therefore, in order to prevent the tip of the exposure section from interfering with the charging section during movement, the relationship between the charging section and the developing section, which function as process units arranged before and after the exposure section, should be sufficiently long. It was necessary to do so, which was a cause of increasing the size of the device.

Further, since the positional relationship between the line head and the image bearing member is important for forming an image, it is very difficult to adjust the position when fixing the line head to the cover.

Therefore, according to the present invention, the line head does not interfere with the charging section when the cover is opened, and the image when the cover is closed is not required even if the space between the charging section and the developing section is not particularly large. An object of the present invention is to provide an image forming apparatus in which the tip end position of a line head with respect to the surface of a carrier can be surely obtained.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a cover which is openably and closably provided on a main body with one end being a pivotal fulcrum, and which opens and closes an upper opening of the main body, and an image carrier provided in the main body. A process unit arranged around the image carrier, a line head rotatably provided on the inner surface side of the cover with a rotation fulcrum and facing the surface of the image carrier when the cover is closed; Biasing means for urging the line head toward the fulcrum of rotation of the cover, a stopper portion for restricting rotation of the line head, and the urging of the line head when the cover is closed. And a guide portion that rotates against the means to position the line head with respect to the image carrier.

[0008]

According to the present invention, when the cover of the image forming apparatus is opened for jamming or the like, the line head is urged by the urging means along with the opening operation of the cover, and the guide portion is formed on the main body. And is finally guided by the stopper to stop its rotation. Further, when the cover is closed, when the cover is closed, the line head is guided by the guide portion, and in the closed state, the line head is positioned at a predetermined position with respect to the image carrier.

As described above, since the line head can keep the moving range of the line head small by the guide portion, it is not necessary to increase the arrangement interval of the process units, and the apparatus can be downsized. Further, when the cover is closed, the tip of the line head can be reliably positioned at a predetermined position on the surface of the image carrier by the guide portion.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a main body 1 of the image forming apparatus is formed by rotatably connecting a lower case 2 and a top cover 3 as an openable / closable cover by a support shaft 4. A power supply and a circuit board 5 are arranged on the bottom surface of the lower case 2. A paper cassette 6 is provided in the lower case 2.
Is provided, a paper transport path 7 for transporting the paper P in the paper feed cassette 6 is provided, and a discharge port 8 is provided at the end of the paper transport path 7. Further, in the paper conveyance path 7, a paper feed roller 9 that is in contact with the uppermost paper P in the paper feed cassette 6, a conveyance roller 10 that conveys the paper P fed by the paper feed roller 9, and an image. Photoreceptor 11 as carrier
A transfer section 12 for transferring the image on the sheet P, and a transfer section 12
The fixing unit 13 that fixes the transferred image on the paper P that has passed through and the discharge roller 14 that discharges the fixed paper P to the outside are sequentially arranged.

Further, the photoconductor 11 is provided inside the lower case 2.
A frame 15 that rotatably supports is provided on the frame 15. The frame 15 has a charging unit 16 that charges the photoconductor 11 to charge it, and a developing unit that develops an electrostatic latent image formed on the surface of the photoconductor 11. A part 17, a cleaning part 18 for cleaning the surface of the photoconductor 11 and a charge removing part (not shown) for uniformly removing the charge on the outer periphery of the photoconductor 11 are held and arranged around the photoconductor 11 described above. Charging section 16, developing section 17,
The transfer unit 12, the cleaning unit 18, and the charge removing unit each function as a process unit.

A line head 19 irradiates the charged portion of the photoconductor 11 with light to form an electrostatic latent image. The line head 19 has a tip end in the longitudinal direction of the photoconductor 11 (direction perpendicular to the plane of the drawing).
And a substrate (not shown) that holds these edge-emitting EL elements along the axial direction of the photoconductor 11. A cylindrical positioning protrusion 20 is provided near one end of the line head 19 in the longitudinal direction, and a rotation restricting protrusion 21 is protruded substantially in the center of the line head 19. The positioning protrusion 20 is provided above the frame 15 of the main body 1.
A guide portion 22 for guiding the line head 19 to a predetermined position on the photoconductor 11 is formed via the guide portion 22. As the guide portion 22 moves upward so that the positioning protrusion 20 can be easily guided when the top cover 3 is closed. It is formed to be wide.

