JP2009282062A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming device can prevent an opening and closing member from turning and being broken, when a plurality of process cartridges are not mounted in a device body. <P>SOLUTION: This image forming device is provided with a plurality of process cartridges 2 which are mountable and dismountable on/from the device body, and the opening and closing member 9a which is turnable between an opening position and a closing position for the device body, and turns the opening and closing member 9a to the opening position to mount and dismount the process cartridge 2. This image forming device includes a turn-restraining member 19 for restraining turn of the opening and closing member 9a by matching with a matching part 22 of the opening and closing member 9a; a turn-restraining member moving means for moving the turn-restraining member 19, between a position where the turn restraining member 19 and the matching part 22 match and a position where they do not match; and a detecting means for detecting whether all the process cartridges 2 are mounted in the device body. If even one of the process cartridges 2 is not mounted in the device body, the turn-restraining member moving means moves the turn-restraining member 19, to a position where they match. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a printer, a facsimile machine, and a copying machine.

  In this type of image forming apparatus, when the opening / closing cover that can be opened and closed with respect to the apparatus main body is opened and the member that is removable with respect to the apparatus main body is replaced, the removable member is not mounted in the apparatus main body. A configuration in which the opening / closing cover cannot be closed is known. With such a configuration, it is possible to make the user aware that the detachable member is not mounted in the apparatus main body.

  In the image forming apparatus described in Patent Document 1, an opening / closing cover that is rotatable between an open position and a closed position with respect to the apparatus main body is rotated from the closed position to the open position, and is provided in the apparatus main body. The toner box containing the waste toner is detached and replaced. In addition, a restricting member that restricts the rotation of the opening / closing cover by closing the middle of the rotation path between the open position and the closed position of the opening / closing cover is attached to the apparatus body so as to be rotatable. ing. When the toner box is mounted in the apparatus main body, the regulating member is pushed by the toner box and retracts to a position where the middle of the rotation path is not blocked. When the toner box is removed from the apparatus main body, the toner box is not pressed from the toner box, so that the toner box is rotated from a position where the toner box is not blocked to a position where the middle of the rotation path is blocked. Thus, in a state where the toner box is not mounted in the apparatus main body, even if the opening / closing cover rotated to the open position when the toner box is replaced is rotated toward the closed position, the rotation path The opening / closing cover and the restricting member come into contact with each other during the movement of the opening / closing cover, and the rotation of the opening / closing cover is restricted. That is, the opening / closing cover cannot be rotated further from the position in contact with the regulating member toward the closed position, and the opening / closing cover cannot be closed with respect to the apparatus main body.

Japanese Patent No. 3244994

  In addition to the toner box described in Patent Document 1, the image forming means such as a charging device and a developing device for forming an image on the photosensitive member can be used together with the photosensitive member as a member detachable from the apparatus main body. There is a process cartridge that is housed in a housing and configured to be detachable from the apparatus main body. By applying the configuration for restricting the rotation of the opening / closing cover described in Patent Document 1 to such a process cartridge, the opening / closing cover is attached to the apparatus main body in a state where the process cartridge is not mounted in the apparatus main body. It is thought that it can be prevented from closing.

  However, when the configuration for restricting the rotation of the open / close cover described in Patent Document 1 is applied to a color image forming apparatus having a plurality of process cartridges for forming images of different colors, the above-described process is performed corresponding to each of the process cartridges for each color. A plurality of regulating members are provided. For this reason, each restricting member is rotated in conjunction with the attaching and detaching operations of the process cartridges of the respective colors, and a position where the middle of the rotation path is blocked and a position where the blocking is not blocked can be taken. However, the opening / closing cover rotated to the open position can be rotated to a position where it comes into contact with the regulating member in the middle of the rotation path even when the process cartridge is removed from the apparatus main body. Therefore, if all of the process cartridges are not attached to the main body of the apparatus and the cover is accidentally closed, the open / close cover and the restricting member may collide violently, resulting in damage to the open / close cover or restricting member. Arise.

  The present invention has been made in view of the above problems, and an object thereof is to rotate an opening / closing member with respect to an apparatus main body when at least one of a plurality of process cartridges is not installed in the apparatus main body. It is an object to provide an image forming apparatus that can prevent the opening / closing member from being damaged.

In order to achieve the above-mentioned object, the invention of claim 1 is characterized in that an image forming means such as a charging means and a developing means for forming an image on a latent image carrier is accommodated in a casing together with the latent image carrier. A plurality of process cartridges detachably attached to the apparatus main body, and an opening / closing member that can rotate between an open position and a closed position with respect to the apparatus main body about a rotation shaft provided on the apparatus main body. In the image forming apparatus in which the plurality of process cartridges can be attached / detached by rotating the opening / closing member from the closed position to the open position, the engagement portion provided in the opening / closing member in the vicinity of the rotation shaft The rotation restricting member that restricts the rotation of the opening / closing member and the rotation restricting member is moved between a position where the rotation restricting member and the fitting portion are engaged with each other and a position where the opening / closing member is not engaged with the apparatus main body. A rotation restricting member moving means for moving the plurality of programs in the apparatus main body. Detecting means for detecting whether or not all of the cartridges are mounted, and the rotation restricting member moving means is based on a detection result of the detecting means and at least of the plurality of process cartridges in the apparatus main body. In the case where even one is not mounted, the rotation restricting member is moved to the fitting position.
According to a second aspect of the present invention, in the image forming apparatus according to the first aspect of the present invention, the image forming apparatus further includes a rotation member urging unit that urges the rotation regulating member toward the fitting position, and the detection unit is flexible. One end having a property is a first string-like member connected to the apparatus main body, and is provided at a position where the process cartridge is pressed against the process cartridge when the process cartridge is mounted on the apparatus main body. The moving means is a second string-like member, one end of which is connected to the end of the first string-like member that is not connected to the apparatus main body, and the other end is connected to the rotation restricting member. The second string-like member is pulled by the first string-like member in accordance with the bending of the first string-like member when all of the process cartridges are in pressure contact with the first string-like member. The rotation restricting portion against the urging force of the rotation restricting member urging means There are those characterized by being configured to move toward a position not the fit from a position above fitted.
According to a third aspect of the present invention, in the image forming apparatus of the second aspect, the first string-like member and the second string-like member are integrally formed.
According to a fourth aspect of the present invention, in the image forming apparatus according to the first aspect, the detection means is an optical sensor provided corresponding to each of the plurality of process cartridges.
According to a fifth aspect of the present invention, in the image forming apparatus of the first, second, third, or fourth aspect, when the opening / closing member is at least in the closed position, the biasing means for biasing the process cartridge is opened / closed. It is provided in the member.
According to a sixth aspect of the present invention, in the image forming apparatus according to the second or third aspect, the image forming apparatus further includes a biasing unit that biases the process cartridge when the openable / closable member is at least in the closed position. The biasing force of the biasing means is larger than the biasing force of the rotation restricting member biasing means.
According to a seventh aspect of the present invention, in the image forming apparatus of the second, third, or sixth aspect, the central axis of the latent image carrier protrudes outside the casing, and the process cartridge is mounted in the main body of the apparatus. In this case, the central axis is configured to come into contact with the first string-like member.
According to an eighth aspect of the present invention, in the image forming apparatus according to the second, third, sixth or seventh aspect, the length of the first string-shaped member is adjusted by winding the first string-shaped member. It has an adjustment means.
According to a ninth aspect of the present invention, in the image forming apparatus of the first, second, third, fourth, fifth, sixth, seventh, or eighth aspect, the fitting portion has a concave shape, and the rotation restricting member is the fitting portion. It has a convex shape that fits into the concave shape of the part, and the rotation of the opening and closing member is restricted by fitting the concave shape of the fitting part and the convex shape of the rotation restricting member It is characterized by that.
According to an eleventh aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, or tenth aspect, the rotation restricting member has a groove shape provided in the apparatus main body. The rotation restricting member is movable in a linear direction along the groove shape.
According to a twelfth aspect of the present invention, in the image forming apparatus according to the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth, tenth, or eleventh aspects, the latent image is written on the latent image carrier. Writing means to perform, and the opening / closing member holds the writing means.

