JPS6280671A - Photoreceptor positioning device for electrophotographic equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

TECHNICAL FIELD The present invention relates to an electrophotographic apparatus that removably holds a unit structure including a photoreceptor.

An electrophotographic device is a device that has a process of exposing a photoreceptor to form an electrostatic latent image and developing the electrostatic latent image with a developer, such as a printer, an electrophotographic copying machine, etc. It is.

PRIOR ART In general, a photoreceptor is removably attached to an electrophotographic apparatus for maintenance or the like.Instead of simply making the lightning element removable alone, the photoreceptor is supported by a single unit structure. There is a device in which the entire unit structure can be removed or attached. In this case, the unit structure includes, in addition to the photoreceptor, a photoreceptor cleaning device, a static elimination brush, a developing device, and the like.

Conventionally, in a device in which a unit structure including a photoreceptor is removable, the entire unit structure is supported by guide rails or other supporting means provided on the main body of the electronic gear device. According to this device, various devices surrounding the photoreceptor are taken in and out together with the photoreceptor, so that the positional relationships between the photoreceptor and the various RIWs around the photoreceptor can be maintained precisely. However, since the photoreceptor itself is not directly attached to the main body of the electrophotographic apparatus, the positional relationship between the photoreceptor and the main body of the electrophotographic apparatus is not necessarily constant.

Here, the location of the photoreceptor within the main body of the electrophotographic apparatus is very important. For example, even if the photoreceptor is attached to and removed from the electrophotographic apparatus along with the unit structure, the transfer charger LL is usually fixed to the main body of the electrophotographic apparatus separately from the unit structure. In such a case, if the position between the photoreceptor and the main body of the electrophotographic apparatus is not precisely constant, the transfer operation by the transfer charger will not be performed uniformly, which may result in defective transfer.

Also, in the case of transferring a developed image formed on a photoconductor onto a transfer paper, there is a device G that feeds the transfer paper from a paper feed tray placed an appropriate distance away from the photoconductor. If the position between the photoconductor and the main body of the electrophotographic device is not exactly constant, the distance between the paper feed tray and the photoconductor will not be constant, which may cause transfer misalignment. be.

Purpose of the Invention In view of the above points, the present invention provides a structure in which the photoconductor f fD is easily attached to the main body of the photoconductor even when one unit structure on the photoconductor is attached to and detached from the main body of the photoconductor. The purpose is to enable positioning.

Structure The above object is achieved by providing a support for positioning the electrophotographic device/equipment with respect to the main body of the electrophotographic device at a position near the rotation axis of the photoconductor in the unit structure including the photoconductor. .

The present invention will be fully explained below based on examples.

FIG. 2 is a sectional view showing the entire printer as an electrophotographic apparatus using the photoreceptor positioning device according to the present invention. First, the entire operation of the printer will be explained based on this drawing.

A drum-shaped photoreceptor 1 provided approximately at the center of the printer is rotated clockwise, and its surface is first uniformly charged by a band 1 charger 2. Next, the photoreceptor 1 is exposed to laser light B from the laser exposure device 3. Laser light B is to be modulated by the image signal from controller board 4 and is therefore exposed by laser light B. An electrostatic latent image corresponding to an image signal is formed on the photoreceptor 1 .

Reference numeral 5 denotes a so-called F'ONT cartridge for specifying all types of characters to be printed.

The electrostatic latent image is developed by a developing device 6 into a developed image. The image is then transferred from the paper feed tray 7 to the paper feed roller 9.
It is superimposed on the transfer paper 8 fed through the registration rollers 10'i, and further transferred onto the transfer paper under the discharge of the transfer charger 1 (transfer operation). Thereafter, the transfer paper undergoes a fixing operation by a fixing device 12, and then is transferred to an upper paper discharge section 13.
, or is ejected into the paper ejection tray 14.

The above-mentioned charger 2, laser exposure device 3, and other types of equipment are started and stopped by a driver provided on a driver board 15 disposed on the controller board 4.

The controller board 4 and driver board 15 are housed in a shield case 16 for noise shielding.

Reference numeral 17 is a power supply section.

From the paper feed tray 7 to the paper output section 13 or the paper output tray 14
In case the transfer paper becomes jammed in the transfer paper conveyance path leading to the transfer paper, or for maintenance, etc., the illustrated printer has a hinge section (not shown) that has the printer stopper frame 18 and the printer lower frame 19 on the back side of the drawing.
The printer upper frame 18 can be lifted completely upwards around the hinge part to open the upper surface of the printer lower frame 19. In order to make it easier to remove the transferred transfer paper, the photoreceptor 1, the developing device 6, etc. are housed in the image forming unit case 20 to form one unit structure, and the left end of the image forming unit case 20 is pin 21 in
The image forming unit case 20 can be rotated relative to the printer lower frame 19 around the pin 2, and by rotating the image forming unit case 20 upward as shown by arrow A, an image including the photoreceptor can be formed. The entire unit can be lifted upwards. When the image forming unit (the entirety is indicated by the reference numeral 22 in FIG. 3) is lifted upward in this way, the transfer paper conveyance path below the image forming unit and the equipment extending into the transfer paper conveyance path, such as the transfer charger 11, are removed. To be released. Therefore, removal of jammed transfer paper and maintenance of each device can be performed very easily.

