JP2012098408A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent opening of a pair of frames without using a dedicated connection member.SOLUTION: A reconveyance unit 110 comprises a pair of side faces 110A disposed on both sides in the width direction of a recording sheet, a first engaging part 111 disposed outside in the width direction with an opening from each side face 110A and a first connection part 121 for connecting the first engaging part 111 and the side face 110A so that the opening is opened toward the attaching direction of a reconveyance unit 110. The pair of frames 21 comprises a second engaging part 121 disposed inside in the width direction with an opening from an inner face 21A and a second connection part 122 for connecting the second engaging part 121 and the inner face 21A so that the opening is opened toward the opposite side of the attaching direction and are configured such that the first engaging part 111 engages with the outside in a width direction of the second engaging part 121 when the reconveyance unit 110 is located in the inside position.

Description

  The present invention relates to an image forming apparatus having a pair of frames for holding an image forming unit.

  2. Description of the Related Art Conventionally, an image forming apparatus is known in which an image forming unit that forms an image on a sheet and a pair of frames that are held so as to sandwich the image forming unit are contained in an exterior component (see Patent Document 1). Specifically, in this technique, the upper and lower portions of the pair of frames are joined by a dedicated connecting member for connecting the pair of frames.

JP 2003-107822 A

  However, the above-described technique has a problem in that the cost is increased because all of the upper and lower portions of each frame are coupled by a dedicated connecting member. In addition, in order to reduce costs, it may be possible to adopt a structure in which a part of the dedicated connecting member is removed, but in this case, when force is applied in the direction in which the pair is separated from the pair of frames at the removed part. Causes a problem that a pair of frames are opened.

  Accordingly, an object of the present invention is to suppress the opening of a pair of frames without using a dedicated connecting member.

The present invention that solves the above-described problems includes an image forming unit that forms an image on a recording sheet, a pair of frames that are opposed to each other with the image forming unit interposed therebetween, and that holds the image forming unit, and is disposed between the pair of frames. In a state in which the front and back of the recording sheet that is provided so as to be movable between the inner position and the outer position moved outward from the inner position and on which the image is formed on one side by the image forming unit are reversed. A re-conveying unit that constitutes a part of re-conveying means for re-conveying the recording sheet to the image forming unit, wherein the re-conveying unit includes a width direction of the recording sheet. A pair of side surfaces disposed on both sides of the first side, a first engagement portion disposed on the outer side in the width direction with a gap from each side surface, and the gap opening toward the mounting direction of the re-transport unit. The first person A first connecting portion connecting the parts with the side surface, are provided,
The pair of frames have a second engagement portion disposed on the inner side in the width direction with a gap from an inner surface, and the second engagement so that the gap opens toward a side opposite to the mounting direction. And a second connecting portion that connects the inner surface to the inner surface, and when the re-conveying unit is positioned at the inner position, the first engaging portion has the width of the second engaging portion. It is characterized by engaging outward in the direction.

  According to the present invention, when the re-conveying unit is positioned at the inner position, the first engaging portion engages the width direction outside of the second engaging portion, so that the pair of frames can be opened by the re-conveying unit. Can be suppressed.

  According to the present invention, the opening of the pair of frames can be suppressed without using a dedicated connecting member.

It is explanatory drawing which shows the laser printer which concerns on embodiment of this invention. It is a disassembled perspective view which shows a pair of frame and the unit for re-conveyance. FIG. 6 is an explanatory diagram illustrating a state where a paper feed tray is located at a movement position. It is explanatory drawing which shows the state which the re-conveyance unit was located in the outer side position. It is sectional drawing when the circumference | surroundings of a 1st locking member are cut by the horizontal surface. It is sectional drawing when the circumference | surroundings of a 2nd lock member are cut by the horizontal surface. They are the rear view (a) and sectional drawing (b) which show a 1st engaging part and a 2nd engaging part. It is a perspective view which shows the modification of a 1st engaging part and a 2nd engaging part.

