JPH10254191A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device whose operability is improved. SOLUTION: An automatic feeder(AF) 110 is loaded to a document platen cover (DF) 12 and the AF 110 is integrated with the DF 12, then, two document insertion ports are formed. One is a 1st document insertion port 122, and in the case the document is inserted through the 1st document insertion port 122, such a document stopping mode is accomplished that the document is placed and left on the document platen glass and the document is scanned and exposed by an optical system. The other port is the 2nd document insertion port 138, and in the case the document is inserted through the 2nd document insertion port 138, such a document-through mode is accomplished that the document is carried and exposed by the optical system which is at a standstill.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an image forming apparatus such as a copying machine and a printer.

[0002]

2. Description of the Related Art Conventionally, copying machines using an electrophotographic system have been widely used. This electrophotographic copier
For example, while rotating a drum-shaped image carrier (photosensitive drum) at a predetermined process speed, the photosensitive drum is uniformly charged by a charger, and light carrying image information recorded on a document is transferred to the photosensitive drum. To form an electrostatic latent image, develop the electrostatic latent image to form a developed image, transfer this developed image to a recording medium such as recording paper, fix the transferred image, and print a printed image ( (A copy image).

In such a copying machine, an original platen glass on which an original is placed is generally disposed on the top surface of the copying machine main body. An optical system for exposing a document placed on the platen glass to obtain an image signal carrying image information is arranged below the platen glass.

There are two methods of exposing a document with an optical system. One of the methods is to stop the document on a platen glass and to expose the document while scanning the document with the optical system. This is a method called mode. Another method is a method called a document through mode in which the optical system is stopped at a predetermined position below the platen glass and the document is exposed by the optical system while the document is conveyed on the platen glass.

When copying one original on a plurality of recording papers, the original may be stopped on the original platen glass, so that the original stop mode is convenient. On the other hand, when copying a document having a size longer than the platen glass, in the document stop mode, a portion of the document protrudes from the platen glass and cannot be copied, so the document through mode must be used.

The above-described optical system is usually formed on a recording paper, a light source for irradiating the original with light, a plurality of mirrors for forming an optical path for irradiating the photosensitive drum with light reflected by the original. It has a lens for changing the magnification of the image. Here, the light source and the first mirror that first receives the reflected light from the document constitute a first mirror base as a unit configuration. The second and third mirrors that receive the reflected light following the first mirror also constitute a second mirror base, and are connected to the first mirror base that reciprocates to scan the original with the light source. It reciprocates following the first mirror base.
As a result, the distance from the light source to the photosensitive drum does not change, and a constant optical path length is secured.

When copying in the original through mode, it is necessary to prevent the third mirror of the second mirror stand located in the same area as the lens from colliding with the lens. The lens moves according to the magnification of the image, but the maximum magnification, for example, 2
When it reaches 00%, it comes closest to the second mirror stand. At this time, the lens and the third mirror are spaced at a fixed interval (for example, 10
mm), the position of the third mirror is determined so as to open by only mm. As a result, the fixed position of the first mirror base connected to the second mirror base having the third mirror is naturally determined.

[0008]

In a conventional copying machine, the size of a document to be copied is generally determined for each copying machine. Therefore, only one of the above-described document stop mode and document through mode is provided. Not adopted. Therefore, in the case of a copying machine capable of copying originals of various sizes, there is a problem that usability is poor.

Further, as described above, when copying in the original through mode, regardless of the magnification of the image, a position where the lens and the third mirror do not collide at the maximum magnification, that is,
The optical system is stopped so that the light source is located substantially at the center of the platen glass table. Therefore, the document inserted from the document insertion slot starts to be irradiated with light from the light source when it reaches almost the center of the document table glass table regardless of whether the magnification of the image is large or small. For this reason, compared with the case where the light source is located near the document insertion slot, the timing at which the light from the light source starts to be emitted is delayed, so that the copying time is lengthened and the usability is poor.

The present invention has been made in view of the above circumstances, and has as its object to provide an image forming apparatus which is easy to use.

