JP2017088393A - Sheet feeder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet feeder capable of detecting sheets placed on a first tray and a second tray without increasing a length of the first tray.SOLUTION: A tray body 302 is used to place feed sheets having a first size. An extension tray 303 is used to place feed sheets having a second size larger than the feed sheet having the first size. A sheet length detection sensor 304 is provided at the extension tray 303 and detects the feed sheet placed on the extension tray 303. A control part 150 determines a size of the sheet on the basis of detection results of an inlet sensor 208, the sheet length detection sensor 304, and a width detection mechanism 307.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sheet supply apparatus that is provided in an image reading apparatus, an image forming apparatus, a sheet processing apparatus, and the like and supplies a supply sheet to an apparatus main body.

  The sheet supply apparatus is provided in an image reading apparatus, an image forming apparatus, a sheet processing apparatus, and the like, and extracts supply sheets placed on the first tray one by one from the upper level and supplies them to the apparatus main body. Patent Document 1 shows a manual feed tray which is an example of a sheet supply apparatus. The manual feed tray is accommodated on the side surface of the apparatus main body, and can be deployed outward from the apparatus main body to place the supply sheet.

  In Patent Document 1, it is possible to extend the second tray from the leading end of the first tray to the upstream side in the sheet conveyance direction, and to extend the supply sheet placement surface to the upstream side in the sheet conveyance direction. Then, based on the detection result by the detection unit provided at a position away from the sheet feed port in the sheet conveyance direction in the first tray, the supply sheets placed on the first tray and the second tray The length in the transport direction is determined.

JP 2014-177336 A

  When the supply sheets placed on the first tray and the second tray become large, the detection unit is provided at a position further away from the sheet feeding port to the upstream side in the sheet conveyance direction. Thereby, the 1st tray in which a detection part is provided becomes long, becomes large, and leads to the enlargement of a sheet supply apparatus. When the first tray becomes longer, it leads to an increase in the working space of the sheet supply apparatus required for the apparatus main body, which is contrary to the miniaturization and space saving of the apparatus main body.

  An object of the present invention is to provide a sheet supply apparatus that can detect sheets placed on a first tray and a second tray without lengthening the first tray.

  The sheet feeding apparatus of the present invention is for placing a first tray for placing a first size feeding sheet and a feeding sheet having a second size larger than the first size feeding sheet. A second tray that can extend the first tray; and a detection unit that is provided on the second tray and detects a supply sheet placed on the second tray. .

  In the sheet supply apparatus of the present invention, it is possible to detect the sheets placed on the first tray and the second tray without lengthening the first tray.

1 is a perspective view of an image forming apparatus. 1 is an explanatory diagram of a configuration of an image forming apparatus. 3 is an explanatory diagram of a configuration of a control system of the image forming apparatus. FIG. It is a perspective view of a manual feed tray. FIG. 6 is a vertical cross-sectional view along the sheet conveyance direction of the manual feed tray. It is explanatory drawing of the engagement structure of a tray main body and an expansion tray. It is a flowchart of sheet size automatic detection control. 10 is an explanatory diagram of a configuration of a manual feed tray according to Embodiment 2. FIG. 10 is an explanatory diagram of a configuration of a manual feed tray according to Embodiment 3. FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Embodiment 1>
(Image forming device)
FIG. 1 is a perspective view of the image forming apparatus. FIG. 2 is an explanatory diagram of the configuration of the image forming apparatus. FIG. 3 is an explanatory diagram of the configuration of the control system of the image forming apparatus. As shown in FIG. 1, the image forming apparatus 100 includes an image forming unit 130 that forms a monochrome image using a laser beam. The image forming unit 130 forms an image on the sheet fed from the paper feeding unit 110 disposed in the lower part of the image forming apparatus 100. On the right side surface of the image forming apparatus 100, a manual feed tray (multi-tray) 300 that is developed outward from the apparatus main body and forms a sheet stacking surface is provided.