  In the present invention, when the detecting means detects that one of the plurality of process cartridges is not mounted in the apparatus main body, the turning restricting member is moved by the turning restricting member moving means to the fitting portion of the opening / closing member. Move to the position where it fits. Thereby, the fitting part of the opening / closing member and the rotation restricting member are engaged to restrict the turning of the opening / closing member. Therefore, when no process cartridge is mounted in the apparatus main body, the opening / closing member rotated to the open position with respect to the apparatus main body can be rotated to the closed position when the process cartridge is replaced. Disappear. Therefore, the opening / closing member and the regulating member are configured to restrict the turning of the opening / closing member by bringing the opening / closing member that rotates from the open position toward the closed position into contact with the regulating member in the middle of the rotation path. The open / close member and the regulating member are not damaged due to a violent collision.

  As described above, according to the present invention, when any one of the plurality of process cartridges is not mounted in the apparatus main body, the opening / closing member is restricted from rotating with respect to the apparatus main body, and the opening / closing member is prevented from being damaged. There is an excellent effect of being able to.

[Embodiment 1]
Hereinafter, a first embodiment of an electrophotographic printer (hereinafter simply referred to as a printer) will be described as an image forming apparatus to which the present invention is applied.
First, the basic configuration of the printer will be described. FIG. 2 is a schematic configuration diagram showing the printer. In this figure, the printer includes four process cartridges 2Y, M, C, and K for forming yellow, magenta, cyan, and black (hereinafter referred to as Y, M, C, and K) toner images. Yes. These use Y, M, C, and K toners of different colors as the image forming material, but the other configurations are the same and are replaced when the lifetime is reached. Taking a process cartridge 2K for forming a K toner image as an example, as shown in FIG. 3, a drum-shaped photosensitive member 1K as a latent image carrier, a drum cleaning device 3K, a charge eliminating device (not shown), and a charging device 4K. And a developing device 5K. The process cartridge 2K, which is an image forming unit, is detachable from the printer main body, so that consumable parts can be replaced at a time.

  The charging device 4K uniformly charges the surface of the photoreceptor 1K that is rotated clockwise in the drawing by a driving unit (not shown). The uniformly charged surface of the photosensitive member 1K is exposed and scanned by the laser beam L to carry an electrostatic latent image for K. The electrostatic latent image for K is developed into a Y toner image by a developing device 5K using K toner (not shown). Then, intermediate transfer is performed on an intermediate transfer belt 66 described later. The drum cleaning device 3K removes transfer residual toner attached to the surface of the photoreceptor 1K after the intermediate transfer process. The static eliminator neutralizes residual charges on the photoreceptor 1K after cleaning. By this charge removal, the surface of the photoreceptor 1K is initialized and prepared for the next image formation. Similarly, in the process cartridges (2Y, M, C) of other colors, (Y, M, C) toner images are formed on the photoreceptors (1Y, M, C) in the same manner, and the intermediate transfer belt 66 described later is formed. Intermediate transfer.

  The developing device 5K includes a vertically long hopper 6K that stores K toner (not shown) and a developing unit 7K. In the hopper 6K, an agitator 68K that is rotationally driven by a driving means (not shown), a stirring paddle 61K that is rotationally driven by a driving means (not shown) below the vertical direction, and a rotational drive that is driven by a driving means (not shown) in the vertical direction. A toner supply roller 68K and the like are disposed. The K toner in the hopper 6K moves toward the toner supply roller 68K by its own weight while being stirred by the rotational drive of the agitator 61K and the stirring paddle 62K. The toner supply roller 68K has a metal cored bar and a roller portion made of foamed resin or the like coated on the surface of the metal core, and the K toner in the hopper portion 6K is adhered to the surface of the roller portion. Rotate.

  In the developing unit 7K of the developing device 5K, a developing roller 67K that rotates while contacting the photoreceptor 1K and the toner supply roller 68K, and a thinning blade 64K that contacts the tip of the developing roller 67K are disposed. Yes. The K toner attached to the toner supply roller 68K in the hopper 6K is supplied to the surface of the development roller 67K at the contact portion between the development roller 67K and the toner supply roller 68K. When the supplied K toner passes through the contact position between the roller and the thinning blade 64K as the developing roller 67K rotates, the layer thickness on the roller surface is regulated. Then, the K toner whose layer thickness has been regulated adheres to the electrostatic latent image for K on the surface of the photosensitive member 1K in the developing region which is the contact portion between the developing roller 67K and the photosensitive member 1K. By this adhesion, the electrostatic latent image for K is developed into a K toner image.

  Although the process cartridge 2 for K has been described with reference to FIG. 3, the process cartridges 2Y, M, and C for Y, M, and C are also subjected to Y, M on the surfaces of the photoreceptors 1Y, M, and C by a similar process. , C toner images are formed.

  In FIG. 2 shown above, a writing device 70 is disposed above the process cartridges 2Y, 2M, 2C, and 2K in the vertical direction. The writing device 70 serving as a latent image writing device optically scans the photosensitive members 1Y, M, C, and K in the process cartridges 2Y, 2M, 2C, and 2K with a laser beam L emitted from a laser diode based on image information. . By this optical scanning, electrostatic latent images for Y, M, C, and K are formed on the photoreceptors 1Y, 1M, 1C, and 1K. Note that the writing device 70 is configured so that the laser light (L) emitted from the light source is polarized in the main scanning direction by a polygon mirror that is rotationally driven by a polygon motor (not shown), and the photosensitive member 1 is passed through a plurality of optical lenses and mirrors. Is irradiated. You may employ | adopt what performs optical writing by the LED light emitted from several LED of the LED array.

  Below the process cartridges 2Y, 2M, 2C, and 2K, there is disposed a transfer unit 65 that moves the endless intermediate transfer belt 66 endlessly in the counterclockwise direction while stretching. In addition to the intermediate transfer belt 66, the transfer unit 65, which is a transfer means, includes a driving roller 63, a driven roller 69, four primary transfer rollers 83Y, 83M, 83C, 83K, a secondary transfer roller 80, a belt cleaning device 81, a cleaning device. A backup roller 82 and the like are provided.

  The intermediate transfer belt 66 is stretched by a driving roller 63, a driven roller 69, a cleaning backup roller 82, and four primary transfer rollers 83Y, 83M, 83C, and 83K disposed inside the loop. Then, it is moved endlessly in the same direction by the rotational force of the driving roller 63 that is driven to rotate in the counterclockwise direction in the figure by a driving means (not shown).

  The four primary transfer rollers 83Y, 83M, 83C, and 83K sandwich the intermediate transfer belt 66 that is moved endlessly in this manner between the photoreceptors 1Y, 1M, 1C, and 1K. By this sandwiching, a primary transfer nip for Y, M, C, and K where the front surface of the intermediate transfer belt 66 and the photoreceptors 1Y, 1M, 1C, and 1K abut is formed.

  A primary transfer bias is applied to the primary transfer rollers 83Y, 83M, 83C, and 83K by a transfer bias power source (not shown), whereby electrostatic latent images on the photoreceptors 1Y, 1M, 1C, and 1K, A transfer electric field is formed between the primary transfer rollers 83Y, 83M, 83C, and 83K. In place of the primary transfer rollers 83Y, 83M, 83C, 83K, a transfer charger or a transfer brush may be employed.

