JP2006151667A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device, having an in-drum delivery paper space covered with an upper surface and side surfaces, capable of increasing the number of delivery sheets that can be loaded, and preventing breakage of sheets or occurrence of carrying defective or jamming. <P>SOLUTION: Delivery paper guide members to regulate both end parts of delivered sheets are provided at right and left ends of the space to be roughly parallel to a delivery surface of a sheet delivery part in the in-drum delivery paper space. Paper inserting surfaces of the delivery paper guide members to get in contact with sheet end parts are movable up and down. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile, and more particularly to an image forming apparatus in which a sheet discharge space is provided in an apparatus housing between an image reading unit and an image forming unit. .

  For example, in an image forming apparatus including an image reading unit 1 that reads an image of a document and an image forming unit 2 that forms an image on a sheet, such as an electrophotographic copying machine, a printer, and a facsimile, an image is formed at an upper position of the device. In many cases, the reading unit 1 is arranged (FIG. 6).

  In recent years, so-called multi-function machines that have both printer and copier functions and facsimile functions have been increasing for the purpose of cost reduction and apparatus installation space reduction.

  In this multifunction device, the image reading unit 1 and the image forming unit 2 are arranged separately, and an in-body discharge space 3 for discharging and stacking sheets on which images are formed is formed between them. In general, a paper discharge type image forming apparatus in the apparatus housing in which the paper discharge unit is prevented from projecting to the side surface of the apparatus and the occupation area is reduced.

  However, the configuration having the in-body discharge space 3 as described above has the following problems.

  The image reading unit 1 is disposed immediately above the in-cylinder sheet discharge space 3, and the side surface part around the in-cylinder sheet discharge space 3 is also excluded except for the sheet outlet 4 for taking out stacked sheets. The image reading unit 1 or the image forming unit 2 is often covered like a wall.

  For this reason, the height and width of the in-body discharge space 3 are reduced, and the number of sheets stacked is reduced as compared with the case where the upper surface and the side surface of the in-body discharge space 3 are open.

  The above problem can be easily solved by enlarging the in-cylinder sheet discharge space 3, but a new problem arises that the apparatus main body is enlarged simultaneously with the in-cylinder sheet discharge space 3. When the image reading unit 1 moves upward, the user has to perform an image reading operation at a high position. The work at a high position makes it difficult to set the document on the image reading unit 1, and depending on the height of the user, there is a possibility that the hand cannot be reached when setting the document on the image reading unit 1, resulting in a decrease in usability. There is a fear. Therefore, it is difficult to easily expand the in-body discharge space 3.

  Further, when the sheet is curled by the heat applied by the heating device 58 when the toner image carried on the sheet surface is heated and fixed on the sheet surface, as shown in FIG. There is also a problem that the number of stacked sheets is greatly reduced due to the ceiling surface of the inner discharge space 3.

  Alternatively, as shown in FIG. 8, the leading edge of the sheet is caught by the ceiling surface of the in-body discharge space 3, and the subsequent sheet is rounded into a cylindrical shape, or the sheet falls from the back of the apparatus to the outside of the apparatus. There was also a problem that the number of sheets decreased.

  If the curl of the ejected sheet is large, the newly ejected sheet collides with the curled part of the already stacked sheet, causing the sheet to bend and be damaged, or the sheet to fall out of the device. There is also a possibility of causing a conveyance failure. In this case, the number of stacked sheets is reduced, and there is a problem that the stacked sheets are not neatly aligned.

  In an environment where the curl of the sheet is likely to occur, such as when the fixing temperature rises as the printing speed of the image forming apparatus increases, or when the sheet absorbs moisture and contains a large amount of moisture, the above problem becomes more prominent. Become.

In order to solve the above problem, Japanese Patent Laid-Open No. 2004-137070 proposes a method of providing a paper discharge guide member 10 that regulates both ends of a sheet discharged into the in-body paper discharge space 3 (FIG. 1). It is possible to increase the number of stacked sheets by preventing the discharged sheet from the discharged sheet guide member 10 from curling.
JP 2004-137070 A

  However, when the sheet discharge guide member 10 is introduced, the number of sheets stacked increases. However, when a large number of sheets exceeding the limit are discharged into the in-cylinder discharge space 3, the sheet stacking surface of the in-cylinder discharge space 3 A large amount of paper bundle is sandwiched between the paper passing surfaces 11 of the paper discharge guide member 10, and the uppermost surface of the paper bundle and the paper passing surface 11 are pressed against each other. If a new sheet is discharged further, the resistance when entering between the uppermost surface of the paper bundle and the paper passing surface 11 increases, and the sheet may be broken or damaged, or in the worst case. There is a risk that a conveyance failure (jam) may occur.