<Overall configuration of laser printer>
Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of a laser printer as an example of an image forming apparatus will be described, and then the features of the present invention will be described in detail.

  In the following description, the direction will be described with reference to the user when using the laser printer. That is, in FIG. 1, the left side toward the paper surface is “front side (front side)”, the right side toward the paper surface is “rear side (back side)”, the back side toward the paper surface is “left side”, and it faces the paper surface. Let the near side be the “right side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

  As shown in FIG. 1, the laser printer 1 includes a feeder unit 3 for feeding a sheet P as an example of a recording sheet into the apparatus main body 2, and an image forming unit 4 for forming an image on the sheet P. , A re-transport means 100.

  The feeder unit 3 feeds a sheet feed tray 31 as an example of a sheet cassette that is detachably attached to the lower portion of the apparatus main body 2 and a sheet P stored in the sheet feed tray 31 toward the image forming unit 4. And a paper feed mechanism 32.

  The image forming unit 4 includes a scanner unit 5, a process cartridge 6, a transfer roller TR, and a fixing device 7.

  The scanner unit 5 is provided in an upper part in the apparatus main body 2 and includes a laser light emitting unit, a polygon mirror, a lens, a reflecting mirror, and the like (not shown). In the scanner unit 5, a laser beam is irradiated on the surface of a photosensitive drum 81 described later by high-speed scanning.

  The process cartridge 6 is detachable from the apparatus main body 2 and includes a drum cartridge 8 having a photosensitive drum 81 and a developing cartridge 9 having a developing roller 91 and toner.

  In the process cartridge 6, the surface of the rotating photosensitive drum 81 is uniformly charged by a charger (not shown) and then exposed by high-speed scanning of a laser beam from the scanner unit 5. As a result, the potential of the exposed portion is lowered, and an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 81.

  Next, the toner in the developing cartridge 9 is supplied to the electrostatic latent image on the photosensitive drum 81 by the rotationally driven developing roller 91, and a toner image is formed on the surface of the photosensitive drum 81. Thereafter, the paper P is conveyed between the photosensitive drum 81 and the transfer roller TR, whereby the toner image carried on the surface of the photosensitive drum 81 is transferred onto the paper P.

  The fixing device 7 includes a heating roller 71 and a pressure roller 72 that is disposed to face the heating roller 71 and presses the heating roller 71. In the fixing device 7 configured as described above, the toner transferred onto the paper P is thermally fixed while the paper P passes between the heating roller 71 and the pressure roller 72.

  The paper P thermally fixed by the fixing device 7 is conveyed to a paper discharge roller R disposed on the downstream side of the fixing device 7 and is discharged from the paper discharge roller R to the outside of the apparatus main body 2.

  The re-conveying means 100 includes a paper discharge roller R that switches back the paper P that has been partially discharged out of the apparatus main body 2 and a guide member that guides the switched back paper P to the re-conveying unit 110 through the rear side of the fixing device 7. (Not shown) and a re-conveying unit 110. The re-conveying unit 110 constitutes a part of the re-conveying means 100 and mainly includes a plurality of pairs of re-conveying rollers RR for conveying the surface-printed paper P to the upstream side of the image forming unit 4. And a guide member (not shown) are integrally provided, and are detachable from the apparatus main body 2.

  In this re-conveying means 100, the paper P is conveyed again to the image forming unit 4 in a state where the front and back of the paper P on which the image is formed on the front surface (one surface) is reversed by the image forming unit 4. As a result, an image is formed on the back surface of the paper P by the image forming unit 4, and double-sided printing is executed.

<Device structure>
Next, the structure of the apparatus main body 2 will be described in detail.
As shown in FIG. 2, the apparatus main body 2 is opposed to the image forming unit 4 (scanner unit 5 or the like), holds a pair of frames 21 that hold the image forming unit 4, and the image forming unit 4 and the pair of frames 21. And an exterior component 22 covering the.

