JP4324879B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a laser printer.

  2. Description of the Related Art Conventionally, so-called tandem type image forming apparatuses are known in which image carriers corresponding to yellow, magenta, cyan, and black toners are arranged in parallel in the horizontal direction. In this tandem type color laser printer, each color toner image is formed almost simultaneously on each photosensitive drum, and each color toner image is sequentially superimposed and transferred from each photosensitive drum to a sheet that sequentially passes through each photosensitive drum. Therefore, a color image can be formed at almost the same speed as a monochrome laser printer.

As such a tandem type image forming apparatus, a frame for integrally supporting the image carriers of the respective colors is provided, and the frame is slidably attached to and detached from the apparatus main body, and is formed on each image carrier. There has been proposed one in which a developing cartridge for developing an electrostatic latent image is detachably attached to a frame (see, for example, Patent Document 1).
JP 2003-15378 A

  In such an image forming apparatus, the developing cartridges for each color must be mounted at the correct position with respect to the frame, and the developing cartridges for each color must be arranged in the correct order. If each color developer cartridge is mounted in the frame in the wrong order, and the frame is mounted in the main body of the apparatus, an error has occurred in the correspondence between the developer cartridge and the image carrier. The formed electrostatic latent image is developed with toner of a color other than the corresponding color, and there is a problem that a normal color image is not formed.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an image forming apparatus capable of preventing the unit frame from being accommodated in the main body casing when there is an error in the mounting position of the cartridge with respect to the unit frame.

To achieve the above object, an invention according to claim 1, in images forming device, is slid displaced and state of being pulled out and the main body casing, a state of being accommodated in the main body casing from the main casing A unit frame and a developer container that is provided for each color and contains a developer container, and is detachably attached to the unit frame, and protrudes outward from the cartridge in each cartridge. Based on the position of the identification unit in a process in which the unit frame is accommodated in the main body casing, and an identification unit that is provided in a state and arranged at different positions in a direction orthogonal to the sliding direction of the unit frame for each color. Incorrect mounting detection for detecting erroneous mounting of the cartridge to the unit frame And a stage, the erroneous mounting detection means, said in the main body casing, the unit frame is arranged on a path passing each the identification unit when it is accommodated in the main body casing, the slide of the unit frame It includes a switch that is aligned in a direction orthogonal to the direction and that detects the passage of each identification unit.

  According to such a configuration, the switch for detecting the passage of each identification unit is arranged on a path through which each identification unit passes when the unit frame is accommodated in the main body casing, and the sliding direction of the unit frame They are aligned in the orthogonal direction. Therefore, when the unit frame is accommodated in the main body casing, the order in which the switches detect the passage of the identification unit corresponds to the arrangement order of the cartridges in the unit frame. Accordingly, the arrangement order of the cartridges in the unit frame can be detected based on the order in which each switch detects the passage of the identification unit, and detection of erroneous mounting of the cartridge to the unit frame can be achieved.

The invention according to claim 2, in images forming apparatus, the main body casing and said a unit frame which is slid displaced kept housed in the main body casing and a state of being pulled out from the main body casing, each color Each of which is provided with a developer accommodating portion for accommodating a developer, is detachably mounted on the unit frame, and is provided in a state of projecting outward from the cartridge in each cartridge. An identification unit disposed at a different position in a direction orthogonal to the sliding direction of the unit frame, and in a process in which the unit frame is accommodated in the main body casing, based on the position of the identification unit, and a erroneous installation detecting means for detecting the erroneous mounting of the cartridge, the erroneous The attachment detection means is provided in the main body casing, and the cartridges are mounted at regular positions with respect to the unit frame, and the identification portions abut on each other in a state where the unit frame is accommodated in the main body casing. Each switch is disposed at a position, and includes a switch for detecting each of the identification units.

  According to such a configuration, when the cartridges are mounted in the unit frame in the correct arrangement order, when the unit frame is accommodated in the main body casing, the identification unit contacts all the switches, and all the switches are An identification part is detected. On the other hand, when the cartridges are mounted on the unit frame in the wrong order, the identification unit provided on the cartridge mounted at the wrong position does not contact the switch, and the switch does not detect the identification unit. Therefore, based on the detection result of each switch, it can be determined whether or not the cartridges are mounted on the unit frame in the correct arrangement order, thereby achieving detection of erroneous cartridge mounting on the unit frame. it can.

The invention according to claim 3, in images forming apparatus, the main body casing and said a unit frame which is slid displaced kept housed in the main body casing and a state of being pulled out from the main body casing, each color Each of which is provided with a developer accommodating portion for accommodating a developer and is detachably attached to the unit frame, and an identification portion which is provided in each cartridge and is disposed at a different position for each color. And an erroneous mounting detection means for detecting erroneous mounting of the cartridge with respect to the unit frame based on the position of the identification unit in the process in which the unit frame is housed in the main body casing , Each of the cartridges includes an identification groove, and each of the identification grooves is formed in the unit frame. The cartridges are aligned on a circular arc in a state where the cartridges are mounted at regular positions, and the erroneous mounting detection means is disposed at the center of the circular arc and rotates around the unit frame. The free end portion is provided so as to be swingable about the rotation shaft, and each cartridge is mounted at a normal position with respect to the unit frame, and the unit frame is accommodated in the main body casing. Includes a swinging member that is fitted in each of the identification grooves and is movable on the arc.

  According to such a configuration, when the cartridges are mounted on the unit frame in the correct arrangement order, the grooves formed in the cartridge are aligned on the arc, and the free end of the swing member moves on the arc. It becomes possible. On the other hand, if the cartridges are mounted in the unit frame in the wrong order, the grooves formed in the cartridges are not aligned on the arc, so that the free end portion of the swing member is moved (swing of the swing member). Is blocked. Thereby, it is possible to detect the erroneous mounting of the cartridge to the unit frame.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect , the unit frame is formed on the unit frame, and each cartridge is mounted at a normal position with respect to the unit frame. Including a guide groove for guiding the movement of the free end portion of the swinging member when mounted on the main body casing.
According to such a configuration, when the cartridges are mounted in the unit frame in the correct arrangement order, the grooves formed in the cartridges are aligned on the arc so that the unit frame is mounted on the main body casing. The free end portion of the swing member moves in the groove aligned on the arc by the guide groove. On the other hand, if the cartridges are attached to the unit frames in the wrong order, the grooves formed in the cartridges do not align on the arc, and the unit frame is attached to the main body casing while By preventing the movement of the free end portion, it is possible to detect erroneous mounting of the cartridge on the unit frame.

According to a fifth aspect of the present invention, there is provided the image forming apparatus according to any one of the first to fourth aspects, further comprising an image carrier that is held by the unit frame and forms an electrostatic latent image on the surface. It is characterized by being.

  According to such a configuration, since the image carrier is held in the unit frame, when there is no developer stored in the developer storage portion of the cartridge, the image carrier is left in the unit frame, Only the cartridge can be removed from the unit frame and replaced. Therefore, it is possible to prevent the image carrier from being exchanged together with the cartridge, and it is possible to reduce the cost associated with the exchange of the cartridge.

According to a sixth aspect of the present invention, in the image forming apparatus according to the fifth aspect , the cartridge supplies a developer to the image carrier to develop the electrostatic latent image into a visible image. An agent carrier is provided.
According to such a configuration, since the developer carrying member is provided in the cartridge, when the developer runs out, the developer carrying member can be replaced with a new one.

According to the first aspect of the present invention, it is possible to detect the arrangement order of the cartridges in the unit frame based on the order in which each switch detects the passage of the identification unit, and to detect erroneous mounting of the cartridge to the unit frame. Can be achieved.
According to the second aspect of the present invention, it is possible to determine whether or not the cartridge is mounted in the unit frame in the correct arrangement order based on the detection result of each switch. Detection of mismounting can be achieved.

According to the third aspect of the present invention, when the cartridges are mounted in the unit frame in the wrong order, the grooves formed in the cartridges are not aligned on the arc, and the free end portion of the swing member By preventing this movement (swinging of the swinging member), detection of erroneous mounting of the cartridge with respect to the unit frame can be achieved.
According to the fourth aspect of the present invention, it is possible to detect erroneous mounting of the cartridge with respect to the unit frame by preventing the movement of the free end portion of the swing member while the unit frame is mounted on the main body casing. Can do.
According to the fifth aspect of the present invention, it is possible to prevent the image carrier from being replaced together with the cartridge, and to reduce the cost associated with the replacement of the cartridge.