  As shown in FIG. 2, the image forming unit 130 surrounds the photosensitive drum 101 and includes a corona charger 102, an exposure device 103, a developing device 104, a transfer conveyance unit 105, and a drum cleaning unit 106. The corona charger 102 irradiates the photosensitive drum 101 with charged particles accompanying corona discharge to charge the photosensitive drum 101 to a uniform potential.

  The exposure device 103 scans the surface of the photosensitive drum 101 with a laser beam to form an electrostatic latent image. The developing device 104 carries toner on a developing roller 104s that is a developer carrying member that rotates around a non-rotating magnet 104m, and develops an electrostatic latent image on the photosensitive drum 101 that is an image carrying member into a toner image. .

  The transfer conveyance unit 105 transfers the toner image carried on the photosensitive drum 101 to the sheet P, and conveys the sheet P on which the toner image is transferred to the fixing device 107. The sheet P to which the toner image has been transferred is heated and pressed by the fixing device 107 to fix the image on the surface. The drum cleaning unit 106 rubs the photosensitive drum 101 with a cleaning blade, and collects transfer residual toner on the surface of the photosensitive drum 101.

  The sheet feeding unit 110 feeds a standard size sheet P stored in the cassette 111 to the image forming unit 130. The feeding roller 112 sends the uppermost sheet in the cassette 111 to the separation unit 113. The separation unit 113 conveys the sheet at a nip between a conveyance roller that rotates in the forward direction and a driven roller that is driven in the reverse direction and is driven to rotate by the conveyance roller. The separation unit 113 delivers the uppermost sheet P to the pre-registration conveyance unit 202 and pushes back the multi-feed sheet overlapped with the uppermost sheet P to the cassette 111.

  The pre-registration conveyance unit 202 delivers the sheet P to the registration conveyance unit 120. In the stopped state, the registration conveyance unit 120 abuts the sheet P on the nip to correct the skew of the sheet P, starts rotating in accordance with the timing of the toner image on the photosensitive drum 101, and transfers the sheet P to the transfer conveyance unit 105. Deliver.

  The transfer conveyance unit 105 supports the transfer belt 105a over the separation roller 105b and the support roller 105c that also drive the transfer belt 105a. The transfer conveyance unit 105 attracts the sheet P to the transfer belt 105a and conveys the sheet P to the transfer unit T1. The transfer roller 105d presses the inner surface of the transfer belt 105a to form a transfer portion T1 between the photosensitive drum 101 and the transfer belt 105a, and a sheet P passing through the transfer portion T1 is applied with a positive voltage. The toner image is transferred to. The sheet onto which the toner has been transferred is discharged out of the apparatus via the fixing device 107.

  The fixing device 107 forms a nip by pressing the pressure roller 107b against the fixing roller 107a. A non-rotating lamp heater 107c is disposed on the central axis of the fixing roller 107a. The lamp heater 107c is ON / OFF controlled so that the surface temperature of the fixing roller 107a detected by a temperature sensor (not shown) is maintained at a predetermined target temperature.

  As illustrated in FIG. 3, the control unit 150 includes a CPU 155, a ROM 157, and a RAM 156. The control unit 150 controls the sheet feeding unit 110, the pre-registration conveyance unit 202, the registration conveyance unit 120, the image forming unit 130, and the fixing device 107 illustrated in FIG. 2 based on an operation signal input by the user through the operation unit 151. .

(Bypass tray)
FIG. 4 is a perspective view of the manual feed tray. FIG. 5 is a cross-sectional view of the manual feed tray along the sheet conveyance direction. FIG. 6 is an explanatory diagram of the engagement structure between the tray body and the expansion tray. In FIG. 5, (a) is an expansion tray accommodation state, (b) is an extension tray pulling state, and (c) is a large-size sheet detection state. In FIG. 6, (a) is the expansion tray accommodation state, (b) is the expansion tray pulled out state, and (c) is the expansion tray engaged state.

