JP2002193527A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wingless type image forming device having a function of a facsimile machine preventing occurrence of jam caused by increase of paper on a paper stack tray when much paper on which received results are printed is stacked on the paper stack tray. SOLUTION: A stack face of the paper stack tray 30 is inclined downward in a paper delivery direction for forming the stack face of the tray 30 almost free from resistance to physically restrict a move of the paper.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus having a wingless type paper discharge portion applied to a facsimile machine, a copying machine, a digital copying machine, a printer, or a multifunction machine having these functions.

[0002]

2. Description of the Related Art At the present time, as the demand for space saving of equipment is increasing, it has become a major problem in facsimile machines and copiers how to reduce the size of a machine.
Among them, a machine of a type in which a recording paper stack tray does not protrude from a main body (hereinafter referred to as a wingless type) has attracted attention.

FIG. 14 is a block diagram of a conventional wingless type facsimile apparatus, wherein 1 is an apparatus main body of the facsimile apparatus, 2 is a photosensitive drum, 3 is a cleaning unit,
Is a charger for charging the photosensitive drum 2 to a predetermined potential, 5 is an optical writing unit for scanning the photosensitive drum 2 charged by the charger 4 with a laser beam, and 6 is an electrostatic unit formed on the photosensitive drum 2. A developing device for developing a latent image to form a toner image; 7, a toner magazine for supplying toner to the developing device 6; 8, a transfer roller in contact with the outer peripheral surface of the photosensitive drum 2;
9 is a fixing device having a pressure roller and a heating roller, 10
Is a paper feed cassette which accommodates recording paper and is detachably attached to the apparatus main body 1. Reference numerals 11, 12, and 13 denote a pair of conveying rollers, a pair of registration rollers, and a pair of conveying rollers for conveying recording paper along a recording paper conveying path. Paper discharge roller pair, 14 is paper discharge roller pair 1
A paper ejection sensor 15 that is disposed in front of 3 and detects recording paper;
Denotes a recording paper stack tray which is a paper discharge unit formed on the upper surface of the apparatus main body 1. The recording paper discharged by the discharge roller pair 13 is stacked on the recording paper stack tray 15.

Reference numeral 20 denotes a scanner unit for reading a document image and converting it into an image signal.
Serves to convey along the document loaded in the document feed tray 21 to the document feed path, reading a document image sensor 22
And the read document is discharged onto the document stack tray 23.

A wingless type facsimile apparatus as shown in FIG. 14 is installed with stack trays 15 and 23 and a document feed tray 21 in consideration of a reduction in installation space which has been strongly demanded in recent years. Is configured not to increase in area. That is, in the wingless type facsimile machine, the devices of the trays 15, 21, 23 are arranged such that the projection area of the stack trays 15, 23 and the document feed tray 21 with respect to the installation surface of the apparatus falls within the projection area of the apparatus body 1. The amount of protrusion from the main body 1 is set.

Further, as shown in FIG. 14, the stack surfaces of the stack trays 15 and 23 are inclined upward in the sheet discharge direction, and the trailing end of the discharged recording paper is placed between the stack surface and the sheet discharge port. The recording paper after discharge is held in an aligned state by making contact with the step.

[0007]

However, in the case of the wingless type facsimile apparatus, the stacked recording paper overflows (recording from the recording paper stack tray) as compared with the case where the recording paper stack tray protrudes from the main body. Since it is difficult for paper to spill out), stacking more than a specified number of recording papers may cause a paper jam at the paper discharge port. In particular, in a device such as a facsimile machine that continues to receive data unattended even during long vacations, for example, even if a multi-stage paper cassette is provided, stacking all of the recording papers loaded in all the cassettes requires a large size. This is not possible due to problems such as pod cost and the like, and there is a high possibility that the above problem will occur.

[0008] In the case of a non-wingless type, the user removes the recording paper stack tray from the main body and prepares a tray such as a cardboard box below for long vacations.

According to the present invention, when a large amount of reception (number of sheets exceeding the number of stacks specified in the equipment) is performed during a long vacation with a wingless type facsimile apparatus, a special work is performed on the main body side. It is an object of the present invention to provide an image forming apparatus capable of outputting all received documents without causing jams.