  When the Y toner formed on the surface of the photoreceptor 1Y of the process cartridge 2Y for Y enters the above-described primary transfer nip for Y as the photoreceptor 1Y rotates, the photosensitive toner is exposed to the effect of the transfer electric field and nip pressure. Primary transfer is performed on the intermediate transfer belt 66 from the body 1Y. The intermediate transfer belt 66 on which the Y toner image has been primarily transferred in this way passes through the primary transfer nips for M, C, and K along with the endless movement thereof, and the photoreceptors 1M, C, and K. The upper M, C, and K toner images are sequentially superimposed on the Y toner image and primarily transferred. A four-color toner image is formed on the intermediate transfer belt 66 by this superimposing primary transfer.

  The secondary transfer roller 80 of the transfer unit 65 is disposed outside the loop of the intermediate transfer belt 66 and sandwiches the intermediate transfer belt 66 between the driven roller 69 inside the loop. By this sandwiching, a secondary transfer nip where the front surface of the intermediate transfer belt 66 and the secondary transfer roller 80 abut is formed. A secondary transfer bias is applied to the secondary transfer roller 80 by a transfer bias power source (not shown). By this application, a secondary transfer electric field is formed between the secondary transfer roller 80 and the driven roller connected to the ground.

  Below the transfer unit 65 in the vertical direction, a paper feed cassette 84 that stores a plurality of recording papers P in a bundle of sheets is slidably attached to the printer housing. In the paper feed cassette 84, a paper feed roller 85 is brought into contact with the top recording paper P of the paper bundle, and the recording paper is rotated by rotating it in a counterclockwise direction in the drawing at a predetermined timing. P is sent out toward the paper feed path 86.

  A registration roller pair 87 is disposed near the end of the paper feed path 86. The registration roller pair 87 stops the rotation of both rollers as soon as the recording paper P delivered from the paper feed cassette 84 is sandwiched between the rollers. Then, rotation driving is resumed at a timing at which the sandwiched recording paper P can be synchronized with the four-color toner image on the intermediate transfer belt 66 in the above-described secondary transfer nip, and the recording paper P is directed to the secondary transfer nip. Send it out.

  The four-color toner image on the intermediate transfer belt 66 brought into close contact with the recording paper P at the secondary transfer nip is secondarily transferred onto the recording paper P under the influence of the secondary transfer electric field and nip pressure. Combined with the white color of P, a full color toner image is obtained. When the recording paper P having the full-color toner image formed on the surface in this manner passes through the secondary transfer nip, the recording paper P is separated from the secondary transfer roller 80 and the intermediate transfer belt 66 by the curvature. Then, the toner is fed into a fixing device 34 to be described later via a post-transfer conveyance path 88.

  Untransferred toner that has not been transferred to the recording paper P adheres to the intermediate transfer belt 66 after passing through the secondary transfer nip. This is cleaned from the belt surface by a belt cleaning device 81 in contact with the front surface of the intermediate transfer belt 66. A cleaning backup roller 82 disposed inside the loop of the intermediate transfer belt 66 backs up the cleaning of the belt by the belt cleaning device 81 from the inside of the loop.

  The fixing device 34 forms a fixing nip by a fixing roller 34a containing a heat source such as a halogen lamp (not shown) and a pressure roller 34b that rotates while contacting the fixing roller 34a with a predetermined pressure. The recording paper P fed into the fixing device 34 is sandwiched between the fixing nips such that the unfixed toner image carrying surface is brought into close contact with the fixing roller 34a. Then, the toner in the toner image is softened by the influence of heating and pressurization, and the full color image is fixed.

  The recording paper P discharged from the fixing device 34 passes through the post-fixing conveyance path 89 and then reaches the branch point between the paper discharge path 90 and the pre-reversal conveyance path 41. On the side of the post-fixing conveyance path 89, a switching claw 42 that is rotationally driven around a rotation shaft 42a is disposed. By the rotation, the vicinity of the end of the post-fixing conveyance path 89 is closed. Or open it. At the timing when the recording paper P is sent out from the fixing device 34, the switching claw 42 stops at the rotational position indicated by the solid line in the drawing, and the vicinity of the end of the post-fixing conveyance path 89 is opened. Therefore, the recording paper P enters the paper discharge path 90 from the post-fixing conveyance path 89 and is sandwiched between the rollers of the paper discharge roller pair 91.

  When the single-sided print mode is set by an input operation to an operation unit including a numeric keypad (not shown) or a control signal sent from a personal computer (not shown), the recording sandwiched between the paper discharge roller pair 91 is performed. The paper P is discharged out of the machine as it is. Then, it is stacked on the stack portion that is the upper surface of the upper cover 50 of the housing.

  On the other hand, when the duplex printing mode is set, the trailing edge of the recording paper P conveyed through the paper discharge path 90 while the front end is sandwiched between the paper discharge roller pair 91 passes through the post-fixing conveyance path 89. The switching claw 42 is rotated to the position of the one-dot chain line in the drawing, and the vicinity of the end of the post-fixing conveyance path 89 is closed. Almost at the same time, the paper discharge roller pair 91 starts reverse rotation. Then, the recording paper P is conveyed while the rear end side is directed to the top, and enters the pre-reversal conveyance path 41.

  FIG. 2 shows the printer from the front side. The front side in the direction perpendicular to the drawing is the front side of the printer, and the back side is the rear side. In the drawing, the right side of the printer is the right side and the left side is the left side. The right end portion of the printer is a reversing unit 40 that can be opened and closed with respect to the housing body by rotating about a rotating shaft 40a. When the paper discharge roller pair 91 rotates in the reverse direction, the recording paper P enters the pre-reversal conveyance path 41 of the reversing unit 40 and is conveyed from the upper side to the lower side in the vertical direction. Then, after passing between the rollers of the pair of reverse conveying rollers 43, it enters the reverse conveying path 44 that is curved in a semicircular shape. Furthermore, while the upper and lower surfaces are reversed as the sheet is conveyed along the curved shape, the traveling direction from the upper side in the vertical direction to the lower side is also reversed, and conveyed from the lower side in the vertical direction toward the upper side. Is done. Thereafter, the toner enters the secondary transfer nip again through the above-described paper feed path 86. Then, after the full-color image is secondarily transferred collectively to the other surface, the post-transfer conveyance path 88, the fixing device 34, the post-fixation conveyance path 89, the paper discharge path 90, and the paper discharge roller pair 91 are sequentially passed. And discharged outside the machine.

  The reversing unit 40 described above has an external cover 45 and a rocking body 46. Specifically, the external cover 45 of the reversing unit 40 is supported so as to rotate about a rotation shaft 40a provided in the housing of the printer main body. By this rotation, the outer cover 45 opens and closes with respect to the housing together with the swinging body 46 held therein. As shown by the dotted line in the figure, when the outer cover 45 is opened together with the swinging body 46 therein, the paper feed path 86 formed between the reversing unit 40 and the printer body side, the secondary transfer nip, and after the transfer. The conveyance path 88, the fixing nip, the post-fixing conveyance path 89, and the paper discharge path 90 are vertically divided into two and exposed to the outside. Thus, jammed paper in the paper feed path 86, the secondary transfer nip, the post-transfer conveyance path 88, the fixing nip, the post-fixation conveyance path 89, and the paper discharge path 90 can be easily removed.

  The swing body 46 is supported by the external cover 45 so as to rotate about a swing shaft (not shown) provided in the external cover 45 in a state where the external cover 45 is opened. When the swinging body 46 is opened with respect to the external cover 45 by this rotation, the pre-reversal transport path 41 and the reverse transport path 44 are vertically divided into two and exposed to the outside. As a result, the jammed paper in the pre-reversal conveyance path 41 and the reversal conveyance path 44 can be easily removed.

  The upper cover 50 of the printer casing is supported so as to be rotatable about the shaft member 51 as shown by the arrow in the figure, and is opened with respect to the casing by rotating counterclockwise in the figure. It becomes a state. And the upper opening of a housing is exposed greatly.