  As shown in FIG. 1, the image forming unit 130 can form an image on a sheet fed from the manual feed tray 300 of the sheet feeding device 160. A manual feed tray (multi-tray) 300 is accommodated on the side surface of the apparatus main body 100 </ b> A of the image forming apparatus 100. As shown in FIG. 2, the tray main body 302 of the manual feed tray 300 is accommodated on the side wall surface of the apparatus main body 100 </ b> A by rotating around the rotation shaft 321 at the lower end. The tray main body 302 is rotated about the rotation shaft 321 and is unfolded from the side surface of the apparatus main body 100A of the image forming apparatus 100 to the outside.

  A tray body 302, which is an example of a first tray, is for placing a first-size supply sheet. The expansion tray 303, which is an example of the second tray, is for placing a supply sheet of a second size larger than the supply sheet of the first size. The expansion tray 303 is accommodated in the tray body 302 and can be extended to the upstream side in the sheet conveying direction. The extension tray 303 is pulled out from the tray main body 302 developed outward to the upstream side in the sheet conveyance direction, and extends the sheet placement surface to the upstream side.

  As shown in FIG. 4, a sheet length detection sensor 304, which is an example of a first detection unit, is provided at an intermediate position in the sheet conveyance direction of the extension tray 303 and detects a supply sheet placed on the extension tray 303. To do. An inlet sensor 208, which is an example of a main body detection unit, detects the leading edge of a sheet placed on the tray main body 302 of the manual feed tray 300.

(Width detection mechanism)
As shown in FIG. 4, the manual feed tray 300 has a pair of side regulating plates 306. The pinion gear 306c meshes with the racks 306a and 306b fixed to the side regulating plates 306 inside the tray main body 302, so that the pair of side regulating plates 306 move in conjunction with the width direction.

  In the width detection mechanism 307 that is an example of the width detection unit, one of the racks 306a and 306b is engaged with a slide variable resistor (slide volume) (not shown). The width detection mechanism 307 can measure the facing distance at the sheet end portion restriction position of the side restriction plate 306 based on the output value of the slide variable resistor. The width detection mechanism 307 detects the length of the sheet placed on the tray body 302 in the sheet width direction orthogonal to the sheet conveyance direction.

  As shown in FIG. 5B, the sheet length detection sensor 304 has a flag 304a that is rotatable about a rotation shaft 304c. As shown in FIG. 5C, the (large size) sheet P2 stacked on the expansion tray 303 rotates the flag 304a, and the flag 304a blocks the photo interrupter 304b, thereby stacking on the expansion tray 303. A sheet is detected.

(Guide structure)
As shown in FIG. 5B, the guide pins 303 a fixed to the extension tray 303 are guided by guide grooves 302 a provided at both ends in the width direction of the tray main body 302. The guide groove 302 a is a guide groove along the movement path of the extension tray 303 provided in the tray main body 302. The guide pins 303 a are a pair of pins whose movement paths are restricted by guide grooves provided in the extension tray 303.

  Guide grooves 302a and guide pins 303a, which are examples of a guide structure, are provided between the tray main body 302 and the expansion tray 303, and the expansion tray 303 is moved away from the sheet stacking surface as the expansion tray 303 is accommodated in the tray main body 302. Guide them away.

  The extension path of the extension tray 303 with respect to the tray body 302 is regulated by the inclination of the guide groove 302a. In the insertion direction of the extension tray 303, the guide groove 302a is inclined so as to be away from the sheet stacking surface.

  As shown in FIG. 5B, the expansion tray 303 moves to the opposite side of the stacking surface in the process in which the expansion tray 303 is accommodated in the tray body 302. As shown in FIG. 5A, the expansion tray 303 is accommodated in the tray main body 302. In a state where the extension tray 303 is accommodated in the tray main body 302, even if the flag 304a is in contact with the tray main body 302, the flag 304a does not shield the photo interrupter 304b.