According to the sixth aspect of the present invention, since the developer carrier is provided in the cartridge, when the developer runs out, the developer carrier can be replaced with a new one.

1. 1 is a side sectional view showing an embodiment of a color laser printer as an image forming apparatus of the present invention.
This color laser printer 1 is a side-by-side tandem color laser printer in which a plurality of process units 15 are arranged in parallel in the horizontal direction, and a sheet as a transfer medium is placed in a box-shaped main body casing 2. A sheet feeding unit 4 for feeding the sheet 3, an image forming unit 5 for forming an image on the fed sheet 3, and a sheet discharge unit 6 for discharging the sheet 3 on which the image is formed. Yes.
(1) Main Body Casing On the upper surface of the main body casing 2, a paper discharge tray 7 for receiving the paper 3 on which an image is formed is formed. In addition, on the upper surface of the main casing 2, an operation panel including operation keys and LED display units is embedded on one side of the paper discharge tray 7. In the main casing 2, a front opening 8 that communicates the inside and outside of the main casing 2 is formed in the side wall on the operation panel side from the center in the vertical direction upward. The front opening 8 is provided with a front cover 9 for opening and closing the front opening 8. The front cover 9 is rotatably supported by a cover shaft (not shown) inserted through the lower end portion thereof. Thus, when the front cover 9 is closed around the cover axis, the front opening 8 is closed by the front cover 9, and when the front cover 9 is opened with the cover axis as a fulcrum (tilted), the front opening 8 is opened. .

In the following description, the side on which the front cover 9 is provided is referred to as the “front side” of the laser printer 1 and the opposite side is referred to as the “rear side”. A horizontal direction orthogonal to the front-rear direction is a width direction in the color laser printer 1.
(2) Paper Feed Unit The paper feed unit 4 includes a paper cassette 10 provided at the bottom of the main body casing 2, a paper feed roller 11 provided above the front side of the paper cassette 10, and an upper front side of the paper feed roller 11. A paper feed path 12 provided and a pair of registration rollers 13 provided at the downstream end of the paper feed path 12 are provided.

The paper 3 is stacked in the paper cassette 10, and the uppermost paper 3 is sent to the paper feed path 12 by the rotation of the paper feed roller 11. In the course of being conveyed on the paper feed path 12, the conveyance direction of the paper 3 sent to the paper feed path 12 is reversed, and after registration by the registration roller 13, the registration roller 13 moves backward. The paper is ejected.
(3) Image Forming Unit The image forming unit 5 includes a scanner unit 14, a process unit 15, a transfer unit 16, and a fixing unit 17.
<Scanner unit>
The scanner unit 14 is arranged over a plurality of process units 15 to be described later in the upper part in the main body casing 2. The scanner unit 14 includes a scanner frame 18 fixed to the main body casing 2 and a scanner casing 19 fixed to the scanner frame 18. In the scanner casing 19, optical members such as four light sources, a polygon mirror, an fθ lens, a reflecting mirror, and a surface tilt correction lens are arranged. A laser beam based on image data emitted from each light source is a polygon mirror. And after passing through the fθ lens and the surface tilt correction lens and being reflected by the reflecting mirror, the surface of the photosensitive drum 20 of each color to be described later of the process unit 15 is irradiated at high speed. .
<Process Department>
A plurality of process units 15 are provided corresponding to a plurality of color toners. In other words, the process unit 15 includes four units, that is, a yellow process unit 15Y, a magenta process unit 15M, a cyan process unit 15C, and a black process unit 15K. These four process units 15 are sequentially arranged in parallel so as to overlap in the horizontal direction at intervals from the front to the rear.

Each process unit 15 includes a photosensitive drum 20 as an image carrier, a scorotron charger 21 and a developing cartridge 22 as a cartridge.
The photosensitive drum 20 has a cylindrical shape, and a drum main body formed by a positively chargeable photosensitive layer whose outermost layer is made of polycarbonate or the like, and a drum shaft extending along the axial direction of the drum main body at the axial center of the drum main body. And. The drum body is provided so as to be rotatable with respect to the drum shaft, and the drum shaft is supported on the both side walls in the width direction of the process frame 35 described later so as not to rotate. Then, the photosensitive drum 20 is rotationally driven in the same direction (clockwise in the drawing) as the moving direction of the conveying belt 29 at a contact position with the conveying belt 29 described later during image formation.

The scorotron charger 21 includes a wire and a grid, and is a positively charged scorotron charger that generates corona discharge when a charging bias is applied. The scorotron charger 21 does not contact the photosensitive drum 20 behind the photosensitive drum 20. Opposing to each other with an interval.
The developing cartridge 22 is disposed in front of the photosensitive drum 20 and includes a housing 23, and a developing roller 24 and a supply roller 25 as a developer carrier in the housing 23.

  The housing | casing 23 is formed in the box shape by which the rear side lower end part was open | released. An upper portion of the housing 23 is a toner storage chamber 26, and each color toner is stored in the toner storage chamber 26. That is, a positively chargeable non-magnetic single-component polymer toner having a yellow color is accommodated in the toner storage chamber 26 of the developing cartridge 22 (hereinafter referred to as “yellow developing cartridge 22Y”) of the yellow process section 15Y. ing. In the toner storage chamber 26 of the developing cartridge 22 (hereinafter referred to as “magenta developing cartridge 22M”) of the magenta process unit 15M, positively charged non-magnetic one-component polymer toner having a magenta color is stored. . In the toner storage chamber 26 of the developing cartridge 22 (hereinafter referred to as “cyan developing cartridge 22C”) of the cyan process section 15C, positively charged nonmagnetic one-component polymer toner having a cyan color is stored. . In the toner storage chamber 26 of the developing cartridge 22 (hereinafter referred to as “black developing cartridge 22K”) of the black process section 15K, positively charged nonmagnetic one-component polymerized toner having a black color is stored. .

  More specifically, for each color toner, a substantially spherical polymer toner obtained by a polymerization method is used. The polymerization toner is a known polymerization such as a suspension polymerization of a styrene monomer such as styrene or an acrylic monomer such as acrylic acid, alkyl (C1 to C4) acrylate, or alkyl (C1 to C4) methacrylate. The main component is a binder resin obtained by copolymerization according to the method, and a toner base particle is formed by adding a colorant, a charge control agent, a wax, etc. to this, and further improves the fluidity. In order to achieve this, an external additive is added.

  As the colorant, the above-mentioned yellow, magenta, cyan and black colorants are blended. Moreover, as a charge control agent, for example, an ionic monomer having an ionic functional group such as an ammonium salt and an ionic monomer such as a styrene monomer or an acrylic monomer can be copolymerized. A charge control resin obtained by copolymerization with a monomer is blended. As external additives, for example, powders of metal oxides such as silica, aluminum oxide, titanium oxide, strontium titanate, cerium oxide and magnesium oxide, inorganic powders such as carbide powders and metal salt powders are blended. Has been.

  The developing roller 24 faces the photosensitive drum 20 from the front side and is in pressure contact with the photosensitive drum 20. In the developing roller 24, a metal roller shaft is covered with a roller portion made of an elastic member such as a conductive rubber material. More specifically, the roller portion is coated with an elastic roller layer made of conductive urethane rubber, silicone rubber, EPDM rubber or the like containing carbon fine particles, and the surface of the roller layer. And a two-layer structure with a coat layer mainly composed of polyimide resin or the like. The roller shaft of the developing roller 24 is rotatably supported on both side walls in the width direction of the housing 23, and a developing bias is applied during image formation.

The supply roller 25 faces the developing roller 24 from the front side and is in pressure contact with the developing roller 24. The supply roller 25 has a metal roller shaft covered with a roller portion made of a conductive sponge member. Further, the roller shaft of the supply roller 25 is rotatably supported on both side walls of the housing 23 in the width direction.
In each process unit 15, the toner of each color stored in each toner storage chamber 26 is supplied to the supply roller 25 and is supplied to the developing roller 24 by the rotation of the supply roller 25 during image formation. At this time, the toner is positively frictionally charged between the supply roller 25 and the developing roller 24 to which a developing bias is applied.

  On the other hand, the scorotron charger 21 generates a corona discharge by applying a charging bias to uniformly positively charge the surface of the photosensitive drum 20. The surface of the photosensitive drum 20 is uniformly charged positively by the scorotron charger 21 as the photosensitive drum 20 rotates, and then exposed by high-speed scanning of the laser light emitted from the emission window of the scanner unit 14. An electrostatic latent image of each color corresponding to the image to be formed on the paper 3 is formed.

