JP2006008270A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device capable of performing both face-down and face-up modes, and opening/closing a face-up delivery tray without going to the image forming device when the face-up delivery is performed. <P>SOLUTION: A face-up tray 3 is generally erected in a vertical direction, and closed in contact with a side face of a body 1. When a paper sheet conveying direction switching means 73 is switched to the face-up direction, a hook 33 engaged with a rotary shaft 73b is unhooked, and the face-up tray 3 is opened by an urging means 32. Gear trains 81, 83 having a clutch mechanism 82 which are connected to a paper sheet delivery roller 75 are connected to a fan-shaped gear 34 provided on the face-up tray 3, and the face-up tray is closed by transmitting the driving force of the paper sheet delivery roller 75 by the clutch mechanism. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus capable of face-up discharge and face-down discharge.

  In the image forming apparatus, when the sheets on which images are formed are discharged, the sheets are discharged face down so that the order is correctly stacked. In many cases, the face-down discharge unit is set on the image forming unit or the fixing unit, and a conveyance path that is bent from the fixing unit to the surface is set. However, when the paper is transported through a bent transport path having a small radius of curvature, the paper may be bent. For this reason, there is already known an image forming apparatus provided with a discharge portion that extends almost straight from the fixing portion so that the sheet is conveyed along a path that does not bend. The discharge portion extending substantially straight from the fixing portion is a face-up discharge portion with the image forming surface of the paper facing upward.

In order to receive the paper discharged face-up, it is necessary to provide a tray. As a tray provided for such a purpose, that is, a face-up tray, a tray that is attached to the outer wall of the image forming apparatus when the user performs face-up discharge, or a tray that is manually opened as in Patent Documents 1 and 2 Has been proposed.
JP 2001-278525 A (page 3, FIG. 2) Japanese Patent Laid-Open No. 11-13389 (page 2 to page 3, FIG. 2)

  In any of the above-described apparatuses, the following problem occurs when the face-up discharge operation is performed without preparing the face-up tray. In the case where the face-up tray is attached to the outer wall of the image forming apparatus, since the face-up tray is not provided, the sheet on which the image is formed falls on the floor and is folded or soiled. In addition, in the paper described in Patent Document 1 or 2, paper on which an image is formed by being blocked by the closed face-up tray is wrinkled or discharged between the discharge roller and the closed face-up tray. The roller is clogged.

  After all, in any of the above-described apparatuses, the user must go to the image forming apparatus to prepare a face-up tray each time the face-up is discharged. In particular, when forming an image from a personal computer installed at a location far from the image forming apparatus, prepare a tray, return to the personal computer, issue an image forming instruction, and take the paper on which the image has been formed to the image forming apparatus. The round trip from the personal computer to the image forming apparatus was troublesome.

  On the other hand, if the face-up discharge tray is left open, cold air enters from the paper discharge port and the warm air inside the main body escapes, so the temperature of the fixing roller that heats the toner image and fixes it to the paper decreases. Since the fixing roller needs to be frequently heated to a predetermined temperature, power is wasted. Furthermore, a person who passes by the image forming apparatus sometimes collides with an open face-up discharge tray.

  Therefore, in the present invention, the face-up tray that can be opened and closed is closed when discharging face-down, and is automatically opened when discharging face-up, thereby saving the trouble of preparing the face-up tray. An object of the present invention is to provide an image forming apparatus capable of eliminating waste.

  Furthermore, the face-up tray automatically closes after the paper is removed after a face-up has been discharged or after a certain amount of time has passed, which makes it difficult to reduce the temperature of the fixing roller and saves power. It is an object of the present invention to provide an image forming apparatus that can prevent a useless accident caused by a person or an object hitting an uptray.

To achieve the above object, in the image forming apparatus of the present invention, a face-up tray that receives paper discharged with the image forming surface facing up, and a face-down tray that receives paper discharged with the image forming surface down. An image forming apparatus comprising: a sheet transport direction switching unit that distributes the sheet after image formation to any one of the trays; and a control unit that controls the entire apparatus.
The face-up tray is attached to the side surface of the main body so that it can be opened and closed. When the face-up tray is closed, the free end faces the side of the main body with the free end facing up. Locking means for capturing and maintaining this when it is closed and biasing means for biasing the face-up tray in the opening direction are provided, and the control unit causes the sheet transport direction switching means to be face-down. When the guide posture to the tray is switched to the guide posture to the face-up tray, the lock unit is released and the face-up tray is opened by the biasing unit.

