JP2002326749A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of reducing noise, improving the durability of paper sheet discharging rollers and reducing power consumption. SOLUTION: In an image forming device provided with a plurality of stacking trays 17 and 20 and paper sheet discharging rollers 18 and 19 to discharge sheet materials to their respective stacking trays 17 and 20, and comprising an FU tray 20, on which the sheet materials discharged by the FU paper sheet discharging roller 18 upperstream of a carrying passage are stacked, supported pivotally so as to be opened and closed, a photo-interrupter 32, a light source cutting off section (lever) 31 for cutting off the light source of the photo- interrupter 32 interlocked with the opening and closing operation of the FU tray 20, and a solenoid 38 for cutting off the drive force transmission from the FU paper sheet discharging roller 18 upperstream of the carrying passage to the an FD paper sheet discharging roller 19 downstream of the carrying passage are provided. Through this constitution, the driving of the FD paper sheet discharging roller 19 downstream of the carrying passage is cut off according to the detected opening state of the FU tray 20.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image forming apparatus such as a printer, a facsimile, a copying machine, etc., which conveys a sheet material to an image forming section.

[0002]

2. Description of the Related Art The configuration of a laser beam printer as an example of a conventional image forming apparatus will be described with reference to FIG.

In the laser beam printer 1 shown in FIG. 3, the drive is transmitted by a gear train from one main motor that rotates all the rollers related to the photosensitive drum 6A and the paper conveyance. Then, a video controller board (not shown) creates an image signal based on information transmitted from an external information device such as a personal computer or a word processor. In response to the image signal generated by the video controller board, the laser beam L is emitted onto the photosensitive drum 6A by reflection of a polygon mirror and a return mirror directly connected to a motor independent of the printer main body.

The photosensitive drum 6A rotates in the direction of the arrow (clockwise) in the figure, and forms an electrostatic latent image sequentially. Then, the electrostatic latent image formed on the photosensitive drum 6A is sequentially visualized as a toner image by toner supplied from a developing unit (not shown) in the process unit 6, and is transferred to the transfer roller 7. Conveyed to the site.

On the other hand, the sheet material S stacked and stored in the paper feed cassette 8 is moved from the uppermost one by a half-moon-shaped paper feed roller 9 which makes one rotation in the direction of the arrow (counterclockwise) in the figure.
Each sheet is sequentially sent out to the sheet feeding path 10A, and is conveyed by the conveying roller pair 11 to the registration roller pair 12 whose rotation is stopped.

After the sheet material S reaches the pair of registration rollers 12, the leading end of the sheet material S abuts the nip of the pair of registration rollers 12, and then the sheet material S is continuously conveyed until a predetermined loop is formed, thereby correcting the skew state. You. The sheet material S for which the correction of the skew state has been completed is conveyed to the transfer section by the registration roller pair 12 which starts rotating at the timing of aligning the position with the toner image on the photosensitive drum 6A. The toner image on the photosensitive drum 6A is transferred.

[0007] The sheet material S on which the transfer of the toner image has been completed is conveyed to the fixing roller 14 through the conveyance guide 13, where the transferred toner image is fixed. When the sheet material S on which the toner image fixing process has been completed is stacked with the print surface facing downward, the sheet material S is transferred from the FU discharge roller 18 to the transport surface 1.
6 and a FD discharge roller 1 passing through a conveyance path formed by a guide surface of the face-up tray 20 opposed thereto.
9 and is discharged onto a discharge tray 17 at the top of the printer body. Here, the driving force of a motor (not shown) is applied to the FU paper discharge roller 18 through the gears 22 and 23 on the fixing unit side.
It is transmitted via a gear 24 on the roller shaft. Then, when the drive is transmitted from the gear train 25 to the gear 28 on the FD roller shaft via the idler gear 27, the FD discharge roller 19 rotates in the direction of the arrow shown in the figure.

