JPH02251872A - Electrophotographic recorder - Google Patents

Abstract

PURPOSE:To stabilize the force with which a developing unit is pressed against a photosensitive body and to ensure the grounding of the developing unit by permitting a developing unit to be elastically brought into contact with an image forming case rectangularly when the developing unit is elastically energized, so as to be grounded, and permitting the image forming case to be elastically brought into contact with a device main body so as to be grounded. CONSTITUTION:In a device main body, the developing unit 16 is pressed against the photosensitive body 13 by elastically energizing springs 26 and 26 in the direction shown by an arrow in figure. A grounding body 31 is attached, and an upper elastic part 31a and an lower elastic part 31b, pressed against the part 31a, are provided. When elastically energized, the developing unit 16 is elastically brought into contact with the image forming case 21 rectangularly to be grounded; and also the image forming case 21 is elastically brought into contact with the device main body to be grounded. Thus, the force with which the developing unit is pressed against the photosensitive body is stabilized, and the grounding of the developing unit is always ensured.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an electrophotographic recording SUt that performs recording using an electrophotographic method, such as a laser printer, laser copying machine, or laser facsimile. In detail, the imaging case will be stored inside the main body of the device.

A developing device is removably housed in the image forming case, and the developing device is elastically biased to be pressed against a photoreceptor.

Conventionally, in this type of electrophotographic recording device, for example,
As shown in the figure, there is an image forming case 1 inside the main body of the device (not shown).
is housed, and a developing device 2 is detachably attached within the image forming case 1. Then, the developing device 2 is elastically biased in the direction of the arrow by springs 4, 4, and pressed against the photoreceptor 3.
Toner is attached to the surface of the photoreceptor 3 to visualize the electrostatic latent image on the surface of the photoreceptor 3.

However, in this type of recording apparatus, if the grounding of the developing device 2 is uncertain, noise may be generated from the developing device 2 and malfunction may occur. Therefore, as shown in the figure, a printed circuit board 5 is provided on the end face of the developing device 2, and an electrode 6 made of phosphor bronze is extended from the circuit board 5 in the opposite direction to the elastic biasing direction of the developing device 2 (the direction indicated by the arrow in the figure). The electrode 6 was sandwiched between the main body electrodes 7, also made of phosphor bronze, attached to the image forming case 1 and grounded.

However, if the force that holds the electrode 6 between the body electrodes 7 is large, the pressing force of the developing device 2 against the photoconductor 3 will become unstable, and on the other hand, if the force that holds the electrode 6 is small, the force at that part will become unstable. There was a problem of insufficient conduction.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve such conventional problems in electrophotographic recording devices, stabilize the pressing force of the developing device against the photoreceptor, and ensure that the developing device is always grounded. .

! Therefore, in the present invention, for example, as shown in the illustrated embodiment below, the image forming case 21 is housed in the apparatus main body 10,
In an electrophotographic recording apparatus in which a developing device 16 is detachably attached in the image forming case 21 and the developing device 16 is elastically biased to press it against the photoreceptor 13, when the elastic bias is applied, the developing device The image forming case 21 is grounded by elastic contact with the image forming case 21, and the image forming case 21 is connected to the apparatus main body 10.
It is characterized by being grounded by making elastic contact with.

Stop-1 (2) Then, the developing device 16 is always brought into reliable elastic contact with the image forming case 21 without affecting the force with which the developing device 16 is pressed against the photoreceptor 13.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 shows a schematic configuration of a laser printer according to an embodiment of the present invention, in which numeral 10 is a main body of the apparatus, and numerals 11 and 11 are paper feed cassettes provided in the main body 10 of the apparatus. Paper 50 fed from the paper feed cassettes 11, 11 in the direction of arrow A
are conveyed to the drum-shaped photoreceptor 13 at the appropriate timing by a pair of registration rollers 12, 12. Photoreceptor 13
is rotated clockwise, and at this time the charger 14
The surface of the photoreceptor 13 is uniformly charged, and a laser beam from the laser optical system 15 is irradiated to form an electrostatic latent image on the photoreceptor 13. This latent image is made visible by toner when it passes through the developing device 16, and this visible image is transferred to the photoreceptor 13 on the sheet of paper 5.
0 by the transfer charger 17, and the transferred paper 5
The visible image on 0 is fixed by a fixing device 18. and,
The paper 50 that has come out of the fixing device 18 is ejected, for example, in the direction of the arrow and is stacked on the paper ejection sections 19. On the other hand, the cleaning device 20 removes residual toner from the photoreceptor 13 after the visible image has been transferred.

