JPH0723795Y2 - Image forming device - Google Patents

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, a liquid crystal printer, and a laser beam printer, and more particularly to an image forming apparatus having a shell open mechanism.

[Prior art]

In recent years, there have been strong demands for miniaturization of various electronic devices, and miniaturization of image forming apparatuses such as electrophotographic copying machines is also desired. This request for downsizing is the same in the so-called shell-open mechanism image forming apparatus in which the upper machine body can be opened to the lower machine body, and recently, a compact and easy-to-use shell-open mechanism image forming apparatus is commercially available. .

In such an image forming apparatus, a paper discharge unit is provided on the upper surface of the image forming apparatus for downsizing. For this reason, the sheet conveying path until the sheet after the transfer reaches the discharge section is narrow and has a large curvature.

Therefore, the conventional image forming apparatus has a shell-open structure in which the sheet conveyance path between the transfer section and the ejection section is opened in consideration of the sheet jam in the sheet conveyance path described above. That is, a locking member is provided on the rotatable upper machine body, a locked member is provided on the lower machine body in the vicinity of the above-mentioned paper transport path, and the upper machine body is locked by fitting the locking member to the locked member. Is going. Further, when the upper machine body is opened, the lock release lever of another member is operated to release the fitting between the locking member and the locked member.

[Problems of conventional technology]

In the above-described conventional image forming apparatus, it seems that jam processing is easy because the paper conveyance path where paper jams are likely to occur is opened. However, if a paper jam has occurred, it may be jammed with a part of the paper being sandwiched between the upper machine side or the lower machine side, for example, the discharge roll or the transport roll, or in some cases between the rolls. There is also a case where paper is jammed in the presence of paper. If the upper machine is opened in such a state, there arises a problem that the paper is opened while being sandwiched between the upper machine or the lower machine, or the paper is shaken. When the paper is jammed, a difficult jam process such as removing the jammed paper from the roller or the like is further forced.

[Purpose of device]

The present invention has been made in view of the above-mentioned conventional drawbacks, and an object of the present invention is to provide an image forming apparatus capable of easily performing jam processing and the like.

[Key points of device]

In order to achieve the above object, the present invention provides a first body including a sheet stacking unit and a discharge unit that carries out and discharges an image-formed sheet onto the sheet stacking unit so that the image surface is reversed. A lock mechanism for locking the first machine body to a closed position, the lock mechanism being provided on the second machine body. In an image forming apparatus configured with a rotatable locking member provided on a first machine body, the discharging portion is on a free end side with respect to the fulcrum shaft, and sandwiches a conveying surface of the sheet. It is characterized by comprising a pair of discharge members facing each other, and one of the discharge members is provided integrally with the locking member.

[Example of device]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In the present embodiment, an example of a printer will be described as the image forming apparatus of the present invention. FIG. 2 is a configuration diagram of the printer 1 having a shell open mechanism.

In FIG. 1, the printer 1 is composed of an upper body U ₁ and a lower body U ₂ , and the upper body U ₁ is configured to be openable with respect to the lower body U ₂ around a hinge 2. Inside the printer 1, a photosensitive drum 3, a charging device 4 for applying a constant charge to the photosensitive drum 3, a developing device 6 for developing an electrostatic latent image formed on the photosensitive drum 3 by a print head 5, and a developing device. It has a transfer device 7 for transferring the subsequent toner image onto the sheet t, and a cleaner 8 for removing the toner remaining on the peripheral surface of the photosensitive drum 3. Further, a paper feed cassette 9 accommodating a paper t can be attached to the lower portion of the printer 1, and a transport roll 11 and the above-mentioned transfer device are provided in a transport path of the paper t carried out by the paper feed roller 10 from the paper feed cassette 9. 7, a separation roll 12, a fixing device 13, paper discharge rolls (pair) 17, 18 and the like are provided. Further, between the fixing device 13 and the paper discharge rolls (pair) 17, 18, a guide plate 15 and a locking member 16 for guiding the conveyed paper t upward with a predetermined curvature are arranged. This locking member 16 guides the paper t to the guide plate.
Along with forming a sheet conveyance path leading upward together with 15, it also plays a role in locking the upper body U ₁ to the lower body U _{2 as} described later in detail.

FIG. 1 is an enlarged view of a portion A surrounded by the one-dot chain line in FIG.
FIG. 3 is a perspective view for explaining the structure of the locking member 16 and its vicinity. The locking member 16 is composed of a locking portion 16a and a conveyance guide portion 16b. The locking portion 16a is a plate-shaped portion provided below the locking member 16 and extending downward, and includes a convex portion 16a 'at the tip. Further, the transport guide portion 16b is a portion including a guide portion 16b ′ provided facing the guide plate 15.

A roll shaft 18b is rotatably provided in the conveyance guide portion 16b through a bearing 18a, and the roll shaft 18b has the above-described paper discharge roll 1
8 is stuck.

Further, the locking member 16 is rotatably supported by 19 via a bearing 19a and is rotatable in the arrow a or a'direction.

On the other hand, a locked member 20 is provided upright on the lower body U ₂ , and a hole 20a is formed in the locked member 20. This is the hole 20a upper body U ₁ is convex portion 16a 'is fitted above the engaging portion 16a when in the closed state. Furthermore, a fixing device 13 is provided in the lower body U ₂ .
Heat roll 13b with built-in heater 13a and pressure roll 13c
Thus, the toner image on the sheet t is thermally fixed. Also, a fixing device
Separation claws 13d, transport rolls 13e, 13f, etc. are also disposed inside the sheet 13, and the sheet t is separated from the heat roll 13b to guide the guide plate 15.
And the locking member 16 to convey the paper t.