(Engagement structure)
As shown in FIG. 6A, the guide groove 302a of the tray body 302 is formed with a pair of recesses 302b on the upstream side in the sheet conveying direction. Guide pins 303a and recesses 302b, which are an example of an engagement structure, are provided between the tray main body 302 and the expansion tray 303, and are engaged in a state of being pulled out from the tray main body 302, and the expansion tray 303 is pulled out. Keep in state.

  As shown in FIG. 6B, the recess 302b is formed in the guide groove 302a to engage the guide pin 303a. The distance between the pair of recesses 302b along the guide groove 302a is equal to the distance between the pair of guide pins 303a of the extension tray 303.

  As shown in FIG. 6C, in the state where the extension tray 303 is pulled out from the tray body 302 to the maximum, the guide pin 303 a is engaged with the recess 302 b to hold the extension tray 303 at the tip of the tray body 302.

  As shown in FIG. 6B, the expansion tray 303 is slid down and accommodated in the tray body 302 when the guide pin 303a and the recess 302b are not engaged. When the front end of the extension tray 303 is lifted and the engagement of the guide pin 303a with the recess 302b is released, the extension tray 303 falls into the tray main body 302 along the guide groove 302a.

(Automatic detection of sheet size)
FIG. 7 is a flowchart of automatic sheet size detection control. The image forming apparatus 100 can execute an automatic sheet size determination sequence in order to omit the sheet size input by the user when the sheet is fed by the manual feed tray 300.

  As shown in FIG. 2, the user selects the manual feed tray 300 on the touch panel 152 of the operation unit 151. As shown in FIG. 7, the control unit 150 detects that the manual feed tray 300 has been selected based on the operation content through the operation unit 151 (S11).

  As shown in FIG. 5, the user places the (small size) sheet P <b> 1 on the manual feed tray 300. As illustrated in FIG. 7, the CPU 155 of the control unit 150 detects that there is a sheet on the manual feed tray 300 based on the detection result of the entrance sensor 208 (Yes in S12).

  As shown in FIG. 4, the user brings the side regulating plate 306 into contact with both end portions in the width direction of the sheet placed on the stacking surface of the tray main body 302. The CPU 155 of the control unit 150 performs the first narrowing of the sheet size by the width detection mechanism 307, and after the first narrowing is performed, the length in the sheet conveyance direction is determined based on the detection result of the sheet length detection sensor 304. The second narrowing down is performed. As shown in FIG. 7, the CPU 155 of the control unit 150 determines whether there are a plurality of sheet size candidates corresponding to the detection result of the width detection mechanism 307 (S13).

  An example in which there are a plurality of sheet size candidates with the same width is A4 size horizontal feed and A3 size vertical feed. When there are a plurality of sheet size candidates (Yes in S13), the CPU 155 of the control unit 150 determines the detection result of the sheet length detection sensor 304 (S14).

  As shown in FIG. 5B, when the sheet length detection sensor 304 does not detect the sheet P1, it is determined to be A4 size lateral feed which is a small size (S18).

  As shown in FIG. 5C, when the sheet P2 is detected by the sheet length detection sensor 304, it is determined that the A3 size longitudinal feed is a large size (S15).

  As shown in FIG. 2, the CPU 155 of the control unit 150 completes the sheet setting and waits for the start of image formation.

  When the user presses the start button of the operation unit 151, the CPU 155 of the control unit 150 feeds the sheet placed on the manual feed tray 300 to the separation unit 301. The separation unit 301 sends the uppermost sheet to the pre-registration conveyance unit 202. The pre-registration conveyance unit 202 conveys the sheet to the registration conveyance unit 120.