[0010]

According to the present invention, there is provided a recording apparatus having a facsimile function, a recording sheet stacking section for stacking recording sheets discharged after an image is recorded, and an apparatus main body. In the image forming apparatus in which the recording paper stack is arranged so as to enter the area of the apparatus main body when viewed in a plan view, the stack surface of the recording paper stack is inclined downward from a horizontal direction. I do. With this configuration, the discharged recording paper is dropped out of the apparatus without being stacked, so that even if a large amount of data is received during a long vacation, the received recording paper can be used to block the paper exit. Therefore, it is possible to prevent the occurrence of a jam.

Further, the present invention is characterized in that a stopper having a predetermined height is provided upright on the stack surface of the recording paper stack section to restrict the movement of the recording paper by contacting the leading end of the recording paper. With such a configuration, the specified number of sheets can be stacked during normal use, so that usability under normal conditions is improved.

Further, the present invention is characterized in that the stopper is configured to be movable. With this configuration, the specified number of sheets can be stacked during normal use,
Usability in normal situations is improved.

The present invention is characterized in that the stopper is configured to be detachable from the recording paper stack portion. With such a configuration, the specified number of sheets can be stacked during normal use, so that usability under normal conditions is improved.

Further, according to the present invention, a recording paper stack tray is attached to the apparatus main body as the recording paper stack portion, and a switching mechanism for switching the inclination of the stack surface of the recording paper stack tray to an upper side or a lower side than the horizontal direction. Is provided. With this configuration, a large amount of reception can be performed at low cost by dropping the recording paper on which the reception information is recorded out of the apparatus. In addition, since it was possible to use it with an upward inclination, during normal use, like a conventional facsimile machine,
Recording paper can be stacked on a recording paper stack tray.

Further, according to the present invention, the recording paper stack tray has a structure in which one side is rotatably mounted on the apparatus main body and the other side is vertically movable, and a rotating shaft of the recording paper stack tray is provided. Is set to be a direction perpendicular to the sheet discharging direction. With this configuration,
The recording paper can be dropped in a direction along the paper discharge direction in the apparatus main body.

According to the present invention, the recording paper stack tray has a structure in which one side is rotatably mounted on the apparatus main body and the other side is movable up and down. Is characterized in that the axial direction is the direction along the paper discharging direction. With such a configuration, for example, in a facsimile apparatus that employs a horizontal flow (as viewed from the front) of a wingless-type image forming apparatus, the main body of the apparatus is disposed on a side of the apparatus. When the recording paper is installed in a place where a wall exists without a gap, the recording paper can be dropped to the front side.

Further, according to the present invention, a spring member is arranged between the recording paper stack tray and the apparatus main body, and when there is no recording paper in the recording paper stack tray, the recording paper stack is biased by the spring member. Maintain a state in which the stack surface of the tray is inclined upward from the horizontal direction, and when a predetermined amount of recording paper is stacked, the stack surface of the recording paper stack tray is lower than the horizontal direction due to the weight of the recording paper. It is characterized by being inclined. With such a configuration, for example, a large amount of the recording paper is stacked on the recording paper stack tray without the user performing the operation of switching the angle of the recording paper stack tray to the downward inclination before the long vacation. In this case, the recording paper can be dropped out of the apparatus main body.

Further, according to the present invention, there is provided a detecting means for detecting a stack amount of the recording paper in the recording paper stack tray, and when the detecting means detects a predetermined stack amount, the recording paper stack tray is rotated so as to be horizontal. And a drive mechanism for inclining downward from the direction. With this configuration, it is possible to operate the recording paper stack tray at a fixed timing without being affected by the type and size of paper used, and the rotation timing of the recording paper stack tray is too early, and In a meaning, it is possible to eliminate the problem that the recording paper is dropped out of the apparatus main body, or the rotation timing is too late, and the recording paper stack tray does not operate to cause a paper discharge jam.

Further, according to the present invention, a recording paper stack tray which is disposed above the recording paper stack portion and stacks recording paper discharged after an image is recorded is provided detachably with respect to the apparatus main body. When the recording paper stack tray is mounted on the apparatus main body, the stack surface of the recording paper stack tray is inclined upward from a horizontal direction. With this configuration, the function of dropping the recording paper on which the received information is recorded out of the apparatus main body and the function of stacking the recording paper on the recording paper stack tray during normal use, like a conventional facsimile machine, are provided. It can be realized with a small number of parts.