Further, the paper discharge roll 17 arranged in the upper machine body U ₁ is subjected to a predetermined biasing force in the direction of arrow b by the leaf spring-shaped spring member 21 via the shaft 17a. Due to this biasing force, the discharge rolls 17,1
The sheet 8 is rotated under pressure contact with a predetermined pressure to eject the sheet t to the sheet ejection tray.

The image forming operation and the opening / closing operation of the upper body U ₁ of the image forming apparatus having the above-described configuration will be described below.

First, when the upper body U ₁ is in the closed state, the locking member 16 engages with the locked member 20 as shown in FIG. 4, and the upper body U ₁
Is kept closed. That is, the convex portion 1 of the locking portion 16a
6a 'is fitted and locked in the hole 20a of the locked member 20. At this time, the locking member 16 is guided by the guide portion 16b 'to the guide plate 1
Together with 5, form a paper transport path. In this state, the printer 1 executes the printing operation, and the operation of the photosensitive drum 3, the charging device 4, the print head 5, the developing device 6, the transfer device 7 and the like causes the paper feeding cassette 9 to feed paper, A toner image is formed on the sheet t conveyed by the conveyance roll 11. The sheet t on which the toner image is formed is heat-fixed by the fixing device 13, curved upward between the guide plate 15 and the locking member 16 and conveyed, and is ejected onto the sheet ejection tray 14 by the sheet ejection rolls 17 and 18. .

When the paper t jams in the paper conveyance path between the guide plate 15 and the locking member 16 or the like while the above printing operation is repeated, the upper machine body U ₁ is opened for jam processing. In this opening operation, when a lock release lever (not shown) is operated, as shown in FIG. The convex portion 16a 'of the locking member 16 is released. After that, the upper body U ₁ is opened upward by the urging force of a torsion bar (not shown).
FIG. 6 is a diagram showing this state. When the upper machine body U ₁ is opened upward, a biasing force is constantly applied to the locking member 16 in the direction of arrow a by a spring or the like (not shown), so that the locking member 16 rotates about the rotary shaft 19 as shown in the figure. Therefore, the locking member
The gap between the guide portion 16b of 16 and the guide plate 15 is widened. Further, the paper discharge roll 18 attached to the roll shaft 18b above the locking member 16 and the paper discharge roll attached to the spring member 21.
The pressure contact between 17 is also eliminated and a slight gap is formed. Therefore,
For example, even a paper jam between the guide plate 15 and the locking member 16 has occurred, the guide plate 15 and the guide portion 16b 'between can perform paper jam easily spread by opening the upper body U _1. Further, since the pressure contact between the paper discharge rolls 17 and 18 is eliminated as described above, even if the jammed paper reaches between the paper discharge rolls 17 and 18, it can be easily removed.

After easily jam as described above, contact the upper body U ₁ when in the closed state, presses the upper body U _1, the locking member 16 to the distal end of the engaged member 20 Lock part 16a
As the upper body U ₁ is further pressed, the tip of the locked portion 20 slides down, and the convex portion 16a ′ of the locking portion 16a is fitted into the hole 20a. After the upper body U ₁ is locked by the lower body U ₂ in this way, the guide portion 16b ′ of the locking member 16 is again guided by the guide plate 15
Together with this, a paper transport path is formed.

[Effect of device]

As described above in detail, according to the present invention, the locking member that forms a part of the paper transport path is rotated in conjunction with the opening and closing of the upper machine body to widen the paper transport path when the upper machine body is opened. Since the sheet is formed and the engagement of the conveying member such as the sheet discharge roll is released, maintenance processing such as sheet jam processing can be easily performed.

Further, since the locking member constitutes a part of the paper transport path, the number of parts can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a main part of the printer of this embodiment, FIG. 2 is an overall configuration diagram of the printer of this embodiment, FIG. 3 is a perspective view of the vicinity of a locking member, and FIGS. The figure is a block diagram for explaining the upper body opening operation of the printer of this embodiment. 15: guide plate, 16: locking member, 16a: locking part, 16
a ′ …… Convex part, 16b …… Transport guide part, 17,18 …… Paper roll, 19 …… Rotary shaft, 20 …… Locked part, 20a …… Hole, 21
...... Spring member, U ₁ …… Upper body, U ₂ …… Lower body.

Claims (3)

[Scope of utility model registration request] 1. A first machine provided with a sheet stacking section and a discharge section for carrying out and discharging the sheet on which the image is formed on the sheet stacking section so that the image surface is reversed, and the first machine. A lock mechanism that has a second body that is openably and closably supported about a fulcrum shaft and that locks the two bodies in a closed position is provided in the locking portion provided in the second body and the first body. In the image forming apparatus configured with a rotatable rotatable locking member, the discharging unit is a free end side with respect to the fulcrum shaft, and a pair of discharging members facing each other so as to sandwich the conveyance surface of the sheet. The image forming apparatus, wherein one of the discharging members is integrally provided with the locking member. 2. The image forming apparatus according to claim 1, wherein the discharging member is a discharging roller. 3. The image forming apparatus according to claim 2, wherein the discharge member is a conveyance guide member.