[0011]

According to a first aspect of the present invention, there is provided an image forming apparatus having an optical system for exposing a document, exposing the document with the optical system, and recording the image on the document. (1) A document stop mode in which a document is stopped and the optical system is exposed while scanning the document, and a single-leaf document is conveyed while the optical system is stopped. And a document feeder for freely selecting a document through mode in which the document is exposed by the optical system.

Here, the document feeder includes: (2) a first document insertion slot for inserting a plurality of placed documents when the document stop mode is selected; and (3) a document through mode selected. And a second document insertion port different from the first document insertion port for inserting a single-sheet document when the document is ejected. (4) Each document ejection port may be different.

(5) In the original through mode, the original transport direction in which the original is transported when the original is exposed is the same as the original discharge direction in which the exposed original is discharged. The document may be transported such that

According to a second image forming apparatus of the present invention for achieving the above object, an optical system having a light source for irradiating a document with light is stopped, and the document is exposed by the optical system while the document is being conveyed. In an image forming apparatus that has an original through mode to form an image recorded on the original on a recording sheet, the optical system includes: (6) When the original through mode is used, the optical system is formed on the recording sheet. The stop position for exposing the original with light from the light source is changed according to the magnification of the image.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Here, an electrophotographic image forming apparatus is shown as an example of the image forming apparatus.

FIG. 1 is a perspective view showing an appearance of a copying machine according to an embodiment.

An openable and closable platen cover 12 is disposed on the top surface of a copying machine (an example of an image forming apparatus according to the present invention) 10, and the platen cover 12 places a document on a platen glass. It also serves as a document feeder (DF) to send. An operation unit 14 for inputting the number of copies and the like is arranged on the front side of the top surface. This copying machine 10
Images can be selectively formed on both cut paper and roll paper,
Four cassettes 16, 18, 20, and 22 (cassettes 16 and 18 are not shown) each accommodating a plurality of cut sheets are provided so as to be able to be taken in and out of the main body of the copying machine 10. Further, a roll paper unit 24 in which roll paper is stored is incorporated in the main body of the copying machine 10 so as to be freely taken in and out. The copying machine 10 also includes a manual feed tray 26 on which small-sized recording paper such as a postcard can be placed, and a paper discharge tray 28 on which recording paper on which an image is formed is stacked. Above the manual feed tray 26, there is provided a toner supply door 32 that opens and closes when the developing unit 30 (see FIG. 2) is taken in and out. Also, four cassettes 16, 18, 2
A front door 34 is provided above and below 0 and 22 so as to be openable and closable. When the front door 34 is opened, a developing lever 36 appears.

Referring to FIG. 2, a procedure for forming an image by the copying machine 10 of FIG. 1 will be described.

FIG. 2 is a schematic diagram showing an outline of the internal structure of the copying machine 10, in which the platen cover 12 is omitted.

Below the platen cover 12 (see FIG. 1),
A document table glass 38 on which a document is placed is arranged.
An optical system that irradiates a document and obtains an image signal carrying image information is disposed below the platen glass 38. This optical system includes a light source 40, a lens 42, and a mirror 4
4, 46, 48, 50, 52, 54. The light source 40 and the mirror 44 are fixed to a first mirror base (not shown), and the mirrors 46 and 48 are fixed to a second mirror base (not shown).

The original placed on the original platen glass 38 is irradiated with light from a light source 40, and reflected light 40a from the original is used as an image signal as a lens 42 and mirrors 44, 46,
The light passes through 48, 50, 52, and 54 to the photosensitive drum 56 disposed below the optical system. The photosensitive drum 56
It has a rotating shaft 56a extending in the direction perpendicular to the plane of FIG. 2 and rotates in the direction of arrow A. Light 40 reflected from original
A primary charger 58 for uniformly charging the photosensitive drum 56 is disposed upstream of the irradiation position of the photosensitive drum 56 in the rotation direction of the photosensitive drum 56. After the photosensitive drum 56 is uniformly charged by the primary charger 58 to form a charged surface, the charged surface is irradiated with the reflected light 40a from the document to form an electrostatic latent image.