  By the way, in recent image forming apparatuses, it is desired that the internal components and apparatuses can be attached and detached without impairing the downsizing, weight reduction, and operability of the image forming apparatus. As a method of attaching and detaching parts and apparatuses, as shown in FIG. 4, a method is performed in which the front cover provided at the front end (the end in the direction of arrow F in the figure) of the housing of the image forming apparatus is opened, FIG. As shown in FIG. 2, a method of opening the left cover provided at the left end of the housing can be considered. Moreover, as shown in FIG. 6, the method of opening and opening the upper cover provided in the upper side edge part of the housing is also considered. For parts and devices that are relatively frequently attached and detached, it is desirable to employ a method in which the upper cover is opened as shown in FIG. By checking the attachment / detachment operation while looking at the inside of the housing from the upper side without taking an unreasonable posture such as squatting, bending the waist, or bending down, the work load is reduced and the occurrence of operation mistakes is suppressed. Because it can. One of the reasons is that the upper part of the image forming apparatus is often used as a paper discharge tray or mounted with a scanner and is likely to be in a position with excellent visibility.

  In the printer according to the present embodiment, the four process cartridges 2Y, 2M, 2C, and 2K shown in FIG. This is because they are replaced when the toner in the developing device runs out. When considering a configuration in which these process cartridges 2Y, 2M, 2C, and 2K are attached / detached by the upper cover opening method as shown in FIG. 6, the most important layout conditions for each of the process cartridges 2Y, 2M, 2C, and 2K are Are arranged side by side. If they are arranged side by side rather than side by side, for example, in order to replace the third unit from the top, it is necessary to attach and detach not only that unit but also the first and second units from the top that do not require replacement. This is because the operability is remarkably deteriorated.

  For this reason, when the side-by-side layout is adopted for the four process cartridges 2Y, 2M, 2C, and 2K, the intermediate transfer belt 66 is in contact with the side-by-side photoconductors 1Y, 1M, 1C, and 1K. As shown in FIG. 2, it is necessary to stretch in a horizontally long posture. Then, the four process cartridges 2Y, 2M, 2C, and 2K that are arranged side by side are arranged vertically above the intermediate transfer belt 66 in the horizontally long position as shown in FIG. 2, or reverse to the layout of FIG. In addition, it is disposed below the intermediate transfer belt 66. Here, in the case of being arranged below the intermediate transfer belt 66, the writing device 70 is in a horizontally long posture so that optical scanning with respect to the four photosensitive members 1Y, 1M, 1C, and 1K is possible, and each process cartridge. It is necessary to dispose below 2. Contrary to the layout shown in FIG. 2, the writing device 70, each process cartridge (2 </ b> Y to K), and the intermediate transfer belt 66 are sequentially stacked from the lower side to the upper side in the vertical direction. However, in the configuration in which the recording paper P is conveyed from the lower side to the upper side in the vertical direction, the fixing device 34 needs to be provided above the intermediate transfer belt 66 that forms the secondary transfer nip. If it is adopted, the left side of the fixing device 34 in the figure becomes a blank space. For this reason, it is difficult to reduce the size and space of the apparatus.

  Therefore, as shown in FIG. 2, the printer according to the present embodiment employs a layout in which the four process cartridges 2Y, 2M, 2C, and 2K are arranged side by side and disposed above the intermediate transfer belt 66 in the landscape orientation. is doing. In this layout, as shown in the drawing, the horizontally oriented optical writing device is disposed above the four process cartridges 2Y, 2M, 2C, and 2K. Then, the four process cartridges 2Y, 2M, 2C, and 2K and the writing device 70 can be arranged on the side of the fixing device 34 as shown in the figure to avoid the generation of a blank space.

  On the other hand, regardless of whether the process cartridges 2 arranged side by side are disposed above or below the horizontally-oriented intermediate transfer belt 66, the writing device 70 is set in advance before the attachment / detachment operation for each process cartridge 2 is performed. It is necessary to save from the position facing the process cartridge 2. For example, when each process cartridge 2 is arranged above the intermediate transfer belt 66 as in this printer, the writing device 70 is placed above each process cartridge (2Y to K) as shown in FIG. It will be arranged. In such a layout, even if the upper cover 50 is opened with respect to the housing body, the writing device 70 is in the way, and the process cartridges 2 immediately below it cannot be exposed. For this reason, it is necessary to retract the writing device 70 from directly above each process cartridge 2 before performing the attaching / detaching operation to each process cartridge 2.

  In the printer, as described above, each process cartridge 2 is disposed above the intermediate transfer belt 66 and the writing device 70 is disposed thereon from the viewpoint of miniaturization and space saving. Therefore, it is necessary to retract the writing device 70 from directly above each process cartridge 2. In the method of opening the upper cover 50 as in the present printer, the writing device 70 is retracted so that one end side of the writing device 70 is rotatably supported by a frame or the like in the housing. It may be configured such that it is pivoted like an open / close door, retracted from directly above each process cartridge 2, or set directly above. Further, the writing device 70 is held on the lower surface side of the upper cover 50 that can be opened and closed, and the writing device 70 is retracted from directly above each process cartridge 2 as the upper cover 50 is opened and closed, or set directly above. It may be configured to do.

  However, in any configuration, the writing device 70 and the photoreceptors 1Y, 1M, 1C, and 1K in the housing are caused by the backlash of the writing device 70 that can be slidably moved or turned and the backlash of the upper cover 50. An error occurs in the relative position. And this error will reduce the writing position accuracy of the writing device 70. A decrease in writing position accuracy causes image blurring, image omission, vignetting, and the like. Further, in the configuration in which a plurality of process cartridges 2 are arranged as in the present printer, color misregistration is caused.

  FIG. 7 shows the state of the writing device 70, the process cartridge 2, the main body frames 8a and 8b, and the upper frames 9a and 9b at the writing operation position when performing operations such as image formation. The support portion 10a of the writing device 70 passes through the holding hole 11a of the upper frame 9a, and is held in engagement with a holding groove 12a that is a positioning portion provided in the main body frame 8a.

  Here, the support portion 10a and the holding hole 11a pass through with a predetermined gap. For example, as shown in FIG. 8, the support portion 10a is urged by the compression spring 127 and contacts the holding groove 12a of the main body frame 8a. It touches. Therefore, the writing device 70 can be accurately positioned with respect to the main body frame 8a without being affected by the position accuracy of the upper frame 9a, and the deterioration of the writing position accuracy of the writing device 70 is suppressed. can do.

  Further, in the present embodiment, the state as shown in FIG. 7 is “the writing device 70 is in the closed position”.

  FIG. 9 shows a state in which the writing device 70 is rotated with respect to the main body frames 8a and 8b and the writing device 70 is moved to the open position which is the retracted position. The fulcrum shaft 13 is supported at both ends by the main body frames 8a and 8b, and rotatably supports the upper frames 9a and 9b. Although not shown, the support portion 10a is in contact with the holding hole 11a by a compression spring 127. As a result, the writing device 70 and the upper frame 9a can be rotated together while suppressing the writing device 70 from rattling intensely. At the time of maintenance, the process cartridge 2 can be easily taken out from the apparatus main body by setting the state shown in FIG.

  In the present embodiment, the state as shown in FIG. 9 is defined as “the writing device 70 is completely in the open position”.

  As shown in FIG. 10, the fulcrum shaft 13 is provided with a torsion spring 14a so as to urge the upper frame 9a in the opening direction. By providing the torsion spring 14a on the fulcrum shaft 13 in this manner, the user releases the lock between the main body frame 8 and the upper frame 9a with a lock lever (not shown) while the writing device 70 is in the closed position. Even if the upper frame 9a is not held, the writing device 70 is completely rotated to the open position by the urging force of the torsion spring 14a.

  FIG. 11 shows an external view of the process cartridge 2. The process cartridge 2 has the photosensitive member 1 as described above, and the central shaft 15 of the photosensitive member 1 penetrates the side surface of the process cartridge 2 and protrudes to the outside as shown in FIG. Further, the process cartridge 2 is provided with a guide shape 16 a and a positioning shape 17 a that protrude in the same direction as the central axis 15 of the photoreceptor 1.