[0020]

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

FIG. 1 is a side view showing the internal structure of the apparatus according to the first embodiment of the present invention, FIG. 2 is a perspective view showing the appearance of FIG. 1, and 30 is a recording paper discharged by a paper discharge roller pair 13. Is a recording paper stack tray, 31 is an operation panel having a display panel and various input keys, and 32 is a box. The same members as those in the prior art shown in FIG. 14 are denoted by the same reference numerals, and detailed description is omitted.

According to the prior art apparatus shown in FIG. 14, the stack surface of the recording paper stack tray 15 is inclined upward in the paper discharging direction. The stack surface is inclined downward in the sheet discharging direction.

The stack surface of the recording paper stack tray 30 is formed so that there is almost no resistance that physically restricts the movement of the recording paper. Therefore, the discharge roller pair 1
The recording paper discharged by the recording paper stack tray 3
0, slides along the stack surface, falls out of the device body 1,
It is stored in a box 32 arranged next to the apparatus body 1.

With this configuration, the recording paper discharged by the discharge roller pair 13 slides down on the recording paper stack tray 30 inclined downward from the horizontal. Also, even if there is a recording sheet that does not slip off from the recording sheet stack tray 30, there is little resistance because there is no physical restriction on the movement, and the recording sheet is easily pushed out by the next discharged recording sheet. It will not be.

Incidentally, in FIG.
Although the inclination starts from a position at a certain distance (A in the figure) from, the inclination may be started from immediately below the discharge roller pair 13. Further, depending on the design, it may not be linear as shown in the figure, but may be a curved surface.

In FIG. 1, the stack surface of the recording paper stack tray 30 is inclined downward in the paper discharging direction. However, as shown in FIG. 3, the stack surface of the recording paper stack tray 30 is inclined in the paper discharging direction. On the other hand, it may be inclined downward at a right angle. Here, an advantage of the wingless type is that three surfaces (left, right, and rear) of the device can be attached to a wall. Therefore, if the right side of the apparatus shown in FIG. 2 is attached to the wall, the recording paper is stacked on the recording paper stack tray 30, and there is a possibility that a jam may occur soon, and the intended effect cannot be obtained. However, according to the apparatus shown in FIG. 3, the recording paper is moved to the user side. That is, the recording paper stack tray 30 may be configured to be inclined in the direction in which the purpose is achieved.

FIG. 4 is a perspective view showing a main part of an apparatus according to a second embodiment of the present invention.
Reference numeral 0 denotes a stopper that stands on the downstream end in the sheet discharging direction and regulates the movement of the recording sheet. Reference numeral 36 denotes a slide groove that supports the stopper 35 slidably in the sheet discharging direction. The same members as those in the prior art shown in FIG. 14 are denoted by the same reference numerals, and detailed description is omitted.

In normal use (when there is no large amount of reception during a long vacation, etc.), it is more convenient to stack recording paper on the recording paper stack tray 30 to some extent.

By providing the stopper 35 as shown in FIG. 4, recording paper can be stacked up to a certain specified number of sheets. As a result, when a predetermined number or more is received, the recording paper stack tray 30 itself is inclined downward, so that the recording paper passes over the stopper 35 and overflows. In addition, by making it detachable from the apparatus main body, if it is removed on the day before the long vacation, the recording paper will drop more reliably when a large amount of data is received. Since the stopper 35 can be moved in the direction of the arrow along the slide groove 36,
The height of the trailing end of the stacked recording paper can be adjusted so that the discharged recording paper is reliably stacked on the already stacked recording paper, and the stacking property is improved.

FIGS. 5, 6 and 7 are perspective views showing another configuration of the apparatus according to the second embodiment of the present invention.

According to the apparatus shown in FIG. 5, the stopper 37 is rotatably attached to the end of the recording paper stack tray 30.
Of the recording paper so as not to hinder the advance of the recording paper. By providing a plurality of the stoppers 37 at positions corresponding to the recording paper size, the stoppers 37 are set up according to the paper size to be used by the user. Performance can be improved. For long vacations,
By closing the stopper 37 and storing it in the recess 38, the recording paper can be dropped outside the apparatus main body 1. In addition, the stopper 37 may be not removed, will not be lost.

According to the apparatus shown in FIG. 6, the stopper 39 having a flat plate shape is attached to the recording paper stack tray 30 so that it can be pulled up and down and stored. When not used, it is stored in the recording paper stack tray 30 so as not to hinder the progress of the recording paper. By providing a plurality of the stoppers 39 at positions corresponding to the size of the recording paper, if the stoppers 39 are set up according to the size of the recording paper used by the user, the stacking property during normal use can be improved. At the time of a long vacation, etc., by closing the stopper 39, the same operation and effect as the device shown in FIG. 4 can be obtained. Also, since it does not have to be removed, there is no loss.

