JP7125672B2 - Sheet conveying device and image forming device - Google Patents

Description

The present invention relates to a sheet conveying device and an image forming apparatus.

2. Description of the Related Art Conventionally, a sheet conveying device that conveys a sheet on a sheet placing surface is known.

For example, Japanese Patent Application Laid-Open No. 2002-100000 discloses a method for conveying a document by executing a conveying operation selected according to the size of the document to be conveyed, in order to prevent deterioration of the conveying accuracy when the document (sheet) is small. An automatic document feeder (sheet feeder) is disclosed.

2. Description of the Related Art In a sheet conveying apparatus that conveys a normal size sheet using a sheet mounting surface, it has been proposed to convey a small size sheet on the sheet mounting surface. In this sheet conveying apparatus, the sensor may make an erroneous detection, and in this case, there is a problem that the intended conveying operation is not executed.

In order to solve the above-described problems, the present invention provides a sheet conveying apparatus for conveying a sheet on a sheet mounting surface, comprising: tray detection means for detecting whether or not an auxiliary tray is installed on the sheet mounting surface; A sheet conveying means for conveying a sheet by executing a conveying operation selected according to a detection result of the tray detecting means, and an auxiliary tray selected when the tray detecting means detects that the auxiliary tray is installed. and operation receiving means for receiving a selection operation as to whether or not to cause the sheet conveying means to execute the sheet conveying operation .

According to the present invention, in a situation where the tray detecting means erroneously detects that the auxiliary tray is installed even though the auxiliary tray is not installed, the auxiliary tray transport is performed when the sheet is transported on the sheet placement surface. It is possible to avoid a situation in which the operation is executed.

1 is a schematic configuration diagram showing a copier according to an embodiment; FIG. FIG. 2 is a schematic configuration diagram showing the automatic document feeder of the present embodiment together with the upper part of the scanner; FIG. 2 is a control block diagram of the entire automatic document feeder; FIG. 2 is a block diagram showing a main part of an electric circuit of a fixed image reading unit; FIG. 2 is a top view of the automatic document feeder; FIG. 5 is a view for explaining the positional relationship in the width direction between a document table and a pickup roller; FIG. 2 is a schematic diagram showing a paper feed auxiliary tray installed on a document table and members for conveying documents of an automatic document feeder; FIG. 2 is a schematic diagram showing a paper feed auxiliary tray installed on a document table and a pickup roller; FIG. 10 is a view for explaining document set detection by a set detection mechanism for small size; FIG. 4 is a front view showing a document placing table on which an auxiliary paper feeding tray can be installed; The figure which shows the bottom face of a paper feed auxiliary tray. FIG. 10 is a view showing how the auxiliary paper feed tray is installed on the document placing table; FIG. 4 is a flow diagram of document conveyance control; FIG. 10 is a view showing an example of an image displayed on the image display section of the operation section when the document is conveyed when the auxiliary paper feed tray is installed; 10 is a flow chart showing the flow of determination processing for determining erroneous detection by an auxiliary tray detection sensor according to Modification 1; 11 is a flow chart showing the flow of determination processing for determining erroneous detection by an auxiliary tray detection sensor according to modification 2; FIG. 11 is an explanatory diagram showing an example of a jam display screen displayed on the image display section of the operation section according to Modification 2; 11 is a flowchart showing transport control during document transport in Modification 3; FIG. 12 is an explanatory diagram showing an example of a jam display screen displayed on the image display section of the operation section in Modification 3;

An embodiment in which the present invention is applied to an electrophotographic copying machine, which is an image forming apparatus, will be described below.
First, the basic configuration of the copying machine 1 according to this embodiment will be described.
FIG. 1 is a schematic configuration diagram showing a copying machine 1. As shown in FIG.
The copier 1 includes an image forming section 3 as an image forming means, a transfer paper feeding section 2 and a document conveying and reading unit 6 . A document feeding and reading unit 6 as document feeding and reading means has a scanner 4 as a document reading device fixed on the image forming section 3 and an automatic document feeding device 5 as a sheet feeding device supported by the scanner 4 . is doing.

The transfer paper feeding unit 2 has a plurality of stages of transfer paper feeding cassettes 21 (21a, 21b, 21c) capable of accommodating cut sheets of transfer paper P in a stacked state. In each transfer paper feed cassette 21 (21a, 21b, 21c), transfer paper P (for example, blank paper) of a sheet size preselected from a plurality of sheet sizes, for example, is oriented in the vertical or horizontal feeding direction. are to be accommodated.

The transfer paper feeding unit 2 is a transfer paper feeding device that sequentially picks up the transfer papers P stored in the transfer paper feeding cassettes 21 (21a, 21b, 21c) from the uppermost layer side and separates and feeds them. 22 (22a, 22b, 22c). Further, the transfer paper feeding section 2 is provided with various rollers such as a transfer paper transport roller pair 23 . A transfer paper feeding path 24 that conveys the transfer paper P fed from the individual transfer paper feeding devices 22 (22a, 22b, 22c) to a predetermined image forming position of the image forming section 3 by these various rollers. to form

The image forming section 3 includes an exposure device 31 which is a latent image forming means, and drum-like photosensitive members 32K, 32Y, 32M and 32C which are latent image carriers. Further, developing devices 33K, 33Y, 33M, and 33C filled with toners of black (K), yellow (Y), magenta (M), and cyan (C) are provided. The image forming section 3 also includes an intermediate transfer belt 34 as an intermediate transfer body, a secondary transfer device 35 for transferring the toner image on the intermediate transfer belt 34 to the transfer paper P, and a transfer paper P on which the toner image is transferred. and a fixing device 36 for fixing the toner image on.

The exposure device 31 is adapted to generate the laser light L for exposure of each color based on the image read by the scanner 4, for example. Further, the exposure device 31 exposes the photoreceptors 32K, 32Y, 32M, and 32C of each color with the laser light L to expose the surfaces of the individual photoreceptors 32K, 32Y, 32M, and 32C to electrostatic charges of the respective colors corresponding to the read image. It forms a latent image.

The developing devices 33K, 33Y, 33M, and 33C bring thin layers of toner close to the facing photoreceptors 32K, 32Y, 32M, and 32C, respectively, to form electrostatic latent images on the surfaces of the photoreceptors 32K, 32Y, 32M, and 32C. Toner is supplied to develop a visible image.

In the image forming section 3, the toner images developed on the individual photoreceptors 32K, 32Y, 32M, and 32C are superimposed and primarily transferred onto the intermediate transfer belt 34 to form a color toner image on the intermediate transfer belt 34. FIG. This color toner image is transferred from the intermediate transfer belt 34 to the transfer paper P at the secondary transfer nip where the intermediate transfer belt 34 and the transfer conveyor belt 35b of the secondary transfer device 35 arranged below the intermediate transfer belt 34 are in contact with each other. is secondarily transcribed to The transfer paper P onto which the color toner image has been transferred is transported to the fixing device 36 by the transfer transport belt 35 b of the secondary transfer device 35 . When the transfer paper P is heated and pressurized by the fixing device 36, the color toner image on the transfer paper P is melted, the color toner image is fixed on the transfer paper P, and a color image is recorded on the transfer paper P. be.

The image forming section 3 has a transfer paper transport path 39a for transporting the transfer paper P transported from the transfer paper feeder 2 through the transfer paper feed path 24 toward the secondary transfer nip. In the transfer paper transport path 39a, first, the pair of registration rollers 37 adjusts the transport timing and transport speed of the transfer paper P. As shown in FIG. Then, the transfer paper P, which has passed through the secondary transfer nip and the fixing device 36 in synchronization with the belt velocities of the intermediate transfer belt 34 and the transfer transport belt 35b, is discharged onto the paper discharge tray 38 by the paper discharge roller pair 90. It is designed to The image forming section 3 also has a transfer paper manual feed path 39b for feeding the transfer paper P placed on the manual feed tray 25 into the transfer paper feed path 39a on the upstream side of the registration roller pair 37. have.

Below the secondary transfer device 35 and the fixing device 36, a switchback transport path 39c and a reverse transport path 39d are provided, each having a plurality of transport rollers, transport guides, and the like. When images are formed on both sides of the transfer paper P, the switchback transport path 39c is used to transfer the transfer paper P on which the image has been fixed to one of the two surfaces at one end (the left end in FIG. 1). enter from After that, switchback transport is performed to retreat (move in the direction opposite to when entering). The reversing conveying path 39d turns over the transfer paper P that has been switchback conveyed by the switchback conveying path 39c, and feeds it to the registration roller pair 37 again. By the switchback transport path 39c and the reversing transport path 39d, the transfer paper P which has undergone the image fixing process on one side is reversed in its traveling direction and then turned upside down, and is again transferred to the secondary transfer nip. enter the The transfer paper P is ejected onto the paper ejection tray 38 after the image is subjected to secondary transfer processing and fixing processing on the other side of the two sides.

The scanner 4 includes a first carriage 41 carrying an illumination unit and a mirror member, a second carriage 42 carrying a mirror member, an imaging lens 43 , an imaging section 44 and a first contact glass 45 . . These constitute a first surface reading section 40 for reading the image of the first surface of the document S conveyed on the first contact glass 45 . The first side referred to here is one side of the automatically fed document S, for example, the image side on the front side. Further, the scanner 4 includes a second contact glass 46 on which the document S is placed, and an abutment member 47 for abutting and positioning one side of the document S. As shown in FIG.

