Image forming apparatus

Abstract

Ensure that the laser beam is reliably blocked even when opening and closing the cover during the attachment or detachment of replacement units other than the cartridge. [Solution] The device comprises a cartridge P, a laser scanner 2, a fixing device 80, a shutter 2S, and a door 20. The shutter 2S is movable between a shielding position that blocks the laser light when the fixing device 80 is detached from the device body 1A, and a transparent position that does not block the laser light when the fixing device 80 is attached to the device body 1A and the door 20 is closed.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus that forms an image on a recording medium using a cartridge.

Background Art

[0002] Conventional image forming apparatuses have adopted a cartridge system in which an electrophotographic photosensitive member and process means acting on the electrophotographic photosensitive member are integrated into a cartridge, and this cartridge is detachable from the main body of the image forming apparatus. According to the cartridge system, since the maintenance of the apparatus can be performed by the user himself / herself without relying on a service technician, the operability can be improved. Therefore, this cartridge system is widely used in image forming apparatuses. In an image forming apparatus adopting the cartridge system, a mechanism for shielding laser light is incorporated so that the laser light is not inadvertently irradiated when replacing the cartridge or performing maintenance on other various components. As these mechanisms, there are those in which the shutter member is opened and closed in conjunction with the opening and closing of the cover when the cartridge is detached and attached, and those in which the shutter member is opened and closed in conjunction with the detachment and attachment of the cartridge (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In conventional technology, when opening and closing the cover to insert or remove a cartridge, the laser shutter opens and closes in accordance with the cartridge insertion / removal operation, so the laser light does not irradiate the outside. Some image forming apparatuses have a configuration in which the cover is opened and closed not only for inserting and removing cartridges, but also for inserting and removing replacement parts such as the fuser and secondary transfer unit for maintenance, and the aforementioned replacement units shield the laser light regardless of whether a cartridge is present or not. In image forming apparatuses with such a configuration, it is necessary for the laser shutter to open and close in accordance with the insertion and removal operations of replacement parts other than cartridges.

[0005] This invention was made under such circumstances, and aims to reliably block laser light even when the cover is opened and closed when attaching or detaching replacement units other than the cartridge. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the present invention has the following configuration.

[0007] (1) An image forming apparatus comprising: a cartridge having an image carrier and detachable from the main body of the apparatus; a scanner that emits laser light to form a latent image on the image carrier; a fixing device that is detachable from the main body of the apparatus and fixes a toner image onto a sheet onto which a toner image developed from the latent image formed on the image carrier has been transferred; a shielding member capable of shielding the optical path of the laser light emitted from the scanner; and an opening / closing member that can be opened and closed relative to the main body of the apparatus for attaching and detaching the cartridge and the fixing device, wherein the shielding member is movable between a shielding position that shields the laser light when the fixing device is detached from the main body of the apparatus and a transmission position that does not shield the laser light when the fixing device is attached to the main body of the apparatus and the opening / closing member is closed.

[0008] (2) An image forming apparatus comprising: a cartridge having an image carrier and detachable from the main body of the apparatus; a scanner that emits laser light to form a latent image on the image carrier; a fixing device that is detachable from the main body of the apparatus and fixes a toner image onto a sheet onto which a toner image developed from the latent image formed on the image carrier has been transferred; an opening / closing member that can be opened and closed relative to the main body of the apparatus for attaching and detaching the cartridge and the fixing device; a first detection means for detecting whether the fixing device is attached to the main body of the apparatus; a second detection means for detecting whether the opening / closing member is in an open or closed state; and a control means for enabling the scanner to emit laser light or controlling the scanner so as not to emit laser light based on the detection results of the first and second detection means.

[0009] (3) An image forming apparatus comprising: a cartridge having an image carrier and detachable from the main body of the apparatus; a scanner that emits laser light to form a latent image on the image carrier; a fixing device detachable from the main body of the apparatus for fixing a toner image onto a sheet onto which a toner image developed from the latent image formed on the image carrier has been transferred; an interlock that can switch between a power-off state in which no power is supplied to the main body of the apparatus and a power-supply state in which power is supplied to the main body of the apparatus; and an opening / closing member that can be opened and closed relative to the main body of the apparatus for attaching and detaching the cartridge and the fixing device, wherein the interlock is in the power-off state when the fixing device is detached from the main body of the apparatus, and is in the power-supply state when the fixing device is attached to the main body of the apparatus and the opening / closing member is closed. [Effects of the Invention]

[0010] According to the present invention, laser light can be reliably blocked even when the cover is opened and closed when attaching or detaching replacement units other than the cartridge. [Brief explanation of the drawing]

