JPH0450594B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a two-part copying apparatus which is improved by providing a developing section of a developing device so as to be retractable from an image forming surface.

[Prior art]

The internal functions and arrangement of a typical electrophotographic copying machine are as shown in FIG.

In the figure, a sheet of recording paper P is delivered one by one from a paper feed cassette 2 installed in a copying machine 1, passes through a first paper feed roller 3, is reversed, and then reaches a second paper feed roller 4, where its leading edge is exposed to the photosensitive material described later. The timing and conveyance speed are adjusted so as to coincide with the leading edge of the toner image formed on the body drum 5.

On the other hand, prior to this, the photoreceptor drum 5, which is uniformly charged on its circumferential surface by the charging electrode 6 and rotates in the direction of the arrow, moves the document in the horizontal direction in synchronization with the peripheral speed of the photoreceptor drum 5. The image of D is exposed to the exposure lamp 7.
An electrostatic latent image is sequentially formed on the circumferential surface by a focusing light transmitting member (trade name, self-occurring lens) 8.

As the latent image on the photosensitive drum 5 continues to rotate, a toner image is developed by the developing section of the developing device 9, that is, the developing sleeve 9a, and becomes a visible state.

The photoreceptor drum 5 further rotates and combines with the recording paper P described above, and after the transfer pole 10 transfers the toner image on the photoreceptor drum 5 onto the recording paper P, the recording paper P is separated. It is separated and separated at the pole 11.

The separated recording paper P is fed to the fixing roller 13 via the conveyance roller 12, and after melting and fixing the toner image, the paper P is sent from the discharge port 15 by the paper discharge roller 14 to a paper discharge tray provided outside the copying machine 1. (not shown)
sent to.

Further, after separating the recording paper P, the photosensitive drum 5 further rotates in the direction of the arrow to remove the electrode 16.
After the charge is removed by the cleaning device 17, the cleaning blade 17a of the cleaning device 17 scrapes off the residual toner adhering to the photosensitive drum 5, and the scraped toner is transferred to the cleaner box 18.
be accommodated in. On the other hand, the photoreceptor drum 5 is again subjected to charge by the charging electrode 6 in order to form an electrostatic latent image based on the next document.

Note that 19 is an insertion slot for recording paper when it is manually fed, and 3a is its first feeding roller.

In an electrophotographic copying machine with such functions, the photosensitive drum 5, whose performance deteriorates or the surface is scratched with use, and the cleaning plate 17a, whose performance deteriorates easily due to wear, are periodically replaced with new ones. Since the developer cartridge 9b needs to be replaced and the developer cartridge 9b must be frequently replenished with toner, these members are designed to be removable. In particular, since the photosensitive drum 5 is developed with the developer attached to the developing sleeve 9a, the two are arranged extremely close to each other, and especially when a one-component developer is used, the degree of proximity is large. When attaching or removing the photoreceptor drum 5 or the developing device 9, extreme care must be taken to avoid damage to the photoreceptor due to contact.

Therefore, in order to facilitate the handling of these members, a device equipped with a device for manually retracting the developing device 9 before removing the photoreceptor drum 5,
Alternatively, when the developing device 9 is pulled out, it can be pulled out along a guide rail and moved away from the photoreceptor drum 5, or it can be moved away from the photoreceptor drum 5 using a moving device for the developing device 9 used during warm-up of the copying machine. A number of proposals have been made, including a type that allows the user to move, but all of these methods require expensive parts such as solenoids, many rams and other mechanical parts, resulting in a high-cost component structure. Since it is done manually, there is a risk of forgetting it and the workability is poor.

For convenient inspection, parts replacement, repair, and troubleshooting, such problems can be solved using a two-part system in which the upper machine frame 1a is connected to the lower machine frame 1b so that it can be opened and closed with the hinge H as the center of rotation, as shown in Figure 1. This is considered to be an unavoidable problem even in copying machines.

[Purpose of the invention]

In the present invention, the developing sleeve of the developing device is automatically retracted from the image forming surface of the photoreceptor drum and maintained in a separated position when the upper machine frame is opened, so there is no need to worry about forgetting to operate the mechanism. The purpose of this invention is to provide a simple and simple two-part type copying device.

[Structure of the invention]

The present invention relates to a two-part copying apparatus in which an upper machine frame housing a photoreceptor drum, a developing device, etc., is openable and closable with respect to a lower machine frame, and the upper machine frame is opened and tilted. The developing device is configured so that it rotates under its own weight, moves to a predetermined position, and stops. On the other hand, in a copying machine that can be divided and opened using one end parallel to the central axis of the photoreceptor drum as a supporting shaft, the developing device has a rotating shaft parallel to the central axis provided in the upper machine frame. When the upper machine frame is closed relative to the lower machine frame, the developing device is rotatable about the rotation axis due to a rotational moment based on its own weight. The developing section of the developing device is biased so as to be positioned with a set gap from the image forming surface of the photoreceptor drum, and the upper machine frame is divided and released from the lower machine frame. This is achieved by a copying apparatus characterized in that the developing section of the developing device is configured to be spaced apart from the image forming surface of the photosensitive drum.