The first carriage 41 is provided below the first contact glass 45 and the second contact glass 46 so as to be movable in the horizontal direction in FIG. 1 and to be positionally controllable. Illumination light from the light source provided in the illumination unit can be reflected by the mirror member to irradiate the exposure surface side of the document S. As shown in FIG. Reflected light reflected by the exposure surface of the document S passes through each mirror member mounted on the first carriage 41 and the second carriage 42 , enters the imaging lens 43 , and is imaged by the imaging lens 43 . Then, the imaging unit 44 reads the formed image.

The scanner 4 can expose and scan the image surface of the document S placed on the second contact glass 46 while moving the first carriage 41 and the second carriage 42 at a speed ratio of 2:1, for example, while the light source is on. It is possible. The scanner 4 reads a document image with the imaging unit 44 during this exposure scanning, thereby exhibiting a fixed document reading function (a so-called flatbed scanner function).

Further, the scanner 4 can stop the first carriage 41 at a fixed position directly below the first contact glass 45 . The scanner 4 is designed so that it can perform a moving document reading function (a so-called ADF scanner function) for reading the image of the first side of the document S being automatically conveyed without moving the optical system consisting of the light source, the reflecting mirror, and the like. It's becoming

Further, the copier 1 includes a second side reading section 48 incorporated in the automatic document feeder 5 in addition to the first side reading section 40 in the scanner 4 . The second surface reading unit 48 scans the second surface of the document S after passing over the first contact glass 45, for example, the image surface on the back side.

The automatic document feeder 5 is connected to the scanner 4 fixed to the upper part of the image forming section 3 of the copying machine 1 via a hinge mechanism so as to be capable of opening and closing. The automatic document feeder 5 is rotated between an open position exposing the first contact glass 45 and the second contact glass 46 in the scanner 4 and a closed position covering the first contact glass 45 and the second contact glass 46. It is possible.

Next, the automatic document feeder 5 will be further described with reference to FIG.
FIG. 2 is an enlarged configuration diagram showing the main configuration of the automatic document feeder 5 together with the upper portion of the scanner 4. As shown in FIG.
The automatic document feeder 5 includes a document set portion A, a separation/conveyance portion B, a registration portion C, a turn portion D, a first reading/conveying portion E, a second reading/conveying portion F, a paper ejection portion G, a stacking portion H, and the like. ing. The document conveying portion 54 of the automatic document conveying device 5 of the present embodiment constitutes a path for conveying the document S from the position detected by the abutting sensor 72 on the downstream side of the separation conveying portion B to the reading entrance roller 97. . The automatic document feeder 5 is of a sheet-through type having a document feed port for receiving the document S set in the document setting section A and a document discharge port for discharging the document S having the image read into the stack section H. It is an automatic document feeder. A document feeding and reading unit 6 equipped with an automatic document feeding device 5 feeds a sheet-shaped document S, which is a recording medium to be read, to a first surface reading unit 40 and a second surface reading unit 48 which are fixed reading device units. Image reading is performed while conveying at a speed of .

The document setting section A has a document placement table 53 as a sheet placement section on which a bundle of documents S is placed so that the first surface of the documents S faces upward. The separation/conveyance unit B includes a pickup roller 80, a separation belt 84, a reverse roller 85, and the like, and separates the originals S one by one from a bundle of originals S set on the plate surface (sheet mounting surface) of the original platen 53. and then transported. The registration section C has a function of primarily abutting and aligning the document S conveyed from the separating and conveying section B, and a function of pulling out and conveying the document S after being aligned. The turning section D has a curved conveying path, and turns the original document S conveyed in this curved conveying path so that the original document S is turned upside down while being folded back so that the first surface of the original document S is turned to the lower first surface. It is conveyed so as to face the reading unit 40 (see FIG. 1).

In the first reading/conveying section E, the document S is conveyed on the first contact glass 45 made of platen glass. Then, while the document S is being conveyed, the image of the first side of the document S is read from below the first contact glass 45 by the first side reading section 40 arranged inside the scanner 4 . The second reading/conveying unit F conveys the document S that has passed through the first reading/conveying unit E by means of the second reading unit facing rollers 96 arranged below the second surface reading unit 48, while conveying the second surface of the document S. , is read by the second surface reading unit 48 . The paper discharge section G discharges the document S that has passed through the second reading/conveying section F toward the stack section H outside the apparatus. The stacking unit H stacks and holds the document S after reading is completed on the document stacking table 55 .

FIG. 3 is a control block diagram of the entire automatic document feeder 5. As shown in FIG.
A controller 100 that is a control section of the automatic document feeder 5 controls a series of operations of each motor, various sensor sections, and a fixed image reading section 500 . Each of the motors 101 to 105 is a drive unit that drives the operation of conveying the document S, and the fixed image reading unit 500 is the first side reading unit 40 or the second side reading unit 48 .

FIG. 4 is a block diagram showing the main part of the electric circuit of the fixed image reading section 500. As shown in FIG.
The stationary image reading unit 500 is composed of a light source unit 200, a sensor chip 201, an image processing unit 204, a frame memory 205, an output control circuit 206, an interface circuit (hereinafter referred to as I/F circuit 107), and the like. The light source unit 200 includes an LED array, a fluorescent lamp, a cold cathode tube, or the like. A plurality of sensor chips 201 are arranged side by side in the main scanning direction (the direction orthogonal to the document conveying direction). The plurality of OP amplifier circuits 202 are individually connected to each of the plurality of sensor chips 201 . The plurality of A/D converters 203 are individually connected to each of the plurality of OP amplifier circuits 202 .

The sensor chip 201 includes a photoelectric conversion element called a 1:1 contact image sensor (CIS) and a condenser lens. Prior to the document S entering the reading position of the stationary image reading section 500 , the controller 100 sends a lighting signal to the light source section 200 . As a result, the light source unit 200 is turned on and irradiates the light toward the surface of the document (the first surface in the case of the first surface reading unit 40 and the second surface in the case of the second surface reading unit 48). Reflected light reflected from the surface of the document S is condensed by the condensing lenses of the plurality of sensor chips 201 onto photoelectric conversion elements and read as image information. Image information read by each sensor chip 201 is amplified by an OP amplifier circuit 202 and then converted into digital image information by an A/D converter 203 . Note that a CCD may be used instead of the same size contact image sensor (CIS).

The digital image information obtained in this manner is input to the image processing unit 204 and subjected to shading correction and the like, and then temporarily stored in the frame memory 205 . Thereafter, the output control circuit 206 converts the data into a data format acceptable to the body control section 111 , and then outputs the image data to the body control section 111 via the I/F circuit 107 . The controller 100 outputs a timing signal for notifying the timing at which the leading edge of the document S reaches the reading position of the stationary image reading section 500, a lighting signal for the light source, a power supply, and the like. The timing signal is a signal for treating image data after the timing as valid data.

A stack of documents S to be read is set on the document table 53 with the first surface facing upward. The document table 53 supports the leading end of the document S, and has a movable document table 53b that can swing in the directions of arrows ab in FIG. and a fixed document table 53a for supporting the . Further, the document table 53 includes side guides that abut against both ends of the document S in the width direction (the direction perpendicular to the transport direction of the document S and the direction perpendicular to the plane of FIG. 2). The document S set on the document table 53 is positioned in the width direction by abutting side guides against both ends in the width direction.

A set filler 62, which is a swingable lever member, is provided above the movable document table 53b. When the document S is not set on the document table 53, the set filler 62 is at the position indicated by the dashed line in FIG. This position is a position where the document set sensor 63 can detect the set filler 62 . By detecting the set filler 62 with the document set sensor 63 , it can be found that the document S is not set on the document table 53 .

When the document S is set on the document table 53 , the leading edge of the document S pushes up the set filler 62 . Along with this, the set filler 62 moves from the detection position of the document set sensor 63 . When the document set sensor 63 no longer detects the set filler 62 , it detects that the document S has been set, and the document set sensor 63 transmits this detection signal to the controller 100 . The controller 100 transmits the received detection signal to the body control section 111 that controls each device of the document feeding and reading unit 6 via the I/F circuit 107 .

On the fixed document table 53a, a plurality of document length sensors 58 as sheet presence/absence detecting means, each of which is a reflective photosensor for detecting the length of the document S in the conveying direction or an actuator type sensor capable of detecting even one document. (58a, 58b, 58c, 58d). These document length sensors determine the approximate length of the document S in the transport direction. The arrangement of the plurality of document length sensors 58 is such that it is possible to determine at least the length or width of the same document size.

The automatic document feeder 5 has a pickup roller 80 above the movable document table 53b. The pickup roller 80 is rotationally driven by a drive transmitted from the paper feed motor 102 . Further, the separation belt 84 and the reverse roller 85, which form a separation nip as a separation section, are rotationally driven by a drive transmitted from the paper feeding motor 102. As shown in FIG.