[0011] [Figure 1] Diagram illustrating the overall configuration of the printer in Example 1. [Figure 2] Diagram showing the door open state in Example 1, Diagram showing the movement state of the fixing device [Figure 3] A diagram showing the extension state of the transfer unit and tray unit in Example 1, and a diagram showing the extension state of the transfer unit alone. [Figure 4] Diagram showing the laser shielding state by the fixing device of Example 1. [Figure 5] Diagram showing the fixing device and the link operation linked to the door in Example 1. [Figure 6] Diagram showing the configuration of the shutter in Example 1 [Figure 7] Top view and cross-sectional view showing the scanner configuration including the shutter of Example 1 [Figure 8] Cross-sectional view showing the shielding and transmission states of the shutter in Example 1. [Figure 9] Figure showing the fixing device and sensor detection operation linked to the door in Example 2. [Figure 10] This figure shows the fixing device and the interlock detection operation linked to the door in Example 3. [Modes for carrying out the invention]

[0012] The embodiments for carrying out this invention will be described in detail below with reference to the drawings, based on examples. However, the dimensions, materials, shapes, and relative arrangements of the components described in these embodiments should be appropriately modified depending on the configuration of the device to which the invention is applied and various conditions. In other words, the scope of this invention is not intended to be limited to the following embodiments. [Examples]

[0013] [Overall structure] Using Figure 1, the printer 1 as an image forming apparatus will be described. In the following description, the vertical direction will be the Z direction, the direction in which the replacement unit described later is pulled out will be the X direction, and the direction perpendicular to the Z direction and the X direction will be the Y direction. Figure 1 is a diagram illustrating the overall configuration of the printer 1 of Embodiment 1. The printer 1 is an electrophotographic color laser beam printer that forms an image on a sheet S (on the recording material) as a recording material. The printer 1 has a device body (housing) 1A, a scanner (exposure device) 2, a control unit 3, and a door 20 as an opening / closing member that can be opened and closed relative to the device body 1A. The printer 1 has a sheet feeding unit 30, a transfer unit 40, a tray unit (tray unit, moving unit, support unit) 50, and a fixing device 80. The part including the device body 1A and the door 20 can also be called the main frame 100. The main frame 100 includes the exterior of the printer 1. The device body 1A houses the laser scanner 2 (scanner), the control unit 3, the sheet feeding unit 30, the transfer unit 40, the tray unit 50, and the fixing device 80. The sheet feeding unit 30 has a loading tray 31 for loading sheets S and a supply roller 32. The loading tray 31 can be pulled out in the direction of the door 20 to replenish the sheets S.

[0014] The tray unit 50 has a tray (support member, drawer) 51 and cartridges PY, PM, PC, PK. The tray 51 has a tray handle 52. The cartridges PY, PM, PC, PK are detachably mounted to the tray 51. Each of the cartridges PY, PM, PC, PK is detachable from the tray 51 independently of one another. The cartridges PY, PM, PC, PK each contain toner (developer) of yellow (Y), magenta (M), cyan (C), and black (K), respectively. The cartridges PY, PM, PC, PK have the same configuration except for the different colors of the toner they contain. Therefore, the configuration and operation of any one of the cartridges PY, PM, PC, PK may be described, and the description of the others may be omitted. Also, when it is not necessary to distinguish between the cartridges PY, PM, PC, PK, the cartridges PY, PM, PC, PK may simply be referred to as cartridge P. The tray unit 50 can be said to have a plurality of cartridges P and a tray 51 to which the plurality of cartridges P are detachably mounted.

[0015] In Example 1, the tray unit 50 has a plurality of photosensitive drums (image carriers, photoreceptors) 61, a plurality of charging rollers 62 (charging members), and a plurality of developing rollers (developer carriers, developing members) 71. Specifically, the tray unit 50 has four photosensitive drums 61, four charging rollers 62, and four developing rollers 71. The rotational axis directions of the photosensitive drum 61, the developing roller 71, and the charging roller 62 are parallel. The portion for forming a black (K) image is called the black station (first station), the photosensitive drum 61 of the first station is called the first photosensitive drum, the developing roller 71 is called the first developing roller, and the charging roller 62 is called the first charging roller. The portion for forming a cyan (C) image is called the cyan station (second station), the photosensitive drum 61 of the second station is called the second photosensitive drum, the developing roller 71 is called the second developing roller, and the charging roller 62 is called the second charging roller. The portion for forming a magenta (M) image is called the magenta station (third station), the photosensitive drum 61 of the third station is called the third photosensitive drum, the developing roller 71 is called the third developing roller, and the charging roller 62 is called the third charging roller. The portion for forming a yellow (Y) image is called the yellow station (fourth station), the photosensitive drum 61 of the fourth station is called the fourth photosensitive drum, the developing roller 71 is called the fourth developing roller, and the charging roller 62 is called the fourth charging roller.