〔Example〕

2 and 3 show an embodiment of a two-part copying device equipped with a developing device according to the present invention. FIG. 2 shows a state in which the copying device is used with the upper machine frame closed. FIG. 3 shows a state in which the upper machine frame is opened and inspection for paper feeding defects and other parts are inspected and replaced.

A two-part copying apparatus 51 shown in FIG. 2 has an upper machine frame 5 that accommodates image forming process members, with the boundary being the recording paper conveyance surface from the manual paper feed port to the paper discharge port.
1a and a lower machine frame 51b, which are connected by a hinge shaft H, so that the upper machine frame 51a can be freely opened.

The upper machine frame 51a accommodates a photosensitive drum 55 as image forming process members, a charging electrode 56, an exposure lamp 57, a focusing light transmitter 58, a cleaning device 67, a developing device 59, etc., while the lower machine frame 51b includes a second paper feed roller 54 as a paper feed and transport member, a group of transport rollers including a fixing roller 63, and electrodes 60 for transfer and separation.
61, a paper feed cassette 52, a driving power source, etc. are accommodated therein.

Furthermore, in the present invention, the developing casing 59c of the developing device 59 in the upper machine frame 51a is housed in a guide rail 71 that is fitted in a circumscribed manner thereto, and a shaft M is fixed to the upper machine frame 51a.
The developing casing 59c and the guide rail 71 are configured to be able to rotate together with the upper machine frame 51a as a fulcrum, as shown in FIG.
When the copying device 51 is closed and in use, the developing casing 59c and the guide rail 71 receive a clockwise rotation moment due to gravity about the axis M, and the guide rail 71 is rotated inside the upper machine frame 51a. It is stopped by coming into contact with an end 72a of a panel 72 fixed to the panel 72.

In this state, the developing sleeve 59a of the developing device 59 forms an appropriate distance from the photoreceptor drum 55, and the latent image on the photoreceptor drum 55 is formed by the toner supplied from the toner cartridge 59b. It has become possible to satisfy the function of developing images. As is well known, the above-mentioned distance is 1 mm or less in development using a one-component developer, and several mm in development using a two-component developer.

Next, open the upper machine frame 51a clockwise and approximately
When the angle of 45° is reached, the upper machine frame 51a is locked in the open state by a stay device (not shown) provided between the upper machine frame 51a and the lower machine frame 51b, and stopped in the state shown in FIG. 3. do.

At this time, the developer casing 59c and the guide rail 71 rotate under the counterclockwise rotational moment due to gravity with the M axis as a fulcrum, and the guide rail 71 separates from the end 72a and reaches its top 7.
1a comes into contact with the inner wall of the panel 72 and is stopped.

In this state, the developing sleeve 59a of the developing device 59 is spaced apart from the outer circumferential surface of the photoreceptor drum 55, and the distance can be set to a sufficient distance so that replacement and attachment/detachment of the photoreceptor drum 55 will not be hindered. be.

Therefore, when the photoreceptor drum 55 is attached or removed for replacement, there is no danger of the outer peripheral surface of the photoreceptor drum 55 coming into contact with the developing device 59 and causing scratches on the photoreceptor surface. Since it can be attached and detached parallel to the outer peripheral surface of the photoreceptor drum 55 along the line 71, inspection, cleaning, toner replenishment, etc. can be easily performed without damaging the outer peripheral surface of the photoreceptor drum 55. In this embodiment, the developing device is set from the side of the copying machine body via a guide plate, but it is also possible to remove the document table provided at the top of the copying machine and insert and set the developing device from the top. It is. In this case, the upper part of the bearing is opened, and the shaft provided in the developing device is set.

〔Effect of the invention〕

According to the present invention, the developing device can be automatically moved to its developing position or retracted position as the copying machine is opened and closed using gravity, and the attachment/detachment and inspection of the photoreceptor drum can be easily and safely performed. Since it is possible to provide a two-part type copying apparatus, it is possible to prevent the developer from scattering without damaging the surface of the photoreceptor in the developing section.

[Brief explanation of the drawing]

FIG. 1 is a general internal configuration diagram of a copying machine. 2 and 3 are internal configuration diagrams of a two-part type copying machine according to the present invention, showing two embodiments thereof. 51... Copying device, 51a... Upper machine frame, 51
b... Lower machine frame, 55... Photosensitive drum, 59...
...Developing device, 59a...Developing sleeve, 59b
...Toner cartridge, 59c...Developer casing, 71...Guide rail, 71a...Top part,
72...Panel, 72a...End, H...Hinge,
M...Axis.

Claims (1)

[Scope of Claims] 1. An upper machine frame having at least a photoconductor drum and a developing device can be divided and opened with respect to a lower machine frame using one end parallel to the central axis of the photoconductor drum as a supporting axis. In the copying apparatus, the developing device is rotatable about a rotation axis parallel to the central axis provided in the upper machine frame, and the upper machine frame is closed with respect to the lower machine frame. In this state, the developing section of the developing device is positioned with a set gap from the image forming surface of the photoreceptor drum due to a rotational moment based on its own weight around the rotating shaft. While being energized, the upper machine frame is separated from the lower machine frame.
A copying apparatus characterized in that the developing section of the developing device is separated from the image forming surface of the photosensitive drum by opening the developing device.