The movable document table 53b is driven by the bottom plate lifting motor 105 to swing in the directions of arrows ab in FIG. When the set filler 62 and the document set sensor 63 detect that the document S is set on the document table 53, the controller 100 causes the bottom plate lifting motor 105 to rotate forward. As the bottom plate lifting motor 105 rotates forward, the movable document table 53b rotates in the direction of arrow a in FIG. 2, and the free end side (left side in FIG. 2) of the movable document table 53b rises. Along with the free end side of the movable document table 53b, the bundle of originals S set on the original table 53 also rises, and the uppermost surface of the bundle of originals S comes into contact with the pickup roller 80. As shown in FIG.

The pickup roller 80 is rotatably supported at one end (right end in FIG. 2) of the pickup bracket 252 . The pick-up bracket 252 is rotatable in the directions of arrows cd in FIG. 2 around the document feeding unit drive shaft 253 on the other end side (left end side in FIG. 2). The pickup bracket 252 is configured to rotate in the direction of arrows cd in FIG. The pick-up roller 80 is moved in the direction of the arrow cd in FIG. 2 by rotating the pickup bracket 252 in the direction of the arrow cd in FIG. A pickup bracket 252 that supports the pickup roller 80 has a bracket detected portion 254 . Further, the frame of the main body of the automatic document feeder 5 is provided with a table elevation sensor 59 at a position above the pickup bracket 252 .

The table elevation sensor 59 is a sensor that detects whether or not the pickup roller 80 is at an elevated position by detecting the presence or absence of the bracket detected portion 254 at the detection position. This is a light transmission optical sensor that detects whether light emitted from the light emitting unit is blocked at a detection position between the light emitting unit and the light receiving unit. The presence of the bracket detected portion 254 at the detection position of the table elevation sensor 59 is detected by the bracket detected portion 254 blocking the light at the detection position.

Pickup roller 80 rotates in the direction of arrow d in FIG. 2 and is in a lowered state. Rotate in the direction to rise. By detecting this with the table elevation sensor 59, it is possible to detect that the movable document table 53b has been raised to the upper limit. By detecting that the movable document table 53b has risen to the upper limit, the pickup lifting motor 101 and the bottom plate lifting motor 105 stop, and the document S is nipped between the movable document table 53b and the pickup roller 80. be.

The table elevation sensor 59 is a sensor that detects that the bottom plate has been raised to the upper limit and that the upper surface of the stack of originals S is maintained at an appropriate feeding height. When the table lift sensor 59 is turned on to detect the bracket detection portion 254, the movable document table 53b, which is the bottom plate, stops rising, and paper feeding is repeated. By repeating the feeding, the upper surface position of the bundle of originals S is lowered, and when the detection state of the table elevation sensor 59 is turned OFF, the movable original table 53b is raised and the control is repeated so that the table elevation sensor 59 is turned ON again. . With such control, the position of the upper surface of the stack of originals S can always be maintained at a height suitable for feeding.

When all the documents S set on the document table 53 are fed, the controller 100 reverses the bottom plate lifting motor 105 and moves the movable document table 53b to the home position so that the next bundle of documents S can be set. lower. When the movable document table 53b descends to the home position, the home position sensor 60 detects the filler provided under the movable document table 53b.

In this embodiment, both the movable document table 53b and the pickup roller 80 are provided with an elevating mechanism. However, as a mechanism for sandwiching the document S, only one of the movable document table 53b and the pickup roller 80 may be provided with an elevating mechanism.

The user designates a double-sided reading mode or a single-sided reading mode using the operation unit 108 shown in FIG. When the copy start button is pressed, body control unit 111 transmits a document feed signal to controller 100 via I/F circuit 107 . As a result, the sheet feeding motor 102 is driven in the forward rotation direction. A pick-up roller 80 is rotationally driven by forward rotation of the paper feed motor 102 to pick up several (ideally one) originals S on the original table 53 . The rotation direction of the pickup roller 80 at this time is the direction (clockwise direction in FIG. 2) in which the uppermost document S of the stack of documents S on the document table 53 is conveyed toward a separation nip described later.

Here, when setting the double-sided reading mode or the single-sided reading mode, all the originals S set on the original table 53 may be set in the same manner, or (first sheet, second sheet, . . . . . , different settings may be made for each document S (nth sheet). As a different setting, for example, the first and tenth sheets of the original document S out of the total of ten original sheets S are set to the double-sided reading mode, and the other originals S are set to the single-sided reading mode.

The document S sent out by the pickup roller 80 is sent to the separation entrance 49 of the separation nip, which is the contact position between the separation belt 84 and the reverse roller 85 . The separation belt 84 is stretched between a paper feed drive roller 82 and a paper feed driven roller 83. When the paper feed motor 102 rotates forward, the paper feed drive roller 82 rotates to change the paper feed direction (clockwise direction).

A reverse roller 85 is in contact with the lower stretched surface of the separation belt 84 . The reverse roller 85 is driven to rotate in a direction opposite to the paper feed direction (clockwise direction in FIG. 2) by forward rotation of the paper feed motor 102 . As described above, since the surface movement direction in the separation nip between the separation belt 84 and the reverse roller 85 is opposite, the uppermost document S and the lower document S of the bundle of documents S are separated, and the uppermost document S is separated. Only one document S can be fed.

Specifically, at the separation nip, which is the contact portion between the separation belt 84 and the reverse roller 85, the surface of the separation belt 84 moves in the paper feeding direction. On the other hand, the surface of the reverse roller 85 tends to move in the direction opposite to the sheet feeding direction, but the drive transmission portion of the reverse roller 85 is provided with a torque limiter. Therefore, when the force directed to the surface of the reverse roller 85 in the sheet feeding direction is greater than the upper limit torque of the torque limiter, the reverse roller 85 rotates counterclockwise in FIG. 2 so as to move the surface in the sheet feeding direction. do.

The reverse roller 85 is in contact with the separation belt 84 with a predetermined pressure. The reverse roller 85 is in direct contact with the separation belt 84 or in contact with the separation belt 84 via only one document S (when only one document S is nipped in the separation nip). state), it rotates with the separation belt 84 or the document S. That is, the reverse roller 85 rotates in the counterclockwise direction in FIG. 2, which is the sheet feeding direction.

On the other hand, the torque limiter is set so that when two or more documents S are nipped in the separation nip, the co-rotating force is lower than the upper limit torque of the torque limiter. Therefore, the reverse roller 85 rotates in the clockwise direction in FIG. 2, which is the opposite direction to the co-rotating direction. By rotating the reverse roller 85 in a direction opposite to the rotation direction of the reverse roller 85, the originals S conveyed toward the separation nip, other than the uppermost original S, are rotated by the reverse roller 85 in the feeding direction. Gives movement in the opposite direction. As a result, the excess document S can be pushed back, and only the top document S can be separated from the plurality of documents S, thereby preventing double feeding.

The document S separated into one sheet by the action of the separation belt 84 and the reverse roller 85 is caused to enter the registration section C. As shown in FIG. Then, the document S is further fed by the separation belt 84, the leading edge thereof is detected by the abutting sensor 72, and then further transported, so that the leading edge of the document S abuts against the pull-out roller 86 whose rotation is stopped. The feeding motor 102 which is being driven at this time is driven for a predetermined time after the abutting sensor 72 detects the leading edge of the document S, and then stopped. As a result, the document S is conveyed by a predetermined distance from the detection position of the document S by the abutting sensor 72 . As a result, the transport of the document S by the separation belt 84 is stopped while the document S is pressed against the pull-out roller 86 with a predetermined amount of deflection.

When the abutment sensor 72 detects the leading edge of the document S, the pick-up lifting motor 101 is rotated to retract the pickup roller 80 from the upper surface of the document S, and the document S is transported only by the transport force of the separation belt 84. . As a result, the leading edge of the document S enters the nip formed by the pair of pull-out rollers 86, and alignment (skew correction) of the leading edge of the document S can be performed.

As described above, the pull-out roller 86 has a skew correction function and is a roller for conveying the skew-corrected document S to the intermediate roller 66 after separation. By driving the paper feed motor 102 in reverse, one of the two rollers forming the pullout roller 86 is rotationally driven, and the document S is conveyed. When driving the sheet feeding motor 102 in reverse, drive is input to the pullout roller 86 and the intermediate roller 66 , and drive is not input to the pickup roller 80 , the separation belt 84 and the reverse roller 85 . That is, when the paper feed motor 102 rotates forward, the drive is transmitted to the pickup roller 80, the separation belt 84, and the reverse roller 85, and when the paper feed motor 102 rotates in the reverse direction, the drive is transmitted to the pullout roller 86 and the intermediate roller 66. It is configured to

The document S sent out by the pull-out roller 86 passes directly below the document width sensor 73 . The document width sensor 73 is a sensor in which a plurality of paper detection sensors, such as reflective photosensors, are arranged in the document width direction (the direction perpendicular to the paper surface of FIG. 2). Based on which paper detection sensor detects the document S, the size of the document S in the width direction is detected. The length of the document S in the transport direction is the length from when the leading edge of the document S is detected by the abutment sensor 72 until when the abutment sensor 72 stops detecting the document S (the trailing edge of the document S passes). Detected from motor pulses based on timing. The original document S conveyed by the rotational drive of the pullout roller 86 and the intermediate roller 66 enters the turn portion D conveyed by the intermediate roller 66 and the reading entrance roller 97 .

