JPH03249060A - Sheet discharging device for image forming unit - Google Patents

Abstract

PURPOSE:To attempt improvement in operability of an user while holding remarkable miniaturization of a device installation area by composing a sheet mounting part to be movable at least to a first position and a second position, and providing the sheet mounting part with a guide part for regulating the discharge direction of a sheet to be discharged from it. CONSTITUTION:A photosensitive drum 4 is disposed under a device 1, respective process units 6 for forming images on the photosensitive drum 4 are disposed around the upper periphery of the photosensitive drum 4, and optical units 10 for printing image information on the photosensitive drum 4 are disposed over the process units 6. Feed parts 11, 17 and discharge parts 16a, 16b for sheets P are disposed on both sides of the optical units 10, and a sheet mounting part 18 for mounting the discharged sheets P is provided. The sheet mounting part 18 is composed to be selectively movable at least to a first position A and a second position B. A guide part 18c for regulating the discharge direction oN the sheets P discharged from the sheet mounting part 18 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to an image forming apparatus such as a desktop type electrophotographic printer, and more particularly to a sheet discharging device in an image forming apparatus.

(b) Prior Art In recent years, electrophotographic page printers that form images on photosensitive drums using inexpensive and compact light emitting elements such as lasers and LEDs have come into widespread use.

Conventionally, the printer has been used as a small computer terminal in a LAN or the like by many users, and a plurality of computers have been connected to such a printer.

FIG. 12 shows a printer of the type described above. In the figure, a cassette b for storing sheets P is inserted from the front side of the printer a, and while the sheet P is conveyed horizontally, an image is formed on the sheet P at an image forming section C located approximately in the center. The paper is conveyed almost horizontally, and at the left end, it is folded back and transferred from the paper output section d to the upper paper output tray e.
It is designed to be discharged.

However, the conventional printer a shown in FIG. 12 has the drawback that it requires a large installation area, such as the cassette b being inserted into the front and the sheet P being conveyed horizontally. To compensate for this, each device is placed vertically. That is, a process unit that performs image formation is placed above the photosensitive drum, an optical unit is placed above this process unit, and a sheet feeding section and a sheet discharging section are placed in parallel on both sides of this optical unit. However, printers have been devised that reduce the footprint of the printer.

(c) Problems to be Solved by the Invention However, the above-mentioned vertical printers have a drawback in that it is difficult to distinguish between face-up paper discharge and face-down paper discharge.

Therefore, the present invention makes the arrangement space compact by configuring the sheet stacking section to be swingable, and
It is an object of the present invention to provide a sheet ejecting device for an image forming apparatus that can be used by switching between face-up and face-down sheet ejection.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned circumstances. For example, referring to FIGS. 1 and 4, the photosensitive drum (
4) is disposed below the device (1), and the photosensitive drum (4)
Each process unit (6) for forming an image on the photosensitive drum (4) is disposed around the upper side of the photosensitive drum (4), and an optical unit (10) for printing image information on the photosensitive drum (4) is arranged between the process units. (6), and the feeding section (11, 12> and the discharging section (16a) of the sheet (P).
, 16b) are disposed on both sides of the optical unit, and a sheet stacking section (18) that stacks the ejected sheet (P).
In the image forming apparatus (1), the sheet stacking section (18) has at least a first position (A) and a second position (B).
) and is configured to be selectively movable.
The sheet stacking section (18) or the sheet stacking tray (18)
It is characterized by

Further, the sheet stacking section (18) or the discharging section (16a
, 16b) so as to be rotatable around the paper ejection roller (17).

Further, the sheet stacking section (18) is characterized by including a guide section (18c) that regulates the discharge direction of the sheet (P) discharged.

0) Function Based on the above configuration, a latent image is formed on the lower photosensitive drum (4) by the light beam scanned by the optical unit (10) at the upper center of the image forming apparatus (1), and the latent image is formed on the photosensitive drum (4) below. The photosensitive drum (
4) Form a toner image on the sheet (P), which is fed from the sheet (P) feeding section (11, 12) disposed on the negative side of the optical unit (10). ) and after forming an image on the sheet (P) with this toner image, the sheet (P) is transferred to the sheet stacking section by the sheet (P) discharge section (16a, 16b) disposed on the other side of the optical unit 10). (18) The sheet (P) on which the image is formed is discharged and stacked. At this time, the sheet stacking section (18) selects and moves at least the first position (A) and the second position (B).

Also, the sheet stacking section (18) is connected to the discharging section (16a, 16b).
) in any direction around the discharge roller shaft (17) to change the stacking posture of the sheets (P).