A support 24 is formed on the inner surface of the top cover 3 to rotatably support both sides of the line head 19 around a rotation fulcrum 23. The line head 19 includes a line head 19 and a support 24. It is urged toward the support shaft 4 side (counterclockwise direction in the figure) by a spring 25 that is tensioned between them. The turning operation is performed by the arc-shaped elongated hole 26 formed as a stopper portion in the support 24 and the line head 19.
It is regulated by the rotation regulating projection 21 formed on the. The long hole 26 opens the top cover 3, and when the positioning protrusion 20 comes to a position where it comes off the guide portion 22, the rotation restricting protrusion 21 comes into contact with one end of the long hole 26 and the line head 1
It is formed so that the rotation operation of 9 is stopped.

In such a structure, the top cover 3
2, the line head 19 is positioned so that the positioning protrusion 20 is located at the bottom of the guide portion 22 and focuses on the surface of the photoconductor 11 as shown in FIG. At this time, the line head 19 is in a state of resisting the biasing force of the spring 25.

Next, when the top cover 3 is opened for jamming and maintenance, the lower case 2 (not shown) and the top cover 3 are disengaged, and the top cover 3 is moved upward with the support shaft 4 as the center. As the line head 19 is rotated, the positioning protrusion 20 moves along the guide portion 22 while being pulled toward the support shaft 4 by the spring 25, and the line head 19 moves away from the photoconductor 11. Then, the positioning protrusion 20 is disengaged from the guide portion 22, but the rotation of the line head 19 is stopped when the rotation restricting protrusion 21 formed on the line head 19 reaches one end of the arc-shaped elongated hole 26. Therefore, the line head 19 is rotated while the movement range of the top cover 3 is kept small by the guide portion 22 as the top cover 3 is rotated.
The top cover 3 can be opened without interfering with 6.

Next, when the top cover 3 is closed after the jam processing and maintenance are completed, when the top cover 3 is gradually closed, the line head 19 whose rotation is restricted at one end of the long hole 26 is closed. , The positioning protrusion 20 contacts the guide portion 22, rotates clockwise along the guide portion 22, and the positioning protrusion 20 is positioned at the bottom portion of the guide portion 22 with the top cover 19 closed. The positioning of the photoconductor 11 and the tip of the line head 19 is completed. Therefore, the line head 19 can be reliably positioned with respect to the photoconductor 11 when the top cover 3 is closed, and it is possible to prevent the vibration of the top cover 3 and the influence of the positional deviation due to the mounting accuracy.

[0017]

As described above, according to the present invention, when the cover is closed, the line head can be guided by the guide portion so that the tip of the line head can surely face the predetermined position with respect to the image carrier. Also, when the cover is opened, the line head can be rotated to the spindle side in conjunction with the opening operation of the cover, and the movement range of the line head can be suppressed to a small range, so that the interval between the components in the main body is increased. It is not necessary and has the effect of being able to achieve downsizing of the device.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view showing the internal structure of an image forming apparatus with a cover opened.

FIG. 2 is a vertical sectional front view showing a state in which a cover is closed in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main body 3 Top cover 11 Image carrier (photoreceptor) 16 Process unit (charging part) 19 Line head 22 Guide part 25 Energizing means (spring) 26 Long hole

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location B41J 29/00 G02B 26/10 BG03G 15/00 101 8910-2H 15/04 116 9113-2C B41J 29/00 B

Claims (1)

[Claims] 1. A cover, which is provided on the main body so as to be openable and closable with one end as a rotation fulcrum, and which opens and closes an upper surface opening of the main body, an image carrier provided in the main body, and an arrangement around the image carrier. Process unit, a line head that has a rotation fulcrum on the inner surface side of the cover and is rotatably provided, and faces the surface of the image carrier when the cover is closed. An urging means for urging the fulcrum side, a stopper portion for restricting the rotation of the line head, and the line head for rotating the line head against the urging means when the cover is closed. An image forming apparatus comprising: a guide unit that positions the line head with respect to the image carrier.