When the printing surface is stacked upward (face-up stacking), a face-up tray (hereinafter referred to as an FU tray) 20 which can be opened and closed is turned around a fulcrum 21 as shown by a chain line in FIG. Rotate clockwise to open and make a loading tray. Therefore, the sheet material S on which the fixing process has been performed is transferred to the FU sheet discharging roller 1 disposed immediately thereafter.
8 and are stacked on the FU tray 20. At this time, the FD paper discharge roller 19 also keeps rotating because the drive is transmitted from the gear train 24 to the gear 28.

[0009]

As described above, in the prior art, when the FU tray 20 is open, the FD discharge roller 19 is located downstream of the FU discharge roller 18, and although the FU discharge roller 19 is not used at all. The drive is transmitted and continues to rotate. For this reason, the drive gear train and the FD discharge roller 19 required excessive durability.

When the FU tray 20 is opened, an FD discharge roller 19 provided near the FU tray 20 is provided.
The driving noise generated by the gear train for transmitting the drive
Easily leaks to the outside, increasing the noise level. Therefore, it is necessary to separately take measures such as a soundproof wall for noise prevention.

Furthermore, when the FU tray 20 is opened, a separate blind member is required to prevent the user from touching the gear train. Therefore, the cost is increased and the degree of freedom of design is significantly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an image forming apparatus capable of reducing noise, improving the durability of a discharge roller, and reducing power consumption. It is in.

[0013]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a plurality of stacking trays; and a discharge roller for discharging a sheet material onto each of the stacking trays. An image forming apparatus comprising a stacking tray on which a sheet material discharged by an output roller on the upstream side is stacked so as to be openable and closable, wherein a photointerrupter and the photointerrupter are linked with opening and closing operations of the stacking tray. And a means for interrupting the drive transmission from the upstream paper discharge roller to the downstream paper discharge roller, and detecting the open state of the stacking tray to control the downstream paper discharge roller. Driving is shut off.

According to a second aspect of the present invention, there are provided a plurality of discharge stacking trays and a discharge roller for discharging the sheet material onto each of the stacking trays, and the discharge roller on the upstream side of the conveyance path discharges. In an image forming apparatus having a stacking tray for stacking sheet materials pivotally supported so as to be openable and closable, a photointerrupter, a lever that intercepts a light source of the photointerrupter in conjunction with the opening and closing operation of the stacking tray, and a downstream side An independent drive source for driving the transport roller is provided, and the independent drive source for the downstream discharge roller is stopped by detecting an open state of the stacking tray.

[0015]

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

<Embodiment 1> FIG. 1 is a partial sectional view showing the structure of a sheet conveying unit, a stacking unit, and a driving unit of an image forming apparatus according to Embodiment 1 of the present invention. The same elements as those shown in FIG. 3 are denoted by the same reference numerals.

The element 32 on the electric circuit board 4 shown in FIG. 1 is a photo interrupter, and when the FU tray 20 is closed, the light source cutoff section 31 of the FU tray 20 blocks the light source of the photo interrupter 32. Further, in a state where the FU discharge tray 20 is opened with the rotation center 21 as a fulcrum (in a state indicated by a chain line 20 ′ in FIG. 1), the light source cutoff unit 31 rotates to the position of 31 ′ and the light source of the photointerrupter 32 is rotated. open. Thereby, the photo interrupter 32
By transmitting the information to the CPU after being converted into an electric signal, the open / close state of the FU tray 20 can be detected.

The gear 24 on the shaft of the FU discharge roller 18 is
Drive is transmitted from an idler gear 23 in conjunction with a main motor (not shown) as a drive source.

A solenoid 38 having a moving shaft 39 which moves up and down by an electric signal, a swing gear 34 swinging about a shaft 36 of an idler gear 35, an idler gear 33 to which drive is transmitted from the swing gear 34, and the idler gear 33 to F
An idler gear 26 for transmitting the drive to the D discharge roller 19,
27 and a gear 2 provided on the shaft of the FD discharge roller 19
8. The moving shaft 39 of the solenoid 38 from the idler gear 33
Release lever 3 for transmitting the movement of the gear to the swing gear 34
The drive system is constituted by the spring 7 and the spring 40.