[Example 1]
Next, in the present embodiment, a configuration in which the writing device 70 in the open position can be moved to the closed position only when all the process cartridges 2 are mounted in the apparatus main body will be described.

  FIG. 1 shows a main body frame 8a, an upper frame 9a, a fulcrum shaft 13, and a string as seen from the inside of the apparatus main body when the writing apparatus 70 is completely moved to the open position and all process cartridges 2 are taken out from the apparatus main body. The states of the member 18, the moving member 19, the string member winding member 20, the tension spring 21, the fitting member 22, and the pulley 23 are shown. Note that the writing device 70 supported by the upper frame 9a is not shown for easy viewing of the drawing.

  The string member 18 has an end 18 a fixed to the main body frame 8 a via a string member winding member 20, and an end 18 b connected to the end 21 a of the tension spring 21. An end 21b of the tension spring 21 is fixed to the main body frame 8a, and urges the string member 18 in the direction of arrow Ca in FIG.

  The string member 18 is not limited to a string-like member such as a wire, but includes a member that deforms almost without expansion or contraction when an external force is applied, such as a belt-like member.

  Further, a movable member 19 that is movable with respect to the main body frame 8a is fixedly attached to the string member 18, and when the string member 18 is displaced, the movable member 19 has a groove shape 25 provided in the main body frame 8a. 6 can move only in the direction of arrow Da and arrow Db in FIG.

  In the state of FIG. 1, the moving member 19 is urged in the direction of arrow Da in FIG. 1 through the string member 18 by the urging force of the tension spring 21, and the moving member 19 moves in the direction of arrow Da in the figure through the string member 18. The concave shape 24 of the fitting member 22 fixedly attached to the upper frame 9a and the convex shape of the moving member 19 are fitted together. Since the moving member 19 and the fitting member 22 are engaged in this manner, the rotation of the upper frame 9a is restricted. Therefore, when the process cartridge 2 is not mounted in the apparatus main body, the upper frame 9a is rotated. Thus, the writing device 70 cannot be moved to the closed position.

  FIG. 12 shows the main body frame 8a, the upper frame 9a, the fulcrum shaft 13, the string member 18, the moving member 19, and the string member winding member as seen from the inside of the apparatus main body when all the process cartridges 2 are mounted in the apparatus main body. 20, the state of the tension spring 21, the fitting member 22, and the pulley 23 is shown. In FIG. 12, the outer shape of the process cartridge 2 is indicated by a broken line for the sake of explanation.

  The main body frame 8a has a process cartridge guide groove 26. In the process of mounting the process cartridge 2 in the apparatus main body, the central shaft 15 of the photosensitive member 1 protruding from the side surface of the process cartridge 2, the guide shape 16a, and The process cartridge 2 is inserted in the direction of arrow E in FIG. 12 along the positioning shape 17a along the process cartridge guide groove 26 provided in the main body frame 8a. At this time, the central shaft 15 of the photosensitive member 1 contacts the string member 18 before hitting the lower end of the process cartridge guide groove 26. Then, when the process cartridge 2 is further inserted in the direction of arrow E in FIG. 12, the central shaft 15 of the photosensitive member 1 is pressed against the string member 18 and bent against the lower end of the process cartridge guide groove 26 while being bent. The

  Thus, when all the process cartridges 2 are mounted in the apparatus main body, the string member 18 is pulled in the direction of arrow B in FIG. Then, the tension spring 21 extends in the direction of arrow G in FIG. 12, and the moving member 19 moves in the direction of arrow Db in FIG. 12 along the groove shape 25 of the main body frame 8a via the string member 18. By moving the moving member 19 in this manner, the fitting between the convex shape of the moving member 19 and the concave shape 24 of the fitting member 22 is released.

  As described above, when the engagement between the moving member 19 and the engagement member 22 is released, the upper frame 9a can be rotated, and the user presses the upper frame 9a and the writing device 70 as shown in FIG. The writing device 70 can be moved to the closed position.

  Further, as shown in FIG. 13, the upper frame 9a has a plurality of compression springs 27 corresponding to the respective process cartridges 2. When the writing device 70 is in the closed position, the process cartridges are moved by the compression springs 27. 2 is pressed in the direction of arrow H in FIG.

  Thereby, when the process cartridge is mounted, the central shaft 15 of the photosensitive member 1 does not hit the lower end of the process cartridge guide groove 26 because the string member 18 is not sufficiently bent by the urging force of the tension spring 21, so that the process cartridge 2 can be moved. Even if the writing device 70 is slightly lifted, when the writing device 70 is moved to the closed position, the process cartridge 2 is moved downward by the urging force of the compression spring 27, and the central shaft 15 of the photosensitive member 1 abuts against the lower end of the process cartridge guide groove 26. And is positioned at the correct position. Therefore, it is desirable to fix the moving member 19 at a position where the moving member 19 is fitted with the fitting member 22 only when only one process cartridge 2 is not mounted in the apparatus main body.

  In this way, in this embodiment, it is possible to prevent displacement of the process cartridge 2 due to the urging force of the tension spring 21.

  Further, since the urging force of the compression spring 27 is larger than the urging force of the tension spring 21, the process cartridge 2 is moved downward more reliably by the urging force of the compression spring 27, and the central shaft 15 of the photosensitive member 1 is moved to the process cartridge. Since it can abut against the lower end of the guide groove 26, it is possible to further prevent displacement.

  As described above, by preventing the positional displacement of the process cartridge 2, it is possible to suppress image defects such as color displacement that may be caused by the positional displacement of the process cartridge 2 during image formation.

  Further, since the compression spring 27 is provided, even when the user closes the upper frame 9 vigorously, the compression spring 27 acts as a cushioning material, and damage to the writing device 70 due to impact can be avoided.

  Here, when the process cartridge 2 is not mounted in the apparatus main body, the buffering effect by the compression spring 27 is lost. Therefore, if the upper frame 9a is closed rapidly, the writing device 70 may be damaged. It is necessary to provide. However, in this embodiment, since the upper frame 9a can be rotated and the writing device 70 can be moved to the closed position only when all the process cartridges 2 are mounted in the apparatus main body, the buffer member is not necessary. Therefore, the cost can be reduced.

  In this embodiment, as shown in FIG. 14, a string member take-up member 20 for winding the string member 18 around the main body frame 8a is provided. The string member winding member 20 is provided with a cylindrical hole 28, and the string member 18 is wound around the string member winding member 20 as shown in FIG. 14 through the end portion 18 a side of the string member 18 in the hole 28. I'm wearing it. The string member take-up member 20 can be rotated by the user from the outside in the circumferential direction of the string member take-up member 20. For example, when the string member 18 is stretched over time, the user can The length of the string member 18 can be finely adjusted by rotating the take-up member 20 in the direction of arrow I in FIG.

[Modification]
In this modification, the string member 18 described above is formed by connecting a string member 118 and a string member 218 as shown in FIG.

  The string member 118 has an end portion 118a fixed to the main body frame 8a via the string member winding member 20, and an end portion 118b connected to a connecting member 123 that can rotate with respect to the apparatus main body. The string member 218 has an end 218 a connected to the connecting member 123 and an end 218 b connected to the end 21 a of the tension spring 21. The end 21b of the tension spring 21 is fixed to the main body frame 8a, and urges the end 218b side of the string member 218 in the direction of arrow Ca in FIG.