  The CPU 155 of the control unit 150 determines the image formation timing by detecting the sheet position fed to the pre-registration conveyance unit 202 based on the output of the writing sensor 204. The registration conveyance unit 120 starts to rotate at the timing of the head of the electrostatic latent image formed on the photosensitive drum 101, and delivers the sheet P to the transfer belt 105a. The sheet P is conveyed by the transfer belt 105a and is pressed against the photosensitive drum 101 to transfer the toner image.

  As described above, the CPU 155, which is an example of a control unit, acquires sheet length information based on detection results from the entrance sensor 208 and the sheet length detection sensor 304. Further, the size of the sheet is determined based on the detection results of the entrance sensor 208, the sheet length detection sensor 304, and the width detection mechanism 307.

(When the extension tray is not pulled out)
As shown in FIG. 5A, the expansion tray 303 may be used without being pulled out from the tray body 302.

  However, the length of the tray main body 302 in the sheet conveyance direction is set to a length (less than ½ of the length in the sheet conveyance direction) in which a large size sheet falls in the reverse direction of the sheet conveyance direction and cannot be stacked. For this reason, when trying to place a large size sheet (P2) in a state where the extension tray 303 is not pulled out from the tray body 302, the user intuitively pulls out the extension tray 303 from the tray body 302 and uses it.

  On the other hand, when the user places the small size sheet (P1) on the manual feed tray 300, the extension tray 303 shown in FIG. 5A is pulled out even when the extension tray 303 shown in FIG. Even in the absence, the output of the sheet length detection sensor 304 is the same. Therefore, the control unit 150 determines that the sheet placed on the manual feed tray 300 is a small size without any problem.

(When the extension tray is pulled out halfway)
If the extension tray 303 is pulled out halfway, the sheet length detection sensor 304 may detect the sheet length at a position different from the original position, resulting in erroneous detection.

  However, as shown in FIG. 6C, the guide pin 303a is engaged with the recess 302b only when the expansion tray 303 is pulled out to the longest position, and the expansion tray 303 is connected to the front end portion of the tray main body 302. Retained. When the guide pin 303a is not engaged with the recess 302b, as shown in FIG. 6A, the expansion tray 303 falls into the tray main body 302 by its own weight and returns to the storage state before being pulled out. Return. For this reason, the sheet is not placed in a state where the extension tray 303 is pulled out halfway from the tray main body 302.

  The length of the mounting surface of the tray main body 302 in the sheet conveyance direction is ½ or less of the length of the maximum size sheet conveyed to the apparatus main body 100A. It is 200 mm which is 1/2 or less of the length of the sheet of A3 vertical feeding size.

(Comparative example)
In the image forming apparatus of the comparative example, as shown in Patent Document 1, in the manual feed tray 300 shown in FIG. 4, the tray main body 302 has a width detection mechanism 307 and a plurality of sheets that detect sheets at different positions in the sheet conveyance direction. And a length detection sensor.

  The control unit detects the width of the sheet by the width detection mechanism 307 and determines the approximate size of the sheet placed on the manual feed tray 300. Then, when there are a plurality of candidates for the sheet size to be discriminated, the control unit determines which sheet size of the plurality of candidates the placed sheet is based on the detection result by the plurality of sheet length detection sensors. To determine whether or not

  However, in the image forming apparatus of the comparative example, since the sheet length detection sensor is disposed in the tray body, it is difficult to reduce the size of the tray body 302. As a result, in the manual feed tray 300 shown in FIG. 4, the length of the tray main body 302 increases, and the space for accommodating the tray main body 302 in the apparatus main body 100A shown in FIG. Since the length of the tray main body 302 in the sheet conveyance direction is increased, the folding space of the manual feed tray 300 is increased.

  Further, as the length of the tray main body 302 in the sheet conveyance direction increases, as shown in FIG. 1, the amount of protrusion of the tray main body 302 when the tray main body 302 is expanded from the apparatus main body 100A increases. For a user who uses only the small size sheet of the apparatus main body A4 laterally fed, it is necessary to provide an unnecessary space on the side surface of the image forming apparatus 100.