  (1) An object of the first invention related to the present application is to solve the above-mentioned problem, and even when a large number of sheets are stacked in the in-cylinder discharge space, the newly discharged sheets are smoothly discharged into the in-cylinder discharge space. The number of sheets that can be stacked is increased.

  (2) The object of the second invention relating to the present application is to adjust the force required to raise the sheet passing surface of the sheet discharge guide member to an appropriate value by attaching a biasing member, and the number of sheets that can be stacked. Is to ensure the effect of increasing.

  (3) An object of the third invention related to the present application is to surely prevent sheet breakage and conveyance failure by temporarily stopping the operation of the apparatus when the amount of paper bundle exceeds a limit value. .

  (4) An object of the fourth invention related to the present application is to improve usability by indicating to the user that the apparatus has once stopped or a means for returning as a message.

(5) The object of the fifth invention related to the present application is to raise the discharge surface 11 when a large amount of sheets are stacked in the in-cylinder discharge space, so that newly discharged sheets can be smoothly discharged into the cylinder. It is possible to enter the paper space and to ensure the effect of increasing the number of sheets that can be stacked.

  (1) An image reading unit that reads an image of a document is provided at the top of the apparatus, and an image forming unit that forms an image on a sheet is provided below the image reading unit with a space therebetween, and the image reading unit and the image reading unit In an image forming apparatus in which a sheet discharge unit is provided in a space in the apparatus housing formed between the image forming unit and the sheet stacking surface of the sheet discharge unit, the both ends of the discharged sheet are regulated from the upper surface. An image forming apparatus characterized in that a sheet discharge guide member to be provided is provided at both left and right ends of a space in the apparatus housing, and a sheet passing surface contacting the sheet end of the sheet discharge guide member is movable in the vertical direction.

  Even when a large number of sheets are stacked in the in-cylinder discharge space, newly discharged sheets can smoothly enter the in-cylinder discharge space, and the number of sheets that can be stacked can be increased.

  (2) The image forming apparatus according to (1), further comprising an urging unit that urges a sheet passing surface of the sheet discharge guide member upward or downward.

  By attaching the urging member, the force required to raise the sheet passing surface of the sheet discharge guide member can be adjusted to an appropriate value, and the effect of increasing the number of sheets that can be stacked can be ensured.

  (3) Provided with a rising detection means for detecting an increase in the sheet passing surface, when detecting that the sheet passing surface has risen above a predetermined amount, the operation of the image forming apparatus is temporarily stopped, and a new sheet is loaded on the sheet discharge unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is not discharged.

  By temporarily stopping the operation of the apparatus when the amount of the paper bundle exceeds the limit value, it is possible to reliably prevent the sheet from being damaged and the conveyance failure.

  (4) When the sheet passing surface rises above a predetermined amount and the operation of the image forming apparatus is stopped, a message is displayed to the user informing the user that the image forming apparatus has stopped and a method for returning the image forming apparatus. The image forming apparatus according to claim 1, wherein:

  Usability can be improved by indicating to the user a message indicating that the apparatus has once stopped or has returned.

  (5) Elevating means for raising and lowering the sheet passing surface is provided, and a loading amount detecting means for detecting the amount of sheets stacked on the sheet discharge unit is provided, and the amount of stacked sheets exceeds a predetermined amount. 5. The image forming apparatus according to claim 1, wherein the sheet passing surface is raised by the elevating unit when the image is detected.

  When a large number of sheets are stacked in the in-cylinder discharge space, the discharge surface 11 is raised, so that newly discharged sheets can enter the in-cylinder discharge space smoothly and increase the number of sheets that can be stacked. The effect to be made can be ensured.

  As described above, according to the present invention, in the image forming apparatus having the in-cylinder discharge space, even when a large number of sheets are stacked in the in-cylinder discharge space, newly discharged sheets are smoothly discharged into the in-cylinder. It becomes possible to enter the paper space, and the number of sheets that can be stacked can be increased.

  Further, by attaching the urging member, the force required to raise the sheet passing surface of the sheet discharge guide member can be adjusted to an appropriate value, and the effect of increasing the number of sheets that can be stacked can be ensured. .

  Further, by temporarily stopping the operation of the apparatus when the amount of the paper bundle exceeds the limit value, it is possible to surely prevent the sheet from being damaged or transported.

  In addition, usability can be improved by indicating to the user that the device has been temporarily stopped or a means for returning.