In the automatic document feeder 5, when the document S is conveyed from the registration section C to the turn section D by rotational driving of the pull-out roller 86 and the intermediate roller 66, the conveyance speed at the registration section C is changed to that at the first reading and conveying section E. is set higher than the transport speed of As a result, the processing time for sending the document S to the first reading/conveying unit E is shortened.

When the reading entrance sensor 67 detects the leading edge of the document S, the paper feed motor 102 starts decelerating. At the same time, the reading motor 103 is driven to rotate forward. By driving the reading motor 103 to rotate forward, the reading entrance roller 97, the reading exit roller 92, and the second reading exit roller 93 are rotationally driven in the conveying direction. By decelerating the sheet feeding motor 102, the rotational speed of the intermediate roller 66 rotationally driven by the sheet feeding motor 102 is decelerated. As a result, the transport speed of the document S can be made the same as the transport speed in the first reading transport section E before the leading edge of the document S enters the nip formed by the upper and lower rollers of the reading entrance roller 97 .

When the registration sensor 65 detects the leading edge of the document S moving from the turn portion D toward the first reading/conveying portion E, the controller 100 in FIG. 3 decelerates the driving speed of each motor over a predetermined period of time. As a result, the transport speed of the document S is decelerated over a predetermined transport distance. Then, the controller 100 controls the document S to be temporarily stopped before the first reading position 700 where the image of the first side of the document S is read by the first side reading section 40 . Further, along with this temporary stop control, the controller 100 transmits a signal to stop the reading entrance roller 97 to the main body control section 111 via the I/F circuit 107 .

Subsequently, when the controller 100 receives a reading start signal from the body control unit 111, the reading motor 103 starts to be driven. At this time, the reading motor 103 is adjusted so that the feeding speed of the document S rises to a predetermined feeding speed by the time the leading edge of the document S stopped before the first reading position 700 reaches the first reading position 700 . control the drive of As a result, the document S is transported toward the first reading position 700 while the transport speed of the document S is increased.

Next, the controller 100 calculates the timing at which the leading edge of the document S reaches the first reading position 700 based on the pulse count of the reading motor 103 . Then, at the calculated timing, the controller 100 transmits a gate signal indicating the sub-scanning direction effective image area of the first surface of the document S to the body control unit 111 . The transmission of this gate signal continues until the trailing edge of the document S leaves the first reading position 700 , and the first side of the document S is read by the first side reading section 40 .

Further, as shown in FIG. 2, the upper surface of the abutment member 47 is inclined so that the height on the left end side is lower. As a result, the tip of the document S that has passed through the first reading position 700 can be scooped up by the inclination of the abutment member 47 and directed toward the nip of the reading exit roller 92 .

The leading edge of the document S that has passed through the first reading/conveying section E and the nip of the reading exit roller 92 is detected by the discharge sensor 61 and then conveyed to the second reading/conveying section F. After that, the document S that has passed through the second reading/conveying section F is conveyed to the paper discharge section G. In the case of a single-sided reading mode in which only one side (first side) of the document S is read, reading of the second side of the document S by the second side reading section 48 is unnecessary. Therefore, when the paper discharge sensor 61 detects the leading edge of the document, the paper discharge motor 104 starts rotating forward, and the upper paper discharge roller of the document paper discharge roller 94 in FIG. 2 rotates counterclockwise in the figure. drive.

Further, the timing at which the trailing edge of the document S leaves the nip of the document ejection roller 94 is calculated based on the pulse count of the ejection motor 104 after the ejection sensor 61 detects the leading edge of the document S. FIG. Then, based on this calculation result, the driving speed of the discharge motor 104 starts to be decelerated at the timing immediately before the trailing edge of the document S leaves the nip of the document discharge roller 94 . This deceleration control enables the document S to be discharged onto the document stack table 55 to be discharged at such a speed that it does not jump out of the document stack table 55 .

On the other hand, in the double-sided reading mode for reading both sides (the first side and the second side) of the document S, the following control is executed. That is, the timing from when the leading edge of the document S is detected by the discharge sensor 61 until the leading edge of the document S reaches the second surface reading unit 48 is calculated based on the pulse count of the reading motor 103 . At this calculated timing, the controller 100 transmits a gate signal indicating the effective image area of the second side of the document S in the sub-scanning direction to the body control section 111 . The transmission of this gate signal continues until the trailing edge of the document S leaves the second reading position of the second side reading section 48 , and the second side of the document S is read by the second side reading section 48 .

A second surface reading unit 48 as reading means includes a contact image sensor (CIS). For the purpose of preventing vertical reading streaks caused by glue-like foreign matters adhering to the document S adhering to the reading surface, the reading surface is subjected to a coating process. In addition, at a position facing the second surface reading unit 48 across the sheet conveying path through which the original S passes, a second reading unit serving as an original document supporting means for supporting the original S from the non-reading surface side (first surface side) is provided. A section facing roller 96 is provided. The second reading unit facing roller 96 suppresses floating of the document S with respect to the second surface reading unit 48 at the second reading position, and functions as a reference white portion for acquiring shading data in the second surface reading unit 48. have a role to play.

The automatic document feeder 5 of this embodiment includes two fixed image reading units 500, a first surface reading unit 40 and a second surface reading unit 48, as conveyed document reading means for reading the image of the conveyed document S. . The configuration for reading the images on both sides of the document S is not limited to the configuration in which two fixed image reading units 500 are provided. It is also possible to switch back the document S whose front surface has been read by one fixed image reading unit 500, and read the back surface when the document S passes through the reading position of the fixed image reading unit 500 again. .

FIG. 5 is a top view of the automatic document feeder 5. FIG.
A setting reference surface 112 for setting a document is provided at one end (back side of the device) of the document table 53 in the document width direction (hereinafter simply referred to as "width direction"). A side fence 117 is provided on the document table 53 , and the side fence 117 is slidable in the width direction along a rail 113 provided on the document table 53 .

The document set on the document table 53 is positioned on the document table 53 by bringing one end in the width direction into contact with the setting reference surface 112 and bringing the other end in the width direction into contact with the side fence 117 . The document is positioned by the setting reference surface 112 and the side fences 117, so that the document is transported from the document table 53 without being skewed.

As a method of setting the document on the document table 53, there is a method of providing a pair of side fences and setting the document at the center of the document table 53 in the width direction by the pair of side fences. In the method of setting the document at the widthwise center of the document table 53 by means of a pair of side fences, the side fences contacting the edges of the document in the widthwise direction to restrict movement of the document in the widthwise direction extend in the transport direction. If it is lengthened, there is a problem that the operability of the side fence is deteriorated. In addition, since the side fences are provided on the document table 53 so as to be slidable in the width direction, play is inevitable. As a result, if the regulating surface is elongated in the transport direction, the document may not be set parallel to the transport direction. As a result, the side fences cannot be provided to the vicinity of the pickup roller 80, and the document cannot be regulated by the pair of side fences to the end, which may cause skew. In particular, when a plurality of documents having different widths are set on the document table 53, narrow documents are likely to be skewed because only one of the pair of side fences is regulated.

On the other hand, in the method of setting the document on the document table 53 by making one width direction end of the document contact the setting reference plane 112, as in the present embodiment. , the setting reference surface 112 can be lengthened in the document conveying direction. As a result, the document can be regulated by the setting reference surface 112 up to the vicinity of the pickup roller 80 . Therefore, it is possible to prevent the document conveyed from the document table 53 from being skewed. In particular, when a plurality of documents having different widths are set on the document table 53, the setting reference surface 112 restricts the narrow document whose other widthwise end is not restricted by the side fence to the vicinity of the pickup roller 80. It is possible to effectively suppress the occurrence of skew.

FIG. 6 is a diagram for explaining the positional relationship in the width direction between the document table 53 and the pickup roller 80. As shown in FIG.
Reference numeral 62 in the drawing denotes a set filler, which is rotatably attached to the set reference plane 112 . A hole into which the tip of the set filler 62 is inserted is provided in the table surface (sheet mounting surface) of the document table 53 . A document set sensor 63 composed of a transmissive optical sensor is provided on the bottom surface of the document table 53 . As shown in FIG. 6, when the document is not set on the document table 53, the tip of the set filler 62 is positioned between the light emitting part and the light receiving part of the document set sensor 63, and the light from the light emitting part is received. blocking. When the document is set on the document table 53, the leading edge of the document pushes the set filler 62 in the conveying direction, and the set filler 62 rotates. Then, the leading edge of the set filler 62 is retracted from between the light emitting portion and the light receiving portion of the document setting sensor 63, and the light receiving portion detects the light from the light emitting portion. This makes it possible to detect that the document has been set.

The pickup roller 80 is normally provided so as to align with the width direction center of the pickup roller 80 at the width direction center of the most frequently transported document so that the most frequently transported document can be stably transported. Therefore, the distance W1 from the setting reference surface 112 to the center of the pickup roller 80 in the width direction is (1/2) the width of the document most frequently transported. For example, when the widthwise center of the pickup roller 80 is aligned with the widthwise center of A4T (longitudinal) 210 [mm], the distance W1 is 105 [mm].