When the photosensitive drum 20 further rotates, when the toner carried on the surface of the developing roller 24 and positively charged is brought into contact with the photosensitive drum 20 by the rotation of the developing roller 24, the photosensitive drum 20 is rotated. The electrostatic latent image formed on the surface, that is, the surface of the photosensitive drum 20 that is uniformly positively charged, is supplied to an exposed portion that is exposed to laser light and has a lowered potential. As a result, the electrostatic latent image on the photosensitive drum 20 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 20 corresponding to each color.
<Transfer section>
The transfer unit 16 is disposed along the front-rear direction in the main body casing 2 above the paper cassette 10 and below the process unit 15. The transfer unit 16 includes a drive roller 27, a driven roller 28, a conveyance belt 29, and a transfer roller 30.

The drive roller 27 is disposed on the lower rear side of the photosensitive drum 20 of the black process unit 15K. The drive roller 27 is rotationally driven in the direction opposite to the rotation direction of the photosensitive drum 20 (counterclockwise in the figure) during image formation.
The driven roller 28 is disposed on the lower side in front of the photosensitive drum 20 of the yellow process portion 15Y and is opposed to the driving roller 27 in the front-rear direction. The driven roller 28 is driven to rotate in the same direction as the driving roller 27 (counterclockwise in the figure) when the driving roller 27 is driven to rotate.

  The conveyor belt 29 is an endless belt, and is formed of a resin such as conductive polycarbonate or polyimide in which conductive particles such as carbon are dispersed. The conveyor belt 29 is wound between the driving roller 27 and the driven roller 28, and the wound outer contact surface is in contact with all the photosensitive drums 20 of the respective process units 15. Is arranged.

Then, the driven roller 28 is driven by the driving roller 27, and the conveying belt 29 is photosensitive between the driving roller 27 and the driven roller 28 on the contact surface facing the photosensitive drum 20 of each process unit 15. It travels in the clockwise direction in the figure so as to move in the same direction as the drum 20.
The transfer roller 30 is disposed so as to face the photosensitive drum 20 of each process unit 15 and the conveyor belt 29 in the conveyor belt 29 wound between the driving roller 27 and the driven roller 28. Each transfer roller 30 has a metal roller shaft covered with a roller portion made of an elastic member such as a conductive rubber material. The roller shaft of the transfer roller 30 extends along the width direction and is rotatably supported, and a transfer bias is applied during transfer. Each transfer roller 30 rotates in the same direction as the circumferential movement direction of the conveyor belt 29 (clockwise in the drawing) on the contact surface facing the conveyor belt 29.

  Then, the sheet 3 fed from the sheet feeding unit 4 is conveyed from the front to the rear by the conveyor belt 29 that is circulated by driving of the driving roller 27 and driven of the driven roller 28. It is conveyed so as to sequentially pass through the image forming positions between the 15 photosensitive drums 20. During the conveyance, toner images corresponding to the respective colors carried on the photosensitive drums 20 of the respective process units 15 are sequentially transferred, whereby a color image is formed on the paper 3.

  That is, for example, when a yellow toner image carried on the surface of the photosensitive drum 20 of the yellow process unit 15Y is transferred to the paper 3, the magenta toner carried on the surface of the photosensitive drum 20 of the magenta process unit 15M is then transferred. The toner image is transferred onto the sheet 3 on which the yellow toner image has already been transferred, and the cyan toner image carried on the surface of the photosensitive drum 20 of the cyan process unit 15C and the black process unit 15K by the same operation. The black toner image carried on the surface of the photosensitive drum 20 is transferred in a superimposed manner, whereby a color image is formed on the paper 3.

In the formation of such a color image, the color laser printer 1 forms a monochrome image because each process unit 15 has a tandem apparatus configuration in which a plurality of process units 15 are provided corresponding to each color. A toner image corresponding to each color can be formed at almost the same speed as the speed, thereby achieving rapid color image formation. Therefore, it is possible to form a color image while reducing the size.
<Fixing part>
The fixing unit 17 is disposed behind the transfer unit 16. The fixing unit 17 includes a heating roller 31 and a pressure roller 32. The heating roller 31 is made of a metal base tube having a release layer formed on the surface thereof, and a halogen lamp is provided along the axial direction thereof. Then, the surface of the heating roller 31 is heated to the fixing temperature by the halogen lamp. The pressure roller 32 is provided so as to press the heating roller 31.

The color image transferred onto the sheet 3 is heated and pressed while the sheet 3 is conveyed to the fixing unit 17 and passes between the heating roller 31 and the pressure roller 32, so that the sheet 3 is heated. It is fixed.
(4) Paper Discharge Unit The paper discharge unit 6 includes a paper discharge path 33 and a paper discharge roller 34.

The paper discharge path 33 has an upstream end adjacent to the fixing unit 17 at the lower side, so that the paper 3 is fed rearward, and a downstream end at the upper side to the paper discharge roller 34. Adjacent and formed as a substantially U-shaped paper 3 conveyance path so that the paper 3 is discharged forward.
The paper discharge roller 34 is provided as a pair of rollers at the downstream end of the paper discharge path 33.

The sheet 3 on which the color image is thermally fixed in the fixing unit 17 is discharged forward by the sheet discharge roller 34 after the conveyance direction is reversed in the forward and backward directions in the process of being conveyed on the sheet discharge path 33. . The discharged paper 3 is placed on a paper discharge tray 7 on the upper surface of the main casing 2.
2. FIG. 2 is a side sectional view showing a state in which the front cover 9 of the color laser printer 1 is opened. FIG. 3 is a side sectional view showing a state in which the process unit 15 is pulled out from the front opening 8 of the color laser printer 1.

The four process parts 15 are integrally supported by a process frame 35 that is slidable in the front-rear direction with respect to the main body casing 2. The developing cartridge 22 of each process unit 15 is detachably attached to the process frame 35 from above.
3. Slide Structure of Process Frame The process frame 35 is formed in a substantially rectangular frame shape surrounding the four process parts 15, and includes guide parts 36 that extend linearly in the front-rear direction on the outer surfaces on both sides in the width direction.

On the other hand, in the main casing 2, guide rails 37 are provided in which both guide portions 36 of the process frame 35 are slidably fitted. The guide rail 37 is formed in a concave shape so as to face and contact the upper surface, the lower surface, and the side surface in the width direction of the guide portion 36, and is provided to extend linearly in the front-rear direction from the vicinity of the front opening 8 to the vicinity of the fixing portion 17. It has been.
The process frame 35 is attached between the guide rails 37 so as to be slidable in the front-rear direction with respect to the main body casing 2 by fitting both guide portions 36 into the guide rails 37 from the front. Further, in this state, the upper surface, the lower surface, and the side surface in the width direction of the guide portion 36 are opposed to the guide rail 37, whereby the process frame 35 is supported by the guide rail 37 without rattling in the vertical direction and the width direction. The

As shown in FIG. 2, when the process frame 35 is pushed into the main body casing 2 as far as it will go, the process unit 15 supported by the process frame 35 is disposed between the scanner unit 14 and the transfer unit 16. As shown in FIG. 3, when the front cover 9 is opened and the process frame 35 is pulled out of the main casing 2 from the front opening 8, the process unit 15 supported by the process frame 35 is exposed.
4). Incorrect mounting detection means In the state where the process frame 35 is pulled out of the main casing 2, the developing cartridge 22 can be mounted on and removed from the process frame 35 from above.

  The developing cartridges 22 for the respective colors are mounted on the process frame 35 so that the yellow developing cartridge 22Y, the magenta developing cartridge 22M, the cyan developing cartridge 22C, and the black developing cartridge 22K are arranged in this order from the front side. It must be accommodated in the casing 2. For example, if the magenta developing cartridge 22M and the cyan developing cartridge 22C are mistakenly attached, the magenta developing cartridge 22M is erroneously attached to the cyan process unit 15C, and the cyan developing cartridge 22C is erroneously attached to the magenta process unit 15M, the cyan process unit 15C. An electrostatic latent image (an electrostatic latent image to be visualized as a cyan toner image) formed on the photosensitive drum 20 is developed with magenta toner and formed on the photosensitive drum 20 of the magenta process unit 15M. Since an electrostatic latent image (an electrostatic latent image to be visualized as a magenta toner image) is developed with cyan toner, a normal color image cannot be formed on the paper 3.

