JPS6032066A - electrophotographic equipment - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the structure of an electrophotographic apparatus that can be divided into upper and lower parts.

The drive system of a conventional electrophotographic apparatus that can be divided into upper and lower parts will be explained with reference to FIG. The arrow indicates the direction of rotation of the gear. The electrophotographic apparatus l is divided into upper and lower parts along the line AA, with an upper unit la and a lower unit la.
b is the opening/closing hinge 17 on the paper feed side of the electrophotographic device l.
The upper unit /a is pivoted and opened by rotating it clockwise. According to the gear 2a fixed to the shaft of the drive motor tacho at the right end of the upper unit /a, the rotational force is transmitted to the gear 5 coaxial with the photosensitive drum through a gear system with a 3° intermediate gear horizontally and to the left. Furthermore, intermediate gears 6, 7
The rotational force is transmitted to the gears /J and /J coaxial with the fixing roller through the gear system of intermediate gears t and 9 of the lower unit l-/b. A gear coaxial with the old fixing roller/J passes through the intermediate gear/11 gear system and then a gear 13 coaxial with the paper ejection roller.
The rotational force is transmitted to. Further, the rotational force is transmitted from the intermediate gear DA to gears /g and /9, which are coaxial with the register roller, through a gear system of intermediate gears -○, 1, and 3, to gear 3, which is coaxial with the paper feed roller.

The intermediate gears g and 9 are supported by a support frame 10 rotatably supported by the shaft 9a of the intermediate gear t so that the intermediate gear g and the intermediate gear D mesh with each other. The supporting frame IO is engaged with a tension spring /l that is engaged with the lower unit and is biased counterclockwise.

When restoring the state shown in Fig. 1 from the state in which the upper unit (a) and the lower unit (lb) are divided into parts centering around the opening/closing hinge (l) as shown in Fig. 2, the tips of the teeth collide with the intermediate gear (t). When they are aligned, the tooth tips of the intermediate gear 7 push the intermediate gear g against the bias of the tension spring ii and rotate the supporting frame 10 clockwise, thereby preventing damage to the intermediate gears 7 and 5. When the tooth tips of the intermediate gear 7 rotate due to the rotation transmitted from the drive motor, the intermediate gear 7. & is engaged, and the support frame lθ is returned to its original position by the biasing force of the tension spring //. Intermediate gear? , is in the direction of rotating the support frame 10 counterclockwise, so that the driving force is sufficiently transmitted.

A means of meshing the intermediate gear 1 using the support frame 10 is also necessary between gear llr and 19, which are coaxial with the register roller, but since it is a small gear that transmits small power, it is necessary to All you have to do is leave it there. Fixer! The rotational force required to drive the paper is large, especially in the case of a pressure fixing device, the rotational force when the paper passes through is approximately the same as the required rotational force of the entire device.
reach. If the fuser, which is coaxial with the gear octopus, and the motor of the upper unit za are separated from each other as shown in Figure 1, the fuser's drive connection will have a complicated structure, and the heavy load, especially in the case of a pressure fuser, will cause twisting of the main body side plate. This causes vibration.

In the conventional example, the lower unit)/b has a fixing device, so the power transmission device is complicated and has a large number of parts.

■ If a jam occurs in the paper feed section, the paper feed roller remains in the lower unit, which may cause the paper to get caught in the paper feed roller and tear the paper when clearing the jam, making removal difficult.

■ The drive motor is located at the right end of the upper unit)/a, and the fuser, which requires the most rotational force, is located at the left end of the lower unit lb, so it is necessary to increase the rigidity of the frame of the electrophotographic device. , and the power transmission efficiency of the gears becomes poor, resulting in a large amount of power loss.

(2) A paper feed roller that operates intermittently and has load fluctuations is located in the lower unit lb, and may twist and vibrate between it and the power source side of the upper unit/a.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic apparatus that can easily handle jams, increase the rigidity of the main body drive system, and that can operate stably with a small number of parts.

The present invention is an electrophotographic apparatus that can be divided into upper and lower parts with a hinge as the center of rotation or a link or the like, in which an upper unit is provided with a fixing device.

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

3 and 4 are vertical cross-sectional views of the central part in the width direction showing an embodiment of the present invention, and FIG. 4 shows a state in which FIG. 3 is divided into upper and lower parts. The electrophotographic apparatus is provided with an opening/closing hinge 17 below the fixing unit 3 at the left end of the electrophotographic apparatus 1, and the upper unit 1-7a and the lower unit/b are centered around the opening/closing hinge 1 with the BB line as a boundary. It is rotatable. The photosensitive drum 26 is provided almost in the center of the upper unit la, the drive motor tassel is provided at the left end of the upper unit 1-7a, the drive motor is provided in the upper unit la between the fixing device 2S and the photosensitive drum roller, and the drive motor tacho is provided in the upper unit la between the fixing device 2S and the photosensitive drum roller, and the driving motor tacho is provided in the upper unit la between the fixing device 2S and the photosensitive drum roller. A paper ejection roller 2Q is provided on the left side. A cleaner 2g and a developer core are provided in the upper unit la on the left and right sides of the photosensitive drum 26 in close proximity to the photosensitive drum 2b.

