JPS6080882A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent the operator from contacting with a heat roller and having a burn during treatment of a jam, etc. by forming an image forming device which is openable above and below to two parts in such a way that said device can be separated between fixing rolls and shielding at least one of a fixing roll pair when said device is open. CONSTITUTION:An image forming body is dividable and openable around the point A to an upper unit P and a lower unit Q with a path for conveying paper as a boundary. A fixing part 10 is also separated to the upper part and the lower part when said body is opened. When the body is opened upon generation of a trouble such as a jam, the point C of a hinge 10 parts from a supporting member 24 and the hinge 20 is turned downward around the point B by the own weight of the hinge 20 and a guard cover 19 and the energizing force of a leaf spring 23; at the same time the front end D of the cover 19 descends along the outside circumference of a bearing 12 and further the cover 19 turns around the point C unit the top end D covers a heat roller 11. The operator is thus prevented from contacting directly with the roller 11.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image forming apparatus such as an electrophotographic copying machine, and particularly to a shielding means for a fixing roll.

[Prior art]

2. Description of the Related Art Conventionally, there is an electrophotographic copying machine that has a structure in which a main body can be separated into an upper part and a lower part, that is, a so-called open shell structure. FIG. 1 is a block diagram of such an open-shell photocopying machine.

In FIG. 1, inside the main body of the electrophotographic copying machine.

A photoreceptor 1 and a charging device 2 around the photoreceptor 1. Image exposure device 3. Developing device 4. It has image forming means such as a transfer device 5 and a cleaning device 6, and further includes a fixing section 7. In this J configuration, charging, image exposure,
Development, transfer, cleaning.

A series of fixing steps are performed to form a copy image.

The main body of the electrophotographic copying machine can be divided and opened into an upper unit 1-P and a lower unit Q, with the transport path as a boundary, and Figure 1 shows the divided and opened state. In the configuration shown in Figure 1, when the fuser unit 7 is opened, the fixing unit 7 is not separated into an upper part and a lower part, and is left as it is in the lower part Q, but in conjunction with the opening operation, the fixing unit 7 is also separated into an upper part and a lower part. Some configurations include

[Problems with conventional technology]

However, it is not shown in FIG. j゛In a true copying machine, the fixing section 7 is not separated into an upper part and a lower part when opened;
It is extremely difficult to handle jams in the fixing unit 7. Furthermore, in a structure in which the fixing section 7 is separated into an upper part and a lower part in conjunction with the opening operation of the main body, it is extremely easy to clear a jam in the fixing section 7. Since the rollers are directly exposed on the paper conveyance path, there is a risk that the worker will come into contact with the heated rollers during jam removal, resulting in burns or other injuries.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks of the conventional image forming apparatus, it is an object of the present invention to provide an image forming apparatus provided with means for shielding the heat roller of the fixing section exposed when the main body is opened.

[Key points of the invention]

In order to achieve the above object, the present invention provides an image forming apparatus which has a fixing means consisting of a pair of fixing rolls and has a structure that can be divided and opened into a first main body and a second main body. It is characterized in that the fixing roller pair is opened to a maximum of 1000 yen, and when the fixing roll pair is opened, the number of the fixing roll pairs is small (means for shielding one of them is installed).

[Embodiments of the invention]

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

FIGS. 2 and 3 are block diagrams of an image forming apparatus showing an embodiment of the present invention, and FIG. 2 shows a closed state.

FIG. 3 shows an open state, FIGS. 4 and 5 are enlarged sectional views of the fixing section, and FIG. 4 shows a closed state.

FIG. 5 shows the opened state, and FIG. 6 is a perspective view of FIG. 5 seen from the rear side.

As shown in FIG. 2, the image forming apparatus of the present invention includes a photoreceptor 1 in the main body, 411 electric devices 2, image exposure devices 3. Developing device 4. Image forming means such as a transfer device 5 and a cleaning device 6 are also provided.

Furthermore, it is configured to include a fixing section 10. Manoko.

A cassette 8 is installed at the bottom of the main body to store paper for self-feeding. It becomes.

Further, the main body of the image forming apparatus has an open shell structure that can be divided and opened into upper part t/P and lower part J-2 part Q with the paper conveying path as a fulcrum point.

At the time of this opening, the fixing unit 10 is also separated into an upper part and a lower part (
(See Figure 3).

Next, the structure of the fixing unit 10 will be explained in more detail with reference to FIG.
6, is supported by a lower side plate 13 via a bearing 12, and is in pressure contact with a press roller 15 supported by a lower side plate 14. The guide plate 17 is for guiding the paper to the pressure contact portion of the roller pair 11.15, and the paper is guided to the roller pair 11.15 heated by the heater 16.
The center of the image is fixed so that the image is fixed through the pressure contact portion and is discharged to the outside of the machine through the guide plate 18.