  Therefore, the color laser printer 1 is provided with a mechanism for detecting an error in the mounting position of the developing cartridge 22 with respect to the process frame 35. That is, on the upper surface of the housing 23 of each developing cartridge 22, the block-shaped identification portion 38 protrudes upward at different positions in the width direction (direction orthogonal to the sliding direction of the process frame 35) for each color. Is provided. On the other hand, in the main body casing 2, each developing cartridge 22 is mounted at a normal position with respect to the process frame 35 on the lower surface of the scanner frame 18 of the scanner unit 14, and the process frame 35 is accommodated in the main body casing 2. In this state, a facing member 39 is provided to face the identification portion 38 of each developing cartridge 22 from the rear side. Each opposing member 39 projects from the lower surface of the scanner frame 18 with a projecting amount smaller than the distance between the lower surface of the scanner frame 18 and the upper surface of the developing cartridge 22, and is narrower in the width direction than the identification unit 38. Is formed.

FIG. 4 is a plan view schematically showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order and the process frame 35 is accommodated in the main casing 2.
When the developing cartridge 22 is mounted in the correct arrangement order on the process frame 35, the yellow developing cartridge 22Y, the magenta developing cartridge 22M, the cyan developing cartridge 22C, and the black developing cartridge 22K are arranged in this order from the front side in the process frame 35. line up. At this time, the process frame 35 is slid rearward from the state pulled out of the main body casing 2, and the identification portions 38 provided in the developing cartridges 22 interfere with the opposing members 39 in the main body casing 2. Without being pushed into the main casing 2 to the innermost depth. In a state where the process frame 35 is pushed to the innermost part of the main casing 2, the identification portion 38 of each developing cartridge 22 faces the facing member 39 in the front-rear direction.

FIG. 5 is a side sectional view showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the wrong arrangement order. FIG. 6 is a side sectional view showing a state in the middle of housing the process frame 35 in which the developing cartridge 22 is mounted in the wrong arrangement order in the main casing 2, and FIG. 7 is a schematic plan view thereof. It is.
In the state shown in FIG. 5, the magenta developing cartridge 22M and the black developing cartridge 22K are mistaken, and the developing cartridge 22 has a yellow developing cartridge 22Y, a black developing cartridge 22K, a cyan developing cartridge 22C, and a magenta developing cartridge 22M from the front side. Arranged in order. At this time, when the process frame 35 is slid rearward from the state pulled out of the main casing 2, as shown in FIGS. 6 and 7, the identification unit 38 of the magenta developing cartridge 22 </ b> M, The opposing member 39 that is opposed to the main casing 2 while being pushed into the innermost part of the casing 2 is opposed to and abutted in the middle of the slide. As a result, further sliding of the process frame 35 is prevented, and detection of erroneous mounting of the developing cartridge 22 with respect to the process frame 35 is achieved.

  As described above, when the developing cartridges 22 are mounted on the process frame 35 in the correct arrangement order, the identification portions 38 provided on the developing cartridges 22 interfere with the opposing members 39 in the main body casing 2. The process frame 35 can be accommodated in the main casing 2 without any problem. In the accommodated state, the identification portion 38 of each developing cartridge 22 faces the opposing member 39 in the front-rear direction. On the other hand, if the developing cartridge 22 is attached to the process frame 35 in the wrong arrangement order, the identification unit 38 provided on the developing cartridge 22 attached at the wrong position may be regarded as the process frame 35 originally being the main casing. 2, the process frame 35 is opposed to and abutted against the opposing member 39 that is opposed to being completely accommodated in the body casing 2. Thereby, in the process in which the process frame 35 is accommodated in the main casing 2, detection of erroneous mounting of the developing cartridge 22 with respect to the process frame 35 is achieved. Therefore, in a state where each developing cartridge 22 is not mounted at the correct position with respect to the process frame 35 (a state where the developing cartridge 22 is mounted on the process frame 35 in an incorrect arrangement order), the process frame 35 is attached to the main casing. 2 can be prevented. As a result, it is possible to reliably form a normal color image on the paper 3 by supplying toner of a corresponding color to the photosensitive drum 20 of the process unit 15 of each color.

  Further, since the identification portion 38 protrudes above the housing 23 of the developing cartridge 22, the process frame 35 is accommodated in the main casing 2 when the developing cartridge 22 is mounted on the process frame 35 in the wrong arrangement order. In the middle of this, the identification portion 38 provided on the developing cartridge 22 mounted at the wrong position and the opposing member 39 can be brought into contact with each other with certainty.

Furthermore, since the identification part 38 is arrange | positioned in the position which is different in the width direction for every color, each identification part 388 can be reliably arrange | positioned in a different position for every color.
In addition, since the photosensitive drum 20 is held by the process frame 35, when the toner stored in the toner storage chamber 26 of the developing cartridge 22 runs out, the development is performed with the photosensitive drum 20 remaining in the process frame 35. Only the cartridge 22 can be removed from the process frame 35 and replaced. For this reason, it is possible to prevent the photosensitive drum 20 from being replaced together with the developing cartridge 22, and to reduce the cost associated with the replacement of the developing cartridge 22.

Further, since the developing roller 24 is provided in the developing cartridge 22, when the toner in the toner storage chamber 26 runs out, the developing cartridge 22 can be replaced with a new one together with the developing roller 24.
5. Second Embodiment FIGS. 8 and 9 are side sectional views of a color laser printer according to a second embodiment. FIG. 10 is a plan view schematically showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order and the process frame 35 is accommodated in the main casing 2. 8 to 10, portions corresponding to the above-described portions are denoted by the same reference numerals as those portions. Further, in the following, detailed description of each part given the same reference numeral is omitted.

In the color laser printer 1 according to the second embodiment, instead of the facing member 39, a switch 40 for detecting the passage of each identification unit 38 when the process frame 35 is accommodated in the main body casing 2 is provided. Yes.
The switch 40 is arranged along the front end of the lower surface of the scanner frame 18 of the scanner unit 14. Specifically, as shown in FIG. 10, the switch 40 is arranged on the path through which each identification unit 38 passes when the process frame 35 is accommodated in the main casing 2, as shown in FIG. 10, at the front end of the lower surface of the scanner frame 18. They are arranged one by one and aligned in a row in the width direction perpendicular to the slide direction of the process frame 35.

  When each developing cartridge 22 is mounted on the process frame 35 and this process frame 35 is accommodated in the main casing 2, the identification portion 38 of each developing cartridge 22 passes the position of the switch 40 in the process of accommodation. When the identification unit 38 passes the position of the switch 40, the identification unit 38 comes into contact with the actuator of the switch 40, and the identification unit 38 pushes the actuator upward. Thereby, the passage of the identification unit 38 by the switch 40 is achieved. Since the switches 40 are aligned in the width direction, the order in which each switch 40 detects the passage of the identification unit 38 corresponds to the order in which the developing cartridges 22 are arranged in the process frame 35.

In this manner, when the developing cartridge 22 is mounted in the process frame 35 in the correct arrangement order, examples of detection timing of each switch 40 when the process frame 35 is accommodated in the developing cartridge 22 are shown in FIGS. Shown in
FIG. 11 is a diagram illustrating an example of the detection timing of each switch 40 at the time of initial setting (when each developing cartridge 22 is first attached to the process frame 35 and the process frame 35 is accommodated in the main body casing 2). .

  The empty process frame 35 is pulled out from the main body casing 2, and the developing cartridges 22 are mounted in the correct arrangement order on the process frame 35 as shown in FIG. 8, and the process frame 35 is shown in FIG. When 35 is accommodated in the main casing 2, as shown in FIG. 11, the switch 40 (switch “A”) arranged on the path through which the identification unit 38 (identification unit “1”) of the black developing cartridge 22K passes. ), The switch 40 (switch “B”) disposed on the path through which the identification unit 38 (identification unit “2”) of the cyan developing cartridge 22C passes, and the identification unit 38 (identification unit “3”) of the magenta development cartridge 22M. ) And the identification unit 38 of the yellow developing cartridge 22Y disposed on the path through which the yellow developing cartridge 22Y passes. Identifying portion "4") is arranged on a path through the switch 40 (switch "D") is, in this order, to detect the passage of the identification unit 38, respectively.