Note that the reference numerals in parentheses are for illustrative purposes only, and do not limit equivalent configurations.

(f) Example The present invention will be described in detail below with reference to the drawings.

In Figure 1, 1 is a vertical laser beam printer that is an image forming device, and a powerful power supply unit 2 is located at the bottom.
A powerful drive motor 3 is provided at the lower left side of the power source section 2, and a photosensitive tram 4 is provided at the upper center of the shaft. It is designed to be rotated by a photosensitive drum 4.

A process unit 6 is placed around the upper side of the photosensitive tram 4.
A cleaner 7, a charging roller 8, and a developing device 9 are provided.

An optical unit 10 is disposed above the process unit 6, and a cassette 11 for sheets P is provided on the right side of the optical unit 10 and the process unit 6 in a substantially perpendicular direction. A paper feed roller 12 picks up the sheets P in the cassette 11 at the lower left end of the paper feed roller 11, and a friction butt 13 separates the sheets one by one.

A registration roller 14 is provided upstream of the photosensitive drum 4 and the transfer charger 5 and downstream of the paper feed roller 12, and a fixing roller 15 is provided at a mid-height position on the left side of the printer 1. .

A pair of paper ejection rollers 16a and 16b is provided above the fixing roller 15, as shown in FIGS. 2 to 4.

As shown in FIG. 4, a paper discharge tray 18 made of transparent plastic or the like is supported on the shaft 17 of the paper discharge roller 16a. This paper discharge tray 18 includes a large plate-shaped tray 18a extending outward from the center, and a large plate-shaped tray 18a extending outward from the center.
The cylindrical parts 18b and 18c formed at the base end of the cylindrical part 1
A lower portion 18d extending outward from the end of the tray 18c via a curved surface portion, and a side plate portion 18e connecting the tray 18a and the lower portion 18d.
The tray 18a and the lower part 18d are made up of 9
It forms an angle close to 0 degrees. In the state shown in FIG. 3, the bottom portion 18d is seated on the lower portion 19a of the side plate 19 of the main body which is inclined inward, and the tray 18a is inclined diagonally inward and functions as a lid during face-down paper ejection. The device is designed to take the first device A.

Further, as shown in FIG. 4, the cylindrical portion 18c is connected to the tray 1
8a or seat P when taking the second device B tilted outward.
It acts as a guide to determine the direction of discharge.

Also, a protruding member 16c is attached to the rollers 16a and 16b.

A guide is provided between each pair of rollers, the process unit 6 is a removable process cartridge, and the right side plate 20 of the main body, which faces the side plate 19 of the main body, has a plurality of grooves centered around the lower end. As shown in FIGS. 1 and 2, when the tray is rotated clockwise to the position shown by the broken line, it can also be used as a tray when paper is fed from the right side. A paper feed roller pair 21 is provided for this purpose. In addition,
FIG. 5 is a perspective view of the paper discharge tray 18.

Next, the operation of this embodiment will be explained.

The light beam scanned by the optical unit 10 or the photosensitive tram 4
irradiate. On the other hand, the photosensitive drum 4 is cleaned of toner paper powder etc. by the cleaner 7 and is uniformly charged by the charging roller 8.
A latent image is formed on the surface of the toner image, and a toner image is formed on this latent image by the developing device 9. On the other hand, the sheets P in the cassette 11 are picked up by the paper feed roller 12, separated one by one by the friction butt 13, and then placed on the registration rollers 1.
4, the posture of the sheet P is regulated and conveyed in synchronization with the photosensitive drum 4, so that the toner image on the photosensitive tram 4 is aligned with the sheet P.
The toner image is transferred onto the sheet P by the transfer charger 5, and after being fixed on the sheet P by the fixing roller 15, it is ejected upward by a pair of ejecting rollers 16a and 16b. At this time, when the tray 18a is in the first device A, the sheet P is ejected facing in the direction of arrow C, and the rear end of the sheet P is kicked out by the kicking member 16c, as shown in FIG. . Then, the pages are stacked face down on the main body side plate 19 in page order.

Note that since the tray 18a is transparent, its condition can be visually confirmed from the outside.

When the tray 18a or the second device B is in the fourth
As shown in the figure, the sheet P is guided by the cylindrical portion 18C and discharged in the direction of the arrow, and the rear end of the sheet P is kicked out by the kicking member 16c, and the sheet P
is ejected face up. After discharge, sheet P
The image formation status can be checked immediately.

As explained above, this laser beam printer is vertical, so the installation area is small, and the paper output tray 18
Since the paper can be ejected face-up and face-down in an inclined state, the above-mentioned installation area can be kept small, and the user's operability can be further improved.