  In the present modification, when the process cartridge 2 is mounted in the apparatus main body as shown in FIG. 16, the central shaft 15 of the photoreceptor 1 contacts the string member 118 before hitting the lower end of the process cartridge guide groove 26. When the process cartridge 2 is further inserted in the direction of arrow E in FIG. 16, the central shaft 15 of the photoreceptor 1 is pressed against the string member 118 and bent against the lower end of the process cartridge guide groove 26 while being deflected. The

  In this modification, when all the process cartridges 2 are mounted in the apparatus main body, the amount of bending of the string member 118 in pressure contact with the process cartridge 2 increases, and the linear distance between both ends of the string member 118 is greater than before the process cartridge is mounted. Will also be shorter. Accordingly, the connecting member rotates clockwise in FIG. 123 and the string member 218 is pulled downward in FIG. 16, so that the tension spring 21 extends in the arrow G direction in FIG. 16, and the moving member 19 moves the string member 218. And moves in the direction of arrow Db in FIG. 16 along the groove shape 25 of the main body frame 8a. Then, when the moving member 19 moves in the direction of the arrow Db in FIG. 16, the fitting between the convex shape of the moving member 19 and the concave shape 24 of the fitting member 22 is released.

  As described above, when the engagement between the moving member 19 and the engagement member 22 is released, the upper frame 9a can be rotated, and the user presses the upper frame 9a and the writing device 70 as shown in FIG. The writing device 70 can be moved to the closed position.

  In this modification, the string member 118 is wound around the string member take-up member 20 through the end 118a side of the string member 118 in the cylindrical hole 28 of the string member take-up member 20 rotatably attached to the main body frame 8a. ing. Then, the user can adjust the length of the string member 118 by rotating the string member winding member 20.

[Example 2]
In this embodiment, the basic configuration is the same as that of the first embodiment. However, as shown in FIG. 18, the rotation operation of the upper frame 9 between the closed position and the open position where the writing device 70 is movable is restricted. Different regulation mechanisms.

  In this embodiment, a notch shape 29 is provided in the fitting member 22 that rotates integrally with the upper frame 9 a around the fulcrum shaft 13.

  Further, the main body frame 8a is provided with a rotating member 30 that can rotate about the rotating shaft 31, and in the state shown in FIG. 18, the rotating member 30 is indicated by an arrow in FIG. 18 by a compression spring 32 provided in the apparatus main body. It is biased in the L direction. The state shown in FIG. 18 is a state in which at least one process cartridge 2 is not mounted in the apparatus main body. In this state, the rotating member 30 and the notch shape 29 are fitted together, and the upper frame is interposed via the fitting member 22. 9 is restricted from rotating in the direction of arrow J in FIG. 18 (direction in which the writing device 70 is closed).

  On the other hand, when all the process cartridges 2 are mounted in the apparatus main body, the string member 18 is pulled downward in FIG. 18 as in the first embodiment, and the rotating member 30 rotates in the direction of arrow S in FIG. The engagement between the notch shape 29 of the fitting member 22 and the rotating member 30 is released. By releasing the engagement between the fitting member 22 and the rotating member 30 as described above, the upper frame 9 can be rotated in the direction of arrow J in FIG. 18 (direction in which the writing device 70 is closed).

[Embodiment 2]
Next, a second embodiment in which the present invention is applied to a printer as an image forming apparatus as in the first embodiment (hereinafter, this embodiment is referred to as “second embodiment”) will be described. Note that the basic configuration of the printer according to the second embodiment is the same as that of the first embodiment, and a description thereof will be omitted.

[Example 3]
In this embodiment, as shown in FIG. 19, a plurality of optical sensors 53 are provided corresponding to each process cartridge 2, and whether or not all the process cartridges 2 are mounted in the apparatus main body is determined by the optical sensor 53. To detect.

  In this embodiment, the optical sensor 53 composed of a light emitting element and a light receiving element is arranged so that the light emitting element and the light receiving element face each other with the process cartridge 2 in between in a state where the process cartridge 2 is mounted in the apparatus main body. It is arranged. When the light emitted from the light emitting element is shielded by the process cartridge 2 and cannot be received by the light receiving element, it is detected that the process cartridge 2 is mounted in the apparatus main body. Further, when the process cartridge 2 is removed from the inside of the apparatus main body and the light emitted from the light emitting element is not shielded by the process cartridge 2 and can be received by the light receiving element, it is detected that the process cartridge 2 is not installed in the apparatus main body. To do. By performing such detection for each color process cartridge 2, it is possible to detect whether or not all of the plurality of process cartridges 2 are mounted in the apparatus main body.

  The optical sensor 53 is not limited to the configuration described above, and any configuration that can detect whether or not the process cartridge 2 is mounted in the apparatus main body using the optical sensor 53 may be used. For example, when the process cartridge 2 is provided with a reflection part for reflecting light, light emitted from the light emitting element is reflected by the reflection part, and the reflected light is received by the light receiving element provided on the same side as the light emitting element, the inside of the apparatus main body It is also possible to detect that the process cartridge 2 is mounted, and when the reflected light cannot be received by the light receiving element, it is detected that the process cartridge 2 is not mounted in the apparatus main body.

  Further, a driving device (not shown) for moving the movable member 19 that is movable with respect to the main body frame 8a is provided, and the moving member 19 is moved along the groove shape 25 provided in the main body frame 8a by the driving device in FIG. It can move only in the direction of arrow Ma and arrow Mb.

  When the optical sensor 53 detects that any one of the plurality of process cartridges 2 is not mounted in the apparatus main body, the driving member moves the moving member 19 in the direction of the arrow Ma and is fixed to the upper frame 9a. The concave shape 24 of the fitting member 22 attached to the convex portion and the convex shape of the moving member 19 are fitted together. Thus, when the moving member 19 and the fitting member 22 are engaged with each other, the rotation of the upper frame 9a is restricted, and when any one of the plurality of process cartridges 2 is not mounted in the apparatus main body, the upper frame 9a is moved. The writing device 70 cannot be moved to the closed position by rotating.

  In this way, if even one of the plurality of process cartridges 2 is not mounted in the apparatus main body, the writing device 70 in the open position cannot be moved to the closed position by rotating the upper frame 9. Thus, it is possible to make the user aware that there is a process cartridge 2 that has been forgotten to be mounted in the apparatus main body, and it is possible to prevent image formation from being performed without the process cartridge 2 being mounted in the apparatus main body.

  Further, since the upper frame 9 cannot be rotated unless all of the plurality of process cartridges 2 are mounted in the apparatus main body, the upper frame 9a is rotated when the writing device 70 is moved from the open position to the closed position. Thus, the upper frame 9a rotated toward the closed position is brought into contact with a regulating member that regulates the rotation of the upper frame 9a so that the upper frame 9a does not further rotate toward the closed position. As in the configuration in which the rotation is restricted, the upper frame 9a and the writing device 70 are not damaged by the user closing the upper frame 9a vigorously.

  On the other hand, when all the process cartridges 2 are mounted in the apparatus main body based on the detection result by the optical sensor 53, the moving member 19 is moved along the groove shape 25 of the main body frame 8a by the driving device in the direction of arrow Mb in FIG. When the movement is performed, the fitting between the convex shape of the moving member 19 and the concave shape 24 of the fitting member 22 is released. Thus, the upper frame 9a can be rotated by releasing the engagement between the moving member 19 and the engagement member 22, and the user presses the upper frame 9a or the writing device 70 as shown in FIG. The writing device 70 can be moved to the closed position.

  Further, in this embodiment, as shown in FIG. 21, a plurality of compression springs 27 corresponding to each process cartridge 2 are provided on the upper frame 9a, and are pressed by the compression springs 27 in the direction of arrow N in FIG. . As a result, it is possible to prevent displacement of the process cartridge 2 mounted in the apparatus main body.

  That is, when the writing device 70 is moved to the closed position, the process cartridge 2 is pressed downward by the urging force of the compression spring 27 and the central shaft 15 of the photosensitive member 1 is reliably abutted against the lower end of the process cartridge guide groove 26. Positioned in the correct position.

  As described above, by positioning the process cartridge 2, it is possible to prevent the positional deviation of the process cartridge 2, and it is possible to suppress image defects such as a color deviation that may be caused by the positional deviation of the process cartridge 2 during image formation. .