When the switch 40 detects the passage of the identification unit 38 in this order, it can be determined that the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order.
In the following description, for the sake of simplicity, the identification unit 38 of the black development cartridge 22K is referred to as identification unit “1”, the identification unit 38 of the cyan development cartridge 22C is referred to as identification unit “2”, and the magenta development cartridge 22M. The identification unit 38 is referred to as identification unit “3”, and the identification unit 38 of the yellow developing cartridge 22Y is referred to as identification unit “4”. Further, the switch 40 arranged on the passage route of the identification unit “1” is referred to as a switch “A”, and the switch 40 arranged on the passage route of the identification unit “2” is referred to as a switch “B”. The switch 40 disposed on the passage route of the identification unit “3” is referred to as a switch “C”, and the switch 40 disposed on the passage route of the identification unit “4” is referred to as a switch “D”.

FIG. 12 is a diagram illustrating another example of the detection timing of each switch 40 at the time of initial setting.
The switch “B” is mounted on the developing cartridge 22 in the correct arrangement order on the empty process frame 35 pulled out from the main casing 2, and the process frame 35 is arranged on the path through which the identification unit “2” passes. ”Is pushed into the main casing 2 to a position where the passage is detected, and then is pulled out from the main casing 2 and then accommodated in the main casing 2.

  In this case, as shown in FIG. 12, in the process in which the process frame 35 is pushed halfway into the main casing 2, the switch “A” and the switch “B” are switched in this order from the identification unit “1” and the identification unit “ 2 "is detected. Thereafter, once the process frame 35 is pulled out from the main casing 2, although not shown, in the process of being pulled out, the switch “B” and the switch “A” are switched in this order to the identification unit “2” and the identification unit “ The passage of “1” is detected. When the process frame 35 is completely accommodated in the main casing 2, as shown in FIG. 12, the switch “A”, the switch “B”, the switch “C”, and the switch “D” However, the passage of the identification unit 38 is detected in this order.

Even when the switch 40 detects the passage of the identification unit 38 in this order, it can be determined that the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order.
FIG. 13 is a diagram illustrating an example of the detection timing of each switch 40 when the developing cartridge 22 is replaced.

  For example, when the process frame 35 is pulled out from the main casing 2 until the yellow developing cartridge 22Y is exposed, and the yellow developing cartridge 22Y is replaced with a new one, then the process frame 35 is accommodated in the main casing 2. As shown in FIG. 13 (a), in the process in which the process frame 35 is pulled out from the main body casing 2, the switch “D” detects the passage of the identification unit “4”, and then accommodates the process frame 35 in the main body casing 2. In the process, the switch “D” detects again the passage of the identification unit “4”.

As described above, even when the switch “D” continuously detects the passage of the identification unit “4” twice, it can be determined that the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order. .
The process frame 35 is pulled out from the main casing 2 until the magenta developing cartridge 22M is exposed. After the yellow developing cartridge 22Y and the magenta developing cartridge 22M are replaced with new ones, the process frame 35 is accommodated in the main casing 2. 13B, in the process of pulling out the process frame 35 from the main casing 2, the switch “D” and the switch “C” are arranged in this order in the identification unit “4” and the identification unit, respectively. In the process of detecting the passage of “3” and then accommodating the process frame 35 in the main casing 2, the switch “C” and the switch “D” are in the order of the identification units “3” and “4”, respectively. Detect passage.

Even when the switch 40 detects the passage of the identification unit 38 in this order, it can be determined that the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order.
FIG. 14 is a diagram showing still another example of the detection timing of each switch 40 when the developing cartridge 22 is replaced.

  When the process frame 35 is pulled out from the main body casing 2 until the black developing cartridge 22K is exposed and each developing cartridge 22 is replaced with a new one, and then the process frame 35 is accommodated in the main body casing 2, FIG. As shown in the drawing, in the process in which the process frame 35 is pulled out from the main casing 2, the switch “D”, the switch “C”, the switch “B”, and the switch “A” The passage of the part “3”, the identification part “2” and the identification part “1” is detected. Then, in the process in which the process frame 35 is housed in the main casing 2, the switch “A”, the switch “B”, the switch “C”, and the switch “D” are in this order, the identification unit “1” and the identification unit, respectively. The passage of “2”, the identification unit “3”, and the identification unit “4” is detected.

Even when the switch 40 detects the passage of the identification unit 38 in this order, it can be determined that the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order.
15 and 16 are side cross-sectional views showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the wrong arrangement order. FIG. 17 is a plan view schematically showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the wrong order and the process frame 35 is accommodated in the main casing 2. In each of FIGS. 15 to 17, portions corresponding to the above-described portions are denoted by the same reference numerals as those portions. Further, in the following, detailed description of each part given the same reference numeral is omitted.

In the state shown in FIGS. 15 to 17, the yellow developing cartridge 22Y and the magenta developing cartridge 22M are mistaken, and the developing cartridge 22 starts from the front side with the magenta developing cartridge 22M, the yellow developing cartridge 22Y, the cyan developing cartridge 22C, and the black developing cartridge. The cartridges 22K are arranged in this order.
In this manner, when the developing cartridge 22 is mounted on the process frame 35 in the wrong arrangement order, examples of detection timings of the switches 40 when the process frame 35 is accommodated in the developing cartridge 22 are shown in FIGS. 21.

FIG. 18 is a diagram illustrating an example of the detection timing of each switch 40 at the time of initial setting.
The empty process frame 35 is pulled out from the main casing 2 and the developing cartridges 22 are mounted in the wrong arrangement order on the process frame 35 as shown in FIG. When the frame 35 is accommodated in the main casing 2, as shown in FIG. 18, in the process, the switch “A”, the switch “B”, the switch “D”, and the switch “C” are identified in this order. The passage of the part “1”, the identification part “2”, the identification part “4” and the identification part “3” is detected.

Such a detection order is different from the detection order (the order shown in FIG. 11) when the developing cartridge 22 is mounted in the correct arrangement order with respect to the process frame 35. It can be determined that they are mounted in the wrong order.
FIG. 19 is a diagram illustrating another example of the detection timing of each switch 40 at the time of initial setting.

  As shown in FIG. 15, the empty process frame 35 pulled out from the main casing 2 is mounted in the developing cartridge 22 in the wrong order, and the process frame 35 passes through the identification unit “2”. Consider a case where the switch “B” disposed on the path to be moved is pushed into the main casing 2 to a position where the passage “B” is detected, then pulled out from the main casing 2 and then accommodated in the main casing 2. .

  In this case, as shown in FIG. 19, in the process in which the process frame 35 is pushed halfway into the main casing 2, the switch “A” and the switch “B” are in the order of the identification unit “1” and the identification unit “ 2 "is detected. Thereafter, once the process frame 35 is pulled out from the main casing 2, although not shown, in the process of being pulled out, the switch “B” and the switch “A” are switched in this order to the identification unit “2” and the identification unit “ The passage of “1” is detected. When the process frame 35 is completely accommodated in the main casing 2, as shown in FIG. 19, in the process of accommodation, the switch “A”, the switch “B”, the switch “D”, and the switch “C” However, the passage of the identification unit 38 is detected in this order.

The detection order when the process frame 35 is accommodated in the main body casing 2 is the detection order (the order shown in FIG. 12) when the developing cartridge 22 is attached to the process frame 35 in the correct arrangement order. Therefore, it can be determined that the developing cartridge 22 is attached to the process frame 35 in the wrong order.
FIG. 20 is a diagram illustrating an example of the detection timing of each switch 40 when the developing cartridge 22 is replaced.

  For example, the process frame 35 is pulled out from the main casing 2 until the yellow developing cartridge 22Y is exposed, the yellow developing cartridge 22Y is detached from the process frame 35, and the magenta developing cartridge 22M is erroneously attached to the yellow process section 15Y. Then, when the process frame 35 is accommodated in the main casing 2, as shown in FIG. 20A, the switch “D” is moved to the identification unit “4” in the process of being pulled out of the main casing 2. Then, in the process in which the process frame 35 is housed in the main casing 2, the switch “C” detects the passage of the identification unit “3”.

Such a detection order is the same as the detection order (the order shown in FIG. 13A) when the yellow developing cartridge 22Y is correctly replaced and the developing cartridge 22 is attached to the process frame 35 in the correct order. Therefore, it can be determined that the developing cartridge 22 is attached to the process frame 35 in the wrong order.
Further, the process frame 35 is pulled out from the main body casing 2 until the magenta developing cartridge 22M is exposed, and the yellow developing cartridge 22Y and the magenta developing cartridge 22M are respectively detached from the process frame 35, and then the yellow developing cartridge 22Y and the magenta developing. When the cartridge 22M is mistaken and these are respectively attached to the magenta process unit 15M and the yellow process unit 15Y and the process frame 35 is accommodated in the main body casing 2, the process frame 35 is formed as shown in FIG. In the process of being pulled out from the main casing 2, the switch “D” and the switch “C” detect the passage of the identification unit “4” and the identification unit “3” in this order, respectively. In the process of being accommodated in the ring 2, the switch "D" and the switch "C", in this order, to detect the passage of the identification unit "4" and "3" respectively.