According to the apparatus shown in FIG. 7, the flat plate-shaped stopper 40 is inserted into the holes 41 formed in the recording paper stack tray 30 at positions corresponding to the recording paper size. By inserting the stopper 40 into the hole 41 at a position corresponding to the recording paper size and standing up, the stacking property during normal use can be improved. At the time of a long vacation, etc., by removing the stopper 40, the same operation and effect as the device shown in FIG. 4 can be obtained.

FIG. 8 is a side view showing a main part of an apparatus according to a third embodiment of the present invention.
Reference numeral 3 denotes a supporting part. The same members as those in the prior art shown in FIG. 14 are denoted by the same reference numerals, and detailed description is omitted.

The upper surface of the apparatus main body 1 is formed so as to be inclined downward from the paper discharge roller pair 13 in the paper discharge direction. Further, one end of a recording paper stack tray 42 is rotatably attached to a lower portion of the paper discharge roller pair 13. Further, a concave portion 44 is formed in a part of the upper surface of the apparatus main body 1, and a support component 43 is rotatably mounted inside the concave portion 44.

During normal use of the facsimile apparatus shown in FIG. 8, the other end of the recording paper stack tray 42 is lifted,
The support component 43 is erected and the recording paper stack tray 42
8 (a), the stack surface of the recording paper stack tray 42 is maintained in a state of being inclined upward in the paper discharging direction. . As a result, the recording paper discharged from the paper discharge roller pair 13 is stacked on the recording paper stack tray 42.

At the time of mass reception, the engagement state between the engagement groove 42a and the support component 43 is released, and the support component 43 is rotated and housed in the concave portion 44, as shown in FIG. The recording paper stack tray 42 is placed on the upper part of the main body 1.
At this time, the stack surface of the recording paper stack tray 42 is maintained in a state of downward inclination along the downward inclination of the upper surface of the apparatus main body 1. As a result, the recording paper discharged from the paper discharge roller pair 13 slides on the recording paper stack tray 42 and falls outside the apparatus main body 1.

With this configuration, it is possible to easily select a usage mode for normal use in which the recording paper is stacked on the recording paper stack tray 42 and a usage mode for mass reception in which the recording paper is dropped to the outside. And switching becomes possible.

In the case of the facsimile apparatus shown in FIG. 8, if there is a space in the paper discharge direction, as shown in FIG. It is possible to do. Further, FIG.
As shown in (b), the upper surface of the apparatus main body 1 may be inclined downward from the rear side to the front side, and one side of the recording paper stack tray 42 may be rotatably attached to the rear side of the apparatus main body 1. With this configuration, the work of switching the recording paper stack tray 42 up and down can be performed on the front side. Here, since the rotation axis of the recording paper stack tray 42 is directed obliquely upward with respect to the horizontal direction, when the recording paper stack tray 42 is rotated downward, The recording paper stack tray 42 may be formed in a trapezoidal shape so that the end does not come out of the apparatus main body 1. Further, the upper surface of the apparatus main body 1 is lowered in a direction perpendicular to the sheet discharging direction so that the recording paper stack tray 42 is adapted to the apparatus main body 1 when the stack surface of the recording paper stack tray 42 is inclined downward. It may be formed as an inclined surface.

FIG. 10 is a side view showing a main part of an apparatus according to a fourth embodiment of the present invention.
Reference numeral 46 denotes a holding groove. The same members as those in the prior art shown in FIG. 14 are denoted by the same reference numerals, and detailed description is omitted.

The apparatus of the fourth embodiment is arranged below the pair of discharge rollers 13 in the apparatus of the first embodiment shown in FIGS. 1 and 2 as shown in FIG. The holding groove 46 is formed so as to extend into the holding groove 46, and one end of the recording paper stack tray 45 is inserted into the holding groove 46 and held in a detachable state.

During normal use of the facsimile apparatus shown in FIG. 10, one end of the recording paper stack tray 45 is
6, the recording paper stack tray 45 is maintained in a state in which the stack surface of the recording paper stack tray 45 is inclined upward in the paper discharge direction, as shown in FIG. As a result, the recording paper discharged from the paper discharge roller pair 13 is stacked on the recording paper stack tray 46.

