JPH06166209A - Method for positioning writing head and mechanism thereof in image forming apparatus - Google Patents

Abstract

PURPOSE:To maintain the stable positioning relationship of a writing head by a method wherein a swinging means having the writing head is swingably provided on an upper housing and pressed in a direction opposite to an inserting direction of a process cartridge, and the process cartridge is swung by being brought into contact with the swinging means to position the writing head relative to the process cartridge. CONSTITUTION:A writing head swinging member 17 having a writing head 18 is swingably provided on an upper housing 2 and is pressed by a torsion spring 20 in a direction opposite to an inserting direction of a process cartridge 24. The process cartridge 24 is swung by being brought into contact with the writing head swinging member 17 so that the writing head 18 is positioned relative to the process cartridge 24. As a result, in the case where the writing head comprising a convergence rod lens array with a short focus is provided on the upper housing, it does not prevent the process cartridge from being inserted and it is possible to maintain a stable positioning relationship of the writing head relative to a photosensitive body after positioning the process cartridge to a receiving member of a lower housing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a positioning method and mechanism of an image forming apparatus for forming an image on the surface of a rotating photosensitive member by using an optical writing light source such as a light emitting diode (hereinafter referred to as LED).

[0002]

2. Description of the Related Art Generally, an image forming apparatus for forming an image on the surface of a rotating photoconductor includes a charger for uniformly charging the photoconductor surface around the photoconductor, a writing head for writing an electrostatic latent image, an electrostatic latent image. A developing device for developing the latent image with a toner, a transfer device for transferring the toner image onto a sheet, a cleaner for removing the residual toner, and the like are arranged. Normally, the transfer device is located at the lowest position with respect to the photoconductor, and the writing position is provided near the uppermost part because the transfer device is provided at a position facing the photoconductor with the paper path therebetween. For example, the image forming apparatus disclosed in Japanese Unexamined Patent Publication No. 61-279871 is one of them, and according to this publication, an upper casing in which a detachable process cartridge is inserted is closed with respect to a lower casing. And a rotary shaft supporting the photosensitive member of the process cartridge is fitted and positioned in the receiving member of the lower housing, and the write head is provided at a predetermined position of the lower housing sufficiently separated from the process cartridge. It is shown that an electrostatic latent image is formed in the vicinity of the uppermost portion of the surface of the photoconductor by the laser scanner as described above.

[0003]

In the conventional image forming apparatus, if the write head is provided in the lower housing and is positioned with respect to the receiving member of the lower housing, the installation position of the write head is Was free. However, using a converging rod lens array with short focus as the writing head,
When an LED is used as a light source, it must be provided in the upper housing because it is arranged in the vicinity of the photosensitive member, and the positional relationship of the lower housing with respect to the receiving member becomes unstable, making the image of the photosensitive member unclear. I was afraid to do it. Further, when the writing head is provided in the upper housing, the process cartridge is inserted from the front of the image forming apparatus, so that the charging head and the like provided on the process cartridge side are prevented from coming into contact with the writing head. It is necessary to lower the installation position of the sheet, and there is a fear that the sheet after the toner transfer comes into contact with the process cartridge side and the toner moves.

According to the present invention, even if a writing head using a short-focusing converging rod lens array is provided in the upper housing, it does not hinder the insertion of the process cartridge and the process cartridge is not hindered.
The writing head can maintain a stable positional relationship with the photoconductor even after the tray is positioned by the receiving member of the lower housing, and a sufficient space is provided between the sheet after the toner transfer and the process cartridge side. It is an object of the present invention to provide a method of positioning an image forming apparatus and a mechanism therefor.

[0005]

In order to achieve the above object, in a method of positioning an image forming apparatus of the present invention, a rotating means provided with a writing head is rotatably provided in an upper casing and a process carriage is provided. A write head is provided as a mechanism for positioning the write head on the process cartridge by biasing the process cartridge in a direction opposite to the insertion direction and rotating the process cartridge by contacting the rotating means. And a write head rotating member provided with one arm fixed to the process cartridge and the other arm having an abutting portion that abuts on one end of the process cartridge, and an intersecting portion of both arms of the write head rotating member is an upper housing A support shaft that is rotatable with respect to
And a biasing member for biasing the write head rotating member so as to face the process cartridge insertion direction.