  In addition, when a large amount of sheets are stacked in the in-cylinder discharge space, the discharge surface 11 is raised so that newly discharged sheets can smoothly enter the in-cylinder discharge space and can be stacked. The number of sheets can be increased.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS.

  However, the dimensions, materials, shapes, and relative positions of the basic components described in the following examples should be changed as appropriate according to the configuration of the apparatus to which the present invention is applied and various conditions. Unless specifically stated, it is not intended to limit the scope of the present invention only to them.

  1 to 3 are schematic configuration diagrams showing the image forming apparatus of the present embodiment. A paper feed cassette 51 is installed below the image forming apparatus, and a paper feed roller 52 is installed in the vicinity thereof. Further, a charging roller 54, a transfer roller 55, and a developing device 56 are provided around a photosensitive drum 53 as an image carrier. A laser exposure device 57 is installed on the upper side, and a heating device 58 is installed on the left side.

  To form an image, first, the photosensitive drum 53 is rotated in the direction of the arrow, and the surface is uniformly charged by the charging roller 54 during this rotation process. Next, laser light 59 is emitted from the laser exposure device 57, and the laser light 59 is reflected by the reflection mirror 60 and irradiated onto the surface of the photosensitive drum 53, and an electrostatic latent image is formed on the surface of the photosensitive drum 53.

  The developing device 56 contains toner therein, and the toner is carried on a rotating developing sleeve 61 and conveyed to a developing region facing the photosensitive drum 53.

  The toner carried on the developing sleeve 61 is charged by the developing sleeve 61 for rotation and the like, and after the toner layer thickness is regulated by a regulating blade (not shown), the toner reaches the developing area. In the developing area, the toner adheres to the electrostatic latent image on the photosensitive drum 53 and develops, and the latent image is visualized as a toner image.

  A sheet is taken out from the sheet feeding cassette 51 by the sheet feeding roller 52, and the sheet is sent to a transfer nip where the photosensitive drum 53 and the transfer roller 55 are in contact with each other at the timing of image formation on the photosensitive drum 53. The toner image on the photosensitive drum 53 is transferred onto the sheet by the action of the transfer roller 55.

  The sheet on which the toner image has been transferred is heated and pressurized by the heating device 58 and the pressure roller 62, and the toner image is fixed on the sheet to become a permanent image.

  A space is provided between the image reading unit 1 and the image forming unit 2, and an in-body discharge space 3 as a sheet discharge unit is formed in this space. The sheet carrying the permanent image by the heating device 58 is discharged from the discharge port 12 into the in-body discharge space 3 and stacked.

  A sheet take-out port 4 is provided in the in-cylinder discharge space 3, and the user can take out a bundle of sheets stacked in the in-cylinder discharge space 3 from the sheet take-out port 4.

  By providing the in-body discharge space 3, it is not necessary to provide a discharge tray disposed so as to protrude from the side surface of the image forming apparatus, and a space-saving image forming apparatus having no protrusion on the side surface of the apparatus can be realized. it can.

  The image reading unit 1 is provided with a contact glass 5 on an upper surface thereof, and a scanner unit (not shown) is provided therein. The scanner unit reads a document placed on the contact glass 5 and processes image information of the document as image data by photoelectric conversion.

  In this embodiment, an ADF 6 (automatic document feeder) can be attached to the image reading unit 1 as an option.

  The ADF 6 is attached to the upper part of the image reading unit 1 so as to be openable and closable, and is installed so as to cover the contact glass 5 on the upper surface of the image reading unit 1 so as to be openable and closable.

  The documents (document bundle) set on the document table 7 provided above the ADF 6 are conveyed one by one from the lowest document to the contact glass 5, and after the document reading by the image reading unit 1 is completed. Then, it is discharged onto the document discharge table 8.

  When reading a document that is not automatically fed, the ADF 6 can be used as a pressure plate.

  When the optional ADF 6 is not mounted, a pressure plate (not shown) for pressing the document on the contact glass 5 is mounted on the upper surface of the image reading unit 1.

  Next, the movement of the image reading unit 1 when the pressure plate is attached instead of the ADF 6 or when the ADF 6 is used as the pressure plate will be described with reference to FIG.

  A document (not shown) is placed on the contact glass 5. After the ADF 6 is closed and the document is held between the contact glass 5 and the ADF 6, the operation unit 9 is operated to specify the number of copies and the like, and the start button is pressed. Then, reading of the original by the scanner unit is started.

  In this embodiment, a discharge guide member 10 that guides both ends of the sheet discharged from the discharge port 12 is installed in the in-body discharge space 3.