A developing unit 30 for developing an electrostatic latent image is arranged downstream of the irradiation position in the rotation direction of the photosensitive drum 56. The developing device 30 includes a developing sleeve 60 that rotates at a predetermined distance from the photosensitive drum 56, and a developer (toner) is supplied to the photosensitive drum 56 by the developing sleeve 60. The area where the developing sleeve 60 and the photosensitive drum 56 face each other is a developing area where the electrostatic latent image is developed. When the electrostatic latent image reaches the developing area by the rotation of the photosensitive drum 56, the developing device 30 electrostatically charges the electrostatic latent image. The latent image is developed to form a toner image (developed image).

A transfer charger 6 for transferring a toner image onto recording paper is provided downstream of the developing area in the rotation direction of the photosensitive drum 56.
2 are arranged. Photosensitive drum 56 and transfer charger 62
Is a transfer area where the toner image is transferred to the recording paper. When the toner image reaches the transfer area by rotation of the photosensitive drum 56, the toner image is transferred onto the recording paper conveyed to the transfer area. Transcribed.

The recording paper is stored in cassettes 16, 18, 20, and 2.
2 and the paper is sent from the roll paper unit 24 and conveyed to the transfer area. In transporting the recording paper to the transfer area, for example, the cut paper 16a sent out from the cassette 16 or the like by the paper feed roller 64 is made to stand by in a state where the leading end of the cut paper 16a contacts the registration roller 66 to form a loop. Each time, the toner image on the photosensitive drum 56 is conveyed to the transfer area at the timing of reaching the transfer area.

The recording paper onto which the toner image has been transferred is separated from the photosensitive drum 56 by a separation charger 68, conveyed to a conveyor belt 70 rotating in the direction of arrow B, and reaches a fixing unit 72. In the fixing device 72, the toner image is fixed on the recording paper. After the toner image is fixed on the recording sheet, the recording sheet is discharged to a discharge tray 28 from a discharge port (not shown). The residual toner remaining on the photosensitive drum 56 after the transfer is
The photosensitive drum 56 is removed by the cleaning device 74. The residual charges remaining on the photosensitive drum 56 are discharged by a discharge lamp (not shown). As a result, the photosensitive drum 56 is ready for the next image formation.

Referring to FIG. 3, a platen cover (hereinafter referred to as D
F) will be described.

FIG. 3 is a schematic diagram showing the DF 12.

The DF 12 includes a resin housing 80 and rollers and sensors housed in the housing 80. In the vicinity of the recording paper insertion opening 82, a document detection sensor 84 for detecting the inserted document and a paper feed roller 8 for feeding the document to the document table glass 38 (see FIG. 2) in order along the document conveyance direction.
6, a paper feed sensor 88 for detecting the presence or absence of a document, and an image sensor 90 for detecting the leading edge of the document.

On the downstream side of the image sensor 90 in the document transport direction, a transport belt 94 that is stretched over a transport belt driving roller 92 and a transport belt driven roller 93 is disposed. A plurality of pressing rollers 96 are arranged inside the conveying belt 94, and the pressing rollers 96 press the document conveyed by the conveying belt 94 and make the document adhere to the document table glass 38. Downstream of the conveyance belt 94 in the document conveyance direction,
A paper discharge sensor 98 for detecting a discharged document is arranged.

The DF 12 is configured to selectively discharge the original conveyed by the conveying belt 94 in the direction of arrow C (an example of the original conveying direction in the present invention) in two directions. One of the document discharge directions in which the document is discharged is the same direction (the same direction) as the arrow C direction.
The other is a direction (reverse direction, arrow D direction) opposite to the direction of arrow C for discharging a document fed by AF described later. When the document is discharged in this reverse direction, the document is conveyed. The document conveyed by the belt 94 is inverted and discharged.