  The exterior component 22 is made of resin, and an upper panel 221 disposed above the pair of frames 21, a pair of side panels 222 disposed on the outer side in the left-right direction of the pair of frames 21, and the front of the pair of frames 21. And a rear cover 224 disposed behind the pair of frames 21.

  The upper panel 221 has a paper discharge tray portion 221A for placing the paper P discharged by the paper discharge roller R (see FIG. 1), and is joined to the upper ends of the pair of frames 21 by an adhesive. Yes.

  The side panel 222 is fixed to the outer surface in the left-right direction of the pair of frames 21, and a front shaft support portion (not shown) for rotatably supporting the front cover 223 is provided below the front and rear ends. A rear shaft support portion 222A for rotatably supporting the rear cover 224 is provided.

  The front cover 223 is formed in a size corresponding to the front opening 2A (see FIG. 1) formed by the front edge of the upper panel 221, the front edge of the pair of side panels 222, and the upper edge of the front surface of the paper feed tray 31. Has been. The front cover 223 can be opened and closed by the lower end of the front cover 223 being rotatably supported by the pair of side panels 222, whereby the process cartridge 6 can be attached and detached through the front opening 2A. Yes.

  The rear cover 224 has a size corresponding to the rear opening 2B (see FIG. 1) formed by the rear edge of the upper panel 221 and the rear edges of the pair of side panels 222. The rear cover 224 is pivotally supported by a pair of side panels 222 with a pivot shaft 224A provided below the rear cover 224 so that the upper portion pivots about the pivot shaft 224A and can be opened and closed. Thus, it becomes possible to take out jammed paper from the rear.

  The pair of frames 21 are made of metal or resin, and the upper portions are connected by the scanner unit 5. Thereby, the opening of the upper part in the left-right direction is suppressed by the scanner unit 5. Note that the fixing device 7 and the process cartridge 6 (not shown) are not configured to restrict the pair of frames 21 from opening left and right. In particular, in order to favorably support the housing of the fixing device 7 that expands in the left-right direction due to heat with the apparatus main body 2, the fixing device 7 includes a long hole in the left-right direction and a pin-shaped portion that engages with the long hole. Are held by a pair of frames 21.

  In addition, a connecting member 214 that connects the front lower portions of the pair of frames 21 is provided on the front side of the lower portions of the pair of frames 21. Therefore, the connecting member 214 can prevent the front lower portions of the pair of frames 21 from opening left and right.

  And the rear lower part of a pair of flame | frame 21 is suppressed by opening to right and left by being connected by the unit for re-transport 110 instead of providing the connection member 214 as mentioned above. A connection structure between the rear lower portion of the pair of frames 21 and the re-transport unit 110 will be described in detail later.

  A rail portion 215 that supports the paper feed tray 31 to be slidable in the front-rear direction is formed at the lower part of the inner surfaces of the pair of frames 21 so as to extend in the front-rear direction. Thus, the paper feed tray 31 takes out the storage position (see FIG. 1) stored between the pair of frames 21 and the movement position moved outward from the storage position (for example, the paper P as shown in FIG. 3). Can be moved).

  In addition, a pair of rail portions 218 that support the re-transport unit 110 so as to be slidable in the front-rear direction are provided above the rail portion 215 in the pair of frames 21 so as to extend in the front-rear direction. Thereby, the re-transport unit 110 is moved from the inner position (see FIG. 1) between the pair of frames 21 and the outer position moved from the inner position to the outer side (for example, from the apparatus body 2 as shown in FIG. 4). It is possible to move to a position that is out of place.

  As shown in FIG. 5, one first lock member 23 for positioning the paper feed tray 31 at the storage position is provided on each rail portion 215 for supporting the paper feed tray 31. ing. In addition, as shown in FIG. 6, one second lock member 500 for positioning the re-transport unit 110 at the inner position is provided on each rail portion 218 for supporting the re-transport unit 110. Is provided.