  The sheet passing surface 11 of the sheet discharge guide member 10 in contact with both ends of the discharged sheet forms an angle substantially parallel to the sheet stacking surface of the in-cylinder sheet discharge space 3. The distance between the three sheet stacking surfaces is set to be almost constant at any point.

  As shown in FIG. 4, when both ends of the sheet are curled, both ends of the sheet come into contact with the paper discharge guide member 10 installed on the left and right, and the curling is restricted so as not to become larger. Further, even when the leading edge of the sheet is curled as shown in FIG. 8, the curling is suppressed by the discharge guide member 10, so that the leading edge of the sheet can be prevented from hitting the ceiling surface of the in-body discharge space 3. .

  As described above, since the occurrence of curling can be minimized by the paper discharge guide member 10, the number of stacked sheets can be increased.

  In addition, since the sheet discharge guide member 10 regulates the left and right ends of the sheet, the alignment of the stacked sheet bundle can be improved.

  The sheet discharge guide member 10 has a sufficient width so that the curled sheet does not enter the inside of the sheet discharge guide member 10 and the sheet passing surface of the sheet discharge guide member 10 reliably suppresses both ends of the sheet. Things are necessary. However, if the discharge guide member 10 is too wide, the space for the user to take a hand into the sheet take-out port 4 when the user takes out a stack of sheets stacked from the sheet take-out port 4 is reduced and loaded. It becomes difficult to take out the sheet. Considering these, it is necessary to adjust the width of the paper discharge guide member 10 and the interval between the left and right paper discharge guide members 10.

  For example, when the interval between the left and right discharge guide members 10 is 120 to 140 mm, and the width of the discharge guide member 10 is 10 to 60 mm, the A5 size (148 mm × 210 mm) and a sheet wider than the A5 size (A4, B5) (Letter size, etc.), the sheet discharge guide member 10 can regulate both ends of the sheet, and it is possible to handle sheets of various sizes with an appropriate space for the user to put his hand into the sheet outlet 4. can do.

  The paper feed guide member 10 is provided with a rotation shaft and is rotatable about the rotation shaft. When a large amount of sheets are stacked in the in-body discharge space 3 and the curl of the sheet bundle is large, a pressing force F is applied to the sheet passing surface 11 from the sheet bundle (FIG. 2).

  When the pressing force F exceeds a predetermined value due to an increase in the number of stacked sheets or an increase in curl, the sheet feeding guide member 10 rotates to raise the sheet passing surface 11, and the sheet stacking surface of the in-body discharge space 3 The distance between the sheet passing surfaces 11 is increased, and the pressing force F between the sheet bundle and the sheet passing surface 11 is reduced (FIG. 2). Let Fa be the pressing force F when the paper discharge guide member 10 starts to rotate. As the sheet discharge guide member 10 rotates and the sheet passing surface 11 rises, resistance when a sheet newly discharged to the in-body sheet discharge space 3 enters between the sheet bundle and the sheet passing surface 10 is reduced. , It is possible to prevent the sheet from being folded or causing a conveyance failure.

  If Fa is too large, the sheet will be damaged or poorly conveyed before the sheet discharge guide member 10 rotates. Since Fa is determined by the weight and shape of the paper discharge guide member 10, it is necessary to adjust the shape and material of the paper discharge guide member 10 to set Fa to an appropriate value.

  In order to set an appropriate Fa value, the image forming apparatus is operated in a state where the discharge guide member 10 is fixed so as not to rotate, and a large number of sheets are stacked in the in-cylinder discharge space 3 to prevent damage to the sheets. The pressing force F when the conveyance failure occurs is measured. In consideration of safety, a value sufficiently lower than the pressing force F when a sheet breakage or conveyance failure occurs may be set as an appropriate value of Fa.

  If it is difficult to adjust Fa with the shape or material of the paper discharge guide member 10 due to strength or heat resistance, an urging member (not shown) is provided on the paper discharge guide member 10 so that Fa is appropriately adjusted. Value. The direction of urging by the urging member may be either the direction in which the paper passing surface 11 is raised or the direction in which it is lowered.

  As described above, the discharge guide member 10 can be rotated or moved in the vertical direction, so that even when a large number of sheets are stacked in the in-body discharge space 3, newly discharged sheets can be smoothly discharged. It becomes possible to enter the in-body discharge space, and the number of sheets that can be stacked can be increased.

(Second embodiment)
Next, a second embodiment of the present invention will be described.