  In the image forming apparatus of the present invention, the opening / closing fulcrum of the face-up tray rotates as if it is a fan, and a fan-shaped gear provided on the face-up tray and a driving force are transmitted to each part of the image forming apparatus. A main motor, a gear train having a clutch mechanism and transmitting the driving force of the main motor to the fan gear so that the face-up tray is closed, and a face-up tray open / close detection sensor for detecting an open / closed state of the face-up tray And when the face-up tray is open, the control unit switches the paper transport direction switching means to a guide posture toward the face-down tray and simultaneously connects the clutch mechanism to close the face-up tray. First, make sure that the face-up tray is completely closed. Response to the fact that i close detection sensor detects shall release the clutch mechanism.

  Further, in the image forming apparatus of the present invention, a fan-shaped gear provided on the face-up tray that rotates the opening / closing fulcrum of the face-up tray like a fan, a drive gear connected to the fan-shaped gear, A control unit that includes a face-up tray drive motor connected to the center of the drive gear by a main shaft and a face-up tray position detection sensor that detects an open / closed state of the face-up tray; At the same time as switching the sheet conveyance direction switching means to the face-down tray guiding position, the face-up tray drive motor is rotated in the direction in which the face-up tray is closed, and the face-up tray is closed. In response to detection by the tray position detection sensor, It is assumed that stopping the data.

  In the image forming apparatus of the present invention, a paper detection sensor that detects the presence or absence of paper on the face-up tray when the face-up tray is open is provided, and the paper detection sensor is provided on the face-up tray. It is assumed that the control unit does not perform the operation of closing the face-up tray while it is detected that there is.

  Further, in the image forming apparatus of the present invention, a recess is provided in the paper placement surface of the face-up tray so that when the face-up tray is closed, the paper remaining on the paper placement surface is accommodated in the recess. It shall be.

  In the image forming apparatus of the present invention, a lid is provided on the main body side to close the entrance of the depression when the face-up tray is closed. The lid can be retracted into the main body and is always urged. It is assumed that it has been pushed to the advance position.

  In the image forming apparatus of the present invention, the face-up tray is heat-insulated.

  In the image forming apparatus according to the present invention, when the sheet is discharged to the face-up tray that can be opened and closed, the control unit switches the sheet conveyance direction switching unit from the guidance posture to the face-down tray to the guidance posture to the face-up tray. Since the lock means is released and the face-up tray is opened by the urging means, it is possible to save the user from going to the image forming apparatus and opening the face-up tray.

  Further, according to the present invention, when the sheet transport direction switching means is switched to the guide position toward the face-down tray which is in a normal use state in a state where the face-up tray is opened, the clutch mechanism is operated by the control unit and the main mechanism is operated. Because the face-up tray is closed by the power of the motor, it is possible to prevent the warm air inside the image forming apparatus from escaping from the paper discharge port to the face-up tray, and to save power to maintain the temperature of the fixing roller can do. In addition, it is possible to prevent a useless accident caused by a person or object hitting the face-up tray.

  According to the present invention, since the face-up tray is closed by operating the face-up tray drive motor by the control unit in a state in which the face-up tray is opened, the user takes out the paper discharged face-up. Even if the face-up tray is forgotten to close, the warm air inside the image forming apparatus can be prevented from escaping from the paper discharge port to the face-up tray, and the power to maintain the temperature of the fixing roller can be saved. . In addition, it is possible to prevent a useless accident caused by a person or object hitting the face-up tray.

  Further, according to the present invention, the control unit does not perform the operation of closing the face-up tray while detecting that there is paper on the face-up tray with the paper detection sensor open, so that an image is formed. It is possible to prevent malfunctions caused by a sheet falling on the floor, being bent by the face-up tray, or not being completely closed by the sheet.

  Further, according to the present invention, when the face-up tray is closed, even if the paper remains, the paper is stored in the recess, so that the paper on which the image is formed falls to the floor, the paper It is possible to prevent malfunction caused by the face up tray not being completely closed due to the pinch.