  Such a detection order is the detection order when the yellow developing cartridge 22Y and the magenta developing cartridge 22M are correctly replaced and the developing cartridge 22 is mounted in the correct arrangement order on the process frame 35 (FIG. 13B). Therefore, it can be determined that the developing cartridge 22 is attached to the process frame 35 in the wrong arrangement order.

FIG. 21 is a diagram showing still another example of the detection timing of each switch 40 when the developing cartridge 22 is replaced.
The process frame 35 is pulled out from the main body casing 2 until the black developing cartridge 22K is exposed. After each developing cartridge 22 is detached from the process frame 35, the yellow developing cartridge 22Y and the magenta developing cartridge 22M are mistaken. When the process frame 35 is attached to the magenta process unit 15M and the yellow process unit 15Y, respectively, and the process frame 35 is accommodated in the main body casing 2, as shown in FIG. D ”, switch“ C ”, switch“ B ”, and switch“ A ”pass through the identification unit“ 4 ”, the identification unit“ 3 ”, the identification unit“ 2 ”, and the identification unit“ 1 ”in this order, respectively. To detect. Then, in the process in which the process frame 35 is housed in the main casing 2, the switch “B”, the switch “A”, the switch “C”, and the switch “D” are arranged in this order in the identification unit “2” and the identification unit, respectively. The passage of “1”, the identification unit “3”, and the identification unit “4” is detected.

  Such a detection order is the detection order (the order shown in FIG. 14) when the yellow developing cartridge 22Y and the magenta developing cartridge 22M are correctly replaced and the developing cartridge 22 is mounted in the correct arrangement order on the process frame 35. Therefore, it can be determined that the developing cartridge 22 is attached to the process frame 35 in the wrong arrangement order.

  As described above, the switch 40 that detects the passage of each identification unit 38 is disposed on the path through which each identification unit 38 passes when the process frame 35 is accommodated in the main casing 2, and the process frame 35. Are aligned in the width direction perpendicular to the sliding direction. For this reason, when the process frame 35 is accommodated in the main casing 2, the order in which the switches 40 detect the passage of the identification unit 38 corresponds to the arrangement order of the developing cartridges 22 in the process frame 35. Accordingly, the arrangement order of the developing cartridges 22 in the process frame 35 can be detected based on the order in which the switches 40 detect the passage of the identification unit 38, and detection of erroneous mounting of the developing cartridge 22 to the process frame 35 can be detected. Can be achieved.

Further, even when the developing cartridge 22 is attached to the process frame 35 in the wrong arrangement order and the process frame 35 is pushed into the main casing 2, a member that interferes with the identification portion 38 of the developing cartridge 22 in the process. Since it does not exist, there is no possibility that the identification unit 38 is damaged.
Whether the developing cartridge 22 is attached to the process frame 35 in the correct arrangement order or not is determined by, for example, a microcomputer including a CPU, a RAM, and a ROM (see FIG. (Not shown). In this case, a cover open / close detection switch (not shown) for detecting opening / closing of the front cover 9 is provided, and this switch is connected to the microcomputer and each switch 40 is connected to the microcomputer. In the microcomputer, the detection state (on / off state) output of each switch 40 is monitored over a period in which it is determined that the front cover 9 is open based on the output of the cover open / close detection switch. By comparing the detection timing of 40 with the detection timing pattern as described above, it is determined whether the developing cartridge 22 is attached to the process frame 35 in the correct arrangement order or in the incorrect arrangement order. It is good to be done.
6). Third Embodiment FIGS. 22 and 23 are side sectional views of a color laser printer according to a third embodiment. FIG. 24 is a plan view schematically showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order and the process frame 35 is accommodated in the main casing 2. 22 to 24, parts corresponding to the above-described parts are denoted by the same reference numerals as those parts. Further, in the following, detailed description of each part given the same reference numeral is omitted.

  In the color laser printer 1 according to the third embodiment, each developing cartridge 22 is mounted at a normal position with respect to the process frame 35 on the lower surface of the scanner frame 18 of the scanner unit 14 instead of the facing member 39. In the state where the process frame 35 is accommodated in the main casing 2, the switches 41 are arranged at positions where the respective identification portions 38 come into contact with each other.

  As shown in FIG. 22, when the developing cartridge 22 is mounted in the correct arrangement order with respect to the process frame 35 and the process frame 35 is accommodated in the main casing 2 as shown in FIG. As shown, the identification unit 38 provided in each developing cartridge 22 contacts the actuator of each switch 41 and pushes the actuator upward. Therefore, if the actuators of all the switches 41 are pushed up and the switches 41 detect the identification unit 38, it can be determined that the developing cartridge 22 is mounted in the correct arrangement order on the process frame 35. it can.

  25 and 26 are side cross-sectional views showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the wrong arrangement order. FIG. 27 is a plan view schematically showing a state in which the developing cartridge 22 is mounted on the process frame 35 in the wrong order and the process frame 35 is accommodated in the main casing 2. In each drawing of FIGS. 25 to 27, parts corresponding to the above-described parts are denoted by the same reference numerals as those parts. Further, in the following, detailed description of each part given the same reference numeral is omitted.

  In the state shown in FIG. 25, the yellow developing cartridge 22Y and the magenta developing cartridge 22M are mistaken, and the developing cartridge 22 has a magenta developing cartridge 22M, a yellow developing cartridge 22Y, a cyan developing cartridge 22C, and a black developing cartridge 22K from the front side. Arranged in order. As shown in FIG. 26, when the process frame 35 is housed in the main casing 2, the identification portions 38 of the magenta developing cartridge 22M and the yellow developing cartridge 22Y do not come into contact with the switch 41 as shown in FIG. The switches 41 provided in association with the normal mounting positions of the magenta developing cartridge 22M and the yellow developing cartridge 22Y do not detect the identification unit 38, respectively. Therefore, it can be determined that the developing cartridge 22 is attached to the process frame 35 in an incorrect arrangement order.

  As described above, when the developing cartridge 22 is mounted in the process frame 35 in the correct arrangement order, when the process frame 35 is accommodated in the main casing 2, the identification unit 38 contacts all the switches 41. All the switches 41 detect the identification unit 38. On the other hand, if the developing cartridge 22 is mounted on the process frame 35 in the wrong arrangement order, the identification unit 38 of the developing cartridge 22 mounted at the wrong position does not come into contact with the switch 41, and the developing cartridge 22 is properly registered. The switch 41 provided in association with the mounting position of does not detect the identification unit 38. Therefore, based on the detection result of each switch 41, it can be determined whether or not the developing cartridge 22 is mounted on the process frame 35 in the correct arrangement order. Detection can be achieved.

Further, even when the developing cartridge 22 is attached to the process frame 35 in the wrong arrangement order and the process frame 35 is pushed into the main casing 2, a member that interferes with the identification portion 38 of the developing cartridge 22 in the process. Since it does not exist, there is no possibility that the identification unit 38 is damaged.
In the third embodiment, the determination as to whether the developing cartridge 22 is attached to the process frame 35 in the correct arrangement order or whether it is attached in the incorrect arrangement order is made, for example, by CPU, RAM, and the like. This can be performed by a microcomputer (not shown) including a ROM. In this case, as in the case of the second embodiment, a cover open / close detection switch (not shown) for detecting the open / close of the front cover 9 is provided and connected to the microcomputer, and each switch 41 is connected to the microcomputer. Connecting. In the microcomputer, based on the output of the cover open / close detection switch, after the front cover 9 is opened, in response to the front cover 9 being closed, each switch 40 is detected (on / off state). ) And the development cartridge 22 is determined to be attached to the process frame 35 in the correct arrangement order or in the incorrect arrangement order based on the acquired detection state of each switch 41. Good.
7). Fourth Embodiment FIG. 28 is a side sectional view showing a state in which the developing cartridges 22 are mounted in the correct arrangement order on the process frame 35 pulled out from the main body casing 2 in the color laser printer according to the fourth embodiment. It is a top view. 29, FIG. 30, FIG. 31 and FIG. 32 are a side sectional view and a plan view showing a state in which the process frame 35 shown in FIG. FIG. 33 is a side sectional view and a plan view showing a state in which the process frame 35 shown in FIG. 28 to 33, parts corresponding to the above-described parts are denoted by the same reference numerals as those parts. Further, in the following, detailed description of each part given the same reference numeral is omitted.