  As shown in FIG. 5, the first lock member 23 is disposed between the paper feed tray 31 disposed at the storage position and each frame 21, and includes a lock arm 231 and a coil spring 232. .

  The lock arm 231 is formed in a substantially L shape when viewed from above, and the front end 231A thereof is rotatably supported by the rail portion 215 so that the rear end 231B can swing left and right. . In addition, a roller 231C is rotatably provided at the inner end in the left-right direction of the swinging rear end 231B. Thus, friction between the lock arm 231 and the paper feed tray 31 is reduced when the paper feed tray 31 is attached or detached.

  The coil spring 232 is disposed between the frame 21 and the lock arm 231 so as to urge the rear end portion 231B of the lock arm 231 toward the inner side in the left-right direction.

  In addition, positioning concave portions 312 that are in contact with the rollers 231 </ b> C of the first lock member 23 are formed in the left and right side walls on the rear end side of the paper feed tray 31 at the storage position. Specifically, the feed tray 31 is restricted from moving backward by a restriction member (not shown), and the first lock member 23 is configured to press the inclined surface on the rear side of the positioning recess 312. The paper feed tray 31 is pressed against the regulating member and positioned at the storage position. In other words, the first lock member 23 contributes to the positioning of the paper feed tray 31 by urging the paper feed tray 31 and the frame 21 in a direction away from each other.

  As shown in FIG. 6, the second lock member 500 includes a lock arm 231 and a coil spring 232 similar to the first lock member 23 described above. The re-conveying unit 110 has a positioning recess 113 that is substantially the same as the positioning recess 312 described above.

  The re-transport unit 110 is configured such that forward movement is restricted by a restriction member (not shown), and the second lock member 500 is configured to press the front inclined surface of the positioning recess 113. It is pressed against the restricting member and positioned at the inner position. In other words, the second lock member 500 contributes to the positioning of the re-transport unit 110 by urging the re-transport unit 110 and the frame 21 in a direction away from each other.

  As shown in FIG. 2, one second engagement portion 121 that engages with the pair of first engagement portions 111 of the re-transport unit 110 is provided above each second lock member 500. It has been. In addition, in FIG. 2, illustration of the locking members 23 and 500 is abbreviate | omitted for convenience.

  As shown in FIGS. 7A and 7B, the second engaging portion 121 is disposed on the inner side in the left-right direction (inner side in the width direction) with a gap from the inner surface 21A of the frame 21, and the upper end thereof is the first end. It is connected to the inner surface 21 </ b> A via the two connecting portions 122. In other words, the second coupling portion 122 is engaged with the second engagement portion so that the gap between the second engagement portion 121 and the inner surface 21A opens toward the rear (opposite to the mounting direction of the re-transport unit 110). The part 121 and the inner surface 21A are connected.

  On the other hand, the re-transport unit 110 includes a pair of side surfaces 110A disposed on both left and right sides, a first engagement portion 111 disposed on the outer side in the left and right direction with a gap from each side surface 110A, and a first engagement. A first connecting portion 112 that connects the lower end of the joint portion 111 to the side surface 110A is provided. In other words, the first connecting portion 112 has the first engaging portion 111 and the side surface 110A so that the gap between the side surface 110A and the first engaging portion 111 opens forward (in the mounting direction of the re-transport unit 110). Are linked.

  When the re-transport unit 110 is positioned at the inner position, the first engagement portion 111 is engaged with the second engagement portion 121 on the outer side in the left-right direction. Thereby, it is possible to suppress the rear lower portions of the pair of frames 21 from being opened to the left and right by the re-transport unit 110.

  As shown in FIG. 7B and FIG. 1, the first lock member 23 and the second lock member 500, and the first engagement portion 111 and the second engagement portion 121 described above, The moving unit 110 is disposed at the same position in the moving direction). Accordingly, the first engagement portion 111 and the second engagement portion 121 are disposed in the vicinity of the first lock member 23 and the second lock member 500 that urge the pair of frames 21 in the direction to open left and right. Therefore, it is possible to further suppress the left and right opening. In the drawings other than the plan view such as FIG. 1, for convenience, the lock members 23 and 500 are illustrated as simple rectangular blocks.