  Further, since a large size sheet such as A3 vertical feed can be stacked without pulling out the extension tray 303, it is difficult to intuitively determine whether or not the extension tray 303 is pulled out when the sheet is placed on the manual feed tray 300. . There is a greater possibility that the user will perform image formation when the extension tray 303 is pulled out wrong than when the user sees the instruction of the operation unit 151 and puts in and out the extension tray 303.

(Effect of Embodiment 1)
In the first embodiment, since the sheet length detection sensor 304 is disposed on the expansion tray 303, the tray body 302 is downsized and the manual feed tray 300 is smaller than when the sheet length detection sensor 304 is disposed on the tray body 302. Can be configured compactly. A structure for accommodating the manual feed tray 300 in the apparatus main body 100A can be configured to be small and light.

  In the first embodiment, it is not necessary to pull out the expansion tray 303 when using a small size sheet, so that the operating space of the image forming apparatus 100 can be reduced.

  In the first embodiment, the expansion tray 303 is accommodated in the tray main body 302. For this reason, the length of the manual feed tray 300 in the sheet conveyance direction can be small. The recess or opening on the apparatus main body 100A side for storing the manual feed tray 300 may be small.

  In the first embodiment, the sheet length detection sensor 304 is not in contact with the tray main body 302 in a state where the expansion tray 303 is accommodated in the tray main body 302. Therefore, the sheet length detection sensor 304 does not need to erroneously detect the tray main body 302 as a sheet on the expansion tray 303.

  In the first embodiment, the guide groove 302a and the guide pin 303a guide the expansion tray 303 away from the sheet stacking surface as the expansion tray 303 is accommodated in the tray body 302. For this reason, it is possible to avoid erroneous detection of the sheet length detection sensor 304 while keeping the level difference between the tray main body 302 and the expansion tray 303 at the time of expansion small.

  In the first embodiment, the guide pin 303 a is engaged with the recess 302 b in a state where the extension tray 303 is pulled out from the tray main body 302, thereby maintaining the state where the expansion tray 303 is pulled out from the tray main body 302. Therefore, the sheet size can be accurately determined by the sheet length detection sensor 304.

  In the first embodiment, the guide groove 302 a is a guide groove along the movement path of the extension tray 303 provided in the tray main body 302. The guide pins 303a are a pair of pins whose movement paths are restricted by the guide grooves 302a. For this reason, the frictional force between the tray main body 302 and the expansion tray 303 is small, and the expansion tray 303 can be pulled into the tray main body 302 only by gravity without additional spring means.

  In the first embodiment, the recess 302b is formed in the guide groove 302a and engages the guide pin 303a. For this reason, the structure which hold | maintains the extended tray 303 in the state pulled out is realizable by slight process of the guide groove 302a.

  In the first embodiment, the expansion tray 303 is dropped and accommodated in the tray main body 302 when the guide pins 303a and the recess 302b are not engaged. For this reason, the expansion tray 303 does not get in the way when the manual feed tray 300 is stored in the apparatus main body 100A.

  In the first embodiment, the length of the mounting surface of the tray main body 302 in the sheet conveyance direction is ½ or less of the length of the maximum size sheet conveyed to the apparatus main body 100A. For this reason, the user always pulls out the extension tray 303 for a large-sized sheet. When placing a large-sized sheet on the manual feed tray 300, the user can intuitively guide the user to pull out the expansion tray 303. Since large size sheets cannot be stacked on the tray main body 302, the user intuitively pulls out the expansion tray 303 to stack large size sheets. As a result, it is possible to avoid the image formation of a large size sheet in the unintended storage state of the expansion tray 303.

<Embodiment 2>
In the first embodiment, the extension tray 303 having the sheet length detection sensor 304 can be pulled out from the tray main body 302. On the other hand, in the second embodiment, the extension tray 312 having the sheet length detection sensor 313 can be further pulled out from the extension tray 303. Since the other configuration is the same as that of the first embodiment, in FIG. 8, the same reference numerals as those in FIG.