[0006]

When the process cartridge is inserted into the upper casing of the mechanism of the image forming apparatus constructed as described above, one end of the process cartridge comes into contact with the other arm of the write head rotating member to cause the write head. When the rotating member is moved into the urging member and rotated, the write head fixed to one arm is positioned in the process cartridge, and the upper case is closed to the lower case. Positioned on the body. Therefore, according to the present invention, even if the upper head is provided with the write head using the short focus converging rod lens array, it does not hinder the insertion of the process cartridge, and the process cartridge is received in the lower housing. The member can maintain a stable positional relationship with the photoconductor even after positioning, and a sufficient space can be provided between the sheet after toner transfer and the process cartridge side.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. Elements common to the drawings are given the same reference numerals. FIG. 1 is a schematic side view showing the image forming apparatus of the embodiment. FIG. 2 is an explanatory view showing the process cartridge mounted, and FIG. 3 is a perspective view of the write head.

In the image forming apparatus 1, as shown in FIG. 2, the upper housing 2 is moved from the lower housing 4 through the hinge 3 to the arrow AB.
It is provided so that it can rotate in any direction. The lower housing 4 is detachably provided with a cassette 6 for storing the paper 5 and is provided with a paper feeding roller.
The la 7 rotates in the direction of arrow C to feed out the sheets 5 one by one. The fed-out sheet 5 is aligned and timed by the registration roller 8 and then fed toward the transfer roller 10 through the transfer guide portion 9. Transfer roller 1
0 positively charges the paper 5 and the photosensitive drum 11 is applied to the paper surface.
The toner charged negatively is transferred to the fixing device 12. The fixing device 12 sends the paper 5 to the discharge rollers 13 and 14 provided in the upper housing 2 while fixing the toner on the paper surface of the paper 5. The discharge rollers 13 and 14 store the paper 5 in the upper housing 2.
It is discharged to the tray 15 provided on the upper surface of the. The lower housing 4
Is provided with a receiving member 16 having a U groove 16a for positioning a process cartridge which will be described later with the transfer roller 10 interposed therebetween.

As shown in FIG. 3, the upper housing 2 is provided with an L-shaped write head rotating member 17 having one arm 17a and the other arm 17b along the extending direction of the write head 18. is there. A support shaft 19 is fixed to both end surfaces of the intersection of the one arm 17a and the other arm 17b, and is rotatably attached to a side frame (not shown) of the upper housing 2. The write head rotating member 17 is biased in the direction of arrow D by a torsion spring 20 as a biasing member provided on the support shaft 19, as shown in FIG.
That is, one end of the torsion spring 20 abuts on the stopper 21 provided on the end face of the write head rotating member 17,
The other end is in contact with a stopper 22 provided on the upper housing 2. The writing head 18 is provided on one arm 17a of the writing head rotating member 17 via a coil spring 23.

The photosensitive drum 11 is housed in a case 28 together with a charging roller 25, a developing device 26, etc. as a process cartridge 24 as shown by a two-dot chain line in FIG. The process cartridge 24 is attachable to and detachable from the upper housing 2, and is inserted into the cartridge mounting portion 30 along the guide 29 from the front surface of the upper housing 2 in the direction of arrow E as shown in FIG. .

FIG. 4 is an exploded perspective view showing the positional relationship between the write head and the process cartridge. The writing head 18 is provided with a converging rod lens array 32 having a short focus and an LED 33 as a light source on a head frame 31, and positioning holes 34 are provided at both ends of the head frame 31.
35 is provided. In the process cartridge 24, a charging roller 25, a developing device 26 and the like are arranged around the photosensitive drum 11 in a case 28, and side frames 36 and 37 are fixed on both sides of the case 28. I am doing it. Shafts 38 and 39 are rotatably supported on the side frames 36 and 37, respectively, and support the photosensitive drum 11. Head frames 31 are attached to the side frames 36 and 37, respectively.
The convex portions 40 and 41 that fit into the positioning holes 34 and 35 are provided.