The drive release lever 37 is rotatably supported on a support shaft 36 of the idler gear 35. A support shaft 43 of the swing gear 34 is provided at a left end, and a solenoid 38 is moved at a central portion on the right side of the support 36. A receiving hole 42 for transmitting the movement of the shaft 39 and a hole for attaching a spring 40 for pulling the swing gear 34 away from the idler gear 33 are provided at the right end.

When driving is transmitted to the FD discharge roller 19, the moving shaft 39 of the solenoid 38 is lowered by an electric signal, and the drive release lever 37 rotates clockwise about the fulcrum 36. The oscillating gear 34 also rotates in the same manner and the idler gear 3
Meshes with 3. Since the rotation is transmitted to the idler gear 33 in the clockwise direction, the engagement of the idler gear 33 with the swing gear 34 is in the biting direction. By setting the spring pressure of the spring 40 to be smaller than the biting force, after the drive is transmitted, the swing gear 3 can be driven without the rotation force of the drive release lever 37.
4 continues to mesh with the idler gear 33.

When the drive is not transmitted to the FD paper discharge roller 19, the moving shaft 39 of the solenoid 38 is raised by an electric signal to release the meshing state between the swing gear 34 and the idler gear 33. Thereafter, due to the spring force of the tension spring 40, the state of the drive release state is maintained without the tension force of the solenoid 38.

Here, the pulling force of the spring 40, the biting force when the idler gear 33 and the swing gear 34 mesh with each other, and the pulling force and pushing force of the moving shaft 39 of the solenoid 38 have the following relationships.

(Tension force of spring) <(bite force at meshing) (tension force of spring) <(push force of solenoid shaft) (tension force of spring) + (bite force at meshing) <
(Tension Force of Solenoid Shaft) In the above configuration, when the FU tray 20 is closed, its state is detected by the photointerrupter 32, and based on the information, an instruction to push the moving shaft 39 of the solenoid 38 is output and the moving shaft is output. 39 moves. And this moving axis 3
In conjunction with the movement of 9, the swing gear 34 swings via the drive release lever 37 and meshes with the idler gear 33 to transmit the drive.

When the FU tray 20 is opened, the state is detected by the photo interrupter 32 and the solenoid 38
Is pulled, the drive release lever 37 holding the shaft 43 of the swing gear 34 rotates counterclockwise, and the meshing state between the swing gear 34 and the idler gear 33 is released. As a result, the drive to the FD discharge roller 19 is released, and the FD discharge roller 19 stops rotating.

As described above, when the FU tray 20 is opened, the gear train after the idler gear 33 and the FD discharge roller 1
9, the rotation of the gear train and the rotation of the FD discharge roller 19 can prevent the generation of noise.

Further, since the FD discharge roller 19 does not keep running idly, the durability of the FD discharge roller 19 is improved. Furthermore, after the idler gear 33, the FU tray 2
Even if the arrangement is such that the arrangement can be touched when the 0 is open, troubles such as the finger being pulled into the meshing portion do not occur, so that the degree of freedom in the configuration in product design is increased.

Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIG.

FIG. 2 is a partial cross-sectional view showing the structure of the sheet conveying means, the stacking means, and the driving means of the image forming apparatus according to this embodiment. In this figure, the same elements as those shown in FIG. The same reference numerals are given.

The element 32 on the electric circuit board 4 shown in FIG. 2 is a photo interrupter. When the FU tray 20 is closed, the light source cutoff unit 31 blocks the light source of the photo interrupter 32. Further, F is set with the rotation center 21 as a fulcrum.
In a state where the U tray 20 is opened (a state shown by a chain line 20 ′ in FIG. 2), the light source blocking unit 31 rotates to the position of 31 ′ and the light source of the photo interrupter 32 is opened. Thereby, the open / closed state of the FU tray 20 can be detected by being converted into an electric signal by the photo interrupter 32 and transmitted to the CPU.

The FU discharge roller 18 is provided in the first embodiment.
Similarly, the drive is transmitted by an idler gear 23 interlocked with a gear train using a main motor (not shown) as a drive source.

The discharge motor 50, which is a drive source independent of the main motor, the gear 27 attached to the motor shaft, and the F
By the drive gear train including the gear 28 on the axis of the D discharge roller 19, the FD discharge roller 19 can rotate and stop independently of the rotation of the main motor.

