JPH03182446A - Image forming device - Google Patents

Abstract

PURPOSE:To cut off the dust and external light from a feed port with a guard member and prevent the deterioration of a feed means by providing the guard member between the feed port and the feed means. CONSTITUTION:A feed roller cover 11c for preventing dust from sticking to a feed roller 11a is provided along the periphery of the feed roller 11a on the sheet feed side of the feed roller 11a. A guard member 11d guiding a fed transfer material and preventing the light from the feed port 10 from being radiated to the feed roller 11a made of rubber to deteriorate the roller face with ultraviolet rays is provided in the axial direction on the sheet feed side of the feed roller cover 11c. The guide member 11d prevents the external light from entering through the feed port 10 and prevents the infiltration of dust or the like. The guide member 11d concurrently serves as a cover preventing a finger from touching and breaking the feed roller 11a by mistake when the finger is put on the feed port 10 while a copying machine main body 1 is horizontally carried.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an image forming apparatus for forming an image on a transfer material, and more particularly to an image forming apparatus capable of preventing deterioration of a feeding means due to ultraviolet rays.

<Prior Art> Today, image forming devices such as copying machines are widely used, and in these devices, a transfer material is inserted through a feeding port, and the transfer material is transferred to an image forming section by a feeding roller. The toner images are separated and fed one by one, and a toner image is formed in an image forming section.

<Problems to be Solved by the Invention> However, in the above device, if the feeding roller is provided near the feeding port, dust etc. that enter from the feeding port may adhere to the feeding roller or When external light hits the feed roller,
The feeding roller may deteriorate due to ultraviolet rays from outside light.

For this reason, conventionally, the feeding roller was placed in a position slightly in front of the feeding port and away from external light, but this resulted in a long distance between the feeding port and the feeding roller, which made it difficult to miniaturize the device. It was a hindrance.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems, and to provide an image forming apparatus in which the feeding means is provided near the feeding port and the feeding means is miniaturized, but the feeding means is not irradiated with external light. This is what we intend to provide.

Means for Solving the Problems> A typical means according to the present invention for solving the above problems includes a feeding port for feeding a transfer material, and a feeding port for feeding the transfer material inserted from the feeding port. It has a feeding means for feeding, and an image forming means for forming an image on the transfer material fed by the feeding means, and a guard member is provided between the feeding port and the feeding means. It is characterized by this.

<Function> In the above means, even if the feeding means is placed near the feeding port, dust, external light, etc. are blocked by the guard member, and the feeding means is prevented from being deteriorated by ultraviolet rays, etc. It's something you get.

<Embodiment> An embodiment of an image forming apparatus to which the present invention is applied will be described below with reference to the drawings. In this embodiment, a case where an electrophotographic copying machine is used as an image forming apparatus will be described.

Fig. 1 is a perspective view showing the external appearance of the copying machine, Fig. 2 is a partially enlarged explanatory view of the ejection tray, Fig. 3 is an FIA diagram showing the locking operation of the ejection tray, and Fig. 4 is the feeding roller. FIG. 5 is a perspective view of the conveying device, FIG. 6 is a cross-sectional view showing the general structure of the copying machine, and FIGS. It is a cross-sectional explanatory view.

First, the general structure of the copying machine will be explained with reference to FIG.

1 is a main body of the copying machine, and 1a is a casing forming the exterior of the main body 1 of the copying machine.

On the top surface of this housing 1a is a document for placing a document!
! Document placement plate 2 with a platen glass and a placement means
A and a document pressure bonding plate 2b are provided. The document placement plate 2a and the document pressure bonding plate 2b are driven by a driving force transmitted from a drive source, which will be described later, as indicated by the arrow a in the figure.

It moves back and forth in direction b.

Further, a white reference plate 2c for reflecting light irradiated onto the surface of the document is integrally attached to the back side of the document pressure bonding plate 2b.