  Further, according to the present invention, since the lid for closing the entrance of the dent is provided with the face-up tray closed, the appearance of the image forming apparatus can be improved. Also, if the paper on the face-up tray touches the lid during the face-up tray closing operation, the lid will be pushed back into the main unit, preventing malfunctions caused by the paper being caught and the face-up tray not being completely closed. it can.

  Further, according to the present invention, since the heat insulating sheet is attached to the entire inner surface of the face-up tray, it is difficult for the warm air inside the image forming apparatus to be cooled, and it is possible to save power for maintaining the temperature of the fixing roller.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram of a printer according to an embodiment of an image forming apparatus of the present invention. A face-down tray 2 is provided on the upper surface of the main body 1, a face-up tray 3 that can be opened and closed on the left side, and a manual feed tray 43 that can be opened and closed on the right side.

  Inside the main body 1, a paper feeding unit 4, an image forming unit 5, a fixing unit 6 and a control unit 9 are built. First, the paper feed unit 4 will be described. The paper feed unit 4 includes a paper feed cassette 41, a paper feed roller 42, a manual paper feed tray 43, and a paper feed roller pair 44. The paper feed cassette 41 accommodates paper P and is disposed at the bottom of the main body 1. From here, the paper P is sent one by one to the paper transport path 71 by the paper feed roller 42, and transported by the transport roller pair group 72. The manual paper feed tray 43 can be opened and closed and is provided on the right side of the main body 1. By placing the paper P here, like the paper P in the paper feed cassette 41, the paper P is sent one by one to the paper transport path 71 by the paper feed roller pair 44 and transported by the transport roller pair group 72. Is done.

  Next, the image forming unit 5 will be described. The image forming unit 5 includes a photosensitive drum 51 and a charger 52, an optical scanning unit 53, a developing device 54, a transfer roller 55, and a cleaning device 56 disposed around the photosensitive drum 51. When a user issues an instruction for image formation from a personal computer (not shown) connected to the main body 1 directly or via a network (hereinafter abbreviated as “PC”), the control unit 9 receives the instruction, and the photosensitive drum 51 rotates clockwise, and the surface of the photosensitive drum 51 is uniformly charged by the charger 52 first. Next, the surface of the photosensitive drum 51 is irradiated with laser light from the optical scanning unit 53, and the charge corresponding to the portion of the image formed on the paper P or the portion other than the image is erased. An electrostatic latent image is formed on the surface. Then, the developing device 54 supplies toner to the electrostatic latent image on the photosensitive drum 51, and the electrostatic latent image is visualized.

  When the photosensitive drum 51 further rotates and the toner image comes to a position facing the transfer roller 55, the paper P is conveyed between the photosensitive drum 51 and the transfer roller 55 accordingly. At this time, the toner image on the photosensitive drum 51 is transferred onto the paper P by applying a voltage having a polarity opposite to the charging polarity of the toner to the transfer roller 55. Residual toner that has not been transferred onto the photosensitive drum 51 is removed from the photosensitive drum 51 by the cleaning device 56. On the other hand, the paper P onto which the toner image has been transferred is conveyed to the fixing unit 6 in which the fixing roller 61 and the pressure roller 62 are pressed against each other, where the toner image is heated and pressed to be fixed on the paper P. Thereafter, the transport direction of the paper P is switched by the paper transport direction switching means 73, and the paper P is discharged onto the face-down tray 2 or the face-up tray 3 by the face-down discharge roller pair 74 or the face-up discharge roller pair 75.

  FIG. 2 shows the front shape of the sheet conveyance direction switching means 73 and the members in the vicinity thereof. The paper transport direction switching means 73 has a direction switching pin 73a and is rotatable about a rotation shaft 73b. The direction switching pin 73a engages with a direction switching hook 76 that can be moved up and down by a solenoid 76a. When the control unit 9 receives an instruction from the user's personal computer, the sheet transport direction switching unit 73 moves the direction switching hook 76 up and down, thereby guiding the face down tray indicated by a solid line and the face up tray indicated by a broken line. It is switched to the guidance posture to.

  A driving force is transmitted from a main motor (not shown) to the rotating parts in the main body 1, such as the transport roller pair group 45, the face-down discharge roller pair 74, and the face-up discharge roller pair 75. The control unit 9 controls the entire printer.