Whether the document is discharged in the same direction or in the reverse direction is determined by moving the flapper 100 disposed near the discharge port. When the flapper 100 moves so as to be discharged in the same direction and opens the discharge path in the same direction, the document is sandwiched between the pair of discharge rollers 102 and discharged in the same direction as the arrow C direction. When the flapper 100 moves so as to be discharged in the reverse direction,
Since the leading edge of the flapper enters the discharge path in the same direction and guides the document such that the leading end of the document is reversed, the document is transferred to a pair of discharge rollers 1
The DF is ejected in a direction opposite to the direction of the arrow C, and is accommodated in an ejection tray 106 provided above the DF. Note that a paper discharge sensor 10 that detects a discharged document is located slightly upstream of the paper discharge roller 104 in the paper discharge direction.
8 are arranged.

With reference to FIGS. 4, 5, and 6, an auto feeder (hereinafter, referred to as AF) for automatically feeding a plurality of originals will be described.

FIG. 4 is a perspective view showing AF, and FIG.
FIG. 3 is a schematic diagram showing the internal structure of AF. FIG.
Is a schematic diagram showing an AF mounted on the DF, and the same components as those shown in FIG. 3 are denoted by the same reference numerals.

The AF 110 is detachably mounted on the DF 12, and by mounting the AF 110 on the DF 12, an example of the document feeder according to the present invention is constituted. The AF 110 includes a document tray 112 on which a plurality of documents are placed. The original placed on the original tray 112 is conveyed in the direction of arrow C toward the original platen glass 38. An upper cover 114 that covers the inside of the AF 110 is provided at the leading end of the document tray 112 in the document transport direction. The upper cover 114 also has a function of guiding one document fed by the DF. At both ends in the width direction of the upper cover 114, a front cover 116 and a rear cover 118 that cover the inside of the AF 110 are provided. In the upper part of the upper cover 114, the document conveying direction (arrow C
A slide guide 120 that slides according to the document size in a direction orthogonal to the direction (direction) and guides the document fed by the DF is arranged.

At the front end of the document tray 112 of the AF 110 in the document transport direction, a first document insertion port 12 into which a document is inserted is provided.
Slightly downstream of the first document insertion slot 122, a paper feed roller 124 that descends and abuts on the document only during paper feeding and feeds the document, and the document is conveyed to the paper feed roller 124. An AF document detection sensor 126 that is located on substantially the same axis as the paper feed roller and detects whether or not the document is being fed is disposed. The entrance shutter 1 that closes the first document insertion port 122 is located slightly downstream of the paper feed roller 124 in the document conveyance direction.
28 are provided. Further, a separation roller 130 and a conveyance roller 132 are provided slightly downstream of the entrance shutter 128 in the document conveyance direction to convey a plurality of documents one by one.
Is arranged. The document conveyed by the separation roller 130 and the conveyance roller 132 is guided by a pair of guide plates 134 and conveyed to the DF 12. Further, a sheet-through sensor 136 that detects a document guided by the upper cover 114 is disposed at a tip end of the upper cover 114.

As shown in FIG. 6, the AF 110
And the AF 110 and the DF 12 are united to form two document insertion ports. One is the first document insertion port 122 for AF described above. When a document is inserted from the first document insertion port 122, the document is stopped on the document glass table 38 and the document is stopped by the optical system. A document stop mode for exposing while scanning is performed. The other is a second document insertion slot 138 for DF, and the second document insertion slot 13
When an original is inserted from the position 8, the original through mode in which the optical system is stopped at a predetermined position and the original is exposed by the optical system while the original is being transported can be selected in addition to the above-described original stop mode.

FIG. 7A is a perspective view showing a state in which a plurality of originals are inserted into the first original insertion slot 122.
(B) is a perspective view showing a state where one document is inserted into the second document insertion slot 138.

As shown in FIG. 7A, when a document is inserted into the first document insertion slot 122, a plurality of A3 size or A4 size documents 140 can be placed on the document tray 112, for example. On the other hand, when inserting the originals into the second original insertion slot 138, the originals 142 are inserted one by one as shown in FIG. 7B.

