JPH03260662A - Image forming device - Google Patents

Abstract

PURPOSE:To accurately and easily set a gap between an image carrier and a developing roller by supporting the axially supporting part of the image carrier and the shaft parts at both ends of the developing roller by the groove of a frame formed by press work, etc. CONSTITUTION:The projecting part 13a of an image carrier unit 6 is supported by the supporting part 26 of a side plate 2 and the axially supporting part 15 is supported by the groove 11 of the frame 3 so as to fix the unit 6. Then, the lower end of a developing unit 7 is supported by the supporting part 27 of the side plate 2 and the shaft parts 25 at both ends of the developing roller 21 are supported by the groove 12 of the frame 3, so that the unit 7 is fixed. The relative position between the grooves 11 and 12 is easily decided by forming the frame 3 by means of the press work. Therefore, the gap between the image carrier 14 and the developing roller 21 is accurately decided and image quality is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image forming apparatus that forms images based on electrophotography.

Prior Art First, a conventional example is shown in FIG. Reference numeral 2 denotes side plates formed on both sides of the frame 3, and these side plates 2 hold an image carrier unit 6 and a developing unit 7. The image carrier unit 6 includes a shaft support 15 that rotatably supports the image carrier 14 in a case 13, and a charger 16 in the case 13.
It is formed by attaching a cleaning blade 17 and a static eliminator 18. The developing unit 7 is formed by rotatably mounting a developing roller 21 on a toner container 2o in which a toner supply box 19 is mounted. The developing roller 21 is formed by rotatably fitting a sleeve 24 made of a non-magnetic material around the outer periphery of a magnet roller 23, and a shaft portion 25 of the magnet roller 23 projects from both sides of the toner container 2o. Projections 13a protrude from both sides of the case 13 of the image carrier unit 6.
By supporting the support part 26 formed on the edge of the side plate 2 and supporting the shaft support 15 in the V-shaped groove 11 formed in the side plate 2, the image carrier unit 6 is fixed, and the lower part of the toner container 20 is supported. A support portion 27 formed on the inner surface of the side plate 2
The developing unit 7 is fixed by supporting the protrusions 50 protruding from both sides of the toner container 20 in V-shaped grooves 51 formed in the side plate 2 . When forming an image, the outer peripheral surface of the image carrier 14 is charged by applying a voltage to the image carrier 14 with the charger 16, and light corresponding to image data is emitted from an exposure device (not shown) onto the charged portion. An electrostatic latent image is formed by irradiating the signal,
This electrostatic latent image is developed with toner in the developing unit 7.

During this development, the electrostatic latent image is developed by a magnetic brush phenomenon caused by fixing the magnet roller 23 and rotating the sleeve 24. For this purpose, the sleeve 24 and the outer circumferential surface of the image carrier 14 are It is necessary to strictly define the interval.

Problems to be Solved by the Invention Although the positional relationship of the grooves 11 and 51 in the side plate 2 can be easily formed within the allowable dimensions by accurately manufacturing a press mold, the developing unit 7 does not have a protrusion in the groove 51. The developing roller 21 is positioned by supporting the developing roller 50.
Since there are variations in the relative position between the image carrier 14 and the protrusion 50, it is difficult to maintain a constant gap between the image carrier 14 and the developing roller 21.

Means for Solving the Problems An image carrier unit having at least a shaft support for rotatably holding an image carrier, and a developing unit including a developing roller along the image carrier rotatably attached to a toner container. a plurality of grooves for supporting the shaft supports at both ends of the image carrier unit and the shaft portions at both ends of the developing roller are provided in a frame having a support portion that supports the image carrier unit and the developing unit, and the grooves are positioned relative to each other. established and formed.

The image carrier unit is fixed by supporting a part of the working image carrier unit by the support part of the frame and supporting the shaft part of the image carrier by the groove of the frame, and part of the developing unit is supported by the support part of the frame. At the same time, the developing unit is fixed by supporting the shaft portions at both ends of the developing roller in the grooves of the frame, and the relative positions of the plurality of grooves can be easily determined by forming the frame by means such as press working.
By supporting the shaft portion of the image carrier and the shaft portion of the developing roller in each of these grooves, the gap between the image carrier and the developing roller can be determined accurately and easily.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 5. The same parts as those explained in FIG. 7 are designated by the same reference numerals, and the description thereof will be omitted. As shown in FIG. 1, a frame 3 having a pair of left and right side plates 2 is fixedly provided on the lower main body l of the electrophotographic apparatus, and these side plates 2 have guide plates that form a paper conveyance path. 4 is retained. An image carrier unit 6 and a developing unit 7 are held in a basket 5 whose lower surface is open toward the guide plate 4 .