  Furthermore, by providing the compression spring 27, even when the user vigorously closes the upper frame 9a, the compression spring 27 acts as a buffer material, and damage to the writing device 70 due to impact can be avoided.

  Here, in the absence of the process cartridge 2, the buffering effect by the compression spring 27 is lost. Therefore, if the upper frame 9 a is closed rapidly, the writing device 70 may be damaged, and it is necessary to provide a buffer member separately. However, in this embodiment, since the upper frame 9a can be rotated and the writing device 70 can be moved to the closed position only when all the process cartridges 2 are mounted in the apparatus main body, the buffer member is not necessary. Therefore, the cost can be reduced.

[Example 4]
In this embodiment, the basic configuration is the same as that of the third embodiment. However, as shown in FIG. 22, the rotation operation of the upper frame 9a between the closed position where the writing device 70 is movable and the open position is restricted. Different regulation mechanisms.

  In this embodiment, a notch shape 29 is provided in the fitting member 22 that rotates integrally with the upper frame 9 a around the fulcrum shaft 13.

  In addition, a rotating member 30 that can be rotated by a driving device (not shown) around the rotating shaft 31 is attached to the main body frame 8a. The state shown in FIG. 22 is a state in which at least one process cartridge 2 is not mounted in the apparatus main body. In this state, the rotating member 30 and the notch shape 29 of the fitting member 22 are fitted together, and the fitting member 22 is moved. Accordingly, the rotation of the upper frame 9a in the direction of arrow T in FIG. 22 (direction in which the writing device 70 is closed) is restricted.

  On the other hand, when all the process cartridges 2 are mounted in the apparatus main body, the rotating member 30 is rotated in the direction of the arrow Q in FIG. 22 by the driving device, and the notch shape 29 of the fitting member 22 and the rotating member 30 are rotated. The agreement is released. By releasing the engagement between the fitting member 22 and the rotating member 30 in this manner, the upper frame 9a can be rotated through the fitting member 22 in the direction of arrow T (direction in which the writing device 70 is closed) in FIG. Become.

  In the printer according to the second embodiment, power can be supplied from the main power source to the optical sensor 53 or the driving device if the main power source (not shown) of the apparatus main body can supply power to the optical sensor 53 or the driving device. You should do it. If the main power source is turned off and power cannot be supplied from the main power source to the optical sensor 53 or the driving device, the optical sensor 53 or What is necessary is just to supply electric power to the said drive apparatus.

As described above, according to each embodiment, an apparatus in which an image forming unit such as a charging unit and a developing unit for forming an image on the photosensitive member 1 that is a latent image carrier is housed in the casing together with the photosensitive member 1. A plurality of process cartridges 2 detachably attached to the main body, and an upper frame that is an opening / closing member that can rotate between an open position and a closed position with respect to the apparatus main body about a rotation shaft provided in the apparatus main body 9a, and a fitting portion provided on the upper frame 9a in a printer which is an image forming apparatus in which the plurality of process cartridges 2 can be attached and detached by rotating the upper frame 9a from the closed position to the open position. Between the moving member 19 that is a rotation restricting member that engages with the fitting member 22 and restricts the rotation of the upper frame 9a, and a position at which the moving member 19 and the fitting member 22 are engaged with a position of the apparatus body. In moving part A rotation restricting member moving means for moving 19 and a detecting means for detecting whether or not all of the plurality of process cartridges 2 are mounted in the apparatus main body, wherein the rotation restricting member moving means is the detecting means. Based on the detection result, the moving member 19 is moved to the fitting position when at least one of the plurality of process cartridges 2 is not mounted in the apparatus main body. That is, when the detection means that one of the plurality of process cartridges is not mounted in the apparatus main body is detected, the moving member 19 is engaged with the fitting member 22 of the upper frame 9a by the rotation restricting member moving means. Move to the position to be. As a result, the fitting member 22 of the upper frame 9a and the moving member 19 are fitted together to restrict the rotation of the upper frame 9a. Therefore, when no process cartridge 2 is mounted in the apparatus main body, the upper frame 9a rotated to the open position with respect to the apparatus main body when the process cartridge 2 is replaced is rotated to the closed position. Cannot be moved. Therefore, the opening / closing member and the regulating member are configured to restrict the turning of the opening / closing member by bringing the turning member that rotates from the open position toward the closed position into contact with the restriction member in the middle of the rotation path. Does not collide violently and damage the opening / closing member or the regulating member. Therefore, when even one of the plurality of process cartridges is not mounted in the apparatus main body, the upper frame 9a can be restricted from rotating with respect to the apparatus main body, and the upper frame 9a can be prevented from being damaged.
In addition, according to the first embodiment, the tension member 21 is a rotating member urging unit that urges the moving member 19 toward the fitting position, and the detecting unit has a flexible one end. A string member 118, which is a first string member connected to the main body, is provided at a position where the process cartridge 2 is pressed against the process cartridge 2 when the process cartridge 2 is mounted on the apparatus main body. The means is a cord member 218 which is a second cord-like member, one end is connected to an end portion 118b which is not connected to the main body of the cord member 118, and the other end portion 218b is connected to the moving member 119. The string member 218 is pulled by the string member 118 according to the bending of the string member 118 when all of the plurality of process cartridges 2 and the string member 118 are pressed against each other, whereby the tension spring 21 is biased. With this configuration, the moving member 19 moves from the mating position toward the non-fitting position, so that all the process cartridges 2 are mounted on the apparatus main body with a simple configuration as described above. The upper frame 9 can be moved to the closed position only when
Moreover, according to Embodiment 1, since the said 1st string-like member and the said 2nd string-like member were integrally formed as the string member 18, it can be set as a simpler structure.
Further, according to the second embodiment, the detection means is the optical sensor 53 provided corresponding to each of the plurality of process cartridges 2, and as described above, all the process cartridges 2 are apparatus with a simple configuration. The upper frame 9a can be moved to the closed position only when attached to the main body.
Further, according to each embodiment, when the upper frame 9a is at least in the closed position, the upper frame 9a is provided with the compression spring 27, which is a biasing means for biasing the process cartridge 2, so that an image is being formed. It is possible to prevent the process cartridge 2 from deviating from the normal position, and to suppress image defects such as color misregistration that may be caused by the process cartridge 2 deviating from the normal position.
Further, according to the first embodiment, the upper frame 9 is provided with the compression spring 27 which is an urging means for urging the process cartridge 2 when the upper frame 9a is at least in the closed position. Since the urging force is larger than the urging force of the tension spring 21, as described above, it is possible to prevent the process cartridge 2 during image formation from being shifted from the normal position.
Further, according to the first embodiment, the central shaft 15 of the photosensitive member 1 protrudes outside the housing, and when the process cartridge 2 is mounted in the apparatus main body, the central shaft 15 is connected to the first string-like member. By being configured to contact, the central axis 15 of the photosensitive member 1 is also used as a positioning member for the process cartridge 2, so that it is not necessary to add a positioning member or shape to the process cartridge 2 or the like. As a result, it is possible to avoid an increase in cost due to the addition of a positioning-specific member or shape to the process cartridge 2 or the like.
Further, according to the first embodiment, by having the string member winding member 20 that is a length adjusting unit that winds the string member 18 or the string member 118 and adjusts the length of the string member 18 or the string member 118, Since the length of the string member 18 or the string member 118 can be adjusted when the string member 18 or the string member 118 extends over time, the rotation of the upper frame 9a can be appropriately controlled over time.
Further, according to each embodiment, the fitting member 22 has a concave shape 24, the moving member 19 has a convex shape that fits into the concave shape 24 of the fitting member 22, and the concave shape 24 of the fitting member 22 Since the rotation of the upper frame 9a is restricted by fitting the convex shape of the moving member 19, the rotation of the upper frame 9a is restricted by fitting the simple concave shape and the convex shape. Because of the configuration, the cost can be reduced.
Moreover, according to each embodiment, it has the torsion spring 14a which is an opening-and-closing member urging means which urges | biases the upper frame 9a with respect to an apparatus main body, and the upper frame 9a is completely with respect to an apparatus main body. The upper frame 9a is configured so that the fitting member 22 and the moving member 19 are fitted together when they are opened to each other and when any one of the plurality of process cartridges 2 is not mounted in the apparatus main body. The upper frame 9a can be restricted from pivoting in a state where is completely in the open position.
Further, according to each embodiment, the moving member 19 is disposed in the groove shape 25 provided in the apparatus main body, and the moving member 19 is movable in a linear direction along the groove shape 25. Since the shape for guiding the movement of the member 19 is a simple shape, the cost can be reduced.
Moreover, according to each embodiment, it has the writing apparatus 70 which is a writing means which writes a latent image on the photoreceptor 1, and the upper frame 9 hold | maintains the writing apparatus 70, Since the writing device 70 opens and closes with respect to the apparatus main body, the process cartridge 2 can be easily detached and the operability is improved.