Next, another embodiment will be described with reference to FIG. 6 and FIG. In addition, a tray 22f is provided at a position facing the tray 18a, and the sheet P is stored in the paper discharge tray 22 whether the tray 22 discharges the sheet face-down or face-up.

Note that the paper output tray 22 configured in this way can be replaced (
(removable), the output tray 22 can be replaced during copying jobs, and jobs can be organized better.

Next, still another embodiment will be described with reference to FIGS. 8 and 9.

In this embodiment, the paper ejection tray 23 swings as in the previous embodiment, and the paper ejection roller 16b and the paper ejection roller 16
It is constructed so that it can swing around an axis 17 of a.

In this case, since the paper ejection roller 16b swings, the sheet P
The cylindrical portion of the paper ejection tray 18 in the embodiment (shown in FIGS. 1 to 5) 18c is no longer necessary.

Note that since the paper ejection roller 16b moves and the nip portion with the roller 16a moves, the inner guide 24 is moved to the ninth position.
Is it necessary to extend it to the position of the nip portion in the case of the second device B shown in the figure?

Next, another embodiment will be described with reference to FIGS. 10 and 11.

In this embodiment, the paper output tray 25 has a tray 25a added to the paper output tray 23 of still another embodiment shown in FIG. 9, and the effect is different from that shown in FIGS. 6 and 7. It is the same as the example.

In the embodiments shown in FIGS. 8, 9, 10, and 11, the paper is rotated around the paper ejection roller 16a, but it may be rotated around the paper ejection roller 16b. . Further, the paper discharge tray may be rotated about a completely different position, or the paper discharge tray may be configured to be switched between the face-up and face-down paper discharge positions using a mechanical link mechanism.

(g) As described in detail, according to the present invention, the process unit is arranged above the photosensitive drum, the optical unit is arranged above it, and the sheet is fed on both sides of the optical unit. In a vertical image forming apparatus in which a sheet output section and a sheet output section are arranged, in order to switch between face-up sheet output and face-down sheet output, there is no need to provide each sheet output port, and the sheet output section can be tilted sideways. This has made it possible to significantly reduce the installation area of the device and improve operability for the user.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional side view showing the face-down paper discharge state of the embodiment of the present invention, FIG. 2 is a cross-sectional side view showing the paper discharge tray or face-up paper discharge state, and FIG. 3 is the face-town paper discharge state. FIG. 4 is an enlarged sectional side view of the paper ejection tray in the face-up paper ejection state; FIG. 5 is a perspective view of the paper ejection tray;
FIG. 6 is a cross-sectional side view of another embodiment in a face-down paper discharge state, FIG. 7 is a cross-sectional side view of the paper output tray in a face-up paper discharge state, and FIG. 8 is a cross-sectional side view of another embodiment. FIG. 9 is a cross-sectional side view showing the face-down paper discharge state; FIG. 10 is a cross-sectional side view showing the face-down paper discharge state of another embodiment; FIG. 11 is a cross-sectional side view showing the face-down paper discharge state; 1 is a cross-sectional side view of the printer in its face-up paper ejection state, and FIG. 12 is a cross-sectional side view of the conventional printer. 1... Image forming device (laser beam printer),
4...Photosensitive tram, 6...Process unit)
, 10...optical unit), 11゜12...feeding section (
cassette, paper feed roller) 16a, 16b... Paper ejection roller pair 17... Shaft 18... Sheet stacking section (paper ejection tray) 18C... Guide section (cylindrical section) A-...
1st position, B...2nd position, P...sheet

Claims (1)

[Claims] 1. A photosensitive drum is disposed below the device, each process unit for forming an image on the photosensitive drum is disposed around the upper side of the photosensitive drum, and image information is transmitted to the photosensitive drum. An optical unit for printing thereon is disposed above the process unit, a sheet feeding section and a sheet discharging section are disposed on both sides of the optical unit, and a sheet stacking section is provided for stacking the discharged sheets. A sheet discharging device for an image forming apparatus, wherein the sheet stacking section is configured to be movable to at least a first position and a second position. 2. The sheet discharging device in an image forming apparatus according to claim 1, wherein the sheet stacking section is a sheet stacking tray. 3. The sheet discharging device in an image forming apparatus according to claim 1, wherein the sheet stacking section is configured to be rotatable about a paper discharging roller shaft of the discharging section. 4. The sheet ejecting device in an image forming apparatus according to claim 1, further comprising a guide portion for regulating the ejecting direction of the sheet ejected by the sheet stacking portion.