  FIG. 3 shows a first embodiment of the present invention. As shown in the schematic partial configuration diagram of the printer in FIG. 3, the face-up tray 3 is provided with a locking hook 33 that engages with the rotation shaft 73 b of the sheet conveyance direction switching unit 73 in a state in which the face-up tray 3 is closed. Yes. Further, an urging means 32 comprising a torsion coil spring for urging the face-up tray 3 in the opening direction is attached to the opening / closing fulcrum 31 of the face-up tray 3. A heat insulating sheet 37 is attached to the entire inner surface of the face-up tray 3 (the side facing the direction of the main body 1 when the face-up tray 3 is closed).

  Like the enlarged portion of the locking hook 33 and the rotating shaft 73b shown in FIG. 4, the rotating shaft 73b has a shape in which a flat portion is provided on a part of the outer periphery, and the sheet conveying direction switching means 73 is connected to the face-down tray 2. When in the guiding state, it is engaged with the locking hook 33 as shown by the solid line, and the face-up tray 3 is closed as shown in FIG. When the user operates the personal computer to switch the paper transport direction switching means 73 to the state of guidance to the face-up tray 3, the rotation shaft 73b rotates, and the lock hook 33 is lifted as indicated by the broken line to rotate the rotation shaft. The engagement with 73b is released. When the locking hook 33 is disengaged from the rotating shaft 73b, the face-up tray 3 is opened by the urging means 32 as shown in FIG.

  With this configuration, the user can open the face-up tray 3 without discharging to the printer when discharging the face-up. Further, the heat insulation sheet 37 improves the heat retaining performance inside the main body 1 when the face-up tray 3 is closed, so that the temperature drop of the fixing roller 61 can be suppressed, and the fixing roller 61 can be maintained at a predetermined temperature. Therefore, it is possible to reduce the energization amount for saving power.

  Further, in the first embodiment, in the vicinity of the rotation fulcrum 31 of the face-up tray 3, a fan-shaped gear 34 that rotates the rotation fulcrum 31 like a fan as shown in FIGS. A face-up tray open / close detection sensor 35 for detecting the open / close state of the tray 3 is provided. The face-up tray 3 is provided with a paper detection sensor 36 that detects the presence or absence of paper on the face-up tray 3. Both the face-up tray switch garden sensor 35 and the paper detection sensor 36 are light reflecting sensors, and detect that the gear 34 is close or that there is paper on the face-up tray 3. Further, as shown in the schematic configuration diagram of the periphery of the face-up discharge roller pair 75 viewed from the right side surface direction of the main body 1 in FIG. 6, the lower roller 75b of the roller 75a and the roller 75b constituting the face-up discharge roller pair 75. A gear 81 having a clutch mechanism 82 is attached to the rotary shaft 75c so as to freely rotate with respect to the rotary shaft 75c and not to move left and right. Further, a gear train 83 is provided for transmitting the driving force transmitted from the main motor (not shown) to the rotating shaft 75c by the gear 75d to the fan-shaped gear 34 in the direction in which the face-up tray 3 is closed. The rotating shaft 75c receives driving force from the main motor and is always rotating.

  The clutch mechanism 82 will be described with reference to a partial sectional view of the periphery of the connected clutch mechanism in FIG. The clutch mechanism 82 includes a flange 82a fixed to the rotation shaft 75c of the roller 75b, a cylindrical sleeve 82b having one or more teeth 82c provided on the outer periphery, and a clamping spring 82d disposed inside the sleeve 82b. Become. A boss portion 82e is provided on the flange 82a. The boss portion 82e faces the boss portion 81a provided on the gear 81 and has substantially the same diameter as the boss portion 81a. The sleeve 82b is disposed so as to pass the boss portion 81a and the boss portion 82e inward, and is freely rotatable. However, the movement range in the left-right direction in the drawing is limited by the gear 81 and the flange 82a. The clamping spring 82d is constituted by a coil spring, and the inner diameter thereof is a value close to the outer diameter of the boss portion 81a and the boss portion 82e, and the outer diameter is a value slightly smaller than the inner diameter of the sleeve 82b. The clamping spring 82d has one end fixed to the sleeve 82b and the other end fixed to the gear 81, and is arranged so that the inside of the coil is in light contact with the boss portion 81a and the boss portion 82b.