FIG. 3 is a schematic configuration diagram as viewed from the inside of the apparatus main body when the process cartridge of the printer according to the first embodiment is not mounted. FIG. 2 is a schematic cross-sectional configuration diagram of the printer according to the first embodiment. FIG. 3 is a schematic cross-sectional configuration diagram of a process cartridge. The perspective view which shows an example of the image forming apparatus which performs an internal maintenance by the front cover opening / closing system. The perspective view which shows an example of the image forming apparatus which performs an internal maintenance by the left cover opening / closing system. The perspective view which shows an example of the image forming apparatus which performs an internal maintenance by an upper cover opening / closing system. FIG. 3 is a perspective view of the printer when the writing device is in a writing operation position. The schematic block diagram which shows the attachment position of the spring which urges | biases a support part. FIG. 3 is a perspective view of the printer when the writing device is in an open position. The enlarged view of the fulcrum shaft vicinity to which the torsion spring was attached. FIG. FIG. 2 is a schematic configuration diagram viewed from the inside of the apparatus main body in a state where a process cartridge is mounted in the apparatus main body of the printer according to the first embodiment. FIG. 3 is a schematic configuration diagram viewed from the inside of the apparatus main body when the writing apparatus of the printer according to the first embodiment is in a closed position. The enlarged view of the string member winding member vicinity. FIG. 10 is a schematic configuration diagram viewed from the inside of the apparatus main body when a process cartridge of a printer according to a modification is not mounted. FIG. 10 is a schematic configuration diagram viewed from the inside of the apparatus main body in a state where a process cartridge is mounted in the apparatus main body of a printer according to a modification. The schematic block diagram seen from the apparatus main body when the writing apparatus of the printer which concerns on a modification is in a closed position. FIG. 9 is an enlarged view of the vicinity of a fulcrum shaft of a printer according to a second embodiment. FIG. 10 is a schematic configuration diagram viewed from the inside of the apparatus main body when a process cartridge of the printer according to the third embodiment is not mounted. FIG. 10 is a schematic configuration diagram viewed from the inside of the apparatus main body in a state where a process cartridge is mounted in the apparatus main body of the printer according to the third embodiment. FIG. 10 is a schematic configuration diagram viewed from the inside of the apparatus main body when the writing apparatus of the printer according to the third embodiment is in a closed position. FIG. 9 is an enlarged view of the vicinity of a fulcrum shaft of a printer according to a fourth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Process cartridge 8a, 8b Main body frame 9a, 9b Upper frame 10a Support part 11a Holding hole 12a Holding groove 13 Supporting shaft 14a Torsion spring 15 Center axis 16a Guide shape 17a Positioning shape 18 String member 19 Moving member 20 Strap member winding Take-up member 21 Tension spring 22 Fitting member 23 Pulley 24 Concave shape 25 Groove shape 26 Process cartridge guide groove 27 Compression spring 28 Hole 29 Shape 30 Rotating member 31 Rotating shaft 32 Compression spring 50 Upper cover 53 Optical sensor 69 Driven roller 70 Writing device 118 String member 218 String member

Claims (12)

A plurality of process cartridges detachably attached to an apparatus main body, wherein image forming means such as charging means and developing means for forming an image on the latent image carrier are housed in the housing together with the latent image carrier; ,
An opening / closing member capable of rotating between an open position and a closed position with respect to the apparatus main body about a rotation axis provided in the apparatus main body,
In the image forming apparatus in which the plurality of process cartridges can be attached and detached by rotating the opening and closing member from the closed position to the open position.
A rotation restricting member that engages with a fitting portion provided on the opening and closing member near the rotation shaft and restricts the rotation of the opening and closing member;
A rotation restricting member moving means for moving the turn restricting member between a position where the turn restricting member and the fitting portion are engaged with each other and a position where the device is not engaged with the apparatus main body;
Detecting means for detecting whether or not all of the plurality of process cartridges are mounted in the apparatus main body,
Based on the detection result of the detection means, the rotation restricting member moving means is located at a position for fitting the rotation restricting member when at least one of the plurality of process cartridges is not mounted in the apparatus main body. An image forming apparatus that is moved. The image forming apparatus according to claim 1.
A rotation member urging means for urging the rotation regulating member toward the fitting position;
The detecting means is a first string member whose one end having flexibility is connected to the apparatus main body, and is provided at a position where the process cartridge comes into pressure contact with the process cartridge when the process cartridge is mounted on the apparatus main body. ,
The rotation restricting member moving means is a second string-like member, one end of which is connected to the end of the first string-like member that is not connected to the apparatus main body, and the other end is connected to the turn restricting member. And
The second string-like member is pulled by the first string-like member in response to the bending of the first string-like member when all of the plurality of process cartridges are in pressure contact with the first string-like member. Thus, the image forming apparatus is configured such that the rotation regulating member moves from the fitting position toward the non-fitting position against the urging force of the rotation regulating member urging means. . The image forming apparatus according to claim 2.
An image forming apparatus, wherein the first string-like member and the second string-like member are integrally formed. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the detecting means is an optical sensor provided corresponding to each of the plurality of process cartridges. The image forming apparatus according to claim 1, 2, 3, or 4.
An image forming apparatus, wherein the opening / closing member is provided with an urging means for urging the process cartridge when the opening / closing member is at least in the closed position. The image forming apparatus according to claim 2 or 3,
A biasing means provided on the opening and closing member for biasing the process cartridge when the opening and closing member is at least in the closed position;
An image forming apparatus, wherein an urging force of the urging unit is larger than an urging force of the rotation restricting member urging unit. The image forming apparatus according to claim 2, 3 or 6.
The center axis of the latent image carrier protrudes outside the housing;
An image forming apparatus, wherein the central axis is in contact with the first string-like member when the process cartridge is mounted in the apparatus main body. The image forming apparatus according to claim 2, 3, 6, or 7.
An image forming apparatus comprising length adjusting means for winding the first string-like member and adjusting the length of the first string-like member. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6, 7 or 8.
The fitting portion has a concave shape,
The rotation restricting member has a convex shape that fits into the concave shape of the fitting portion,
An image forming apparatus configured to restrict rotation of the opening / closing member by fitting a concave shape of the fitting portion and a convex shape of the rotation restricting member. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9.
Having an opening / closing member urging means for urging the opening / closing member in an opening direction with respect to the apparatus main body;
When the opening / closing member is completely opened with respect to the apparatus main body and when any one of the plurality of process cartridges is not mounted in the apparatus main body, the fitting portion and the rotation restricting member are An image forming apparatus configured to fit together. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
The image forming apparatus according to claim 1, wherein the rotation restricting member is disposed in a groove shape provided in the apparatus main body, and the rotation restricting member is movable in a linear direction along the groove shape. The image forming apparatus according to claim 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11.
Having a writing means for writing the latent image on the latent image carrier;
An image forming apparatus, wherein the opening / closing member holds the writing means.

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