The document stop mode will be described with reference to FIGS.

FIG. 8 shows the DF 12 immediately before a document is inserted.
FIG. 9 is a schematic diagram showing the second insertion port 138 (FIG. 6).
FIG. 7 is a schematic diagram showing a state in which a document is inserted from the original document (see FIG. 1).
FIG. 10 shows a paper ejection sensor 98 for reading the position of the original.
FIG. 4 is a schematic diagram showing a state in which the leading edge of the document has been transported,
FIG. 11 is a schematic diagram showing a state in which the returned document stops on the platen glass. FIG. 12 is a schematic diagram showing a state in which the original is exposed while scanning the original with the optical system.
FIG. 4 is a schematic diagram showing a state in which a document exposed by the optical system is being discharged. In these drawings, the DF 12 is schematically shown, and the AF 110 attached to the DF 12 is omitted. Also, the same components as those shown in FIGS. 1 and 3 are denoted by the same reference numerals.

As shown in FIG. 8, the conveyance belt 94 is stopped until the document detection sensor 84 detects the document 144. As shown in FIG. 9, when a document 144 is inserted from the second insertion port 138 of the AF 110 (see FIG. 7), the document 144 turns on the document detection sensor 84. About one second after this ON, the feed roller 86, the transport belt driving roller 92, the transport belt driven roller 93, and the discharge roller 1
02 rotates in the directions of arrows E, F, G, and H (forward rotation), and the transport belt 94 starts transporting the document 144 at a low speed. In this case, when the automatic document feed mode is released, the leading end of the document 144 turns on the feed sensor 88.
At this position, the rotation of the paper feed roller 86 and the like is stopped, and the original 144 is kept on standby until the user presses a copy start key (not shown).

On the other hand, when in the automatic paper feed mode, the original 144 is conveyed at the same low speed, and
After turning on the DF image sensor 90,
4 begins to be transported. As shown in FIG. 10, when the leading end of the document 144 turns on the paper ejection sensor 98, the transport belt 94 and the like are stopped. About 0.1 second after this stop, as shown in FIG. 11, the paper feed roller 86, the transport belt driving roller 92,
The transport belt driven roller 93 and the paper discharge roller 102 are rotated (reversely rotated) in directions of arrows E ′, F ′, G ′, and H ′, respectively, to stop the document 144 at a predetermined position on the document table glass 38. Thereafter, as shown in FIG. 12, the light source 40 is scanned in the direction of arrow I, and the recording paper 146 is conveyed in the direction of arrow J to start the copying operation. When an image is formed on the recording paper 146 and the recording paper 146 passes through the paper ejection sensor 148 of the copying machine main body as shown in FIG. 13, the paper feeding roller 86, the transport belt driving roller 92, the transport belt driven roller 93 , And the paper discharge roller 102 is again rotated in the directions of arrows E, F, G, and H to discharge the document 144.

The document through mode will be described with reference to FIGS. In the document through mode, the light source 4 is located at a fixed position regardless of the magnification of the image formed on the recording paper.
There is a stop mode in which 0 is stopped, and a change mode in which the stop position of the light source 40 is changed according to the magnification of the image formed on the recording paper. Here, stop mode is explained,
The change mode will be described later with reference to FIGS.

FIG. 14 shows DF1 immediately before the document is inserted.
FIG. 15 is a schematic diagram illustrating a state where the optical system has moved to a document through position. FIG.
FIG. 9 is a schematic diagram showing a state where a document is inserted from the second insertion slot 138 (see FIG. 6). FIG. 17 is a schematic diagram showing a state immediately before the light source is turned on and the exposure is started.
FIG. 4 is a schematic diagram illustrating a state in which a conveyed document is exposed by an optical system. FIG. 19 is a schematic diagram showing a state where an exposed document is being discharged. In these figures,
The DF 12 is schematically shown, and the AF 110 attached to the DF 12 is omitted. The same components as those shown in FIGS. 8 to 13 are denoted by the same reference numerals.