An exposure lamp 29 equipped with a reflector is provided close to the document platen glass 30, and its light beam is reflected by the document in contact with the document platen glass 30, and is transmitted to the photosensitive drum roller via the short focus lens array 31 provided directly below. It is designed to form an image. A primary charger 3a is provided close to the photosensitive drum roller between the cleaner cog and the short focus lens array 31, and a transfer charger 33 is provided below the photosensitive drum roller in the lower unit/1.
1 is provided. The paper feed cassette J4Z is provided below the lower unit lb so that it can be inserted from the left end. A paper feed roller 3S is provided above and in contact with the upper right end of the paper feed cassette 71, and the paper feed guide 36 immediately moves upward and then makes a U-turn to the left to reach the upper unit la near the register roller 37.3g. It is set in. Upper register roller 3
The register roller 3-t is provided in the upper unit /a, and the lower register roller 3-t is provided in the lower unit lb. The conveyor belt 3 is provided on the lower unit)/b and is driven by a conveyor belt drive gear 4IO provided on the side of the upper unit 1.
ing.

The image forming operation is well known and will be omitted here, and the gear system will be explained with reference to FIGS. S and 2.

FIG. S is a side view showing a gear system according to an embodiment of the present invention;
The gear system is arranged on the side of the electrophotographic device. FIG. 6 shows a state in which FIG. S is divided into upper and lower parts. The arrow indicates the direction of rotation of the gear.

The gear lIl shown at the shaft end of the drive motor is provided in the upper unit la, and the rotation of the gear 4'/ is controlled by the unit/a.
The gear 1II is fixed to the fixing roller 2S, which requires a large rotational force, through the intermediate gear dowel lIj provided in the
I, and then via intermediate gear lIk to gear 4'A fixed to the lower sheet discharge roller. In addition, a gear q is fixed to the photosensitive drum unit B via an intermediate gear 7.
The rotational force is transmitted to g from gear l of the drive motor. Rotational force is transmitted from the gear pg of the photosensitive drum to the gear go coaxially fixed to the upper register roller 37 via the intermediate gear 9, and then to the paper feed roller 3 via the intermediate gears si, r, and t.
The rotational force is transmitted to a gear 33 coaxial with j.

On the other hand, the rotational force is transmitted from the intermediate gear 4!7 to the conveyor belt driving gear DA0, which is a gear 1I fixed coaxially with one pulley provided in the lower unit lb and around which the conveyor belt is wound.
The rotational force is transmitted to 0a from the conveyor belt drive gear 41o. The conveyor belt drive gear 4Io is for transmitting a small rotational force, and has a sharp tooth tip and meshes with a small gear Q with a sharp tooth tip.

A fuser that requires large rotational power! Gear 4 that drives! As mentioned above, since the gear 1 is placed very close to the gear 1 of the drive motor, the power transmission efficiency is good.

Furthermore, by placing the main driving parts such as the fixing device, 2s, and the intermittently driven paper feed roller 35, which require the most driving force, in the upper unit la on the drive motor side, twisting can be prevented.
Can prevent vibration.

The drive motor is close to the opening/closing hinge 17, and the fuser roller, which tends to be heavier in the case of pressure fixing than in the case of heat fixing, is very close to the opening/closing hinge 17, and the upper unit is centered around the opening/closing hinge 17. The feeling of weight is reduced by lifting the la.

Note that the division according to the present invention is not limited to a hinge, but also includes a division using a link or the like.

As explained above, in an electrophotographic device that can be divided into upper and lower units, by having the fuser in the upper unit, there is no heavy-load power transmission part between the upper and lower units, simplifying the configuration. Since no load is applied, the machine frame no longer twists or vibrates, and the fuser is firmly fixed.

Furthermore, since the drive motor is provided near the fixing device, power transmission efficiency is good. The paper feed roller has been moved to the upper unit, which reduces twisting and vibration of the machine frame, making it easier to clear paper jams.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional electrophotographic device, and Figure 2 is a cross-sectional view of a conventional electrophotographic device.
FIG. 3 is a vertical cross-sectional view of an embodiment of the present invention; FIG. 4 is a vertical cross-sectional view of FIG. 3 divided into two; FIG. FIG. 6 is a side view showing the gear system of the embodiment, and FIG. 6 is a side view showing the state in which FIG. S is divided into two. /a...upper unit /b-, lower unit co...
Drive moder 7. g...Intermediate gear S...Fuser 3S
...Paper feed roller. ″ Patent Applicant Canon Co., Ltd. Agent Arai

Claims (1)

[Claims] l An electrophotographic apparatus that can be divided into upper and lower parts, characterized in that the upper unit is equipped with a fixing device.