JPH10257U - Image forming device - Google Patents

Abstract

(57) [Problem] To provide an image forming apparatus having a small number of parts and capable of accurately defining a distance between a charging device arranged around an image carrier and the image carrier with a simple operation. I do. A first positioning member for supporting an image carrier and defining a distance between the image carrier and a charger.
And a second unit 11 that presses the charger 15 disposed on the positioning unit 16 of the first unit 12 and is fastened to the first unit 12.
The distance between the charger 15 and the image carrier 3 is precisely defined by a simple operation of mounting the charger 15 on the positioning section 16.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to an image forming apparatus employing an electrophotographic system, and more particularly to a positioning structure of a member arranged around an image carrier such as a photoconductor.

[0002]

[Prior art]

 In an image forming apparatus employing an electrophotographic system, it is necessary to set the surface potential of an image carrier such as a photoconductor to an appropriate value in order to secure a high-quality output image. In the case of a member disposed around the image carrier, such as a corotron-type charger, the distance between the discharge wire and the image carrier, and in the case of a scorotron-type charger, the grid and the image carrier. It is required that the distances be specified with high accuracy.

In order to satisfy such a demand, in a conventional image forming apparatus in which a charger and an image carrier are integrated, a roller 2 is inserted into a discharge wire 1 of the charger as shown in FIG. The roller 2 is brought into close contact with the photoreceptor 3, which is an image carrier, to regulate the distance S between the discharge wire 1 and the photoreceptor 3 to a constant value.

Conventionally, in addition to the one shown in FIG. 11, when a charging device is mounted, whether or not a discharge wire is at an appropriate position with respect to a photoconductor is measured and adjusted. There is also.

[0005]

[Problems to be solved by the invention]

 By the way, according to the conventional example described above, the roller shown in FIG. 11 has a large number of parts because the roller 2 is used, and has a configuration in which the roller 2 is pressed against the photosensitive member 3. If it changes over time, there is a problem that the distance S between the discharge wire 1 and the photoconductor 3 cannot be strictly defined. In addition, when mounting the charger, in the conventional example of measuring whether or not the discharge wire is at an appropriate position with respect to the photoconductor and performing the adjustment work, the measurement and adjustment work is performed manually. There is a problem that the assembling work is complicated, and it is extremely difficult to specify the positioning accuracy with high accuracy.

The present invention has been made in view of the above circumstances, and has an image in which the number of parts is small and the distance between the image carrier and the charger arranged around the image carrier can be accurately defined by a simple operation. It is an object to provide a forming device.

[0007]

[Means for Solving the Problems]

 In order to solve the problems described above, according to the present invention, in an image forming apparatus having an image carrier and a charger disposed at a predetermined position around the image carrier, the image carrier is supported, A first unit having a positioning portion for defining a distance between the image carrier and the charger, and pressing the charger provided at the positioning portion of the first unit, and fastening to the first unit; And a second unit to be used.

[0008]

[Embodiment of the invention]

 Hereinafter, an embodiment of the image forming apparatus according to the present invention will be described in detail.

FIG. 1 is a conceptual perspective view showing a main part of an image forming apparatus 10 according to the present invention.

The image forming apparatus 10 includes a first unit 12 on which a photoreceptor 3 as an image carrier is supported, and a second unit 11 that covers a peripheral surface of the first unit 12. In the example, the second unit 11 is supported by the first unit 12 so as to be rotatable around a shaft (not shown) and is constituted by a plate that covers the peripheral surface of the first unit 12.

On the other hand, a photoconductor 3 as an image carrier is arranged in the first unit 12, and an upper edge 14 a of a housing 14 supporting the photoconductor 3 is arranged around the image carrier. The charging unit 15 is provided, and a positioning unit 16 that defines a distance between the photoconductor 3 and the charging unit 15 is formed.

The positioning portion 16 is constituted by a concave portion 18 into which an insulator block 17 of the charger 15 is inserted.