In addition, the distance W2 from the set reference surface 112 to the end of the pickup roller 80 on the side fence side is made shorter than the minimum width size that can be transported by the automatic document feeder 5, so that the end of the document with the minimum width size is picked up. The rollers 80 are kept out of contact with each other. This is because if the edge of the document hits the pick-up roller 80, the document may be damaged such as edge folds. Therefore, for example, when the B6T size with a width of 128 [mm] is the minimum size, the distance W2 must be 128 [mm] or less. Therefore, the width (length in the rotation axis direction) W3 of the pickup roller 80 is 46 [mm].

In recent years, demand for copies of A6 size originals has been increasing in Europe. Moreover, demand for copies of checks and bills is increasing at financial institutions and the like. Typical check sizes are shown in Table 1 below.

For example, in order to support the size of the check 3, which is 76 mm wide by 169 mm long as shown in Table 1, the distance W2 must be set to 76 mm or less. However, if the distance W2 is set to 76 [mm] or less, the widthwise center of the pickup roller 80 cannot be aligned with the widthwise center of the most frequently transported document size (for example, A4T). As a result, a document having a size that is most frequently transported suffers a transport defect such as skew.

On the other hand, if the widthwise center of the pickup roller 80 is aligned with the widthwise center of the most frequently transported document size (for example, A4T), a check 3 size document of width 76 [mm] x length 169 [mm] can be obtained. is not conveyed by the pickup roller 80 . By widening the width W3 of the pickup roller 80, the pickup roller 80 can be brought into contact with a check-sized document having a width of 76 mm and a length of 169 mm. ] can be fed. However, in this case, since the edge of the document hits the pickup roller 80, the document may be damaged such as edge folds.

Therefore, in the present embodiment, by installing an auxiliary paper feed tray, which is an auxiliary tray, on the document table 53, it is possible to satisfactorily convey small-sized originals, which are small-sized sheets such as check-sized sheets. there is Hereinafter, it demonstrates concretely using drawing.

FIG. 7 is a schematic diagram showing the auxiliary paper feed tray 130 installed on the document table 53 and members for conveying documents of the automatic document feeder 5. FIG. 4 is a schematic diagram showing an auxiliary tray 130 and a pickup roller 80; FIG.
The auxiliary paper feed tray 130 has a small-size set reference surface 132 and a small-size side fence 131 . The small-size side fence 131 is provided on the bottom plate 135 of the auxiliary paper feed tray 130 so as to be slidable in the width direction. In this way, by providing the small-size side fence 131 in the auxiliary paper feed tray 130, the bottom plate 135 of the auxiliary paper feed tray 130 can accommodate documents smaller than the minimum size (B6T) that can be conveyed by the automatic document feeder. Only the small size document Ss can be loaded.

The small-size setting reference surface 132 is positioned closer to the widthwise central side of the document table 53 (the front side of the apparatus) than the setting reference surface 112 of the document table 53 . As a result, the small-size document Ss stacked on the bottom plate 135 of the auxiliary paper feed tray 130 with one end in the width direction in contact with the small-size setting reference surface 132 contacts the pickup roller 80 and is conveyed by the pickup roller 80. can do. Also, as shown in FIG. 7, the side fence side end of the small-size document Ss set on the auxiliary paper feed tray 130 is positioned closer to the side fence (front side) than the side fence side end of the pickup roller 80 . , a set reference surface 132 for small size is formed. For example, when the distance W1 shown in FIG. 6 is set to 105 [mm] and the distance W2 is set to 128 [mm], the small size setting reference plane 132 is separated from the setting reference plane 112 by 52 [mm] or more. position. This makes it possible to position the side fence side edge of the check document having the minimum width size shown in Table 1 (check 3 and check 4) closer to the side fence than the side fence side edge of the pickup roller 80. . As a result, the ends of check documents having the minimum width size shown in Table 1 (check 3 and check 4) do not come into contact with the pickup roller 80, and the occurrence of edge folds and the like can be suppressed. .

As shown in FIG. 7, the width of the separation belt 84 is the same as the width of the pickup roller 80. are matched. Therefore, the small-size originals set on the auxiliary paper feed tray 130 are conveyed by the separation belt 84 satisfactorily without causing edge folds or the like. The pull-out roller 86 is composed of three pull-out conveying rollers 86a, 86b, and 86c, and the small size document is conveyed by the central pull-out conveying roller 86b. The central pull-out conveying roller 86 b has the same width as the pickup roller 80 and has its widthwise center aligned with the widthwise center of the pickup roller 80 . As a result, the small-size document is favorably conveyed by the central pull-out conveying roller 86b without causing edge folds or the like. After that, the small size originals are arranged at the second and third positions from the left side of each roller (intermediate roller 66, reading entrance roller 97, reading exit roller 92, second reading exit roller 93, document discharge roller 94). It is conveyed by two small-size conveying rollers (66b ₁ , 66b ₂ , 97b ₁ , 97b ₂ , 92b ₁ , 92b ₂ , 93b ₁ , 93b ₂ , 94b ₁ , 94b ₂ ).

In the above description, the widths of the pickup roller 80, the separation belt 84, and the central pull-out conveying roller 86b are the same. 132, the small-size set reference surface 132 is configured based on the position of the side fence side end of the widest transport roller among the transport rollers that transport the small-size sheet. For example, the central pull-out conveying roller 86b of the pull-out roller 86 is 10 mm wider than the pickup roller 80 and the separation belt 84, and the central pull-out conveying roller 86b is the widest conveying roller among conveying rollers for conveying small-sized sheets. In the case of a roller, the set reference surface 132 for small size is configured based on the position of the side fence side end of the central pull-out conveying roller 86b. That is, the side fence side end of the small size document set on the auxiliary paper feed tray 130 is placed closer to the side fence side (toward the front side) than the side fence side end of the central pull-out conveying roller 86b. This constitutes the setting reference plane 132 .

In this embodiment, as shown in FIG. 7, there are two second conveying rollers 66b, 97b, 92b, 96b and 94b. As a result, the small-sized original can be conveyed by two conveying rollers, and the small-sized original can be stably conveyed. In addition, the conveying force of these small-size conveying rollers (66b ₁ , 66b ₂ , 97b ₁ , 97b ₂ , 92b ₁ , 92b ₂ , 96b ₁ , 96b ₂ , 94b ₁ , 94b ₂ ) is less than that of other conveying rollers. Set to 1/2 the force. For example, the nip pressure of the small-size conveying rollers (66b ₁ , 66b ₂ , 97b ₁ , 97b ₂ , 92b ₁ , 92b ₂ , 96b ₁ , 96b ₂ , 94b ₁ , 94b ₂ ) is changed to the nip pressure of the other conveying rollers. By halving the conveying force of the conveying rollers for small sizes (66b ₁ , 66b ₂ , 97b ₁ , 97b ₂ , 92b ₁ , 92b ₂ , 96b ₁ , 96b ₂ , 94b ₁ , 94b ₂ ) It can be set to (1/2) of the conveying force of the conveying roller. In this way, the conveying force of the small-size conveying rollers (66b ₁ , 66b ₂ , 97b ₁ , 97b ₂ , 92b ₁ , 92b ₂ , 96b ₁ , 96b ₂ , 94b ₁ , 94b ₂ ) is reduced to that of the other conveying rollers. By setting it to (1/2) of the conveying force, for example, when conveying B6T or A5T size, the conveying force on one end side and the other end side in the width direction can be made substantially the same, thereby suppressing the occurrence of skew. be able to.

In this embodiment, as shown in FIG. 7, the set filler 62 of the automatic document feeder 5 is provided near the set reference surface 112, and when the auxiliary paper feed tray 130 is installed, the auxiliary paper feed tray 130, and set detection cannot be performed. Therefore, the auxiliary paper feed tray 130 has a small-size set detection mechanism 134 for detecting that a small-sized original is set on the auxiliary paper feed tray 130 . The small-size set detection mechanism 134 includes a rotary shaft 134b rotatably supported by the back side housing portion having the small-size set reference surface 132 of the auxiliary paper feed tray 130, and one end of the rotary shaft 134b. It is composed of a set filler 134a for small size provided and a push-in portion 134c for pushing in the set filler 62 provided at the other end of the rotating shaft 134b. Further, the bottom plate 135 of the auxiliary paper feed tray 130 is provided with a notch 135a into which the tip of the small size set filler 134a is inserted.

FIG. 9 is a diagram for explaining document set detection by the set detection mechanism 134 for small size. FIG. 9A shows the state before setting the small size document, and FIG.

As shown in FIG. 9A, when no small size document is set on the auxiliary paper feed tray 130, the tip of the small size set filler 134a is inserted into the notch 135a. At this time, the push-in portion 134c does not push in the set filler 62, and the tip of the set filler 62 is positioned between the light emitting portion and the light receiving portion of the document set sensor 63, blocking the light from the light emitting portion. there is

As shown in FIG. 9(b), when a small size document is set on the auxiliary paper feed tray 130, the leading edge of the small size document pushes the small size set filler 134a, causing the small size set filler 134a to move downward. Rotate it clockwise. When the small-size set filler 134a rotates clockwise in the figure, the push-in portion 134c also rotates clockwise around the rotation shaft 134b, and the set filler 62 is pushed in. As shown in FIG. As a result, the set filler 62 rotates clockwise in the drawing together with the push-in portion 134 c , and the leading end of the set filler 62 retreats from between the light emitting portion and the light receiving portion of the document set sensor 63 . As a result, the light receiving portion of the document set sensor 63 detects the light emitted from the light emitting portion, and the setting of the document is detected.