  The clutch control solenoid 84 will be described with reference to FIG. 7 and a partial sectional view of the periphery of the released clutch mechanism shown in FIG. The clutch control solenoid 84 is a flapper type, and includes a solenoid flapper 84a and an electromagnet 84b. A claw 84c is provided at the tip of the solenoid flapper 84a in parallel with the teeth 82c of the sleeve. The solenoid flapper 84a is made of a magnetic metal plate, and is formed by bending so that the claw 84c engages with the teeth 82c as shown in FIG. 8 when the power source of the clutch control solenoid 84 is OFF. When the power supply of the clutch control solenoid 84 is ON, as shown in FIG. 7, the solenoid flapper 84a is attracted to the electromagnet 84b and elastically deforms, the claw 84c is displaced upward, and the claw 84c is engaged with the teeth 82c. Canceled.

  Next, the driving force transmission operation by the clutch mechanism 82 will be described. When the power source of the clutch control solenoid 84 is ON, the engagement between the claws 84c and the teeth 82c is released as shown in FIG. In this state, the clamping spring 82d is wound around the boss portion 82e of the flange 82a that is rotated by the rotation of the rotating shaft 75c, the sleeve 82b is also rotated, and the clamping spring 82d is wound around the boss portion 81a of the gear 81. The driving force is transmitted to.

  When the power source of the clutch control solenoid 84 is OFF, the claw 84c is engaged with the tooth 82c as shown in FIG. In this state, the flange 82a is rotated by the rotation of the rotating shaft 75c, but the sleeve 82b is fixed by the claw 84C. Although the tightening spring 82d contacts the boss portion 82e of the flange 82a, the rotational direction of the boss portion 82e is a direction that loosens the winding of the tightening spring 82d. Based on the operation of the clutch mechanism 82 described above, the operation of closing the face-up tray 3 will be described with reference to FIGS.

  When the sheet is on the face-up tray 3, the sheet detection sensor 36 detects the sheet, and in response to this, the control unit 9 does not start the operation of closing the face-up tray 3.

  When the user collects the paper from the face-up tray 3, the paper detection sensor 36 stops detecting the paper, and in response to this, the control unit 9 starts an operation of closing the face-up tray 3. That is, the direction switching hook 76 is moved downward to switch the paper transport direction switching means 73 to the inductive position toward the face-down tray 2, and at the same time, the clutch control solenoid 84 is turned on to connect the clutch mechanism 82 and rotate the rotating shaft. The fan-shaped gear 34 is rotated by the driving force of 75c to close the face-up tray 3. Then, the locking hook 33 is engaged with the rotating shaft 73b, and the face-up tray 3 is locked. When the sensor 34 detects that the face-up tray 3 is closed, the control unit 9 turns off the clutch control solenoid and completes the operation of closing the face-up tray 3.

  Here, the installation location of the gear 81 and the clutch mechanism 82 is not limited to the rotating shaft 75c. It may be attached to any rotating shaft as long as the driving force of the main motor is transmitted. In that case, one or a plurality of gears constituting the gear train 83 are provided in accordance with the rotation direction of the gear 81 so that the sector gear 34 is rotated in the direction in which the face-up tray 3 is closed.

  With this configuration, even if the face-up tray 3 is forgotten to be closed when the paper is collected from the face-up tray 3, the face-up tray automatically detects that the paper detection sensor 36 no longer detects the paper. Since 3 closes, the useless accident by colliding with the face-up tray 3 which has been opened can be reduced. Further, since the warm air inside the main body 1 does not continue to be discharged from the sheet discharge port to the face-up tray 3, the temperature drop of the fixing roller 61 can be suppressed, and power can be saved. Furthermore, when the paper is on the face-up tray 3 by the paper detection sensor 36, the face-up tray 3 is not closed, so that the paper on which the image is formed falls on the floor and becomes dirty, There is no bending due to the closing operation.