When a large amount of data is received, the recording paper stack tray 4
By removing the recording paper 5, the recording paper discharged from the paper discharge roller pair 13 slides on the upper surface of the apparatus main body 1 as shown in FIG.

With such a configuration, the operation and effect of the device of the third embodiment can be obtained with a smaller number of parts than the device of the third embodiment.

FIG. 11 is a side view showing a main part of an apparatus according to a fifth embodiment of the present invention.
48 indicates a spring, and 49 indicates a recess. The same members as those in the prior art shown in FIG. 14 are denoted by the same reference numerals, and detailed description is omitted.

One end of a recording paper stack tray 47 is rotatably mounted below the pair of paper discharge rollers 13. Further, a concave portion 49 is formed in a part of the upper surface of the apparatus main body 1, and one end of a spring 48 is attached to the concave portion 49, and the other end of the spring 48 is partially formed on the back side of the recording paper stack tray 47. Attached to. Therefore, the recording paper stack tray 47 is biased above the spring 48.

When the recording paper is not stacked on the recording paper stack tray 47, the stack surface of the recording paper stack tray 47 is inclined upward in the paper discharging direction. Then, as the recording papers are stacked, the recording paper stack tray 47 is rotated by the weight of the recording papers, and eventually falls down completely. The timing of starting the rotation is mainly determined by the spring 48.

With this configuration, even if the angle of the recording paper stack tray 47 is forgotten to be switched before the long vacation, a large amount of reception is possible.

The depth of the concave portion 49 is set so that the spring 48 which is depressed is housed when the recording paper stack tray 47 rotates downward, and the recording paper stack tray 47 comes into contact with the apparatus main body 1. May be. Further, a metal plate is provided on the back surface of the recording paper stack tray 47, and the apparatus main body 1 is provided.
When the recording paper stack tray 47 is completely lowered, the lowered state is maintained, for example, by attaching the magnet to the metal plate when the recording paper stack tray 47 is lowered. A simple mechanism may be provided.

FIG. 12 is a side view showing a main part of an apparatus according to a sixth embodiment of the present invention.
51 is a stack amount detection sensor including a photo sensor and the like,
52 is a drive motor, and 53 is a paper ejection sensor.

One end of a recording paper stack tray 50 is rotatably mounted below the discharge roller pair 13, and a drive motor 52 and a rotation of the driving motor 52 are provided in the apparatus main body 1 in the recording paper stack tray. A transmission mechanism for transmitting the rotation to the rotation shaft of the recording paper stack tray 50 is provided. By rotating the drive motor 52, the inclination angle of the stack surface of the recording paper stack tray 50 can be changed. A stack amount detection sensor 51 is installed near the side of the recording paper stack tray 50 in the apparatus main body 1, and a paper ejection sensor 5 for detecting the leading and trailing edges of the recording paper is provided near the paper ejection roller pair 13.
3 are provided.

FIG. 13 is a block diagram showing a control system of the apparatus shown in FIG. 12, and a CPU 54 controls the entire apparatus.
55, a ROM for storing various programs relating to the apparatus;
56 is a RAM for storing the received image data, 57 is a PSU (Power Supply Unit) for controlling the power supply of the apparatus,
Reference numeral 58 denotes a motor driver for controlling the drive of the drive motor 52.

Each time the paper ejection sensor 53 detects a recording sheet, the stack amount detection sensor 51 monitors the stack amount of the recording sheet on the recording sheet stack tray 50, and when the recording sheet exceeds a prescribed amount, the stack amount becomes larger. The drive motor 52 is turned on to rotate the recording paper stack tray 50, and the stack surface is inclined downward.

With such a configuration, the recording paper stack tray 50 can be operated at an optimum timing without being affected by the paper thickness or the paper size.

[0055]

According to the present invention constructed as described above, in a wingless type image forming apparatus having the function of a facsimile apparatus, for example, a received image can be obtained by lowering the stack surface. When a large amount of reception results are stacked on the recording paper stack tray, such as when the recording paper on which data has been printed cannot be removed from the recording paper stack tray for a long period of time, the recording paper must be sent out of the main unit. Therefore, it is possible to output all the received documents without causing a jam due to an increase in the number of recording sheets on the recording sheet stack tray.

[Brief description of the drawings]

FIG. 1 is a side view showing an internal configuration of an apparatus according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of the apparatus shown in FIG.