The guard cover 19 is rotatably supported at 0 point by a hinge 20 which is rotatably supported at 8 points on the upper side plate 13. Here, the girt' cover 19 is biased in the direction of arrow G by a torsion spring 21 provided at point C.
The tip (1) of the guard cover 19 is in contact with the bearing 12. Further, the hinge 20 is biased downward in the drawing by a leaf spring 23 attached to the upper cover 22. still.

The hinge 20 is supported at point C by a support portion +424 extending from the bottom of the main body, and is prevented from falling below the position shown in FIG. 4. In addition, after fixing, the 5-separation claw 25
This is for separating the paper from the heat roller 11.

The operation of the image forming apparatus 4J having the above configuration will be explained.

When a print button (not shown) is turned on, each device installed in the main unit 9 starts operating, and as the photoreceptor 1 rotates, the charging device 2 uniformly charges the photoreceptor L, and then an image is formed. A light image of a document (not shown) is irradiated by the exposure device 3, and an electrostatic latent image corresponding to the document is formed on the surface of the photoreceptor 1.

The electrostatic latent image is visualized by toner in a developing device 4,
It becomes a toner image. On the other hand, cassette 8 or manual feed tray 9
For paper fed from L; I: ! The light body 1' touches the second tree image in synchronization with the image 1);
Then, the toner image on the photoreceptor 1 is transferred onto a sheet of paper by the transfer device 5. After the transfer, the paper is separated from the light body 1 and further fed through the guide 4 (17").

After the image is fixed in the fixing unit 10, it is ejected from the machine. Further, after the transfer, the toner remaining on the photoreceptor 1 is cleaned off by a cleaning device 6 in preparation for the start of the first process.

Image formation is performed through the above steps, but if a problem such as a jam occurs, open the main body as shown in Figure 3,
Necessary measures can be taken.

By the way, when the main body is opened, in the fixing section 10, by raising the upper unit P, the upper four sides 13 are raised, and when the C point part of the hinge 20 leaves the support member 24,
nm of the hinge 20 and the guard cover 19 and the force of the spring 23 (= J force causes the hinge 20 to rotate downward about point B, and the tip of the guard cover 19 also rotates downward from the bearing 1.
It descends along the outer circumference of 2. Furthermore, due to the force A of the torsion spring 21, the tip of the guard cover 19 is pushed against the bearing 1.
2, it rotates about the 0 point as a fulcrum, and is in the state shown in FIGS. 5 and 6, covering the heat roller 11.

The heat roller 11 is covered with a guard cover 19 in conjunction with the opening operation of the Zunawaji 1 main body. Next, when the main body is closed again, that is, by lowering the upper unit P, the upper side plate 13 is lowered, and the point C of the hinge 20 is first
82 /I, and is guided along the slope portion F of the support portion 4A24 as the upper side plate 13 descends.

Along with this, the hinge 20 rotates upward about point B as a fulcrum against the A' force of the leaf spring 23, and the girt cover 19 also rotates about the 0 point as a fulcrum due to the A' force of the torsion spring 21. Then, the tip portion moves upward along the outer periphery of the bearing 12, and returns to the state where the roller 11 and the press roller 15 are in pressure contact (not shown in FIG. 4). In this state, the guard cover 19 prevents the paper guided by the guide I plate 17 from moving upward.

It also serves to guide the paper to the pressure contact portion of the roller pair 11.15.

In this way, when the main body 9 is opened, the heating element 11 is covered by the guard cover 19.

When handling a jam or the like, there is no problem of accidentally touching the hot roller 11 directly.

In this embodiment, a case has been described in which only the roller on the heat source side of the pair of rollers in the fixing section is shielded, but in the case where both rollers are the heat source.

It is also possible to configure both rollers to be shielded when the main body is opened.

〔Effect of the invention〕

As described above in detail, the image forming apparatus of the present invention has two
Since the heat roller of the fixing section exposed when the main body is opened is shielded, it is possible to remove jams inside the machine extremely safely and easily.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional open-shell electrophotographic copying machine, FIGS. 2 and 3 are block diagrams of an image forming apparatus showing an embodiment of the present invention, and FIGS. 4 and 5 are fixing diagrams. FIG. 6 is a perspective view from the rear side of FIG. 5. 1... Photoreceptor, 2... Charging device. 3... Image exposure device, 4... Developing device. 5... Transfer device, 6... Cleaning device, 7
．． 10... Fixing section. 8...Cassette, 9...Manual feed stand. 11... Heat roller, 12... Bearing. 15... Press roller, 16... Heater, 19
...Guard cover. 20...Hinshi, 21...Torsion spring. 23... Leaf spring, 24... Supporting member. 25...Separation claw patent applicant Casio Al Computer Co., Ltd. IDCI, patent attorney representing the company Yoshiyuki Omachi Figure 2 Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] It has a fixing means consisting of a pair of fixing rolls, a first body and a second body.
In an image forming apparatus having a structure that can be divided into a main body and an openable one,
An image forming apparatus characterized in that an image forming apparatus is provided with means for opening the pair of fixing rolls so as to be separable when the pair is opened, and for shielding at least one of the pair of fixing rolls when the pair of fixing rolls is opened.