The lengths a and b of the sides A and B of the surfaces A, B, C and D constituting the recess 18 are the same as the lengths of the sides e and f of the insulator block 17 at the corresponding positions. They are set to the same length.

The surface C of the concave portion 18 is formed to be inclined outward toward the opening surface of the concave portion 18 as shown in FIG. When the hook 17 is inserted into the concave portion 18, the insulator block 17 is guided downward along the surface C, and the insulator block 17 is brought into close contact with the surfaces A, B, and D of the concave portion 18. The length of the shield 19 (FIG. 1) constituting the charger 15 is such that when the bottom surface of the insulator block 17 is brought into close contact with the surface B which is the bottom surface of the concave portion 18, the concave portion 18 engages with the shield 19. The length is set so that it does not.

That is, the length m from the end face of the insulator block 17 to the shield 19 is set to be longer than the depth 1 of the recess 18. In FIG. 1, reference numeral 20 denotes a conventional screw for fastening the second unit 11 and the casing 14 constituting the first unit 12, and the screw 20 is formed on the second unit 11. The hole 21 is inserted and screwed into a female screw portion 14b formed on the upper edge 14a of the housing 14 facing the housing.

Next, the operation of the above-described image forming apparatus 10 will be described, and the configuration will be described in more detail.

When the charger 15 provided around the image carrier is mounted on the image forming apparatus 10, first, as shown in FIG. 2, a pair of insulator locks 17 provided at both ends of the charger 15 are provided. Is inserted into a pair of concave portions 18 which are positioning portions 16 formed in the housing 14 of the first unit 12. At this time, even if the insertion direction of the insulator block 17 into the concave portion 18 is slightly displaced, the insulator block 17 moves downward along the inclined surface C constituting the concave portion 18, and the bottom surface of the concave portion 18, that is, the photoconductor 3 is charged. Abuts on a surface B that defines the distance from the container 15. The positioning accuracy of the discharge wire 1 with respect to the axial direction and the rotation direction of the photoconductor 3 serving as an image carrier is determined only by the processing accuracy of the concave portion 18 of the first unit 12 and the processing accuracy of the insulator block 17. Become.

Therefore, according to the above-described positioning section 16, a simple operation of abutting the charger 15, which is a member disposed at a predetermined position around the image carrier, against the surface B, which is the bottom surface of the concave portion 18, is performed by a simple operation. The distance between the charger 15 as a member disposed around the image carrier and the photoconductor 3 as the image carrier can be accurately defined without any adjustment in one unit 12.

Thereafter, when the second unit 11 is brought into close contact with the peripheral surface of the first unit 12 and both are fastened with the screw 20 as shown in FIG. 3, the charger 15 is connected to the second unit 11. It is sandwiched and fixed between the first unit 12.

The fastening means for fastening the second unit 11 and the first unit 12 is not limited to the screw.

In the above embodiment, the case where the corotron type charger 15 is used as the charger is described in detail. However, the present invention is not limited to the above embodiment, and the same parts as those in FIG. As shown in FIG. 4, the present invention may be applied to a case where a scorotron type charger 31 having a grid 30 is used. When a scorotron type charger 31 is used, the grid 30 is gripped between the insulator block 17 and the surface B which is the bottom surface of the concave portion 18 as the positioning portion 16 as shown in FIG. 20 causes one of the second unit 11 and the second first unit 12 to be fastened. As described above, when the grid 30 is gripped between the surface B of the concave portion 18 as the positioning portion 16 and the insulator block 17, the distance between the photoconductor 3 and the grid 30 is accurately defined.