Further, in the present embodiment, as shown in FIG. 9B, the leading edge of the set filler 62 emits light from the document set sensor 63 until the leading edge of the small-sized document is positioned downstream of the pickup roller 80 in the transport direction. A set detection mechanism 134 for small size is configured so as not to retreat from between the part and the light receiving part. Specifically, the rotation range of the small-size set filler 134a and the rotation angle of the small-size set filler 134a at which the pushing portion 134c starts pushing the set filler 62 are appropriately set.

In this way, when the leading edge of the small-sized original is positioned downstream of the pickup roller 80 in the transport direction, the leading edge of the set filler 62 is withdrawn from between the light-emitting portion and the light-receiving portion of the original set sensor 63 to detect that the original is set. With this configuration, the pickup roller 80 can be reliably brought into contact with the small-sized document set on the auxiliary paper feed tray 130 when the sheet is conveyed. As a result, it is possible to prevent the occurrence of non-feeding.

Next, the setting of the auxiliary paper feed tray 130 on the document table 53 will be described.
FIG. 10 is a front view showing the document table 53 on which the auxiliary paper feed tray 130 can be installed.
As shown in FIG. 10, the document table 53 is provided with a first positioning hole 115a and a second positioning hole 115b at two locations in the width direction. A fixing magnet 116 for fixing the auxiliary paper feed tray 130 is provided between the first positioning hole 115a and the second positioning hole 115b.

FIG. 11 is a diagram showing the bottom surface of the auxiliary paper feed tray 130. As shown in FIG.
As shown in the figure, on the bottom surface of the auxiliary paper feed tray 130, a first positioning projection 136a and a second positioning projection 136b are fitted into the positioning holes provided in the document table 53 shown in FIG. are provided at predetermined intervals. A metal plate 137 that sticks to the fixing magnet 116 is provided between the first positioning projection 136a and the second positioning projection 136b.

In this embodiment, the document table 53 has an auxiliary tray detection sensor 118 at the position of the fixing magnet 116 as tray detection means for detecting whether or not the auxiliary paper feed tray 130 is installed on the table surface of the document table 53 . is provided. Auxiliary tray detection sensor 118 uses, for example, a current detection sensor that detects a current that flows when metal plate 137 on auxiliary tray 130 sticks to fixing magnet 116 .

The auxiliary tray detection sensor 118 is not particularly limited in detection method, detection location, etc., as long as it is a tray detection member capable of detecting whether or not the auxiliary tray 130 is installed on the surface of the document table 53. . Therefore, for example, whether or not the positioning projections 136a and 136b of the auxiliary tray 130 are fitted into the positioning holes 115a and 115b provided in the document table 53 can be mechanically and optically detected. good. Further, as a tray detection means, when the auxiliary paper feed tray 130 is installed, the user operates the operation unit 108 to input information indicating that the auxiliary paper feed tray 130 has been installed, and based on the input information, the auxiliary paper feed The presence or absence of installation of the tray 130 may be detected.

FIG. 12 is a diagram showing how the auxiliary paper feed tray 130 is installed on the document table 53. As shown in FIG. FIG. 12(a) is a side view, and FIG. 12(b) is a perspective view.
As indicated by the dotted arrow K in FIG. 12A, the auxiliary paper feed tray 130 is moved in the conveying direction, and the leading end of the auxiliary paper feeding tray 130 in the conveying direction is inserted into the automatic document feeder 5. . Specifically, the auxiliary paper feed tray 130 is moved from the automatic document feeder 5 until the front end of the auxiliary paper feed tray 130 abuts against the wall portion 5a (see FIG. 9) against which the front end of the document set on the document table 53 abuts. Insert inside. Next, while lowering the upstream end of the auxiliary paper feed tray 130 in the transport direction, as shown in FIG. The protrusion 136a is inserted into the first positioning hole 115a of the document table 53, and the second positioning protrusion 136b is inserted into the second positioning hole 115b. As a result, the auxiliary paper feed tray 130 is positioned on the document table 53 . Then, when the upstream end portion of the auxiliary paper feed tray 130 in the conveying direction is lowered and the auxiliary paper feed tray 130 is placed on the table surface of the document placing table 53, the metal plate 137 sticks to the fixing magnet 116, thereby assisting the paper feed. A tray 130 is fixed to the document table 53 .

By fixing the auxiliary paper feed tray 130 to the document placing table 53 in this manner, the auxiliary paper feeding tray 130 does not come off from the document placing table 53 when the automatic document feeder 5 is opened with respect to the scanner 4 . can be prevented. Alternatively, a metal plate may be provided on the document table 53, and a fixing magnet may be provided on the auxiliary paper feed tray 130. FIG. Further, in this embodiment, since the auxiliary paper feed tray 130 is fixed to the document table 53 by magnets, the auxiliary paper feed tray 130 can be easily removed from the document table 53 . As a result, it is possible to easily switch from conveying a small size document to conveying a document of a size other than small size.

Here, when the auxiliary paper feed tray 130 is fixed to the document table 53, it is detected that the auxiliary paper feed tray 130 is installed even though the auxiliary paper feed tray 130 is not actually installed. The sensor 118 may erroneously detect. For example, a foreign object may enter the detection area of the auxiliary tray detection sensor 118 and be erroneously detected as the installation of the auxiliary paper feed tray 130 . If such an erroneous detection occurs, when the document S is transported from the document table 53 without using the auxiliary paper feed tray 130, the document transport speed is set to the auxiliary tray transport speed that is slower than the normal transport speed. As a result, the reading speed of the document S is lowered, resulting in a decrease in productivity.

Therefore, in this embodiment, the user can operate the operation unit 108 to select whether to use the normal transport speed or the auxiliary tray transport speed that is slower than the normal transport speed. Specifically, when the user operates the operation unit 108 to display a setting screen for setting enable/disable of the auxiliary tray conveying speed, the setting screen as shown in FIG. The image is displayed on the image display unit 108, and the user selects "ON/OFF".

FIG. 13 is a flowchart of document transport control in this embodiment.
Document transport control determines whether there is valid/invalid information about the auxiliary tray transport speed (S1). When the user selects "ON or OFF" on the previous setting screen (Yes in S1), the feed speed for the auxiliary tray is enabled/disabled according to the selection (S2), and the presence or absence of document set is checked. Determine (S4). If there is no selection operation (No in S1), the auxiliary tray transport speed is disabled (S3), and it is determined whether or not the document is set (S4). When the document set sensor 63 detects the document (Yes in S4) and presses the copy start button of the operation unit 108 (Yes in S5), it is checked whether or not the auxiliary paper feed tray 130 is installed. (S6). Whether or not the auxiliary paper tray 130 is installed is determined based on the detection result of the auxiliary tray detection sensor 118 described above.

If the auxiliary tray 130 is installed (Yes in S6), and if the auxiliary tray transport operation is enabled (Yes in S7), the main body controller determines that the small-size document is transported. 111 (control unit of copying machine 1) (S8). The body control unit 111 controls each device of the document feeding and reading unit 6 for the small size original Ss, for example, by switching the image reading mode of the first surface reading unit 40 to the reading mode corresponding to the small size original Ss. Switch to the corresponding control (small size original mode).

Further, as the document transport speed (transport operation) of the automatic document feeder 5, switching is selected to change the transport speed for the auxiliary tray, which is slower than the normal transport speed when transporting the document S on the document table 53 ( S9). As a result, various problems (such as damage to the small-sized originals Ss) that may occur when the small-sized originals Ss such as checks and bills transported with the auxiliary paper feed tray 130 installed are transported at a normal transport speed are eliminated. can be suppressed.

The auxiliary tray conveying operation is not limited to the conveying speed. Any transport operation may be used as long as the transport operation of the small size document Ss on the auxiliary paper feed tray 130 is more suitable than the normal transport operation when transporting the .

On the other hand, if the auxiliary paper feed tray 130 is not installed (No in S6), the normal transport speed is selected as the document transport speed (transport operation) of the automatic document transport device 5 (S10). As a result, the document S transported from the document table 53 without using the auxiliary tray 130 is transported at a higher normal transport speed than when transported at the low transport speed for the auxiliary tray. read processing can be realized, and high productivity can be realized.

As described above, in this embodiment, the determination (S6) of whether or not the auxiliary tray 130 is installed is based on the detection result of the auxiliary tray detection sensor 118 provided on the document table 53. to decide. As a result, when it is determined that the auxiliary tray 130 is installed (Yes in S6), an auxiliary tray conveying speed slower than the normal conveying speed is selected (Yes in S7, S9), and the auxiliary tray The document is transported at the normal transport speed. On the other hand, when the user selects "OFF", even if it is determined that the auxiliary paper feed tray 130 is installed (Yes in S6), the normal transport speed is set (No in S7, ), the document is fed at the normal feeding speed.