  In the present embodiment, a part of the first engaging part 111 and a part of the second engaging part 121 (a part of the engaging part of the first engaging part 111 and the second engaging part 121) are both. Although it is configured to be in the same position as a part of the first lock member 23 and a part of the second lock member 500, the present invention is not limited to this. For example, as long as a part of the second lock member 500 is at the same position as a part of one of the first engagement part 111 and the second engagement part 121, it may not be the same position as the other.

  In the present embodiment, the lock member 23, the first engagement portion 111, and the second engagement portion 121 are all arranged on the rear side in the front-rear direction, but the present invention is not limited to this. . For example, the lock member 23 may be disposed on the rear side, and the first engagement portion 111 and the second engagement portion 121 may be disposed on the front side.

  In the present embodiment, the first engagement portion 111 and the second engagement portion 121 are provided one above the lock members 23, but the present invention is not limited to this. A plurality of them may be provided. For example, two in the vertical direction may be provided across the lock member 23 (four in total on the left and right). According to this, opening of a pair of flame | frame 21 can be suppressed more reliably.

According to the above, the following effects can be obtained in the present embodiment.
When the re-transport unit 110 is positioned at the inner position, the first engagement portion 111 is engaged with the second engagement portion 121 on the outer side in the left-right direction, and the pair of frames 21 are prevented from being opened by the re-transport unit 110. Therefore, the opening of the pair of frames 21 can be suppressed without using a dedicated connecting member. In particular, in the structure in which a force is applied to the pair of frames 21 in the direction away from each other by the first lock member 23 and the second lock member 500 as in the present embodiment, the above-described effects are exhibited well.

  The second lock member 500, the first engagement portion 111, and the second engagement portion 121 are disposed at the same position in the front-rear direction, so that the second lock member 500 is separated from the second lock member 500 near the second lock member 500. Since the generated urging force can be received by the first engaging portion 111 or the like, the opening of the pair of frames 21 can be effectively suppressed.

  In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below. In the following description, the same reference numerals are given to members having substantially the same structure as in the above embodiment, and the description thereof is omitted.

  In the embodiment described above, the first connecting portion 112 is provided at the lower end of the first engaging portion 111 and the second connecting portion 122 is provided at the upper end of the second engaging portion 121. However, the present invention is not limited to this. The gap between the side surface of the re-transport unit and the first engagement portion opens toward the mounting direction of the re-transport unit, and the clearance between the inner surface of the frame and the second engagement portion is opposite to the mounting direction. It suffices if it is open toward. Specifically, for example, as shown in FIG. 8, a first connection portion 612 is provided at the rear end of the first engagement portion 611, and a second connection portion 712 is provided at the front end of the second engagement portion 711. Also good.

  In this case, the left and right corners of the front end of the first engaging portion 611 and the left and right corners of the second engaging portion 711 may be chamfered obliquely. According to this, when the re-transport unit 110 is inserted, the first engaging portion 611 can surely enter the left and right outer sides of the second engaging portion 711 to be engaged therewith.

  Further, for example, when the connecting member 214 shown in FIG. 2 is provided in the lower rear portion of the pair of frames 21 and the first lock member 23 and the second lock member 500 are arranged on the front side, the re-transport unit A first engagement portion may be provided on the front side of the pair, and a second engagement portion may be provided on the lower front side of the pair of frames 21.

  In the above-described embodiment, the first lock member 23 and the second lock member 500 are provided on the left and right, respectively, but the present invention is not limited to this, and the lock member is at least one of a sheet cassette (or a re-conveying unit). What is necessary is just to arrange | position between these frames. That is, for example, the sheet cassette may be positioned at the storage position by providing a locking member between the sheet cassette disposed so as to be in contact with the other frame and the one frame.