S! on the original 1 plate 2a above! While the placed original is moving in the direction of arrow a, light is irradiated onto the surface of the original by an exposure lamp 3, which is an illumination means provided in the casing la, through a slit 1b provided on the top surface of the casing 1a. Ru. The light reflected from the above document surface is a focusing light transmitter (product name: SELFOC).
, a small-diameter imaging element array such as a bar lens; 4. filter 5
, an image is formed on the circumferential surface of the photosensitive drum 6, which is an image carrier, and exposed.

The photosensitive drum 6 is uniformly charged in advance by a primary charger 7, and an electrostatic latent image is formed by irradiating it with light reflected from the original. This static Ti latent image is made into a visible image by being coated with toner by a developing device 8.

Reference numeral 9 denotes a guide member capable of supplying a plurality of sheets of transfer material, and the transfer material supplied from the feeding port IO is guided by the inclined surface of the guard member lid and passes through the feeding roller 11a and the separating member 11b. - Next, it is conveyed to the stopped registration roller pair 12, and the skew is corrected. The transfer material is electrostatically formed on the photosensitive drum 6 by the registration roller pair I2. In synchronization with the leading edge of the II image, the toner image is conveyed to the transfer section, and the toner image is transferred onto the transfer material by the transfer charger 13.

After the toner image is transferred to the transfer material, the toner remaining on the circular surface of the photosensitive drum 6 is removed by a cleaning device 14. Further, the transfer material after the image transfer is separated from the photosensitive drum 6 and moved by the feed roller 15 to the feed guide 15a.
It is transported to the transport device 16 via. This transport device 1G
The transfer material is conveyed to the fixing device 17, where the transferred image is thermally fixed.Then, the transfer material is conveyed to the fixing device 17, where the transferred image is thermally fixed.
8, and is discharged onto a discharge tray 19, which is a discharge means rotatably attached to the housing 1a. The fixing device 17 has a high thermal conductivity film-like fixing ring 7a passed between rollers and pressed by a pressing member 17b onto a fixing roller 17c having a heat source.

The photosensitive drum 6, the secondary charger 7. The developing device 8.degree. and the cleaning device 14 are housed within a cover 20a, and are integrally constructed as a cartridge 20 that can be detachably installed in the copying machine 1 as a whole. This cartridge 20 is held by a guide holding member 21 provided within the housing la.

Further, above the fixing device 17, an exhaust fan 22 is provided for sucking and exhausting warm air inside the casing 1a.

Next, with reference to FIGS. 7(a) and 7(c), a drive system for the original i3i placing plate 2a and the original pressing plate 2b, which are the original placing means, will be described.

FIG. 7 (al is a schematic sectional view of the copying machine body 1 viewed from the drive source side. When the motor 23 is driven, a driving force is applied to the pinion gear 25 partially exposed on the top surface of the housing 1a through the gear train 24. This pinion gear 25 is connected to a rack 26 provided on the back side of the document placement plate 2a.
By meshing with the holder, it moves in the directions of arrows a and b in the figure. In addition, the above manuscript i! ! The movement range of the placing plate 2a and the original pressure bonding plate 2b is normally within the length range of the ejection tray 19.

Next, a driving force transmission structure in the gear train 24 will be explained with reference to FIG. 7(b).

In the figure, the rotating shaft 27 has a gear 28 on the drive source side.
Gears 29 are coaxially attached to the load side. A torque limiter 30 is provided between the gear 28 and the gear 29 to transmit or release the driving force from the motor 23.

The general structure of this dork printer 30 is that a collar 3 is attached to the side of the gear 29 by a stop ring 30a.
A spring 3 interposed in the axial direction between 0b and the boss 30c
0d, the boss 30c is always pressed toward the gear 2S. By fitting a protrusion 30e having an inclined surface protruding from the outer circumferential surface of the end portion of the boss 30c into a groove 30f having an inclined surface provided on the circumferential surface of the opposing gear 28, the frictional force between the two is The driving force is shifted from gear 28 to gear 29.
It is transmitted to

In this torque limit 30, when a load exceeding a predetermined load torque (for example, 11 kg-cm) is applied, the protrusion 30e slides further into the groove 30 and rises, causing the boss 3
0c moves in the direction of arrow C against the elastic force of spring 30d, thereby canceling the transmission of the driving force from gear 28 to gear 29. Specifically, when a force of 3 kg or more is applied by the platen glass to the gear 25 having a diameter of 28 mg+, the torque limiter 30 is activated.

Next, a discharge tray 19 for discharging transfer material used in the copying machine 1 constructed as described above will be described with reference to FIGS. 1 to 3.

As shown in FIG.
A and a document pressure bonding plate 2b are rotatably attached to the side surface of the housing 1a corresponding to the moving direction.

This discharge tray 19 is constructed by rotatably connecting a front plate 19a and a rear plate 19b so as to be foldable.

Of these, the rear Fi 19b is rotatably attached to the side surface of the housing 1a as described above.

Since it is inconvenient to carry the copying machine 1 with the ejection tray 19 open from the side of the housing 1a, the second ejection tray 19 is
As shown in FIG. 2(a) to FIG. 2(C), after folding the front plate 19a onto the rear plate 19b, both of them are rotated to close the transfer material discharge port 18a. It is necessary to lock it integrally with the side surface of 1a.

In this way, the transfer material discharge port 18a can be blocked and dirt can be prevented from entering, and the discharge tray 18a can be prevented from entering.
9 protrudes up to the upper surface of the housing 1a on which the document placement plate 2a and the document pressure bonding plate 2b move, so that it is effective as a stopper in the event of a malfunction. Therefore, as shown in second (a), projections 19 are formed on both side edges of the rear plate 19b.
c and 19d are provided in a protruding manner, and protrusions 1c and ld are also provided on the side surfaces of the housing 1a corresponding to these protrusions so as to lock the two, respectively.

In addition, in the conventional way, the ejection tray was locked with the side of the copying machine by inserting and locking protrusions on both sides of the ejection tray between a pair of rollers on the side of the copying machine, so the ejection tray was the same on both sides. It was locked to the side of the copying machine by the locking force.

On the other hand, in this embodiment, the original s! The locking force between the protrusion 19C on the drive source side of the placement plate a and the original pressure bonding plate 2b and the protrusion 1c on the housing ld side is made stronger than the locking force between the protrusion 19d and the protrusion d on the operator side.

That is, as shown in FIGS. 3(a) and 3(b), the protrusion 19c
The locking portions of the projections 1c lock the sides perpendicular to the moving direction of the document 1jzlf plate 2a and the document pressure bonding plate 2b. On the other hand, the protrusion 19d and the protrusion d lock the inclined sides of the document placement plate 2a and the document pressure bonding plate 2b in the moving direction.

This is the original manuscript! The driving force of the 1-place plate 2a and the original pressing vi2b is transmitted more strongly when it is closer to the driving source.
This is because, at the time of malfunction, a large load torque is generated on the discharge tray 19 on the drive source side. The locking force of the protrusion 19c and the protrusion 1c is configured to be larger than the maximum load torque (for example, 11 kg·cm) applied to the torque limiter 30.

Therefore, the operator folds the ejection tray 19 over the housing +a.
Even if a copying operation is erroneously started in a state in which the document placement plate 2a and the document pressure bonding plate 2b are locked, movement of the document placement plate 2a and the document pressure bonding plate 2b can be reliably prevented.

In addition, since the locking force between the protrusion 19d on the operator side and the protrusion 1d is weaker than the locking force between the protrusion 19c and the protrusion 1c on the drive source side, the operator releases the locked state of the folded output tray 19. It has the advantage of being easy to use.

Note that the shapes of the projections 19c, ], 9d and the projections 1c, ld are not limited to those of this embodiment, and may be other shapes.

Furthermore, the means for locking the ejection tray I9 and the copying machine main body 1 is not limited to the protrusion as shown in this embodiment, but may also be a locking means using a magnet, for example, by locking the drive source side with three magnets. It is also possible to configure the operation side to be locked with a single magnet.

Next, an outline of the image forming operation of the copying machine 1 configured as described above will be explained with reference to FIGS. 4 to 6.

First, even if a copying operation is accidentally started with the ejection tray 19 folded up and locked to the side surface of the housing 1a,
As described above, the locking force between the ejection tray 19 and the housing 1a is greater than the driving force of the document placement plate 2a and the document pressure bonding plate 2b.
never moves.

Next, after unfolding the folded ejection tray 19 and setting the transfer material in a state where it can be ejected, when the copying operation is started, as shown in FIG. The document placed between the two moves in the directions of arrows a and b in the figure. At this time, the exposure lamp 3 illuminates the housing 1 from inside the housing Ia.
Light is irradiated onto the document surface through a slit 1b provided on the upper surface of the document. The reflected light from the document surface is transmitted to the small-diameter imaging element array 4. An image is formed through a filter 5 on the circumferential surface of a photosensitive drum 6 that carries an image. The photosensitive drum 6 is uniformly charged in advance by a primary charger 7, and an electrostatic latent image is formed by irradiating it with light reflected from the original. This silence! One latent image is made into a visible image by being coated with toner by a developing device 8.

On the other hand, along the guide member 9 for supplying the transfer material,
The transfer material inserted through the feeding port 10 is transferred to the feeding roller Ila.
and the separating member 11b, the sheets are separated one by one, and then the sheets are fed to the stopped registration roller pair I2 to correct the skew.

On the paper feed side (right side in the drawing) of the feed roller lla, there is a fourth
As shown in the figure, a feed roller cover 11c for preventing dust from adhering to the feed roller Ila is provided in the axial direction along the circumferential surface of the roller. Further, on the paper feeding side of the feeding roller cover 11c, it guides the transferred transfer material, and the rubber feeding roller lla is irradiated with light from the paper feeding port 10, causing the roller surface to deteriorate due to ultraviolet rays. A guard member 11d is provided in the axial direction to prevent this.

This guard member lid can prevent outside light from entering through the feed port 10, and can also prevent dust and the like from entering. Further, the guard member lid is a protective cover that prevents the feed roller 11a from being accidentally contacted and damaged when a finger is placed on the feed port IO when the copying machine main body 1 is carried in a horizontal state. It is also used as.

Next, the transfer material is conveyed to the transfer section by the registration roller pair 12 in synchronization with the leading edge of the electrostatic latent image formed on the photosensitive drum 6, and the toner image is transferred to the transfer material by the transfer charger 13. transcribed into.

After the toner image is transferred to the transfer material, the toner remaining on the circumferential surface of the photosensitive drum 6 is removed by a cleaning device 14 in preparation for the next image formation.

The transfer material after the image formation is separated from the photosensitive drum 6, kicked out at the rear end by a feed roller 5, and transported to a transport device 16. The feed roller 15 has step-like jagged edges formed on its outer periphery, and kicks out the rear end of the curved transfer material (9! passed paper) shown by the two-dot chain line in FIG. The downstream conveyance device! It is to be transported to f16.

As shown in FIG. 5, the conveying device 16 has a conveying bell l-16c suspended between cylindrical conveying rollers 16a and 16h, and is rotationally driven by a drive source (not shown). . On both sides of the conveyance roller 16a, a conveyance belt 16 is provided that contacts the rear end of the transfer material or the sheet surface near the rear end, and moves toward the fixing device 17 provided on the downstream side in the conveyance direction.
A flamper 16 which is a kicking means for kicking upwards
6.16e are each mounted coaxially. The flampers 16d and 16e are provided with a plurality of blades on their circumferential surfaces, and these blades contact the rear end of the transfer material to kick the transfer material downstream. Above flamper 1
The interval between 6d and 16e is set to be smaller than the width of the postcard-sized transfer material.

The flampers 16d and 16e reliably transport the transfer material (for example, postcards, etc.) shorter than the distance 2 between the transfer charger 13 and the fixing roller 17c, shown by the solid line in FIG. 6, to the fixing device 17 on the downstream side. 16c. Incidentally, the above-mentioned flapper 16d.