FIG. 3 is a perspective view showing another configuration of the apparatus according to the first embodiment of the present invention.

FIG. 4 is a perspective view showing a main part of an apparatus according to a second embodiment of the present invention.

FIG. 5 is a perspective view showing another configuration of the device according to the second embodiment of the present invention.

FIG. 6 is a perspective view showing another configuration of the device according to the second embodiment of the present invention.

FIG. 7 is a perspective view showing another configuration of the device according to the second embodiment of the present invention.

FIG. 8 is a side view showing a main part of an apparatus according to a third embodiment of the present invention.

FIG. 9 is a perspective view showing the appearance of the apparatus shown in FIG. 8;

FIG. 10 is a side view showing a main part of an apparatus according to a fourth embodiment of the present invention.

FIG. 11 is a side view showing a main part of an apparatus according to a fifth embodiment of the present invention.

FIG. 12 is a side view showing a main part of an apparatus according to a sixth embodiment of the present invention.

13 is a block diagram showing a control system of the apparatus shown in FIG.

FIG. 14 is a configuration diagram of a conventional wingless type facsimile machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Apparatus main body 13 Paper discharge roller pair 30, 42, 45, 47, 50 Recording paper stack tray 31 Operation panel 35, 37, 39, 40 Stopper 36 Slide groove 38, 49 Depression 41 Hole 42a Engagement groove 43 Supporting part 44 Recess 46 Holding groove 48 Spring 51 Stack amount detection sensor 52 Drive motor 53 Discharge sensor 54 CPU 55 ROM 56 RAM 57 PSU 58 Motor driver

Claims (10)

[Claims] A recording paper stack unit that has a facsimile function and stacks recording paper ejected after an image is recorded thereon, so that the recording paper stack unit enters an area of the apparatus main body when the apparatus main body is viewed in a plan view. An image forming apparatus in which a recording paper stack is disposed, wherein the stack surface of the recording paper stack is inclined downward from a horizontal direction. 2. The recording paper stack according to claim 1, wherein
2. A stopper according to claim 1, wherein a stopper having a predetermined height is provided to abut on the leading end of the recording paper to restrict the movement of the recording paper.
The image forming apparatus as described in the above. 3. The image forming apparatus according to claim 2, wherein said stopper is configured to be movable. 4. An image forming apparatus according to claim 2 or 3, wherein the constructed detachably said stopper with respect to the recording sheet stack unit. 5. A recording paper stack unit having a recording paper stack tray attached to an apparatus main body, and a switching mechanism for switching the inclination of a stack surface of the recording paper stack tray to an upper side or a lower side than a horizontal direction. The image forming apparatus according to claim 1, wherein: 6. The recording paper stack tray is configured such that one side is rotatably mounted on the apparatus main body and the other side is movable up and down, and an axial direction of a rotation axis of the recording paper stack tray is provided. 6. The image forming apparatus according to claim 5, wherein the direction is perpendicular to the sheet discharging direction. 7. The recording paper stack tray has a structure in which one side is rotatably attached to the apparatus main body and the other side is vertically movable, and an axial direction of a rotation axis of the recording paper stack tray is provided. 6. The image forming apparatus according to claim 5, wherein the direction is set to a direction along a sheet discharging direction. 8. A stack member of the recording paper stack tray is urged by the spring member when there is no recording paper in the recording paper stack tray, wherein a spring member is arranged between the recording paper stack tray and the apparatus main body. The state where the surface is inclined upward from the horizontal direction is maintained, and when a predetermined amount of recording paper is stacked, the stack surface of the recording paper stack tray is inclined downward from the horizontal direction by the weight of the recording paper. The image forming apparatus according to claim 5, 6 or 7, wherein: 9. A detecting means for detecting a stack amount of the recording paper in the recording paper stack tray, and when the detecting means detects a predetermined stack amount, the recording paper stack tray is rotated so as to be higher than a horizontal direction. 8. The image forming apparatus according to claim 5, further comprising a drive mechanism for inclining downward. 10. A recording paper stack tray, which is disposed above the recording paper stack section and stacks recording paper discharged after an image is recorded, is provided detachably with respect to the apparatus main body. 2. The image forming apparatus according to claim 1, wherein when the stack tray is mounted on the apparatus main body, a stack surface of the recording paper stack tray is inclined upward from a horizontal direction.