Furthermore, on both sides of the basket 5 there are handles 8 and these handles 8.
A V-shaped notch 9° and 10 is formed depending from the upper surface of the holder. Further, the side plate 2 has a V-shaped groove 11.12.
are formed in relative positions to each other. Furthermore, as shown in FIG. 2, these side plates 2 include a support portion 26 that supports the protrusion 13a protruding from both sides of the case 13 of the image carrier 6, and a support portion 27 that supports the lower end of the developing unit 7. is formed. Note that a blade 22 whose lower end is close to the outer periphery of the developing roller 21 is attached to the toner container 20 .

FIG. 3 is a front view of the developing unit 7 viewed from the image carrier 14 side, and FIG. 4 is a side view thereof. A gear 28 driven by a motor (not shown) is fixed to the end of the sleeve 24. are fitted properly. Further, as shown in FIG.
9 is formed.

In such a configuration, the protrusion 1 of the image carrier unit 6
3a is supported by the support part 26 of the side plate 2, and the pivot support 15
By supporting the grooves 11, the image carrier unit 6 can be fixed. Further, the lower end of the developing unit 7 is supported by the supporting portion 27 of the side plate 2, and the shaft portions 25 at both ends of the developing roller 21 are supported by the grooves 12, so that the developing unit 7
can be fixed. Note that the shaft support 15 protrudes from the notch 9 of the basket 5 and is supported by the groove 11, and the shaft portion 25
It also protrudes from the notch 10 of the basket 5 and is supported by the groove 12. Furthermore, the engagement between the groove 12 and the annular groove 29 can also prevent the magnetic roller 23 from moving in the axial direction. By forming the frame 3 by means such as press working, the relative positions of the plurality of grooves 11 and 12 can be easily determined, and each of these grooves 11 and 12 can connect the shaft support 15 of the image carrier 14 and the like. By supporting the shaft portion 25 of the developing roller 21, it is possible to accurately define the gap between the image carrier 14 and the sleeve 24 of the developing roller 21, thereby improving image quality.

As shown in FIG. 6(a), by making the cross-sectional shape of the shaft portion 25 of the developing roller 21 polygonal (for example, quadrangular) and matching the shape of the bottom of the groove 12 with the cross-sectional shape of the shaft portion 25, , the shaft portion 25 can be positioned while being prevented from rotating. Moreover, as shown in FIG. 6(b), the shaft portion 25
A flat part 25a is formed on a part of the outer periphery of the groove 12, and vertical surfaces 31 and 32 are formed at the bottom of the groove 12, and the flat part 25a and the vertical surface 31
Also by bringing the outer circumferential surface of the shaft portion 25 into contact with the vertical surface 32, the shaft portion 25 can be positioned while being prevented from rotating. Further, as shown in FIG. 6(C), the shape of the shaft portion 25 is determined to be a triangular cross-sectional shape with a top at the bottom, and both sides of the shaft portion 25 are supported on both sides of the groove 12.
By supporting the triangular top of the shaft portion 25 with the ■-shaped recess 33 formed at the bottom of the shaft portion 2, the shaft portion 25 can be positioned while being prevented from rotating.

Effects of the Invention As described above, the present invention includes at least an image carrier unit having a shaft support for rotatably holding an image carrier, and a developing roller along the support carrier, which is rotatably attached to a toner container. a developing unit, and a frame having a support portion that supports the image carrier unit and the developing unit, and a plurality of grooves that support the shaft supports at both ends of the image carrier unit and the shaft portions at both ends of the developing roller. are formed at relative positions to each other, a part of the image carrier unit is supported by the supporting part of the frame, and a shaft part of the image carrier is supported by the groove of the frame, so that the image carrier unit is fixed and developed. The developing unit is fixed by supporting part of the unit with the supporting part of the frame and supporting the shaft parts at both ends of the developing roller with the grooves of the frame, and by forming the frame by means such as press working, the multiple grooves are The position can be easily determined, and by supporting the shaft portion of the image carrier and the shaft portion of the developing roller in each of these grooves, the gap between the image carrier and the developing roller can be determined accurately and easily. Therefore, the image quality can be improved.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention,
Figure 1 is an exploded perspective view, Figure 2 is a side view, Figure 3 is a front view of the developing unit, Figure 4 is a side view of the developing unit, and Figure 5 is a side view of the developing unit.
The figure is a sectional view showing a support structure for the shaft portion of the developing roller, and FIG. 6 is a side view showing a modified example of the support structure for the shaft portion of the developing roller.
FIG. 7 is a side view showing a conventional example.

Claims (1)

[Claims] an image carrier unit having a shaft support for rotatably holding at least an image carrier; a developing unit including a developing roller along the image carrier rotatably attached to a toner container; The frame includes a support portion for supporting a developing unit, and a plurality of grooves for supporting the shaft portions at both ends of the image carrier unit and the shaft portions at both ends of the developing roller are formed with mutually determined relative positions. Features of the image forming device.