The image forming unit 22 as a unit structure will be explained based on FIG.

As described above, this image forming unit 22 includes the photoreceptor 1 and the developing device 6 inside the image forming unit case 20. The developing device 6 includes a developing roller 23 that comes into contact with the photoreceptor 1 , a conveying roller 24 , and an agitating member 25 , and supplies developer supplied from a developer supply container 26 to the photoreceptor 1 via the developing roller 23 . supply

A charger 2, a cleaning blade 27, a developer recovery lot 28, and a waste tank 29 are arranged around the photoreceptor 1. When the above-described transfer operation is completed, developer that does not contribute to transfer remains on the photoreceptor 1. This residual developer is removed by the cleaning blade 2.
7 and collected into a waste tank 29 by a developer collection lot 28 rotating clockwise. The charger 2, the cleaning blade 27, the waste tank 29, and the like are all components of the image forming unit 22.

The reason why the image forming unit 22 is rotatably and therefore removably mounted on the printer lower frame 19 is for maintenance, transfer paper removal, etc., as described above, but the problem here is that the image forming unit 22 is When set in the predetermined position of the printer lower frame 19 (the position shown in FIG. 2), the photoreceptor 1 is placed in the printer lower frame 19.
The question is whether or not it is always placed at a constant predetermined position. This is because the transfer charger 11°, paper feed tray 7, etc. are provided in advance on the printer lower frame 19 separately from the image forming unit 22, so the transfer charger 11
The distance between the photoreceptor 1 and the photoreceptor 1 is determined only when the image forming unit 22 is set on the printer lower frame 19. In this case, if there is no play between the pin 21 of the image forming unit case 20 and the printer bottom frame 19, and if the distance from the pin 21 to the photoreceptor 1 is always constant, then the photosensitive material to the printer bottom frame I9 will be removed. Since the position of the body 1 is always fixed, the distance between the transfer charger etc. and the photoreceptor 1 is also kept constant, and no problem occurs. However, in reality, it is very difficult to eliminate play between the pin 21 and the printer bottom frame 19 and to maintain a constant distance from the pin 21 to the photoreceptor 1, and unless some measure is taken, Inconveniences such as transfer failure due to variations in the distance between the photoconductor 1 and the transfer charger 11 or transfer deviation due to variations in the distance between the photoconductor and the paper feed tray 7 occur.

In this embodiment, the following measures are taken to eliminate these inconveniences.

As shown in FIG. 1, the image forming unit case 2° is made as a generally rectangular box, and has an elongated hole 30 formed approximately in the center of its bottom surface for allowing the photoreceptor l to protrude downward. . As shown in FIG. 4, the photoreceptor 1 is provided with rotating shafts 31a and 31b at both ends, and a gear 33 is attached to the second shaft 31a. Rotation @ 3] a
, 3 lb are respectively supported by bearing recesses 323, 32b of the image forming unit case 2o, thereby determining the position of the photoreceptor 1 with respect to the image forming unit case 2o.

A pin 21 provided at the left end of the image forming unit case 2o.
21 is a side plate 34a constituting the printer lower frame 19;
Notch 35a formed in 34b.

35b. As a result, the image forming unit case 20. Therefore, the image forming unit 22 is pivotally mounted to the printer lower frame 9.

Two unit fixing levers 36 and 36 are provided at the right end of the image forming unit case 20.

As shown in FIG. 3, these unit fixing levers 36 are rotatable around the entire center of the image forming unit 37 fixed to the unit case 20, and are further rotated in the square direction by a spring lever (not shown). It is given spring force. A claw 38 is formed at the lower end of the unit fixing lever 36, and a rectangular regular size 39 formed on the side plates 34a+34b.
39 and the claws 38, the image forming unit 20 is fixed between the side plates 34a and 34b.

When lifting the image forming unit 22, the lifting lever 40 integrated with the unit fixing lever 36 is lowered, and the claw 38 and the main body 39 are engaged and raised, and then the entire image forming unit 22 is lifted.