As shown in FIG. 14, the document detection sensor 84
The conveyance belt 94 and the like are stopped until the document 144 is detected. When the document through key of the operation unit 14 (see FIG. 1) is pressed, as shown in FIG. 15, the optical system moves to the document through position, whereby the light source 40 is moved from the home position to almost the center of the document table glass 38. Move and stop. Assuming that the magnification of the image at this time is 100%, the distance between the third mirror 48 and the lens 42 is L1 because the third mirror 48 is located at a position where the lens 42 does not collide at 200%. When the document 144 is inserted from the second insertion slot 138, the document 144 turns on the document detection sensor 84 as shown in FIG. About one second after this ON, the paper feed roller 86, the transport belt driving roller 92, the transport belt driven roller 93, and the paper discharge roller 102 rotate (forward) in the directions of arrows E, F, G, and H, respectively. Then, the paper feed roller 86 starts conveying the original 144 at a low speed.

The conveyed document 144 is fed to the paper feed sensor 8.
When 8 is turned on, the feeding operation of the copying machine main body starts after a predetermined time. When the document 144 is further conveyed and the DF image destination sensor 90 is turned on, the registration roller clutch (not shown) of the copier is turned on after a predetermined time, and the recording paper is conveyed. The predetermined time after the document 144 turns on the DF image destination sensor 90 depends on the magnification of the image formed on the recording paper. When the document 144 turns on the DF image destination sensor 90, as shown in FIG. 17, the light source 40 is turned on and exposure starts.

Thereafter, as shown in FIG.
Is conveyed at a speed corresponding to the magnification of the image, exposed, and a copying operation is performed. An image is formed on the recording paper 146, and as shown in FIG. 19, the recording paper 146 is discharged through a paper discharge sensor 148 of the copying machine main body. On the other hand, the paper feed roller 86, the transport belt driving roller 92, the transport belt driven roller 93, and the discharge roller 102 continue to rotate in the directions of arrows E, F, G, and H, respectively, and discharge the original 144. At this time, the original 1 conveyed at a speed matching the magnification
Immediately before the trailing end of 44
The document 144 is discharged after changing the transport speed at the time of copying.
The reason is that, depending on the magnification, the original is conveyed at a high speed, and if the original is discharged at that speed, the original cannot be loaded on the original tray properly. As described above, by changing the transport speed to 100% copy conveyance speed, it is possible to improve the stackability of the discharged original.

If the original discharge time is allowed to be longer than the current time, it is advantageous for the stackability that the conveying speed is slower than the 100% copying speed.

The above-described original through mode is convenient when the original is longer than the original platen glass 38. in this case,
The document discharge direction is made the same as the document transport direction. In the copying machine 10, the exposed document can be reversed and stored in the paper discharge tray 106 provided above the DF 12, but when the document is reversed, the document may shift and the image may be disturbed. Such image disorder is likely to occur when the document is long. Therefore, in the document through mode of the copying machine 10 of the present invention, when the document 144 is exposed,
4 and the exposed document 144
The direction in which the original is discharged is the same as that of the original, thereby improving the image accuracy.

The change mode described above among the document through modes will be described with reference to FIGS.

FIG. 20 shows the DF1 immediately before a document is inserted.
FIG. 21 is a schematic diagram illustrating a state in which the optical system has moved to a document through position according to the magnification of an image formed on a recording sheet. FIG. 22 is a schematic diagram showing a state where a document is inserted from the second insertion slot 138 (see FIG. 6). FIG. 23 is a schematic diagram showing a state immediately before the light source is turned on and exposure starts, and FIG. 24 is a schematic diagram showing a state in which the conveyed document is exposed by the optical system. FIG. 25 is a schematic diagram showing a state where an exposed document is being discharged. In these figures, the DF 12 is schematically shown, and the AF 1 attached to the DF 12
10 is omitted. The same components as those shown in FIGS. 8 to 13 are denoted by the same reference numerals.