As described above, in this embodiment, the user can select whether or not to transport the document at the auxiliary tray transport speed by operating the operation unit 108 . As a result, when the auxiliary tray detection sensor 118 erroneously detects that the auxiliary paper feed tray 130 is installed even though the auxiliary paper feed tray 130 is not actually installed, the auxiliary tray detection sensor 118 Document transport at the tray transport speed can be prohibited (disabled). In such a situation, if the user disables the auxiliary tray transport speed, even if it is erroneously determined that the auxiliary tray 130 is installed due to false detection (Yes in S6), normal transport can be performed. The speed is set (No in S7, S10), and the normal size document S from the document table 53 that is actually conveyed can be conveyed at the normal conveying speed. Therefore, it is possible to avoid a situation in which the normal size original S is conveyed at a low auxiliary tray conveyance speed due to erroneous detection, and it is possible to suppress a decrease in the reading speed of the original S and a decrease in productivity.

Note that the small-size document Ss is likely to be skewed, so the amount of skew may increase. Therefore, in the case of a small size document, the contact amount when the front edge of the document is brought into contact with the pair of pull-out rollers 86 to perform skew correction may be increased compared to the normal case. Further, it is preferable that the small size document Ss is abutted against the reading entrance roller 97 and subjected to skew correction before reading.
The setting screen for setting enable/disable of the feed speed for the auxiliary tray is displayed on the image display unit of the operation unit 108 when it is determined that the auxiliary paper feed tray 130 is installed (Yes in S6). You may make it display automatically. Furthermore, automatic display of this setting screen may be set to ON/OFF within the system setting screen.

[Modification 1]
Next, a modified example (hereinafter referred to as “modified example 1”) of the processing for determining whether or not the auxiliary paper feed tray 130 in the present embodiment is installed will be described.
In this modified example 1, even though the auxiliary paper tray 130 is not installed on the document table 53, the auxiliary tray detection sensor 118 may erroneously detect that the auxiliary paper supply tray 130 is installed. In order to determine whether or not, the following determination processing is performed.

FIG. 15 is a flowchart showing the flow of determination processing for determining erroneous detection by the auxiliary tray detection sensor 118 in the first modification.
The controller 100 as a determination means starts determination processing when a change occurs in the detection result of the auxiliary tray detection sensor 118 . First, when the auxiliary tray detection sensor 118 detects that the auxiliary paper feed tray 130 is not installed (No in S11), it is determined from the detection result that the auxiliary paper feed tray 53 is placed on the document table 53 as in the above-described embodiment. It is determined that the tray 130 is not installed (S12).

On the other hand, even when the auxiliary tray detection sensor 118 detects that the auxiliary paper feed tray 130 is installed (Yes in S11), if the auxiliary tray detection sensor 118 misdetects, the document is actually loaded. The paper feed auxiliary tray 130 is not installed on the table 53 . Therefore, in the first modification, one of the document length sensors 58 (58a, 58b, 58c, 58d) provided on the document table 53 detects whether or not the auxiliary tray detection sensor 118 is in an erroneous detection state. The determination is made using the document length sensor 58d.

The document length sensor 58d is a sensor that detects the presence or absence of a document at a position where the presence of the document can be detected even when a document of any size that can be set on the document table 53 is set on the document table 53 . For example, when an A4 size or LT size document is set vertically (set so that the short side is parallel to the document transport direction), the document length sensor 58d detects the presence of the document, but the remaining document length sensors 58a, 58b and 58c detect the absence of the document.

The document length sensor 58d detects the presence of the document not only when the document is set on the document table 53, but also when the auxiliary paper feed tray 130 is installed on the document table 53. The sheet presence/absence detection means is configured as follows. Therefore, in the present modified example 1, when the auxiliary tray detection sensor 118 detects that the auxiliary tray 130 is installed (Yes in S11), it is determined whether or not the document length sensor 58d detects the presence of the document. Confirm (S13). Note that the sheet presence/absence detection means used for this confirmation may be another sensor as long as it has the above-described configuration.

When the document length sensor 58d detects that there is no document (No in S13), it is determined that the auxiliary tray detection sensor 118 has erroneously detected that the auxiliary paper feed tray 130 is installed. It is determined that the auxiliary paper feed tray 130 is not installed above (S14). On the other hand, when the document length sensor 58d detects the presence of the document (Yes in S13), it is determined that the auxiliary paper feed tray 130 is actually installed on the document table 53, and the paper feed assist is performed. It is determined that the tray 130 is installed (S15).

[Modification 2]
Next, another modified example (hereinafter referred to as "modified example 2") of the process of determining whether or not the auxiliary paper feed tray 130 is installed in the present embodiment will be described.
In this modified example 2, as in the above-described modified example 1, even though the auxiliary paper feed tray 130 is not installed on the document table 53, if the auxiliary paper feed tray 130 is installed, the auxiliary tray detection sensor 118 determines whether or not there is an erroneous detection state in which erroneous detection occurs, but the content of the determination process is different.

FIG. 16 is a flow chart showing the flow of determination processing for determining erroneous detection by the auxiliary tray detection sensor 118 in the second modification.
The controller 100 as a judgment unit executes judgment processing when judging the size of the document while the document is being conveyed. First, after the document size is determined (S21), it is checked whether or not the document transport speed is set to the auxiliary tray transport speed (S22). At this time, if the normal transport speed is set (No in S22), the determination process is terminated.

If the auxiliary tray transport speed is set (Yes in S22), it is determined whether or not the document size determined in processing step S21 is a document size that cannot be set on the auxiliary tray 130 (S23). ). If it is determined that the document size is a size that can be set on the auxiliary paper feed tray 130 (Yes in S23), the determination process is terminated.

On the other hand, if it is determined that the document size cannot be set on the auxiliary paper feed tray 130 (No in S23), it is determined that the auxiliary tray detection sensor 118 has erroneously detected that the auxiliary paper feed tray 130 is installed. Then, the transport of the document being transported is stopped (S24). Then, the controller 100 notifies the body control unit 111 of instructing jam display. As a result, the body control unit 111 causes the image display unit of the operation unit 108 to display a predetermined jam display screen as shown in FIG.

As shown in FIG. 17, the jam display screen displayed on the image display unit of the operation unit 108 includes a display prompting removal of foreign matter (such as a piece of paper, a sticky note, etc.) that may cause false detection by the auxiliary tray detection sensor 118. things are preferred. Note that the jam display screen may display a moving image or a still image.

[Modification 3]
Next, a modified example of the transport control during document transport in this embodiment (this modified example is hereinafter referred to as “modified example 3”) will be described.
In the present modified example 3, the detection result of the auxiliary tray detection sensor 118 is monitored even while the document is being conveyed, and if it is determined from the detection result that the auxiliary feeding tray 130 has been removed, it is determined that the conveying quality cannot be ensured, and the document is conveyed. stop and jam display.

FIG. 18 is a flowchart showing transport control during document transport in the third modification.
When the detection result of the auxiliary tray detection sensor 118 changes from the presence of the auxiliary paper feed tray 130 to the absence of the paper feed tray 130 while the document is being transported (S31), in the present modified example 3, the transport of the document being transported is stopped (S32). . Then, the controller 100 notifies the body control unit 111 of instructing jam display. As a result, the body control unit 111 causes the image display unit of the operation unit 108 to display a predetermined jam display screen as shown in FIG.

As shown in FIG. 19, the jam display screen displayed on the image display unit of the operation unit 108 indicates that the auxiliary paper feed tray 130 ("small size paper unit" in the example shown in FIG. 19) should be set correctly. It is preferable to include a display prompting Note that the jam display screen may display a moving image or a still image.

In the present embodiment, the sheet conveying device according to the present invention has been described as an example of the automatic document conveying device 5 that conveys a document to the scanner 4, which is an image reading device provided in an image forming apparatus. can't For example, the present invention may be applied to an automatic document feeder that feeds a document to an image reading device that is not provided in an image forming apparatus. Also, the present invention may be applied to a sheet conveying device that conveys a recording sheet to an image forming unit, such as the transfer paper feeding unit 2 or the manual feed tray 25 of the image forming apparatus. Also, the present invention may be applied to a sheet conveying apparatus used in equipment other than the image forming apparatus.

What has been described above is only an example, and each of the following aspects has a unique effect.
[First aspect]
A first mode includes a sheet placing portion (for example, document placing table 53) on which a sheet is placed, an auxiliary tray (for example, paper feed auxiliary tray 130) installed on the upper surface of the sheet placing portion, and the sheet placing portion. A sheet conveying device (for example, an automatic document conveying device 5) comprising a tray detection member (for example, an auxiliary tray detection sensor 118) for detecting the presence or absence of the auxiliary tray installed on the upper surface of the sheet loading device (for example, the auxiliary tray). It is characterized in that the operation of conveying the sheet when installed in the unit is changed by an input from the operation unit.
According to this aspect, a user or the like can change the sheet conveying operation when the auxiliary tray is installed on the sheet stacking section by operating the operation section. As a result, when the tray detection member erroneously detects that the auxiliary tray is installed even though the auxiliary tray is not installed, the auxiliary tray transport operation can be prevented from being executed. It becomes possible. Therefore, in such a situation, it is possible to avoid the situation where the auxiliary tray conveying operation is executed when the sheet is conveyed on the sheet placing surface.