  In the present embodiment, a rising detection means (not shown) for detecting the rising of the sheet passing surface 11 is provided. When a large amount of sheets are stacked in the in-cylinder discharge space 3, when the rise detecting means detects that the sheet passing surface 11 has risen by a predetermined amount or more, the image forming apparatus temporarily stops its operation, and a new sheet is placed in the cylinder. The paper is not discharged into the paper discharge space 3. Further, a message prompting the removal of the sheet bundle filled in the in-body discharge space 3 is displayed on the terminal used by the user or the operation unit 9 of the image forming apparatus.

  When the sheet detecting unit detects that the sheet bundle is removed from the in-body discharge space 3 and the sheet passing surface 11 is lowered to the initial position, the image forming apparatus returns to a restartable state.

  As described above, in this embodiment, it is detected that the sheet in the in-body discharge space 3 is full, and the operation of the image forming apparatus is temporarily stopped, so that the sheet is folded or a conveyance failure occurs. Can be prevented.

(Third embodiment)
Next, a third embodiment of the present invention will be described.

  In this embodiment, a stack amount detecting means (not shown) for detecting the amount of the sheet bundle stacked in the in-body discharge space 3 is provided, and the discharge guide member 10 is rotated to move the sheet passing surface 11 up and down. Rotating means (not shown) is provided.

  When the stacking amount detecting means detects that the amount of the sheet bundle stacked in the in-body discharge space 3 exceeds a predetermined amount, the sheet passing surface 11 is raised by the rotating means. As a result, the pressing force F applied to the sheet passing surface 11 from the sheet bundle stacked in the in-cylinder sheet discharge space 3 is reduced, and the newly discharged sheet to the in-cylinder sheet discharge space 3 is smoothly fed to the sheet bundle and the sheet passing surface. 11, the number of sheets that can be stacked can be increased.

1 is a perspective view of an image forming apparatus according to a first embodiment. FIG. 6 is an explanatory diagram of the rotation of the paper discharge guide member in the first embodiment. 1 is a side sectional view of an image forming apparatus according to a first embodiment. Explanatory drawing of the effect of the paper discharge guide member in a 1st Example. FIG. 3 is a perspective view of the image forming apparatus (when the ADF is opened). The perspective view of the image forming apparatus in a prior art example. Illustration 1 of sheet curling in the in-body discharge space. Illustration 2 of sheet curling in the in-body discharge space.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image reading part 2 Image formation part 3 In-body discharge space 4 Sheet exit 5 Contact glass 6 ADF
DESCRIPTION OF SYMBOLS 7 Document stand 8 Document discharge stand 9 Operation part 10 Paper discharge guide member 11 Paper passing surface 12 Paper discharge port 51 Paper feed cassette 52 Paper feed roller 53 Photosensitive drum 54 Charging roller 55 Transfer roller 56 Developer 57 Laser exposure device 58 Heating device 59 Laser beam 60 Reflecting mirror 61 Developing sleeve 62 Pressure roller F Pressing force applied to sheet passing surface from sheet bundle P Sheet

Claims (5)

  An image reading unit that reads an image of a document is disposed at the top of the apparatus, and an image forming unit that forms an image on a sheet is disposed below the image reading unit with a space therebetween, and the image reading unit and the image forming unit In the image forming apparatus in which the sheet discharge unit is provided in the space in the apparatus casing formed between the sheet discharge unit and the sheet discharge unit that is substantially parallel to the sheet stacking surface of the sheet discharge unit and regulates both ends of the discharged sheet from the upper surface. An image forming apparatus, characterized in that guide members are provided at both left and right ends of a space in the apparatus housing, and a sheet passing surface that comes into contact with an end portion of the sheet of the sheet discharge guide member is movable in the vertical direction.   The image forming apparatus according to claim 1, further comprising an urging unit that urges a sheet passing surface of the sheet discharge guide member upward or downward.   A rise detecting means for detecting the rise of the sheet passing surface is provided. When it is detected that the sheet passing surface has risen above a predetermined amount, the operation of the image forming apparatus is temporarily stopped and a new sheet is not discharged to the sheet discharging unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   When the sheet passing surface rises above a predetermined amount and the operation of the image forming apparatus is stopped, a message is displayed to the user informing the user that the image forming apparatus has stopped and a method for returning the image forming apparatus. The image forming apparatus according to claim 1.   When it is detected that the amount of stacked sheets exceeds a predetermined amount, the sheet passing surface is provided with a raising / lowering means for raising and lowering, and has a stacking amount detecting means for detecting the amount of sheets stacked on the sheet discharge unit. The image forming apparatus according to claim 1, wherein the sheet passing surface is raised by the elevating unit.

Images