As shown in FIG. 20, the document detection sensor 84
The conveyance belt 94 and the like are stopped until the document 144 is detected. When the document through key of the operation unit 14 (see FIG. 1) is pressed, as shown in FIG. 21, the optical system moves to the document through position in accordance with the magnification of the image formed on the recording paper. Also stops at a position corresponding to the magnification of the image. The reading position at which the original is read by the light from the light source 40 changes according to the magnification of the image. For this reason,
Assuming that the magnification of the image at this time is 100%, the third mirror 4
The distance L2 between the lens 8 and the lens 42 is small, and also in the stop mode in FIG.
Is longer. The difference between the distances increases as the magnification decreases. For example, when the image magnification is set to the minimum of 50%, the light source 40 stops near the second insertion port 138, and therefore, the reading position is changed to the second insertion port 138. Be near. As a result, the timing at which the document 144 starts to be exposed is earlier than in the above-described stop mode, and the copy time can be reduced accordingly.

As shown in FIG. 21, when the light source 40 is stopped near the second insertion port 138, the second insertion port 138 is stopped.
When the original 144 is inserted from the beginning, the original 144 turns on the original detection sensor 84 as shown in FIG. This O
About one second after N, the paper feed roller 86, the transport belt driving roller 92, the transport belt driven roller 93, and the paper discharge roller 102 rotate (forward) in the directions of arrows E, F, G, and H, respectively. Then, the conveyance belt 94 starts conveying the document 144 at a low speed.

The conveyed document 144 is fed to the paper feed sensor 8.
When 8 is turned on, the feeding operation of the copying machine main body starts after a predetermined time. When the document 144 is further conveyed and the DF image destination sensor 90 is turned on, the registration roller clutch (not shown) of the copier is turned on after a predetermined time, and the recording paper is conveyed. The predetermined time after the document 144 turns on the DF image destination sensor 90 depends on the magnification of the image formed on the recording paper. When the document 144 turns on the DF image destination sensor 90, as shown in FIG. 23, the light source 40 is turned on and exposure starts.

Thereafter, as shown in FIG.
Is conveyed at a speed corresponding to the magnification of the image, exposed, and a copying operation is performed. An image is formed on the recording paper 146, and as shown in FIG. 25, the recording paper 146 is discharged through the paper discharge sensor 148 of the copying machine main body. On the other hand, the paper feed roller 86, the transport belt drive roller 92, the transport belt driven roller 93, and the paper discharge roller 102 continue to rotate in the directions of arrows E, F, G, and H, respectively, and discharge the document 144. Immediately before the trailing edge of the document 144 passes through the paper ejection sensor 98, the conveyance speed is changed to 100% copy conveyance speed, and the
To discharge. This is because, as described above, the stackability of the discharged document is improved.

The change mode described above is also convenient when the document is longer than the platen glass 38, as in the stop mode, and the document conveyance direction in which the document 144 is conveyed when the document 144 is exposed, and the exposure mode. The image accuracy is improved by setting the same direction in which the discharged document 144 is discharged.

[0057]

As described above, in the first image forming apparatus of the present invention, the original through mode and the original stop mode can be selected according to the original size, so that the apparatus is easy to use.

Here, the document feeder includes a first document insertion slot into which a document is inserted when the document stop mode is selected;
Insert an original when Original Through mode is selected,
In the case where the apparatus is provided with a second document insertion port different from the first document insertion port, it becomes more convenient.

When the document feeder is in the document through mode, the document feed direction in which the document is fed when the document is exposed is the same as the document discharge direction in which the exposed document is discharged. When the original is conveyed, the original is not inverted when the original is discharged, so that the original can be prevented from being shifted, and the image accuracy can be improved.