(Second expansion tray)
FIG. 8 is an explanatory diagram of the configuration of the manual feed tray according to the second embodiment. As shown in FIG. 8, in the second embodiment, the extension tray 312 that is an example of the third tray can be extended from the extension tray 303 that is an example of the second tray to the upstream side in the sheet conveyance direction. Then, the sheet is pulled out from the expansion tray 303 to expand the sheet placement surface to the upstream side. A sheet length detection sensor 313, which is an example of a second detection unit, is provided on the extension tray 312 and detects a sheet placed on the extension tray 312.

  The CPU 155 of the control unit 150 performs sheet detection based on detection results by the entrance sensor 208, a sheet length detection sensor 304 that is an example of a first detection unit, and a sheet length detection sensor 313 that is an example of a second detection unit. Get length information. The control unit 150 determines the size of the sheet based on detection results by the entrance sensor 208, the sheet length detection sensor 304, the sheet length detection sensor 313, and the width detection mechanism 307, which is an example of the width detection unit.

<Embodiment 3>
In the first embodiment, one sheet length detection sensor 304 is arranged on the extension tray 303. On the other hand, in the third embodiment, two sheet length detection sensors 314 and 315 are arranged on the extension tray 303. Since the configuration other than this is the same as that of the first embodiment, in FIG. 9, the same reference numerals as those in FIG.

(Second detection unit)
FIG. 9 is an explanatory diagram of the configuration of the manual feed tray according to the third embodiment. As shown in FIG. 9, in the third embodiment, a sheet length detection sensor 315 that is an example of a second detection unit is provided on the extension tray 303. The sheet length detection sensor 315 detects a sheet placed on the expansion tray 303 on the upstream side in the sheet conveyance direction with respect to the sheet length detection sensor 314 which is an example of a first detection unit.

  The CPU 155 of the control unit 150 performs sheet detection based on detection results by the entrance sensor 208, a sheet length detection sensor 314 that is an example of a first detection unit, and a sheet length detection sensor 315 that is an example of a second detection unit. Get length information. The control unit 150 determines the size of the sheet based on detection results by the entrance sensor 208, the sheet length detection sensor 314, the sheet length detection sensor 315, and the width detection mechanism 307 which is an example of the width detection unit.

<Other embodiments>
The sheet feeding tray, the sheet feeding apparatus, and the image forming apparatus of the present invention are not limited to the specific configuration and control described in the first embodiment. Another embodiment in which a part or all of the configuration of the first embodiment is replaced with an equivalent member is also possible.

  In the first embodiment, the embodiment of the image forming apparatus has been described. However, the sheet feeding destination is not limited to the image forming unit. The sheet feeding destination may be an image forming process such as an inkjet printer, an electrophotographic facsimile machine, a copying machine, or a multifunction machine, an image reading apparatus, or a sheet processing apparatus such as a puncher.

  In the first embodiment, as shown in FIG. 4, the inlet sensor 208 that detects the sheet on the tray main body 302 is arranged on the main body side of the sheet supply device 160. However, the inlet sensor 208 may be provided in the tray main body 302.

  In the first embodiment, the expansion tray 303 is accommodated in the space inside the box-shaped tray main body 302. However, the expansion tray 303 may be slidably disposed on the plate-like tray body 302. The main body 302 provided with the cuts and the expansion tray 303 provided with the cuts may be arranged so that the cuts are engaged with each other so that both can be slid in the cutting direction at the same plane height.

  In the first embodiment, the sheet length detection sensor 304 that operates the photo interrupter 304b by bringing the flag 304a into contact with the sheet is used. However, the sheet length detection sensor 304 may be replaced with an ultrasonic sensor, an electrostatic sensor, or the like.