  In the color laser printer 1 according to the fourth embodiment, as a mechanism for detecting an error in the mounting position of the developing cartridge 22 with respect to the process frame 35, the upper surface of the housing 23 of each developing cartridge 22 is positioned downward. An identification groove 42 that is recessed is formed. As shown in FIG. 28 (a), the identification cartridge 42 of each developing cartridge 22 has each developing cartridge 22 mounted in a normal position with respect to the process frame 35, and the developing cartridges 22 are arranged in the correct order. In the arranged state, as shown in FIG. 28 (b), they are formed so as to be aligned on the same arc. Further, the process frame 35 is provided with a protrusion 43 that protrudes on one side in the width direction for moving a rotation shaft 45 described later when the process frame 35 is accommodated in the main casing 2.

  On the other hand, a rotation shaft rail 44 extending in the front-rear direction along an edge on one side in the width direction of the lower surface of the scanner frame 18 and a movement along the rotation shaft rail 44 are provided in the main body casing 2. When the process frame 35 is accommodated in the main casing 2, the rotation shaft 45 is arranged at the center of the arc in which the respective identification grooves 42 are aligned, and is provided so as to be swingable about the rotation shaft 45. The swing member 46 and a guide groove 48 for guiding the movement of the free end portion 47 of the swing member 46 when the process frame 35 is accommodated in the main body casing 2 are provided.

The free end portion 47 is formed in a protruding shape that protrudes downward from the swinging member 46, penetrates the guide groove 48, and has the same lower end when each developing cartridge 22 is mounted at a regular position. It fits in the identification groove 42 aligned on the arc.
The guide groove 48 extends in the width direction and is slightly curved so that the end on the rotating shaft rail 44 side is directed rearward.

  When the developing cartridge 22 is mounted in the correct arrangement order with respect to the process frame 35 and the process frame 35 is accommodated in the main casing 2, only the black developing cartridge 22 </ b> K is first shown as shown in FIG. 29B, as shown in FIG. 29B, the free end portion 47 of the swing member 46 faces the identification groove 42 of the black developing cartridge 22K in the front-rear direction.

  From this state, when the process frame 35 is pushed into the main casing 2, the projection 43 of the process frame 35 pushes the rotating shaft 45 to move backward, and the free end portion 47 of the swing member 46 moves to the guide groove. While being guided by 48, it moves along the identification groove 42 of the black developing cartridge 22K. Then, as shown in FIG. 30A, when the cyan developing cartridge 22C enters the main casing 2, the free end portion 47 of the swing member 46 becomes cyan developing as shown in FIG. Opposite to the identification groove 42 of the cartridge 22C in the front-rear direction.

  When the process frame 35 is further pushed into the main casing 2, the projection 43 of the process frame 35 moves the pivot shaft 45 further backward, and the free end portion 47 of the swinging member 46 moves into the guide groove 48. It moves along the identification groove 42 of the cyan developing cartridge 22C while being guided. As shown in FIG. 31A, when the magenta developing cartridge 22M enters the main casing 2, as shown in FIG. 31B, the free end portion 47 of the swinging member 46 becomes magenta developing. Opposite to the identification groove 42 of the cartridge 22M in the front-rear direction.

  From this state, when the process frame 35 is further pushed into the main casing 2, the projection 43 of the process frame 35 moves the rotation shaft 45 further backward, and the free end portion 47 of the swing member 46 is It moves along the identification groove 42 of the magenta developing cartridge 22M while being guided by the guide groove 48. As shown in FIG. 32 (a), when the black developing cartridge 22K enters the main casing 2, the free end portion 47 of the swing member 46 becomes black developing as shown in FIG. 32 (b). Opposite the identification groove 42 of the cartridge 22K in the front-rear direction.

  Then, when the process frame 35 is further pushed into the main casing 2, the projection 43 of the process frame 35 pushes the rotating shaft 45 further back to move, and the free end portion 47 of the swing member 46 is moved into the guide groove. While being guided by 48, it moves along the identification groove 42 of the yellow developing cartridge 22Y. Then, as shown in FIG. 33 (a), in a state where the process frame 35 is pushed into the innermost part of the main casing 2 (a state where it is completely accommodated in the main casing 2), as shown in FIG. 33 (b). The free end portion 47 of the swing member 46 reaches the end portion of the guide groove 48 on the rotating shaft rail 44 side, and is detached from the identification groove 22 of the yellow developing cartridge 22Y outward in the width direction.

FIG. 34 is a plan view showing a state in which the developing cartridge 22 is mounted on the process frame 35 in an incorrect arrangement order. FIG. 34A shows a state in which the process frame 35 is pulled out from the main casing 2. ) Shows a state in which the process frame 35 is accommodated in the main casing 2 partway.
In the state shown in FIG. 34, the cyan developing cartridge 22C and the black developing cartridge 22K are mistaken, and the yellow developing cartridge 22Y, the magenta developing cartridge 22M, the black developing cartridge 22K, and the cyan developing cartridge are connected to the process frame 35 from the front side. Arranged in the order of 22C. At this time, the identification grooves 42 of the developing cartridges 22 are not aligned on the same arc. Therefore, as shown in FIG. 34A, when the process frame 35 is pushed out of the main body casing 2 and pushed into the main body casing 2, only the black developing cartridge 22K enters the main body casing 2. As shown in FIG. 34 (b), the free end portion 47 of the swinging member 46 contacts and abuts the position where the identification groove 42 is not formed on the rear surface of the cyan developing cartridge 22C. Thereby, even if the process frame 35 is pushed backward further, the slide of the process frame 35 is prevented, and detection of erroneous mounting of the developing cartridge 22 to the process frame 35 is achieved.

  As described above, when the developing cartridges 22 are mounted on the process frame 35 in the correct arrangement order, the identification grooves 42 formed on the upper surface of the housing 23 of each developing cartridge 22 are aligned on the same arc, When the process frame 35 is mounted on the main casing 2, the free end portion 47 of the swing member 46 moves along the identification groove 42 aligned on the arc by the guide groove 48. On the other hand, if the developing cartridges 22 are attached to the process frames 35 in the wrong order, the identification grooves 42 of the developing cartridges 22 are not aligned on the arc, and the process frames 35 are attached to the main casing 2. On the way, the movement of the free end portion 47 of the swinging member 464 is prevented, so that it is possible to detect erroneous mounting of the developing cartridge 22 to the process frame 35.