According to the second image forming apparatus of the present invention, since the reading position is changed in accordance with the magnification of the image formed on the recording paper, the timing for exposing the document can be made earlier, and the copy time can be shortened accordingly. Can be shortened.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating an appearance of a copying machine according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing an outline of an internal structure of the copying machine shown in FIG. 1;

FIG. 3 is a schematic diagram showing a DF of the copying machine shown in FIG. 1;

FIG. 4 is a perspective view showing an AF of the copying machine shown in FIG. 1;

FIG. 5 is a schematic diagram showing an internal structure of the AF of FIG.

FIG. 6 is a schematic diagram illustrating an AF mounted on a DF.

FIG. 7A is a perspective view illustrating a state where a document is inserted into a first document insertion slot, and FIG. 7B is a perspective view illustrating a state where a document is inserted into a second document insertion slot. FIG.

FIG. 8 is a schematic diagram showing a DF immediately before a document is inserted.

FIG. 9 is a schematic diagram illustrating a state where a document is inserted from a second insertion slot.

FIG. 10 is a schematic diagram illustrating a state in which the leading edge of the document has been conveyed to a paper ejection sensor in order to read the position of the document.

FIG. 11 is a schematic diagram illustrating a state in which a returned document stops on a document table glass.

FIG. 12 is a schematic diagram showing a state in which a document is exposed while being scanned by an optical system.

FIG. 13 is a schematic diagram showing a state in which a document exposed by the optical system is being discharged.

FIG. 14 is a schematic diagram illustrating a DF immediately before a document is inserted in a stop mode.

FIG. 15 is a schematic diagram illustrating a state where the optical system has moved to a document through position.

FIG. 16 is a schematic diagram showing a state where a document is inserted from a first insertion slot.

FIG. 17 is a schematic diagram showing a state immediately before a light source is turned on and exposure starts.

FIG. 18 is a schematic diagram illustrating a state in which a conveyed document is exposed by an optical system.

FIG. 19 is a schematic diagram illustrating a state where an exposed document is being discharged.

FIG. 20 illustrates a DF immediately before a document is inserted in the flat transfer mode.
FIG.

FIG. 21 is a schematic diagram illustrating a state in which the optical system has moved to a document through position in accordance with the magnification of an image formed on a recording sheet.

FIG. 22 is a schematic diagram illustrating a state where a document is inserted from a second insertion slot.

FIG. 23 is a schematic diagram showing a state immediately before a light source is turned on and exposure starts.

FIG. 24 is a schematic diagram showing a state in which a conveyed document is exposed by an optical system.

FIG. 25 is a schematic diagram showing a state where an exposed document is being discharged.

[Explanation of symbols]

 Reference Signs List 10 copier 12 DF 40 light source light 42 lens 44, 46, 48, 50, 52, 54 mirror 110 AF 122 first document insertion port 134 second document insertion port 144 document

Claims (4)

[Claims] 1. An image forming apparatus, comprising: an optical system for exposing a document, exposing the document with the optical system, and forming an image recorded on the document on a recording sheet. A document feeder that can freely select a document stop mode in which the document is exposed while scanning the document, and a document through mode in which the optical system is stopped and the document is exposed by the optical system while the single document is being transported. An image forming apparatus characterized in that: 2. A document feeder comprising: a first document insertion slot for inserting a plurality of placed documents when the document stop mode is selected; and a single leaf when the document through mode is selected. 2. The image forming apparatus according to claim 1, further comprising a second document insertion port different from the first document insertion port, wherein each document ejection port is different from the first document insertion port. 3. 3. The document feeder according to claim 1, wherein in the document through mode, a document transport direction in which the document is transported when the document is exposed is the same as a document discharge direction in which the exposed document is discharged. 3. The image forming apparatus according to claim 1, wherein the original is conveyed to the image forming apparatus. 4. An original through mode in which an optical system provided with a light source for irradiating light on the original is stopped and the original is exposed by the optical system while the original is being conveyed, and an image recorded on the original is In the image forming apparatus for forming on a recording sheet, the optical system includes a stop position for exposing the original with light from the light source according to a magnification of an image formed on the recording sheet when the document through mode is used. An image forming apparatus characterized in that the image forming apparatus changes the image quality.