  A second embodiment of the present invention is shown in the schematic block diagram of the printer in FIG. In the second embodiment, the face-up tray 3 is provided with a recess 38 in which a sheet having a narrower width than that of the face-up tray 3 is accommodated. When the face-up tray 3 is closed, the end of the depression 38 faces upward, and an open entrance is formed at the top. When the face-up tray 3 is closed, a lid 39 is provided on the main body 1 so as to close the entrance at the top of the recess 38. The lid 39 has the same width as the recess 38 and is provided through the lid insertion port 39a provided from the inside of the main body 1 to the side surface of the main body. The lid 39 is urged in a direction to close the inlet at the upper portion of the recess 38 by urging means 39b made of a compression coil spring.

  FIG. 10 is a partial front view of a printer according to the second embodiment of the present invention. In the vicinity of the rotation fulcrum 31 of the face-up tray 3, a fan-shaped gear 34 that rotates the rotation fulcrum 31 like a fan, a face-up tray open / close detection sensor 35 that detects the open / close state of the face-up tray 3, and a face An upper tray closing portion 85 is provided. The face-up tray closing portion 85 has a rotation shaft connected to the center of the face-up tray closing gear 85a and the face-up tray closing gear 85a meshing with the sector gear 34, and the face-up tray closing gear 85a is moved in the direction in which the face-up tray 3 is closed. It comprises a face-up tray closing motor 85b that rotates.

  Similarly to the first embodiment, the face-up tray 3 is provided with a locking hook 33 that engages with the rotation shaft 73b of the paper transport direction switching means 73 in a state in which the face-up tray 3 is closed. A biasing means 32 comprising a torsion coil spring that biases the face-up tray 3 in the opening direction is attached to the opening / closing fulcrum 31 of the face-up tray 3.

  As in the first embodiment, the face-up tray 3 is opened by switching the direction of the paper transport direction switching means 73 to the guiding posture toward the face-up tray 3. When a certain amount of time has elapsed after completion of paper discharge to the face-up tray 3, the control unit 9 starts an operation of closing the face-up tray 3 regardless of the presence or absence of paper on the face-up tray 3. That is, when the direction switching hook 76 is moved downward to switch the sheet conveying direction switching means 73 to the guiding posture toward the face-down tray 2, the face-up tray closing motor 37b is rotated and the face-up tray 3 is closed. The locking hook 33 engages with the rotation shaft 73b, and the face-up tray 3 is locked. Even when there is a sheet on the face-up tray 3, the sheet fits in the recess 38, so that the face-up tray 3 can be closed. When the face-up tray open / close detection sensor 34 detects that the face-up tray 3 is closed, the control unit 9 stops the face-up tray closing motor 37b and completes the operation of closing the face-up tray 3.

  Even when the sheet on the face-up tray 3 is longer in the longitudinal direction than the recess 38, as shown in the partially enlarged view of FIG. 11, when the face-up tray 3 is closed, the lid 39 touches the sheet P, and the urging means 39b. The face-up tray 3 can be closed because it is pushed back into the main body while being urged by. Here, as shown in the partially enlarged view of FIG. 12, the lid 39 can be urged by the urging means 39b made of a torsion coil spring, and can be rotated about the upper end portion as a rotation axis.

  With this configuration, even when the face-up tray 3 is forgotten to be closed, the face-up tray 3 is automatically closed, so that it is possible to reduce unnecessary accidents caused by hitting the opened face-up tray 3. Further, since the warm air inside the main body 1 does not escape from the paper discharge port to the face-up tray 3, the temperature drop of the fixing roller 61 can be suppressed, and power can be saved.

  In addition, even if the paper remains on the face-up tray 3, even if the face-up tray 3 is closed, the paper is stored in the recess 38. And the face-up tray 3 being sandwiched between the face-up tray 3 and the face-up tray 3 cannot be completely closed. For example, malfunctions such as the control unit 9 repeatedly closing the face-up tray 3 that cannot be closed are eliminated.

  Further, when there is no paper on the face-up tray 3 or when the paper is smaller than the depression 38, the lid 39 closes the entrance at the top of the depression 38, so that the appearance is not bad.

  The opening / closing mechanism for the face-up tray of the image forming apparatus according to the present invention can be used not only for the paper discharge tray but also for a manually feedable tray that can be opened and closed. Further, the image forming apparatus is not limited to a printer, and this opening / closing mechanism can be used even with a facsimile, a copying machine, or a combination of these.