In FIG. 3, a notch 40 serving as a support for positioning the photoreceptor is provided in a bearing portion 32a for supporting the rotating shaft of the photoreceptor. - In the vicinity of the other four bearing portions 32b, there is provided a semicircular four portion 41 as another positioning support portion. When holding the image forming unit case 20, the claw 38 of the unit fixing lever 36 is attached to the side plate 34.
When set in the position to engage with the positive size 39 of a, 34b, the above notch 40 and recess 4] are respectively on the side [
It fits into a support pin 43 fixed to an auxiliary side plate 42 connected to the auxiliary side plate 34a and a pin 44 fixed to the second side plate 34b.

The support pin 43 and the notch 40, and the pin 44 and the recess 41 are shaped in advance so that they fit together accurately without any play, so that the image forming unit case 2° is positioned sideways and temporarily with respect to the support pins 43 and 44. The positions for 34a and 34b are determined. In this case, the notch 40 that receives the support pin 43 is the four bearing portion 3 that supports the rotating shaft 31ak of the photoreceptor.
2a, the photoreceptor 1 is accurately positioned at the reference position of the support pin 43.

Furthermore, the case on the other side of the rotating shaft 31b is also supported by a pin 44, which is a reference position, by four supporting parts 41 provided near the four bearing parts 32b.

Therefore, accurate positioning of the photoreceptor 1 is possible.

Incidentally, a gear 47 that meshes with gears 45, 46 and 46 mounted on the support pin 43 in FIG. 3 transmits assistance to the gear 33 (FIG. 4) provided on the photoreceptor 1. or,
Lock knobs 48 provided at the left and right ends of the image forming unit case 20 are for locking the waste tank 29 and the developing device 6, respectively. FIG. 3 shows the locked state.

Furthermore, the right end of the image forming unit case 2o, that is, the side plate 3
At the end of the side that is lifted from 4a and 34b, there is a side plate 3.
Slits 49 and 49 are formed at the positions where they collide with the side plates 4a and 34b and are spaced slightly wider than the thickness of the side plates. When the image forming unit case 20 is set, the side plates 34a and 34b are sandwiched between the slits.As a result, the image forming unit case 20 is supported without play.

As is clear from the above explanation, the image forming unit case 20
is positioned by support pins 43 and pins 44. Therefore, the pivot pins 21, 21 and the notches 3 that receive them
5a + 35b should be loosely fitted.

Note that in the above implementation row, the image forming unit 22 including the photoreceptor 1, the developing device 6, etc. is one unit including the photoreceptor 1)
I think of it as an f+W structure. However, as long as the unit structure includes at least the photoreceptor 1, any other equipment may be included in the structure.

Furthermore, regarding the structure that allows the unit structure to be removed from the main body of the electrophotographic apparatus (in the case of the practical row, the main body side plates 34a and 34b), the practical row adopts a pivoting structure of the pin 21 and the notches 35a and 35b. (Figure 1). However, the present invention is not limited to this, and any removal structure may be adopted, such as a structure in which the entire image forming unit 22 is taken out of the printer lower frame 19 as it is, or a structure in which the unit is pulled out to the front side in FIG. 2.

Furthermore, in the embodiment, a full notch 40' and a recess 41 are provided in the supporting part for positioning the photoreceptor provided in the image forming station 2o, and these are fitted to the pins 43 and 44 of the side plates 34a and 34b. However, the bin may be provided on the image forming unit case 20 side, and the four parts may be provided on the side plate side.

Effects According to the present invention, since the detachable unit structure including the photoreceptor is supported by the main body of the electrophotographic apparatus near the rotation axis of the photoreceptor, the position of the photoreceptor with respect to the main body can be accurately controlled.
I can decide well.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing one embodiment of the present invention, FIG. 2 is an overall side view of a printer using the embodiment, FIG. 3 is a side view of an image forming unit as a unit structure, and FIG. The figure is a perspective view of a photoreceptor. DESCRIPTION OF SYMBOLS 1... Photoreceptor, 22... Image forming unit (unit structure), 31 a
*3 l b...Rotating shaft, 40.41...Supporting part, 21...Bin, 35a + 35b...Notch,
43...Support bin 29mm 1b

Claims (3)

[Claims] (1) In an electrophotographic apparatus that removably holds a unit structure including a photoreceptor, a support part for positioning the electrophotographic apparatus with respect to the main body is provided on the unit structure near the rotation axis of the photoreceptor. A photoconductor positioning device characterized by: (2) The unit structure including the photoreceptor is rotatably supported by the main body of the electrophotographic apparatus, and when the unit structure is supported by the above-mentioned positioning support, the unit structure rotates. 2. The photoreceptor positioning device according to claim 1, wherein the shaft is loosely fitted to the main body of the electrophotographic apparatus so as to be able to shift. (3) The positioning mechanism of the unit structure is performed by engaging the positioning support part on the unit structure with the support pin of the drive gear for driving the photoreceptor. A photoreceptor positioning device according to any one of the first and second items.