1 is a side cross-sectional view illustrating a first embodiment of a color laser printer as an image forming apparatus according to the present invention (a mode in which a facing member facing an identification portion is provided). FIG. 2 is a side sectional view showing a state where a front cover of the color laser printer of FIG. 1 is opened. FIG. 2 is a side sectional view showing a state in which a process part is pulled out from a front opening of the color laser printer of FIG. 1. FIG. 2 is a plan view schematically showing a state in which developing cartridges are mounted in a process frame in the correct arrangement order in the color laser printer of FIG. 1 and the process frame is accommodated in a main body casing. FIG. 2 is a side cross-sectional view showing a state in which the developing cartridges are mounted on the process frame in the wrong arrangement order in the color laser printer of FIG. 1. It is a sectional side view which shows the state in the middle of accommodating the process frame of FIG. 5 in a main body casing. FIG. 6 is an illustrative plan view showing a state in the middle of housing the process frame of FIG. 5 in the main body casing. FIG. 4 is a side sectional view of a color laser printer according to a second embodiment (a mode in which a switch is provided on a moving path of each identification unit), and developing cartridges are mounted in a correct arrangement order on a process frame drawn from a main body casing. Indicates the state. FIG. 9 is a side sectional view of the color laser printer of FIG. 8, showing a state in which the developing cartridges are mounted in a correct arrangement order on the process frame and the process frame is accommodated in the main body casing. FIG. 9 is a plan view schematically showing a state in which the developing cartridges are mounted on the process frame in the correct arrangement order in the color laser printer of FIG. 8 and the process frame is accommodated in the main body casing. FIG. 9 is a diagram illustrating an example of detection timing of each switch when developing cartridges are mounted in the correct arrangement order at the time of initial setting of the color laser printer of FIG. 8. When the color laser printer shown in FIG. 8 is initially set, the process frame in which the developing cartridges are mounted in the correct arrangement order is pushed halfway into the main body casing, and then pulled out from the main body casing, and then accommodated in the main body casing. It is a figure which shows a detection timing when each switch is performed. FIG. 9 is a diagram illustrating an example of detection timing of each switch when the developing cartridges are mounted in the correct arrangement order when the developing cartridge of the color laser printer of FIG. 8 is replaced. FIG. (B) shows an example in which the yellow developing cartridge and the magenta developing cartridge are respectively replaced with new ones. FIG. 10 is a diagram showing still another example of the detection timing of each switch when the developing cartridge of the color laser printer of FIG. 8 is replaced. FIG. 9 is a side cross-sectional view of the color laser printer of FIG. 8, showing a state in which the developing cartridges are mounted in the wrong arrangement order on the process frame pulled out from the main body casing. FIG. 9 is a side cross-sectional view of the color laser printer of FIG. 8, showing a state in which the developing cartridges are mounted on the process frame in the wrong arrangement order and the process frame is housed in the main body casing. FIG. 9 is a plan view schematically showing a state in which the developing cartridges are mounted on the process frame in the wrong order in the color laser printer of FIG. 8 and the process frame is housed in the main body casing. FIG. 9 is a diagram illustrating an example of detection timing of each switch when developing cartridges are mounted in an incorrect arrangement order when the color laser printer of FIG. 8 is initially set. At the time of initial setting of the color laser printer of FIG. 8, the process frame in which the developing cartridges are mounted in the wrong order is pushed halfway into the main body casing, and then is temporarily pulled out from the main body casing, and then the main body casing. It is a figure which shows a detection timing when each switch is accommodated. FIG. 9A is a diagram illustrating an example of detection timing of each switch when developing cartridges are mounted in the wrong arrangement order when the developing cartridge of the color laser printer of FIG. 8 is replaced. An example in which the magenta developing cartridge is mistakenly replaced is shown, and (b) shows an example in which the yellow developing cartridge and the magenta developing cartridge are mistakenly replaced. FIG. 10 is a diagram showing still another example of the detection timing of each switch when the developing cartridge of the color laser printer of FIG. 8 is replaced. A color laser according to a third embodiment (a mode in which a switch is provided at a position where the identification portions of the developing cartridges mounted in the process frame in the correct arrangement order face each other in a state where the process frame is housed in the main body casing). FIG. 3 is a side sectional view of the printer, showing a state in which developing cartridges are mounted in a correct arrangement order on a process frame drawn out from a main body casing. FIG. 23 is a side cross-sectional view of the color laser printer of FIG. 22, showing a state in which the developing cartridges are mounted on the process frame in the correct arrangement order and the process frame is accommodated in the main body casing. FIG. 23 is a plan view schematically showing a state in which the developing cartridges are mounted in the process frame in the correct arrangement order in the color laser printer of FIG. 22 and the process frame is accommodated in the main body casing. FIG. 23 is a side cross-sectional view of the color laser printer of FIG. 22, showing a state in which the developing cartridges are mounted in the wrong arrangement order on the process frame pulled out from the main body casing. FIG. 23 is a side cross-sectional view of the color laser printer of FIG. 22, showing a state in which the developing cartridges are mounted on the process frame in the wrong arrangement order and the process frame is housed in the main body casing. FIG. 23 is a plan view schematically showing a state in which the developing cartridges are attached to the process frame in the wrong order in the color laser printer of FIG. 22 and the process frame is housed in the main body casing. In the color laser printer according to the fourth embodiment (a mode in which a groove is provided on the upper surface of the housing of each developing cartridge), the side showing a state in which the developing cartridges are mounted in the correct arrangement order on the process frame drawn from the main body casing. It is sectional drawing and a top view. It is the (a) sectional side view and (b) top view which show the state (the 1) which accommodated the process frame shown in FIG. 28 in the main body casing to the middle. It is the (a) sectional side view and (b) top view which show the state (the 2) which accommodated the process frame shown in FIG. 28 in the main body casing to the middle. It is the (a) sectional side view and (b) top view which show the state (the 3) which accommodated the process frame shown in FIG. 28 in the main body casing to the middle. It is the (a) sectional side view and the (b) top view which show the state (the 4) in which the process frame shown in FIG. 28 was accommodated in the main body casing to the middle. FIG. 29 is a side (a) sectional view and a (b) plan view showing a state in which the process frame shown in FIG. 28 is completely accommodated in the main casing. FIG. 29 is a plan view illustrating a state in which the developing cartridge illustrated in FIG. 28 is mounted on the process frame in an incorrect arrangement order, where (a) illustrates a state in which the process frame is pulled out from the main body casing, and (b) illustrates a process frame. A state where the frame is accommodated in the main body casing partway is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color laser printer 2 Main body casing 20 Photosensitive drum 22 Developing cartridge 22 Identification groove 24 Developing roller 26 Toner storage chamber 35 Process frame 38 Identification part 39 Opposing member 40 Switch 41 Switch 42 Identification groove 45 Rotating shaft 46 Oscillating member 47 Free end 48 Guide groove

Claims (6)

A body casing;
A unit frame that is slid and displaced between a state accommodated in the main body casing and a state pulled out from the main body casing;
A cartridge that is provided for each color and includes a developer accommodating portion that accommodates the developer, and is detachably attached to the unit frame;
An identification unit that is provided in a state of projecting outward of the cartridge in each of the cartridges, and is disposed at a different position in a direction orthogonal to the sliding direction of the unit frame for each color;
In the process in which the unit frame is housed in the main body casing, an erroneous mounting detection unit that detects erroneous mounting of the cartridge with respect to the unit frame based on the position of the identification unit,
In the main body casing, the erroneous mounting detection means is disposed on a path through which each identification unit passes when the unit frame is accommodated in the main body casing, and is in a direction orthogonal to the sliding direction of the unit frame. aligned, characterized in that it comprises a switch for detecting the passage of each of the identification unit, images forming device. A body casing;
A unit frame that is slid and displaced between a state accommodated in the main body casing and a state pulled out from the main body casing;
A cartridge that is provided for each color and includes a developer accommodating portion that accommodates the developer, and is detachably attached to the unit frame;
An identification unit that is provided in a state of projecting outward of the cartridge in each of the cartridges, and is disposed at a different position in a direction orthogonal to the sliding direction of the unit frame for each color;
In the process in which the unit frame is housed in the main body casing, an erroneous mounting detection unit that detects erroneous mounting of the cartridge with respect to the unit frame based on the position of the identification unit,
The erroneous mounting detection means is provided in the main body casing, each cartridge is mounted in a normal position with respect to the unit frame, and each identification unit is in a state where the unit frame is accommodated in the main body casing. is disposed at a position abutting, characterized in that it comprises a switch for detecting each said identification unit, images forming device. A body casing;
A unit frame that is slid and displaced between a state accommodated in the main body casing and a state pulled out from the main body casing;
A cartridge that is provided for each color and includes a developer accommodating portion that accommodates the developer, and is detachably attached to the unit frame;
An identification unit provided in each cartridge and arranged at a different position for each color;
In the process in which the unit frame is housed in the main body casing, an erroneous mounting detection unit that detects erroneous mounting of the cartridge with respect to the unit frame based on the position of the identification unit,
The identification unit includes an identification groove formed in each cartridge,
Each of the identification grooves is aligned on an arc in a state where each cartridge is mounted at a normal position with respect to the unit frame,
The erroneous mounting detection means includes
A rotating shaft disposed at the center of the arc and moving integrally with the unit frame;
The free end portion is provided so as to be swingable about the rotation shaft, and each cartridge is mounted at a normal position with respect to the unit frame, and the unit frame is accommodated in the main body casing. There characterized in that it comprises a swing member capable of moving the arc over fitted to each said identification groove, images forming device. The free end portion of the swinging member is moved when the cartridge is mounted at a normal position with respect to the unit frame and is mounted on the main body casing. The image forming apparatus according to claim 3 , further comprising a guide groove that guides the image. The held in the unit frame, characterized in that it comprises an image bearing member on which an electrostatic latent image is formed on the surface, the image forming apparatus according to any one of claims 1 to 4. The image forming apparatus according to claim 5 , wherein the cartridge includes a developer carrier that supplies a developer to the image carrier and visualizes the electrostatic latent image. .

Images