1 is a schematic configuration diagram of a printer according to an embodiment of an image forming apparatus of the present invention. Front view of the vicinity of the paper transport direction switching means The partial front view of the printer which concerns on 1st Embodiment Partial enlarged view of the rotation shaft of the locking hook and the paper transport direction switching means The partial front view of the printer of the state which the face-up tray based on 1st Embodiment opened Schematic configuration diagram around the face-up discharge roller pair viewed from the right side of the main unit Partial sectional view around the clutch mechanism in the connected state Partial sectional view of the periphery of the clutch mechanism in a released state Schematic configuration diagram of a printer according to the second embodiment Partial front view of the printer according to the second embodiment Partial enlarged view of a printer according to the second embodiment The elements on larger scale of the face-up tray 3 which concerns on the deformation | transformation aspect of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 2 Face down tray 3 Face up tray 9 Control part 32 Energizing means 33 Locking hook 34 Fan-shaped gear 35 Face up tray open / close detection sensor 36 Paper detection sensor 37 Heat insulation sheet 38 Depression 39 Lid 39a Lid insertion port 39b Energizing means 73 Paper conveying direction switching means 73a Direction switching pin 73b Rotating shaft 81 Gear 82 Clutch mechanism 83 Gear train 85 Face up tray closing portion 85a Face up tray closing gear 85b Face up tray closing motor

Claims (7)

A face-up tray that receives paper discharged with the image forming surface facing up, a face-down tray that receives paper discharged with the image forming surface facing down, and a paper that sorts the paper after image formation to one of the trays In an image forming apparatus including a conveyance direction switching unit and a control unit that controls the entire apparatus.
The face-up tray is attached to the side surface of the main body so that it can be opened and closed. When the face-up tray is closed, the free end faces the side of the main body with the free end facing up. Locking means for capturing and maintaining this when it is closed and biasing means for biasing the face-up tray in the opening direction are provided, and the control unit causes the sheet transport direction switching means to be face-down. The image forming apparatus according to claim 1, wherein when the guide posture to the tray is switched from the guide posture to the face-up tray, the lock unit is released and the face-up tray is opened by the biasing unit.   A fan-shaped gear provided on the face-up tray, which rotates an opening / closing fulcrum of the face-up tray as a fan, a main motor for transmitting a driving force to each part of the image forming apparatus, and a clutch mechanism. A gear train that transmits a driving force of a main motor to the fan-shaped gear so that the face-up tray is closed, and a face-up tray open / close detection sensor that detects an open / closed state of the face-up tray, and the face-up tray is opened In the state, the control unit switches the sheet conveying direction switching means to the guiding posture to the face-down tray, and at the same time, the face-up tray starts to close by connecting the clutch mechanism, and the face-up tray is completely closed. The face-up tray open / close detection sensor detects that Receiving, image forming apparatus according to claim 1, characterized in that releasing the clutch mechanism.   The opening / closing fulcrum of the face-up tray rotates like a fan, the fan-shaped gear provided on the face-up tray, the driving gear connected to the fan-shaped gear, and the center of the driving gear and the main shaft are connected. A face-up tray drive motor and a face-up tray position detection sensor for detecting an open / closed state of the face-up tray, and when the face-up tray is open, the control unit controls the sheet transport direction switching means to the face. The face-up tray drive motor is rotated in the direction in which the face-up tray closes simultaneously with switching to the down-tray guiding position, and the face-up tray position detection sensor detects that the face-up tray has been closed. The motor is stopped The image forming apparatus according to Motomeko 1.   A paper detection sensor that detects the presence or absence of paper on the face-up tray when the face-up tray is open is provided, and while the paper detection sensor detects that there is paper on the face-up tray, The image forming apparatus according to claim 2, wherein the control unit does not perform an operation of closing the face-up tray.   3. A recess is provided in a paper placement surface of the face-up tray, and the paper remaining on the paper placement surface is accommodated in the recess when the face-up tray is closed. The image forming apparatus according to 3.   A lid for closing the entrance of the depression when the face-up tray is closed is provided on the main body side, and the lid can be retracted into the main body and is always pushed out to the advanced position by the biasing means. The image forming apparatus according to claim 5.   The image forming apparatus according to claim 1, wherein the face-up tray is heat-insulated.

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