Incidentally, in the illustrated laser printer, an image forming case 21 is housed within the apparatus main body 10. Inside the image forming case 21, a photoreceptor 13, a developing device 16, a cleaning device 20, etc. are installed. Then, as shown in FIG. 5, the front cover 22
, and the image forming case 21 can be freely pulled out from the apparatus main body 10.

Thus, the photoreceptor 13, developing device 16, cleaning device 20, etc. can be individually attached and detached with a single touch. The developing device 16 is composed of a developing device main body 23 and a toner cartridge 24, but as shown in the figure, only the toner cartridge 24 can be attached and detached independently. In addition,
In FIG. 5, the device main body 10 includes a dedicated table 25
Put it on top.

Now, in the apparatus main body 10, as shown in FIGS. 2 and 3, the developing device main body 23 (that is, the developing device 16) is elastically biased in the direction of the arrow in the figure by the springs 26 and 2-6, and the photoreceptor is 13
press against. By the way, as shown in FIG. 1, the film circuit board 27 is attached to the developing device main body 23 in a direction perpendicular to the elastic biasing direction thereof.The circuit board 27 is provided with a grounding part 28 made of phosphor bronze. . The ground in the developing unit 16 is collected in the ground portion 28, and a comb-like ground contact piece 29 made of a leaf spring is pressed against it. Each of the ground contact pieces 29 has a hemispherical protrusion 29a at the contact portion with the ground portion 28, as shown in FIG.
... to form. As shown in FIGS. 1 to 3, it is attached to the ground plate 30 of the image forming case 21. A grounding body 31 is also attached to the grounding plate 30.

The ground body 31 is provided with an upper elastic part 31a and a lower elastic part 31b that presses against it. Then, the ground piece 32 of the device main body 10 is inserted between the upper and lower elastic parts 31a and 31b. The ground piece 32 is attached to the frame 3 inside the device main body 10.
3 and prepare it in an appropriate position.

As a result, when the imaging case 21 is pulled out from the apparatus main body 10 as shown in FIG.
When the grounding piece 32 is pulled out from between the space between b and the grounding body 31 and the grounding piece 32 are separated, and the imaging case 21 is pushed into the apparatus main body 10, the upper and lower elastic parts 31a and 31b are removed again.
The grounding piece 32 is pushed in between to bring the grounding body 31 and the grounding piece 32 into contact. Furthermore, when the developing device 16 is taken out from the image forming case 21, the grounding portion 28 and the grounding contact piece 29 are separated, and when the developing device 16 is installed inside the image forming case 21, they are separated again. The structure is such that the two parts are in contact with each other.

When the developing device 16 receives vibrations and vibrates in the X direction in FIG. Their contact is ensured by sliding with pieces 29.

Effects of the Invention Therefore, according to the present invention, the force with which the developing device is pressed against the photoreceptor is not affected.

To surely bring a developing device into elastic contact with an image forming case. Therefore, it is possible to always stabilize the pressing force of the developing device against the photoconductor, and to ensure that the developing device is grounded.

[Brief explanation of drawings]

1 to 6 show a laser printer which is an embodiment of the present invention.
The figure is a plan view of the main part, Fig. 3 is an exploded perspective view of the main part, and Fig. 4 is a partial perspective view of the ground contact piece in the main part.
FIG. 5 is an overall external perspective view of the laser printer, and FIG. 6 is an overall schematic configuration diagram of the internal mechanism of the laser printer. 7th
The figure is a partial plan view of the internal mechanism of a conventional electrophotographic recording device. 10... Apparatus body 13... Photoreceptor 16... Developing unit 21... Imaging case

Claims (1)

[Claims] In an electrophotographic recording device in which an image forming case is housed in an apparatus main body, a developing device is removably attached within the image forming case, and the developing device is elastically biased and pressed against a photoreceptor, Then, the electrophotographic recording apparatus is configured such that the image forming case is elastically contacted with the image forming case in a right angle direction to be grounded, and the image forming case is elastically contacted with the apparatus main body and grounded.