[Second aspect]
A second mode is a sheet conveying device (for example, an automatic document conveying device 5) that conveys a sheet (for example, documents S, Ss) on a sheet placing surface (for example, the table surface of the document placing table 53), Tray detection means (for example, auxiliary tray detection sensor 118) for detecting whether or not an auxiliary tray (for example, paper feed auxiliary tray 130) is installed on the surface; sheet conveying means (for example, a controller 100, various rollers 66, 97, 92, 93, 94, and various motors 101 to 105, etc.) for conveying a sheet by executing a speed), and the tray detecting means An operation receiving unit (for example, the operation unit 108) that receives a selection operation as to whether or not to cause the sheet conveying unit to execute the auxiliary tray conveying operation (for example, the auxiliary tray conveying speed) selected when detecting that the tray is installed. ) and is characterized by having
According to this aspect, the user or the like can select whether or not to cause the sheet conveying unit to execute the auxiliary tray conveying operation by performing the selection operation on the operation accepting unit. As a result, when the tray detection means erroneously detects that the auxiliary tray is installed even though the auxiliary tray is not installed, the sheet conveying means is prevented from executing the auxiliary tray conveying operation. can be Therefore, in such a situation, it is possible to avoid the situation where the auxiliary tray conveying operation is executed when the sheet is conveyed on the sheet placing surface.

[Third aspect]
A third aspect is, in the second aspect, determining whether or not the tray detection means is in an erroneous detection state in which the presence of the auxiliary tray is detected even though the auxiliary tray is not installed on the sheet placement surface. and the sheet conveying means, when the judging means judges that the misdetection state has occurred, regardless of the selection operation received by the operation receiving means, determines whether the auxiliary tray It is characterized in that no transport operation is performed.
According to this aspect, when the auxiliary tray is not installed on the sheet placement surface but the tray detection means is in an erroneous detection state that the auxiliary tray is installed, the auxiliary tray transport operation is performed by the sheet transport means. Even if the operation accepting means accepts a selection operation to cause the auxiliary tray to be carried out, the carrying operation for the auxiliary tray is not carried out. Therefore, it is possible to more reliably avoid a situation in which the auxiliary tray conveying operation is executed when the sheet is conveyed on the sheet placement surface.

[Fourth aspect]
In a fourth aspect based on the third aspect, when the determination means determines that the determination means is in the erroneous detection state, the sheet conveying means, regardless of the selection operation received by the operation reception means, The sheet is conveyed by the normal conveying operation when conveying the sheet.
When the auxiliary tray is not installed on the sheet placement surface but the tray detection means is in an erroneous detection state that the auxiliary tray is installed, the sheet is actually conveyed from the sheet placement surface. According to this aspect, the sheet conveyed from the sheet mounting surface in the erroneous detection state can be conveyed by the normal conveying operation. It is possible to realize more suitable transportation than the case of transportation with .

[Fifth aspect]
A fifth aspect is, in the third or fourth aspect, further comprising sheet presence/absence detection means (for example, document length sensor 58d) for detecting the presence/absence of a sheet on the sheet placement surface, and the sheet presence/absence detection means The presence of the sheet is detected even when the auxiliary tray is installed on the sheet placing surface, and the determination means detects the presence of the auxiliary tray when the tray detection means detects the installation of the auxiliary tray. It is characterized in that when the sheet presence/absence detection means detects the absence of a sheet, it is determined that the erroneous detection state has occurred.
According to this aspect, it is possible to determine an erroneous detection state by using the sheet presence/absence detection unit that detects the presence/absence of the sheet on the sheet placement surface.

[Sixth aspect]
A sixth aspect is the second aspect, in which the sheet size detecting means (for example, the document width sensor 73 and the abutting sensor 72) for detecting the size of the conveyed sheet and the auxiliary tray are installed on the sheet placing surface. determination means (e.g., controller 100) for determining whether or not the tray detection means is in an erroneous detection state in which the presence of the auxiliary tray is detected even though the tray detection means is not installed; If the sheet size detection means detects a sheet size that cannot be set on the auxiliary tray when detecting that the auxiliary tray is installed, it is determined that the misdetection state has occurred, and the sheet conveying means performs the determination. The sheet conveyance is stopped when the means determines that the erroneous detection state has occurred.
According to this aspect, it is possible to determine an erroneous detection state using the sheet size detection means for detecting the size of the conveyed sheet. Further, since sheet conveyance is stopped when it is determined that an erroneous detection state has occurred, it is possible to quickly deal with serious problems before continuing sheet conveyance.

[Seventh aspect]
According to a seventh aspect, in any one of the second to sixth aspects, the sheet conveying means detects a sheet It is characterized by stopping transportation.
According to this aspect, when the auxiliary tray is removed while the sheet is being conveyed, the sheet conveying is stopped. Therefore, it is possible to continue the sheet conveying and quickly deal with the problem before a serious problem occurs. Become.

[Eighth aspect]
An eighth aspect is an image forming apparatus including any one of the first to seventh aspects of the sheet conveying device.
According to this aspect, it is possible to realize an image forming apparatus capable of avoiding a situation in which the auxiliary tray conveying operation is executed when the sheet is conveyed on the sheet placement surface.

Reference Signs List 1: Copier 2: Transfer paper feeding section 3: Image forming section 4: Scanner 5: Automatic document feeder 6: Document feeding and reading unit 31: Exposure device 32: Photoreceptor 33: Developing device 34: Intermediate transfer belt 35: Secondary transfer device 35b : Transfer conveying belt 36 : Fixing device 37 : Registration roller pair 38 : Discharge tray 40 : First side reading unit 53 : Original plate 53a : Fixed original table 53b : Movable original table 54 : Original conveying unit 55 : Original stacking table 58 : Original length sensor 59 : Table elevation sensor 60 : Home position sensor 61 : Discharge sensor 62 : Set filler 63 : Original set sensor 65 : Registration sensor 66 : Intermediate roller 67 : Reading entrance sensor 72 : Collision sensor 73 : Document width sensor 80 : Pickup roller 82 : Paper feed drive roller 83 : Paper feed driven roller 84 : Separation belt 85 : Reverse roller 86 : Pullout roller 90 : Paper discharge roller pair 92 : Reading exit roller 93 : First Two reading exit rollers
94 : Document discharge roller 96 : Second reading unit facing roller 97 : Reading inlet roller 100 : Controller 101 : Pickup lifting motor 102 : Paper feeding motor 103 : Reading motor 104 : Paper discharging motor 105 : Bottom plate lifting motor 107 : I/ F circuit 108 : Operation unit 111 : Main body control unit 112 : Setting reference surface 113 : Rail 115a : First positioning hole 115b : Second positioning hole 116 : Fixing magnet 117 : Side fence 118 : Auxiliary tray detection sensor 130 : Paper feed Auxiliary tray 131 : Small size side fence 132 : Small size setting reference surface 134 : Small size setting detection mechanism 135 : Bottom plate 135a : Notch 136a : First positioning projection 136b : Second positioning projection 137 : Metal plate 200 : Light source S: Document Ss: Small size document

JP-A-2001-139169

Claims (7)

A sheet conveying device that conveys a sheet on a sheet placing surface,
tray detection means for detecting whether or not an auxiliary tray is installed on the sheet placement surface;
a sheet conveying means for conveying a sheet by executing a conveying operation selected according to a detection result of the tray detecting means;
and operation receiving means for receiving a selection operation as to whether or not to cause the sheet conveying means to execute the auxiliary tray conveying operation selected when the tray detecting means detects that the auxiliary tray is installed. sheet conveying device. In the sheet conveying device according to claim 1 ,
determining means for determining whether or not the tray detection means is in an erroneous detection state in which the presence of the auxiliary tray is detected even though the auxiliary tray is not installed on the sheet placing surface;
wherein the sheet conveying means does not execute the auxiliary tray conveying operation regardless of the selection operation received by the operation receiving means when the determining means determines that the misdetection state exists. Device. In the sheet conveying device according to claim 2 ,
The sheet conveying means performs a normal conveying operation when conveying the sheet on the sheet mounting surface regardless of the selection operation received by the operation receiving means when the determining means determines that the erroneous detection state exists. A sheet conveying device that conveys a sheet by In the sheet conveying device according to claim 2 or 3 ,
a sheet presence/absence detecting means for detecting the presence/absence of a sheet on the sheet placement surface;
The sheet presence/absence detection means is configured to detect the presence of a sheet even when the auxiliary tray is placed on the sheet placement surface,
The determination means determines that the misdetection state occurs when the sheet presence/absence detection means detects no sheet when the tray detection means detects that the auxiliary tray is installed. Conveyor. In the sheet conveying device according to claim 1 ,
sheet size detection means for detecting the size of the conveyed sheet;
determination means for determining whether or not the tray detection means is in an erroneous detection state in which the presence of the auxiliary tray is detected even though the auxiliary tray is not installed on the sheet placing surface;
The judging means judges that the erroneous detection state occurs when the sheet size detecting means detects a sheet size that cannot be set on the auxiliary tray when the tray detecting means detects that the auxiliary tray is installed. death,
A sheet conveying apparatus, wherein the sheet conveying means stops conveying the sheet when the judging means judges that the erroneous detection state has occurred. In the sheet conveying device according to any one of claims 1 to 5 ,
A sheet conveying apparatus, wherein the sheet conveying means stops conveying the sheet when the detection result of the tray detecting means switches from the installation of the auxiliary tray to the absence of the installation while the sheet is being conveyed. An image forming apparatus comprising the sheet conveying device according to any one of claims 1 to 6 .

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