DESCRIPTION OF SYMBOLS 100 Image forming apparatus, 100A apparatus main body 101 Photosensitive drum, 102 Corona charger 103 Exposure apparatus, 104 Developing apparatus, 104s Developing roller 105 Transfer conveyance part, 105a Transfer belt, 105b Separation roller 105d Transfer roller, 106 Drum cleaning part, 107 Fixing Device 110 Paper feeding unit, 111 cassette, 112 Feed roller, 113, 301 Separating unit 120 Registration conveyance unit, 130 Image forming unit, 150 Control unit 160 Sheet feeding device, 202 Pre-registration conveyance unit, 204 Write sensor 208 Entrance sensor, 300 Manual feed tray, 302 Tray body 302a Guide groove, 302b Recess, 303, 312 Expansion tray 303a Guide pin, 304, 313, 314, 315 Sheet length detection sensor 304a Flag, 304b Photo interrupter, 06 side regulating plate 307 width detection mechanism P1 small-sized sheets, P2 large size sheet, T1 transfer unit

Claims (12)

A first tray for mounting a first size supply sheet;
A second tray that is extendable to extend the first tray to place a second size supply sheet that is larger than the first size supply sheet;
A sheet supply apparatus comprising: a detection unit that is provided on the second tray and detects a supply sheet placed on the second tray.   The sheet feeding apparatus according to claim 1, wherein the second tray is accommodated in the first tray. The detection unit detects a sheet by contacting a supply sheet placed on the second tray,
The said detection part is a non-contact with the supply sheet | seat loaded on the said 1st tray in the state in which the said 2nd tray was accommodated in the said 1st tray, The Claim 2 characterized by the above-mentioned. Sheet feeding device.   The said 1st tray has an engagement structure which engages with the said 2nd tray in the state pulled out from the said 1st tray, and hold | maintains in the said state pulled out. The sheet supply apparatus according to 3.   5. The length of the first tray in the sheet conveyance direction is equal to or less than ½ of the length of a maximum-size supply sheet to be placed. 5. Sheet feeding device. When the detection unit is a first detection unit,
A third tray that is drawn from the second tray to the upstream side in the sheet conveying direction and extends the placement surface to the upstream side;
6. The apparatus according to claim 1, further comprising: a second detection unit that is provided on the third tray and detects a supply sheet placed on the third tray. Sheet feeding device. When the detection unit is a first detection unit,
A second detection unit that is provided in the second tray and detects a supply sheet placed on the second tray on the upstream side in the sheet conveyance direction with respect to the first detection unit is provided. The sheet supply apparatus according to any one of claims 1 to 5. A main body detection unit for detecting a supply sheet placed on the first tray;
The control part which acquires the length information of the supply sheet | seat previously described based on the detection result by the said main body detection part and the said detection part, It has any one of Claim 1 thru | or 7 characterized by the above-mentioned. The sheet supply apparatus according to 1. A width detection unit that is provided in the first tray and detects a length in a width direction orthogonal to a sheet conveying direction of a supply sheet placed on the first tray;
The sheet supply according to claim 8, wherein the control unit determines a size of a supply sheet to be placed on the basis of detection results of the main body detection unit, the detection unit, and the width detection unit. apparatus. A main body detection unit for detecting a supply sheet placed on the first tray;
A control unit that acquires length information of a supply sheet that is placed in advance based on detection results of the main body detection unit, the first detection unit, and the second detection unit. The sheet supply apparatus according to claim 6 or 7. A width detection unit that is provided in the first tray and detects a length in a width direction orthogonal to a sheet conveying direction of a supply sheet placed on the first tray;
The control unit determines the size of the supply sheet to be placed on the basis of detection results of the main body detection unit, the first detection unit, the second detection unit, and the width detection unit. The sheet supply apparatus according to claim 10. A sheet feeding device according to any one of claims 1 to 11,
An image forming apparatus comprising: an image forming unit that forms an image on a sheet fed by the sheet feeding device.

Images