Note that the present invention is not limited to the above-described embodiment, and as shown in FIGS. 6 and 7 in which the same parts as those in FIG. 2 are denoted by the same reference numerals, the lower surface of the second unit 11 or the charger 1 An elastic body 40 such as a spring material or rubber may be attached to the upper surface of the fifth member 5. When the elastic body 40 such as a spring material or rubber is attached to at least one of the lower surface of the second unit 11 and the upper surface of the charger 15, the second unit 11 and the first unit 12 are fastened. In this case, even if there is play between the lower surface of the second unit 11 and the upper surface of the charger 15, the charging device 15 is moved by the pressing force of the elastic body 40 in the concave portion 18 which is the positioning portion 16. Since the contact is made with B, the backlash is absorbed, and the charger 15 is more reliably positioned and fixed at a predetermined position in the concave portion 18 which is the positioning portion 16.

In the embodiment shown in FIGS. 6 and 7, a separate elastic body 40 made of a spring material, rubber, or the like is used, so that the charger 15 can be more securely placed on the positioning surface B in the recess 18. The present invention is not limited to the above-described embodiment, but the present invention is not limited to the above-described embodiment. As shown in FIG. The tongue piece 11a may be integrally formed to protrude, and the upper surface of the charger 15 may be pressed by the tongue piece 11a to more reliably position and fix the charger 15 to the surface B in the concave portion 18. .

Further, as shown in FIG. 9, in which the same parts as those in FIG. 1 are denoted by the same reference numerals, elastic tongues 18 a are formed integrally with the side surfaces D of the pair of recesses 18 constituting the positioning portion 16 by punching. Alternatively, the charger 15 may be pressed in the axial direction by the tongue piece 18a, so that the charger 15 can be more reliably positioned in the axial direction of the photoconductor 3.

When the tongue piece 11a shown in FIG. 8 and the tongue piece 18a shown in FIG. 9 are respectively combined as shown in FIG. 10, only the accuracy of the distance between the photoconductor 3 and the charger 15 is increased. Instead, the positioning accuracy of the charger 15 with respect to the rotation direction of the photoconductor 3 and the positioning accuracy of the charger 15 with respect to the axial direction of the photoconductor 3 are more reliably ensured.

In the above embodiment, the positioning portion 16 is constituted by the concave portion 18. However, the present invention is not limited to the above embodiment, and the positioning portion 16 may be constituted by a groove or a notch. Is also good.

[0027]

[Effect of the invention]

 As described above, in the present invention, in the first unit supporting the image carrier, the positioning unit for defining the distance between the image carrier and the charger is formed, and the first unit fastened to the first unit is provided. Since the charger of the positioning unit is pressed by the unit 2, the distance between the charger and the image carrier can be accurately defined by the simple work of attaching the charger to the positioning unit. Can be.

[Brief description of the drawings]

FIG. 1 is a fragmentary perspective view of an essential part of an image forming apparatus according to the present invention.

FIG. 2 is a sectional view of a main part of FIG.

FIG. 3 is a sectional view of a main part of FIG. 1;

FIG. 4 is a sectional view showing another embodiment of the charger shown in FIG. 1;

FIG. 5 is a sectional view showing another embodiment of the charger shown in FIG. 1;

FIG. 6 is a sectional view showing another embodiment.

FIG. 7 is a sectional view showing another embodiment.

FIG. 8 is a conceptual perspective view of a main part showing another embodiment.

FIG. 9 is a conceptual perspective view of a main part showing another embodiment.

FIG. 10 is a conceptual perspective view of a main part showing still another embodiment.

FIG. 11 is a conceptual perspective view showing a main part of a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 ... Image carrier (photoreceptor) 10 ... Image forming apparatus, 11 ... Second unit 12 ... First unit, 15, 31 ... Charger 16 ... Positioning part

Claims (1)

[Utility model registration claims] An image forming apparatus having an image carrier and a charger disposed at a predetermined position around the image carrier, wherein the image carrier is supported, and the image carrier and the charger are connected to each other. A first unit having a positioning unit that defines a distance; and a second unit that presses the charger disposed on the positioning unit of the first unit and is fastened to the first unit. An image forming apparatus comprising: