JPH03174552A - Image forming device - Google Patents

Abstract

PURPOSE:To accomplish a stable paper feeding operation by providing an opening and closing cover which can be opened so that an image forming means may be exposed on the upper part of a device main body where the mount part of a paper housing means remains. CONSTITUTION:The paper housing means 14 where a paper supplied to the image forming means 29 is housed is mounted on the upper surface part of the device main body 10 which incorporates the image forming means 29. Then, the opening and closing cover 15 which can be opened so that the image forming means 29 may be exposed is provided on the upper part of the device main body 10 where the mount part of the paper housing means 14 remains. Therefore, the paper housing means 14 is always in a state where it does not move in spite of the opening and closing action of the cover 15. Thus, the stable paper feeding operation is accomplished.

Description

Detailed Description of the Invention [Object of the Invention] (Industrial Application Field) The present invention relates to an image forming apparatus such as an electrophotographic copying machine or a laser printer, and specifically relates to an image forming apparatus using an electrophotographic process. The present invention relates to an image forming apparatus that performs.

(Prior Art) In recent years, image forming apparatuses of this type have been miniaturized, and with this miniaturization, an image forming apparatus is formed on the upper part of the apparatus body to facilitate assembly, maintenance, inspection, etc. An apparatus has been put into practical use in which the upper cover, which is an opening/closing lid, can be opened and closed to expose the image forming means inside the main body of the apparatus.

Furthermore, in the case where the upper cover can be opened and closed, in order to reduce the installation space, a paper storage means for storing the paper to be supplied to the image forming means is attached to the top surface of the main body of the apparatus in which the image forming means is built. An image forming apparatus has been put into practical use.

However, in the past, the upper cover was configured to rotate upward at a predetermined angle of about 45 degrees parallel to the paper conveyance direction, so the rotation fulcrum side could not be opened wide. , this part is difficult to work on. In addition, in the case of conventional paper storage means provided on the device main body side, the paper storage means is configured to be displaced together with the upper cover, so if the upper cover is strongly opened or closed, the paper storage means There was a problem in that the storage condition of the paper inside the paper was damaged by vibration, causing a feeding failure.

Additionally, in the past, the fixing means remained on the main body of the apparatus even when the top cover was opened.
There have been problems in that it is difficult to replace the cleaning felt for applying a release agent such as silicone oil to the fixing roller of the fixing means, and it is difficult to replace the cartridge itself when the fixing means is a cartridge.

Furthermore, conventionally, if a mistake in taking out the paper from the paper storage means or a timing shift occurs, it is determined that there is an abnormality in paper transport and the transport system of the paper transport path is immediately stopped. For this reason, the paper may get stuck in the fixing device and stop, and if the fixing roller is used, the paper is held between the rollers and cannot be removed. There was a problem that it was extremely troublesome.

(Problems to be Solved by the Invention) As described above, in the conventional art, the rotation fulcrum side of the upper cover cannot be widely opened, making it difficult to work on this part. Furthermore, in the case of a conventional paper accommodating means provided on the main body side of the apparatus, the state in which the paper is accommodated in the paper accommodating means is impaired by vibrations, causing a feeding failure.

Furthermore, in the conventional art, the fixing means cannot be removed from the main body of the apparatus in the attached state, and maintenance, inspection, replacement, etc. of the fixing means cannot be easily performed.

Furthermore, conventionally, when it is determined that there is an abnormality in paper conveyance, the paper may get stuck in the fixing means and stop, making the paper removal work (jam clearing work) extremely troublesome.

There were other problems.

The present invention has been made based on the above circumstances, and its first object is to be able to widely open the pivot side of the opening/closing lid such as the upper cover, making it easier to work in this area, and Another object of the present invention is to provide an image forming apparatus in which the storage state of sheets stored in a sheet storage means is not impaired by vibrations when an opening/closing lid is opened and closed, and a stable sheet feeding operation is possible.

A second object is to provide an image forming apparatus in which the fixing means can be pulled out from the main body of the apparatus in the installed state, and maintenance, inspection, replacement, etc. of the fixing means can be easily performed. It is something to do.

Furthermore, the third objective is to form an image so that when it is determined that there is an abnormality in paper conveyance, the paper can continue to be conveyed to a position away from the fixing means, and the paper can be easily removed. The aim is to provide equipment.

[Structure of the Invention] (Means for Solving the Problems) As a means for achieving the above-mentioned first object, the present invention provides a structure in which a sheet of paper supplied to the image forming means is mounted on the upper surface of an apparatus body incorporating an image forming means. In an image forming apparatus equipped with a paper accommodating means for accommodating a paper accommodating means, an opening/closing lid that can be opened to expose the image forming means is provided at the upper part of the main body of the apparatus and in a portion where a mounting portion of the paper accommodating means is left. It is something.

Further, as a means for achieving the second object, an image forming apparatus includes an image forming means including a fixing means in the main body of the apparatus and forms an image on a sheet of paper conveyed through a paper conveyance path. An opening/closing lid that can be opened in a direction perpendicular to the conveying direction of the paper is provided on the top surface of the apparatus main body to expose the image forming means, and a fixing means for the image forming means is incorporated in this opening/closing lid. It is something.

Further, as a means for achieving the third object, an image forming apparatus includes an image forming means including a fixing means in the main body of the apparatus and forms an image on a sheet of paper conveyed through a paper conveyance path. paper position detection means for detecting the position of the paper conveyed through the paper conveyance path formed to pass through the fixing means; and paper position detection means for determining the abnormality in paper conveyance based on the detection signal of the paper position detection means, The apparatus is configured to include a control means for controlling the conveyance system to convey the paper in the paper conveyance path to a position away from the fixing means when it is determined that there is an abnormality.

(Operation) That is, according to the means for achieving the first object, the paper storage means is always in a state of not moving regardless of the opening/closing operation of the opening/closing lid. Therefore, stable paper feeding operation is possible without the situation where the storage condition of the paper stored in the paper storage means is damaged by vibration due to the opening/closing operation of the opening/closing lid, which causes feeding defects, as in the conventional case. . Also,
Since the paper storage means is not attached to the opening/closing lid, the opening/closing lid can be opened wide, making it possible to improve the workability of the portion on the rotation fulcrum side.

Furthermore, according to the means for achieving the second objective,
An opening/closing lid is provided on the top surface of the apparatus main body so as to be openable and closable to expose the image forming means, and the opening/closing lid can be opened in a direction perpendicular to the conveying direction of the paper. It has a configuration that incorporates. Therefore, the fixing means can be removed from the main body of the apparatus in the attached state, and maintenance, inspection, replacement, etc. of the fixing means can be easily performed.

Furthermore, according to the means for achieving the third objective,
If it is determined that there is an abnormality in paper conveyance due to an error in taking out the paper or a timing shift, the paper in the paper conveyance path can be conveyed to a predetermined position away from the fixing means, such as in front of the fixing means or a position past the fixing means. can. Therefore, unlike the conventional fixing device, the paper does not stop with being interposed in the fixing device, and the paper can be easily removed.

(Example) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Fig. 2 is an external perspective view of a laser printer as an image forming apparatus of the present invention, Fig. 3 is a rear view thereof, and Fig. 4 is a schematic vertical side view showing its internal configuration. The structure is as follows.

Reference numeral 10 in the figure indicates the main body of a laser printer serving as an image forming apparatus, and has the following configuration. That is, the front surface of the device main body 10 is lowered one step,
A recessed portion 11 is formed as a paper ejection portion. This recess 1
1 is provided with a removable paper discharge tray 12.

Furthermore, notches 12a and 12b as shown in FIG. 2 are formed on both sides of the front edge of the paper discharge tray 12. As shown in FIG. Further, an operation panel 13 is disposed on the right side of the paper ejection tray 12, and a paper cassette 14 as a paper storage means for storing paper P is installed in the upper part of the apparatus main body 10. Further, on the right side of the main body 10, there are a lever 16 for opening and closing the upper cover 15, a power switch 17, and an opening 18, 19, for inserting an IC card (not shown) for adding functions. 20 are provided.

As shown in FIG. 3, an inlet-type power connector 25 for supplying power to the device is provided on the back side of the main body 10, and an opening 26 is provided at the bottom. Furthermore, a shield case 27 made of a metal plate is attached to cover this opening 26. This shield case 27 has a connector 28 for connecting a host device (not shown) such as an electronic computer or a word processor.
．． 28 are provided.

As shown in FIG. 5, the operation panel 13 includes a liquid crystal display 13a that displays the number of sheets, mode, guidance messages, etc., an LED display 13b that lights up and displays various states with LEDs, and a switch 13c that instructs various operations. It is made up of. The LED display 13b indicates whether or not it is connected to an external device, that is, "online" indicating online/offline mode, "ready" indicating that the device main body 10 is ready for operation, and "ready" indicating that the device is being transferred. It is composed of the following indicators: ``Data'' to indicate that the service is available, ``Operator'' to request an operator call, ``Service'' to request a service call, and ``Mode'' to indicate auto/manual.

The switch 13c is constituted by, for example, a menu key, a value key, a numeric keypad (not shown), or the like. The above menu key is composed of two keys, "Next Item" and "Previous Item", and the multiple menu information displayed on the left half of the liquid crystal display 13a is incremented each time the "Next Item" key is pressed. Each time the ``previous item'' key is pressed, the item is decremented and displayed, and these display operations are repeated cyclically.

Ru.

The value key is also composed of two keys, "Next item" and "Previous item", and each time the "Next item" key is pressed, a plurality of value information corresponding to the menu information displayed on the left half of the liquid crystal display 13a is displayed. is incremented to "
Each time the "previous item" key is pressed, the display is decremented and displayed, and these display operations are repeated cyclically.

The operator selects and instructs a desired operation by operating the menu keys and value keys.

Two image forming means for performing a series of electrophotographic processes including a pre-exposure process, a charging process, a developing process, a transfer process, a cleaning process, and a fixing process are housed within the apparatus main body 10. This image forming means 29 has a structure as shown in FIG. That is, a photoreceptor drum 30 as an image carrier is provided approximately in the center of the apparatus main body 10, and a charging means is provided around the photoreceptor drum 30 along the rotational direction shown by arrow A. A charger 31 consisting of a scorotron, an exposure section 33 that receives a laser beam R emitted from an optical unit 32 as an electrostatic latent image forming means, a non-magnetic component type developing device 34 as a developing means, and a corotron as a transfer means. a transfer charger 35, and a drum cleaner device 36 as a cleaning means.
, and a pre-exposure device 37 as a pre-exposure means are arranged in this order.

Further, among these, the photosensitive drum 30, the electrification charger 31, the developing device 34, and the drum cleaner device 36 are integrated as shown in FIG.
Image forming process cartridge (
(electrophotographic process unit) 40.

Further, within the apparatus main body 10, a paper transport path 42 is provided that passes through an image transfer section 41 formed between the photosensitive drum 30 and the transfer charger 35. This paper conveyance path 4
A paper guide 43 is provided upstream of the image transfer section 41 of No. 2.
, an aligning roller pair 44, a paper feed 50-roller 45, and a paper cassette 14 are arranged. In addition, the image transfer section 41
On the downstream side, a paper conveyance guide 47, a heat roller type fixing device 48 as a fixing means, and a pair of paper discharge rollers 49 are arranged. The paper discharge roller pair 49 includes a lower roller 49a and an upper roller 49b, and is provided with a static elimination brush 50 that contacts the non-image forming side of the paper P in the conveying direction.

Near the paper feed roller 45, there is a paper empty switch (not shown) that detects the paper P in the paper cassette 14.
Further, a first paper detection switch 55 as a first paper detection means is provided near the aligning roller pair 44, and a first paper detection switch 55 as a second paper detection means is provided near the paper ejection roller pair 49. Two paper detection switches 56 are provided, respectively, to detect the paper P in the paper transport path 42.

In addition, a substrate accommodating section 5 provided at the lower part of the device main body 10
An engine control board 58 equipped with an engine control circuit that controls each electrical device provided in the apparatus main body 10 to complete the electrophotographic process is disposed at 7. Printer control board 5 equipped with a printer control circuit that controls the operations of 58
is placed.

The printer control board 59 is configured so that up to two boards can be installed depending on the degree of function addition (for example, adding types of fonts, kanji, etc.). Further functions can be added by inserting function-adding ICs (not shown) into three IC card connectors (not shown) arranged in the .

In addition, connectors 28 and 28 are provided on the rear surfaces of the five printer control boards located at the bottom, and these connectors 28 and 28 are connected to the device main body 10 as shown in FIG.
It is attached so as to protrude outside a shield case 27 provided at the lower part of the back surface of the shield case 27.

In addition, an upper cover 15 constituting the upper surface of the apparatus main body 10
On the inner surface, there are devices in the hatched area shown in FIG.
8. The upper roller 49b of the paper ejection roller pair 49 and the static elimination brush 50 are incorporated, and the paper feed roller 45
A paper feed cassette 14 which is integrally constructed is attached.

As shown in FIG. 8, the upper cover 15 can rotate from 0 DEG to 1800 degrees using a pivot means 60 provided on the left end side of the main body 10 as a pivot point.

Then, when the upper cover 15 is rotated upward, as shown in FIG. The upper roller 49b1 and the static elimination brush 50 are in a state in which they are largely displaced upward and further outward until the upper side is completely opened as shown in FIG.

Further, as shown in FIGS. 10 and 11, the pivot means 60 is provided on the device main body 10 side, and the fixed support shafts 61.61
(only one of them is shown), and a rotation support shaft 62 that is protruded from the front and rear of the left end of the upper cover 15, moves together with the upper cover 15, and is supported coaxially with the fixed support shafts 61 and 61.
．． 62 (only one shown) and coil springs 63, 63 straddled over the fixed support shaft 61 and the rotation support shaft 62, respectively, and wound tightly around the peripheral surfaces 61a, 62a.

Further, as shown in FIG. 11, a positioning protrusion 61b is formed on the end surface of the fixed support shaft 61, and is adapted to engage with a positioning hole 62b formed on the end surface of the rotation support shaft 62. The fixed support shaft 61 and the rotation support shaft 62 are always kept coaxial.

In the vicinity of the pivot means 60 configured in this way, the first and eighth
As shown in the figure, a push-up member 64 made of a strong leaf spring bent into a substantially V shape is arranged. Then, due to the restoring force of this push-up member 64, the upper cover 15
can be opened up to 30".

The upper cover 15 also has a fixed support shaft 61 and a rotation support shaft 62.
The friction force generated by tightening the coil springs 63 and 63 can be fixed at any position from 30 degrees to 180'.

This exposes most of the paper transport path 42 and most of the equipment in the image forming process cartridge 40 facing the paper transport path 42, which makes it difficult to remove paper P jams and perform maintenance and inspection on the equipment. and replacement work can be done easily and efficiently.

However, in the image forming operation, the photosensitive drum 3
0 is rotated, the surface potential of the photoreceptor drum 30 is kept constant by the action of the pre-exposure device 37, and then uniformly charged by the action of the charger 31, and the laser beam R
is scanned and exposed onto the photoreceptor drum 30 using the optical unit 32 to form an electrostatic latent image corresponding to the image signal.

This electrostatic latent image on the photosensitive drum 30 is developed by a developing device 34 using a one-component developer consisting of toner t, visualized as a toner image, and sent to an image transfer section 41.

Meanwhile, in synchronization with this toner image forming operation, the paper P taken out from the paper cassette 14 or manually fed from the manual feed guide 65 is transferred to the aligning roller pair 44 and the paper guide 43.
The toner image previously formed on the photosensitive drum 30 is transferred onto the paper P by the action of the transfer charger 35. Next, the paper P is guided by a transport guide 47 to pass through a paper transport path 42 and is fed into a fixing device 48, where the toner image is melted and fixed onto the paper P. After this, the paper ejection roller pair 4
The paper is ejected to the paper ejection tray 12 through the two.

Note that after transferring the toner image onto the paper P, the photosensitive drum 3
The residual toner remaining on the drum 0 is removed by a drum cleaner device 36.

Further, as shown in FIG. 12, the fixing device 48 includes a heat roller 68 having a built-in heater lamp 67, and a pressure roller 69 that is in pressure contact with the heat roller 68. As a result, the toner image is fused and fixed onto the paper P. The Hilt roller 68 and the pressure roller 69 are surrounded by a lower casing 70 and an upper casing 71, and are designed to prevent heat from escaping to the outside as much as possible so as to ensure a favorable temperature atmosphere necessary for fixing.

Further, the cleaner 72 is in contact with the heat roller 68, which is in a normal state where good fixing can always be performed, and the thermistor 73 detects the surface temperature of the heat roller 68 and performs fixing. The temperature is controlled to maintain the required temperature.

Furthermore, within the upper casing 71 and the heat roller 68
A paper guide 75 is disposed near the upstream side of the contact portion 74 between the heat roller 68 and the pressure roller 69 to ensure that the leading edge of the paper P guided to the fixing device 48 is placed between the heat roller 68 and the pressure roller 69. It is designed to guide you. In addition, the fixing device 48
The paper P wrapped around the heat roller 68 is on the paper exit side.
A peeling claw 76 and a paper guide 76 are provided to guide the fixed paper P to a pair of paper discharge rollers 49.

Next, the configuration of the image forming process cartridge 40 will be explained with reference to FIGS. 6 and 12.

As described above, the image forming process cartridge 40 includes the photosensitive drum 30, the charger 31, and the developing device 34.
, and a drum cleaner device 36 are integrated.

As shown in FIG. 6, the photosensitive drum 30 has a diameter of 30 mm.
The surface of an aluminum pipe 79 with a diameter of 1.5 mm is coated with an organic photoreceptor film 80, and is driven in the direction of arrow A (see FIG. 12) from a drive section on the apparatus main body 10 side.

The charger 31 is a device for discharging onto the photosensitive drum 30 and charging it with a negative charge of about -550 volts. It consists of a charge wire 81 made of white tungsten with a thickness of 60μ, a shield case 82 surrounding the charge wire 81, and a grid 83 made of a stainless steel plate 0.2 mm thick. The charge wire 81 is stretched parallel to the surface of the photoreceptor drum 30, and approximately -3000 volts is supplied to one end of the wire by a high-voltage power source on the apparatus main body side.

The grid 83 is connected to the photosensitive drum 3 of the shield case 82.
0 and the charge wire 81,
It forms a mesh of about 2 pitches. It is electrically connected to a Zener diode on the apparatus main body 10 side, and controls the charging potential on the photoreceptor drum 30 to be substantially constant. Note that the Zener diode on the device main body 10 side has a voltage of about 600 volts and is grounded.

The developing device 34 includes an optical unit 3 on the photoreceptor drum 30.
This is a device for developing an electrostatic latent image formed by a laser beam R from 2 into a toner image. As shown in FIGS. 6 and 12, this developing device 34 has a developing section 85 and a toner storage section 86, and the developing section 85 includes a developing roller 90 made of conductive silicone rubber, A blade 91 that negatively charges the toner t while forming a toner layer on the roller 90 and a sponge roller 92 that supplies the toner t onto the developing roller 90 are provided.
A toner conveying bar 94 is provided to convey toner t to the developing section 96. A casing 96 that constitutes a cartridge frame 95 as a support member is provided.

The developing roller 90 is supplied with a developing bias voltage of approximately -400 volts by a high voltage power supply on the apparatus main body 10 side, and is rotated in the direction of arrow B (the direction of arrow B) with respect to the photosensitive drum 30 at a speed approximately three times the peripheral speed ratio. (see Figure 12), the photoreceptor drum 30 and about 1
It rotates in contact with a contact width of 100 mm.

On the other hand, the blade 91 is made of silicone rubber and has a pressure cuff of 0 g.
1(1)2, it is in pressure contact with the developing roller 90.

Note that 250 g of toner t is stored in the toner storage portion 86.
is accommodated, and a standard print amount prints approximately 40
You can get 00 A4 prints.

Further, the toner conveying bar 94 rotates at 10 rpm in the direction of arrow C (see FIG. 12), and conveys the toner t to the developing section 95 little by little.

Further, the drum cleaner device 36 is configured to scrape off residual toner on the photosensitive drum 30 with an elastic blade member (cleaning blade) 97 and collect it in a waste toner collecting section 98 .

The waste toner accumulation section 98 is the toner storage section 8 of the developing device 34.
It has a volume corresponding to 250 g of toner of No. 6, and can accumulate waste toner for the life of the image forming process cartridge 40.

Note that the image forming process cartridge 40 is discarded by the user after printing a predetermined number of sheets, and is replaced with a new image forming process cartridge 40.

Further, a control means 100 is constituted by an engine control board 58 disposed in the board accommodating portion 57 and a printer control board 59 equipped with a printer control circuit for controlling the operation of the engine control board 58. As shown in FIG. 13, a first paper detection switch 55 as the first paper detection means and a second paper detection switch 56 as the second paper detection means are connected to the control means 100. In addition, a conveyance system 102 including a pair of aligning rollers 44 of a paper conveyance path 42, fixing rollers 68, 69, a pair of paper discharge rollers 49, etc. is connected via a conveyance system drive circuit 101.

Then, the paper P transported through the paper transport path 42 by the first paper detection switch 55 and the second paper detection switch 56
The paper position detection switch 55.5
Based on the detection signal No. 6, the control means 100 determines that there is an "abnormality in paper conveyance." When it is determined that this "paper transport abnormality" occurs, the control unit 100 sends a transport system drive circuit 101 to the transport system to transport the paper in the paper transport path to a predetermined position.
A control signal is sent to operate 3.

Then, the paper P in the paper transport path 42 is transported to a predetermined position away from the fixing means, such as in front of the fixing device 48 as shown in FIG. 14, or a position past the fixing device 48 as shown in FIG. After that, the transport system 103 is stopped.

Therefore, the paper P does not stop in the fixing device 48 as in the conventional case, and the paper P can be easily removed.

Also, the position where the rear end of the paper P has passed the aligning roller pair 44, that is, the position where it has passed the boundary position between the movably provided upper cover 15 and the paper cassette mounting portion fixed to the apparatus main body 10 side. It is designed to be transported up to The opening/closing operation of the upper cover 15 is not impaired by the paper P in the conveyance path.

Furthermore, according to the embodiment described above, the paper cassette 14 as a paper storage means is always in a state of not moving regardless of the opening/closing operation of the upper cover 15 as an opening/closing lid. For this reason,
A stable paper feeding operation can be performed without the situation in which the state of accommodation of the paper P stored in the paper cassette 14 is damaged by vibration due to the opening/closing operation of the upper cover 15, which causes a feeding failure, as in the conventional case. Also, since the paper cassette 14 is not attached to the upper cover 15, the upper cover 15
can be opened wide, making it possible to improve workability on the rotation fulcrum side.

Further, the upper cover 15, which is provided on the upper surface of the apparatus main body 10 so as to be openable and closable to expose the image forming means 29, can be opened in a direction perpendicular to the conveyance direction of the paper P. A heat roller type fixing device 48 as a fixing means of the image forming means 29 is incorporated into the image forming means 29.

Therefore, the fixing device 48 can be taken out from the main body 10 in the installed state, and the cleaning felt 72 for applying a release agent such as silicone oil to the heat roller 68, which is a consumable item, can be replaced extremely easily. can be done. Further, maintenance and inspection of the entire fixing device 48 becomes easier, and in the case where the fixing means is made into a cartridge, the cartridge itself becomes easier to replace.

It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without changing the gist.

[Effects of the Invention] Since the present invention is configured as described above, the following effects are achieved.

In the image forming apparatus according to the first aspect, the paper storage means is always in a stationary state regardless of the opening/closing operation of the opening/closing lid. Therefore, a stable paper feeding operation can be performed without the situation where the state of accommodation of the paper stored in the paper storage means is damaged by vibration due to the opening/closing operation of the opening/closing lid, which causes a feeding failure, as in the prior art. Further, since the paper storage means is not attached to the opening/closing lid, the opening/closing lid can be opened wide, and the workability of the portion on the rotation fulcrum side can be improved.

In the image forming apparatus according to claim 2, the opening/closing direction of the opening/closing lid, which is provided on the top surface of the apparatus main body so as to be openable and closable to expose the image forming means, is perpendicular to the conveyance direction of the paper. It can be opened, and the fixing means of the image forming means is incorporated into this opening/closing lid. Therefore, the fixing means can be removed from the main body of the apparatus in the attached state, and maintenance, inspection, replacement, etc. of the fixing means can be easily performed.

Further, in the image forming apparatus according to claim 3, when it is determined that there is an abnormality in paper conveyance due to an error in taking out the paper, a timing shift, etc., the paper in the paper conveyance path is moved in front of or past the fixing means. The image forming apparatus can be transported to a predetermined position away from the fixing means. Therefore, unlike the conventional fixing device, the paper does not stop with being interposed in the fixing device, and the paper can be easily removed.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is an explanatory diagram showing a state in which the upper cover is slightly opened, Fig. 2 is an external perspective view of the entire image forming apparatus, and Fig. 3 is a rear view and a similar view. 4 is a schematic longitudinal side view showing the internal structure, FIG. 5 is a plan view of the operation panel, FIG. 6 is a schematic sectional view of the entire image forming process cartridge, and FIG. 7 is an image that is displaced together with the upper cover. An explanatory diagram showing the area of the forming equipment, FIG. 8 is a conceptual diagram showing the open/closed state of the upper cover, FIG. 9 is an explanatory diagram showing the state where the upper cover is wide open and the upper part of the device main body is released, and FIG. FIG. 11 is an exploded perspective view, FIG. 12 is a partially enlarged view of FIG. 4, and FIG. 13 is a front view showing the structure of the support means.
The figure is a block diagram showing the control system of the paper conveyance path, and FIG. 14 is an explanatory diagram showing the state where the paper is stopped before the fixing device.
FIG. 15 is an explanatory diagram showing a state in which the paper is conveyed to a position past the fixing device and stopped. DESCRIPTION OF SYMBOLS 10... Apparatus body, 14... Paper cassette (paper storage means), 15... Upper cover (opening/closing lid), 29...
- Image forming means, 42...Paper transport path, 48...Fixing means (heat roller type fixing device), 55.56...
Paper position detection switch (paper position detection means)] -OO・
...Control means, 102...Transportation system.

Claims (3)

[Claims] (1) In an image forming apparatus, a paper accommodating means for accommodating paper to be supplied to the image forming means is mounted on the upper surface of an apparatus main body containing an image forming means, the upper part of the apparatus main body and the paper accommodating means An image forming apparatus characterized in that an opening/closing lid that can be opened to expose the image forming means is provided in a portion where the mounting portion is left. (2) In an image forming apparatus that includes an image forming means including a fixing means in the apparatus main body and forms an image on a sheet of paper conveyed through a paper transport path, the image forming means is provided on the upper surface of the apparatus main body. An image forming apparatus characterized in that an opening/closing lid is provided which can be opened in a direction perpendicular to the conveyance direction of the paper to expose the paper, and a fixing means of the image forming means is incorporated in the opening/closing lid. (3) In an image forming apparatus that includes an image forming means including a fixing means in the main body of the apparatus and forms an image on a sheet of paper conveyed through a paper conveyance path, the sheet of paper formed to pass through the fixing means. a paper position detection means for detecting the position of the paper conveyed through the conveyance path; a paper position detection means for determining a paper conveyance abnormality based on a detection signal of the sheet position detection means; An image forming apparatus comprising: a control means for controlling a conveyance system to convey a sheet of paper to a position away from a fixing means.