In the above configuration, when the FU tray 20 is closed, the state is detected by the photo-interrupter 32, and based on the information, the discharge motor 50 rotates clockwise, and via the two gears 27, 28 To rotate the paper discharge roller 19 counterclockwise. Then, when the FU tray 20 is opened, the state is detected by the photo interrupter 32, and the discharge motor 50 is stopped.

As described above, in the present embodiment, since the FD discharge roller 19 is driven by the single discharge motor 50, the FD discharge roller 18 is moved from the FU discharge roller 1 to the FD discharge roller 1.
9 is simplified, and noise due to gear engagement is greatly reduced. In addition, since the start and stop of rotation can be freely performed without being restricted by the main motor, the operation time can be minimized and power consumption can be reduced. In addition, in the present embodiment, the same effects as in the first embodiment can be obtained.

[0035]

As is apparent from the above description, according to the present invention, a plurality of stacking trays and a sheet discharging roller for discharging a sheet material onto each of the stacking trays are provided, and are located on the upstream side of the transport path. In an image forming apparatus in which a stacking tray on which a sheet material discharged by a discharge roller is stacked is pivotally supported so as to be openable and closable, a light source of the photointerrupter and a light source of the photointerrupter are shut off in conjunction with an opening and closing operation of the stacking tray. A lever and means for interrupting drive transmission from the upstream discharge roller to the downstream discharge roller; and detecting the open state of the stacking tray to shut off the drive of the downstream discharge roller. As a result, the effects of reducing noise, improving the durability of the discharge roller, and reducing power consumption can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view illustrating a configuration of a sheet conveying unit, a stacking unit, and a driving unit of the image forming apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a partial sectional view illustrating a configuration of a sheet conveying unit, a stacking unit, and a driving unit of the image forming apparatus according to a second embodiment of the present invention.

FIG. 3 shows a conventional image forming apparatus (laser beam printer).
FIG.

[Explanation of symbols]

 Reference Signs List 17 discharge tray (loading tray) 18 FU discharge roller (discharge roller) 19 FD discharge roller (discharge roller) 20 FU tray (loading tray) 31 light source cutoff section (lever) 32 photo interrupter 38 solenoid (drive) Means for interrupting transmission) 39 Moving shaft 50 Discharge roller (independent drive source) S Sheet material

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) G03G 15/00 530 G03G 15/00 530 F-term (Reference) 2H072 AA09 AA17 CA01 CB01 FA01 FB03 JA02 3F048 AA02 AA04 AA05 AB01 BB02 DA09 DC13 EA15 EB40 3F049 AA10 DA12 DB02 EA24 LA02 LA05 LA07 LB03 3F053 EA02 EA04 EA05 EC07 ED05 LA02 LA05 LA07 LB03 3F054 AA01 AC02 AC03 AC05 BA02 BC04 BJ02 CA23 DA15 DA16

Claims (2)

[Claims] A plurality of stacking trays, and a sheet discharging roller for discharging the sheet material onto each of the stacking trays, wherein the stacking tray for stacking the sheet material discharged by the sheet discharging roller on the upstream side of the transport path is opened and closed. A photo interrupter, a lever that intercepts a light source of the photo interrupter in conjunction with the opening / closing operation of the stacking tray, and a paper output downstream from an upstream paper output roller. An image forming apparatus, comprising: means for interrupting drive transmission to a roller, wherein the drive of the downstream discharge roller is interrupted by detecting an open state of the stacking tray. A plurality of stacking trays, and a discharge roller for discharging the sheet material onto each of the loading trays, wherein the loading tray for loading the sheet material discharged by the discharge roller on the upstream side of the transport path is opened and closed. An image forming apparatus which is pivotally supported, wherein a photo-interrupter, a lever which intercepts a light source of the photo-interrupter in conjunction with an opening / closing operation of the stacking tray, and an independent driving source which drives a downstream conveying roller An image forming apparatus that detects an open state of the stacking tray and stops an independent drive source of a downstream discharge roller.