  In the above-described embodiment, the sheet feeding tray 31 that can be attached to and detached from the apparatus main body 2 is illustrated as a sheet cassette. However, the present invention is not limited to this. For example, the sheet tray 31 is simply provided so as to be movable with respect to the apparatus main body. It may be a sheet cassette that cannot be detached (cannot be detached from the apparatus main body 2 without using a tool such as a screwdriver). Similarly, the re-transport unit may be a unit that can only be moved with respect to the apparatus main body but cannot be removed.

  In the above-described embodiment, paper P such as thick paper, postcard, and thin paper is used as an example of the recording sheet. However, the present invention is not limited to this, and may be, for example, an OHP sheet.

  In the above embodiment, the image forming unit 4 is configured by the scanner unit 5 or the like, but the present invention is not limited to this. For example, an LED head may be used in place of the scanner unit 5, a belt-shaped photosensitive member may be used in place of the photosensitive drum 81, and a slidable support is provided by a guide instead of the heating roller 71. A cylindrical fixing film may be used. Further, instead of the transfer roller TR, another member to which a transfer bias is applied such as a conductive brush or a conductive leaf spring may be used.

  In the above-described embodiment, the pair of frames 21 that hold the image forming unit are arranged on the left and right. However, the present invention is not limited to this. For example, when the re-conveying unit can be pulled out to the left and right, the pair of frames are arranged. You may arrange | position before and after.

  In the above embodiment, the present invention is applied to the laser printer 1. However, the present invention is not limited to this, and the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.

DESCRIPTION OF SYMBOLS 1 Laser printer 4 Image formation part 21 Frame 21A Inner surface 23 1st locking member 31 Paper feed tray 100 Re-transport means 110 Re-transport unit 110A Side surface 111 1st engaging part 112 1st connection part 121 2nd engaging part 122 2nd 2 connecting portion 500 second lock member P paper

Claims (4)

An image forming unit for forming an image on a recording sheet;
A pair of frames facing each other across the image forming unit and holding the image forming unit;
A recording sheet that is provided so as to be movable between an inner position disposed between the pair of frames and an outer position moved outward from the inner position, and in which an image is formed on one surface by the image forming unit. An image forming apparatus comprising: a re-conveying unit that constitutes a part of a re-conveying unit that conveys the recording sheet to the image forming unit again with the front and back sides reversed.
The re-conveying unit includes a pair of side surfaces disposed on both sides in the width direction of the recording sheet, a first engagement portion disposed on the outer side in the width direction with a gap from each side surface, and the gap. A first connecting portion that connects the first engaging portion and the side surface so as to open toward the mounting direction of the re-conveying unit;
The pair of frames have a second engagement portion disposed on the inner side in the width direction with a gap from an inner surface, and the second engagement so that the gap opens toward a side opposite to the mounting direction. A second connecting portion that connects the portion and the inner surface,
The image forming apparatus according to claim 1, wherein when the re-conveying unit is positioned at the inner position, the first engaging portion engages with the outer side in the width direction of the second engaging portion. A sheet cassette that is provided movably between a storage position stored between the pair of frames and a moving position moved outward from the storage position, and that stores a recording sheet to be conveyed to the image forming unit; ,
A first lock member is provided between the sheet cassette and at least one frame to urge the sheet cassette and the one frame away from each other in order to position the sheet cassette at the storage position. The image forming apparatus according to claim 1, wherein:   Between the re-conveying unit and at least one frame, in order to position the re-conveying unit at the inner position, the re-conveying unit and the one frame are urged in directions away from each other. The image forming apparatus according to claim 1, wherein two lock members are provided. The said 2nd lock member is arrange | positioned in the same position as at least one of a said 1st engaging part and a said 2nd engaging part in the moving direction of the said re-conveyance unit. Image forming apparatus.

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