Next, the operation will be described. First, as shown in FIG. 2, the upper casing 2 is lifted up, pivoted in the direction of arrow A to open, and then the process cartridge 24 is inserted into the cartridge mounting portion 30 of the upper casing 2. The tip of the process cartridge 24 abuts on the other arm 17b of the write head rotating member 17, and the write head rotating member 17 is rotated in the direction of arrow F while keeping contact with the other end 17a of the head frame 31. The positioning holes 34 and 35 of the process cartridge 2
4, the convex portions 40 provided on the side frames 36 and 37 of 4,
41 is fitted.

Next, the upper casing 2 is pushed down, rotated in the direction of arrow B, and closed with respect to the lower casing 4. Process car
Shafts 38 and 39 for supporting the photosensitive drum 11 project from the side frames 36 and 37 of the trench 24, and are fitted and positioned in the U groove 16a of the receiving member 16 of the lower housing 4.

Therefore, the photosensitive drum 11 is positioned by the receiving member 16 of the lower housing 4, and the writing head 18
Are side frames 36 and 3 of the process cartridge 24.
By being fitted into the convex portions 40 and 41 of 7, the photosensitive drum 11 is positioned.

[0015]

Since the present invention is configured as described above, it has the following effects.

Rotating means provided with a writing head is rotatably provided on the upper casing, and is biased in the direction opposite to the inserting direction of the process cartridge so that the process cartridge is brought into contact with the rotating means. By rotating the write head so that the write head is positioned on the process cartridge, even when the write head using the short-focusing converging rod lens array is provided in the upper housing, the process cartridge can be easily inserted when the process cartridge is inserted. It does not become an obstacle, and a stable positional relationship can be maintained even after the process cartridge is positioned by the receiving member of the lower housing.

Since it is not necessary to lower the installation position of the charger and the like, a sufficient space can be provided between the paper after transfer and the frame of the process cartridge, and the paper after toner transfer is There is no fear that the toner will move due to contact with the process cartridge side.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram illustrating an image forming apparatus according to an embodiment.

FIG. 2 is an explanatory diagram showing a process cartridge mounted.

FIG. 3 is a perspective view of a writing head.

FIG. 4 is an exploded perspective view showing a positioning relationship.

[Explanation of symbols]

 1 Image Forming Apparatus 17 Writing Head Rotating Member 18 Writing Head 19 Spindle 24 Process Cartridge

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04N 1/036 A 8721-5C

Claims (3)

[Claims] 1. A state in which an upper housing is arranged to be openable and closable with respect to a lower housing, a detachable process cartridge is inserted, the upper housing is closed, and the process cartridge is positioned in the lower housing. In the method of positioning the write head of the image forming apparatus to be used in step 1, the rotating means having the write head is rotatably provided on the upper housing, and the process cartridge is biased in the inserting direction so as to face the process cartridge. A write head positioning method for an image forming apparatus, characterized in that the write head is positioned on the process cartridge by rotating the cartridge by making contact with the rotating means. 2. The upper casing is arranged to be openable and closable with respect to the lower casing, the upper casing having a detachable process cartridge inserted therein is closed, and the process cartridge is positioned in the lower casing. In a write head positioning mechanism of an image forming apparatus to be used, a write head rotating member provided with one arm to which a write head is fixed and the other arm having an abutting portion that abuts on one end of a process cartridge; A spindle for rotatably providing an intersection of both arms of the head rotating member with respect to the upper housing, and a biasing member for biasing the writing head rotating member so as to face the process cartridge insertion direction. A write head positioning mechanism for an image forming apparatus, comprising: 3. The write head positioning of the image forming apparatus according to claim 2, wherein the frame of the write head is provided with a projection or a hole, and the frame of the process cartridge is provided with a hole or a projection. mechanism.