The blades provided in 16e are shown in the figure so that the blades are always tilted down from the conveyance path after conveying the transfer material, so that the rear end does not jump up, especially when conveying large-sized transfer materials. The position of the blade is detected by the colander position sensor and the position is corrected.

Further, on both sides of the conveyance roller 16b, there are rubber rollers 16 for reliably conveying large-sized transfer materials, especially in the width direction.
f and 16g are respectively attached coaxially.

Further, on both sides of the feed roller 15 and the conveyance device 16,
Inner conveyance guides 16h, 16t for guiding the transfer material of postcard size L1 in the width direction, and outer conveyance guides 16j, 16k for guiding the transfer material of plain paper size L2 are provided, respectively. These transport guides +6h, 16i
, 16j, and 16 are the heights of the guide surfaces of feed roller 15.
The bottom is slightly lower than the outer circumference of the

Further, the conveying speed of the conveying device 16 is determined by the conveying speed of the fixing roller 1.
The circumferential speed is set to be slower than the rotational speed of 7c. This can prevent the leading edge of the transfer material onto which the unfixed image has been transferred from hitting the fixing device 17 and disturbing the unfixed image.

On the transfer material conveyed to the fixing device 17 by the conveyance device 16, the unfixed transferred image is thermally fixed, and then the transfer material is discharged from the discharge port 18a onto the discharge tray 19 via the discharge roller pair 1B.

<Effects of the Invention> As described above, in the present invention, since the guard member is provided between the feeding port and the feeding means, dust and external light from the feeding port are blocked by the guard member. Deterioration of the feeding means is prevented.

Further, even if a finger or the like is accidentally inserted through the feeding port, it will not reach the feeding means, so the feeding means is protected in this respect as well.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the appearance of the copying machine, Fig. 2 is a partially enlarged explanatory view of the ejection tray, Fig. 3 is an explanatory view showing the locking operation of the ejection tray, and Fig. 4 is an illustration of the feeding roller. FIG. 5 is a perspective view of the conveyance device, FIG. 6 is a cross-sectional view showing the general structure of the copying machine, and FIGS. 7(a) and 7(b) show the drive system of the document placement means. It is a cross-sectional explanatory view. ■ is the copying machine body, la is the housing, ib is the slit, 1 c
, 1 d, 19 c, 19 d, and 30 e are projections, 2 a is a document placement plate, 2 b is a document pressure bonding plate, 2 c is a white reference plate, 3 is an exposure lamp, 4 is a small-diameter imaging element array, 5 is a filter,
6 is a photosensitive drum, 7 is a primary charger, 8 is a developing device, 9 is a guide member, 10 is a feeding port, lla is a feeding roller, llb
is a separation member, llc is a feeding roller cover, lid is a guard member, 12 is a registration roller pair, 13 is a transfer band N2'
&, 14 is a cleaning device, 15 is a feed roller, 15a
is a feeding guide, 16 is a conveying device, 16a, +6b are conveying rollers, 16c is a conveying belt, 16d, 16e are flappers, 16f, 16g are rubber rollers, 16h, 16t,
16j, 16 is a conveyance guide, 17 is a fixing device, 17a is a fixing belt, 17b is a pressing member, 17c is a fixing roller,
18 is a pair of ejection rollers, 19 is an ejection tray, 19a is a front plate, 19b is a rear plate, 20 is a cartridge, 20a is a cover, 21 is a guide holding member, 22 is an exhaust fan, 23 is a motor, 24 is a gear train, 25 is a pinion gear, 26 is a rack, 27 is a rotating shaft, 28.29 is a gear, 30 is a dowel shaft, 30a is a stop ring, 30b is a collar,
30c is a boss, 30d is a spring, and 30f is a groove.

Claims (1)

[Scope of Claims] A feeding port for feeding a transfer material, a feeding device for feeding the transfer material inserted from the feeding port, and a transfer device fed by the feeding device. An image forming apparatus comprising: an image forming means for forming an image on a material; and a guard member provided between the feeding port and the feeding means.