[0016] Cartridge PK is mounted on the black station, cartridge PC is mounted on the cyan station, cartridge PM is mounted on the magenta station, and cartridge PY is mounted on the yellow station, respectively. In Example 1, cartridge PK is called the first cartridge, cartridge PC is called the second cartridge, cartridge PM is called the third cartridge, and cartridge PY is called the fourth cartridge. The numbers such as first, second, third, and fourth are used for convenience of explanation. The photosensitive drum 61, the charging roller 62, and the developing roller 71 may be provided in either cartridge P or tray 51. In Example 1, cartridge P has the photosensitive drum 61, the charging roller 62, and the developing roller 71.

[0017] The transfer unit 40 includes a belt 41, a primary transfer roller 42, a cleaning unit 43, a drive roller 46 for driving the belt 41, and a tension roller (driven roller) 47. The printer 1 is equipped with an optical sensor 44 for detecting the toner image (developer image) transferred to the belt 41. The belt 41 is positioned below the photosensitive drum 61 and is able to contact the photosensitive drum 61 so that a primary transfer section is formed between the belt 41 and the photosensitive drum 61. The printer 1 also has a secondary transfer roller 45 (transfer member) that contacts the belt 41 so that a secondary transfer section is formed. The secondary transfer section is formed between the belt 41 and the secondary transfer roller 45. The rotational axis directions of the primary transfer roller 42, the drive roller 46, the tension roller 47, and the secondary transfer roller 45 are parallel. A pair of registration rollers 4 is positioned in front of the secondary transfer section.

[0018] (Fusing device) The fixing device 80 includes a fixing unit 81 and a flapper 5. When an image forming operation is performed on the sheet S, the fixing device 80 is in the use position. When the shutter 2S, described later, is in a transparent state, the fixing device 80 in the use position shields the laser beam from the door 20 at the upstream end with respect to the projection direction of the laser beam and the door 20. The fixing device 80 is housed inside the main body 1A when in the use position. The fixing device 80 is also configured to heat the sheet S when in the use position. In Embodiment 1, the fixing unit 81 includes a heating unit (heating roller) including a heater and a pressurizing unit (pressurizing roller).

[0019] The movement of the transfer unit 40 and the tray unit 50 will be explained using Figures 1, 2, and 3. Note that some reference numerals have been omitted in Figures 1 to 3. Figure 2(a) shows the printer 1 with the door 20 open. Figure 2(b) shows the printer 1 with the fuser 80 moved. Figure 3(a) shows the printer 1 with the transfer unit 40 and the tray unit 50 extended. Figure 3(b) shows the printer 1 with the transfer unit 40 extended independently.

[0020] The transfer unit 40 and the tray unit 50 are movable from the inside to the outside of the device body 1A. In the horizontal direction X, the device body 1A has a first end 1b1 with an opening 1A1 and a second end 1b2 opposite to the first end 1b1. The tray unit 50 is movable through the opening 1A1 to a first inner position inside the device body 1A and to a first outer position outside the device body 1A. The transfer unit 40 is movable through the opening 1A1 to a second inner position inside the device body 1A and to a second outer position outside the device body 1A. The opening 1A1 may include an opening through which the tray unit 50 passes and an opening through which the transfer unit 40 passes. When the transfer unit 40 moves from the second inner position to the second outer position, at least the belt 41 moves, and at least a portion of the belt 41 protrudes from the device body 1A toward the outside of the device body 1A.

[0021] The direction in which the tray unit 50 moves from the first inner position to the first outer position is called the tray removal direction Dd1, and the direction opposite to the tray removal direction Dd1 is called the tray mounting direction Da1. The tray removal direction Dd1 can be described as the direction from the second end 1b2 to the first end 1b1. The direction in which the transfer unit 40 moves from the second inner position to the second outer position is called the transfer removal direction Dd2, and the direction opposite to the transfer removal direction Dd2 is called the transfer mounting direction Da2. In the transfer removal direction Dd2, the drive roller 46 is located downstream of the tension roller 47. The transfer removal direction Dd2 can be described as the direction from the second end 1b2 to the first end 1b1.

[0022] The tray removal direction Dd1 and the tray mounting direction Da1 are directions that intersect (preferably orthogonal to) the rotation axis direction of the photosensitive drum 61. The transfer removal direction Dd2 and the transfer mounting direction Da2 are directions that intersect (preferably orthogonal to) the rotation axis direction of the drive roller 46. The rotation axis direction of the drive roller 46 is parallel to the rotation axis direction of the photosensitive drum 61. In the horizontal direction X, a fixing device 80 is positioned on one end of the device body 1A (the side on which the first end portion 1b1 is located).

[0023] The door 20 attached to the device body 1A is movable between a closed position and an open position. As shown in Figure 1, when the door 20 is in the closed position (closed state), the door 20 covers the opening 1A1. As shown in Figure 2(a), when the door 20 is in the open position (open state), the opening 1A1 is exposed. As shown in Figure 1, when the door 20 is in the closed position, the door 20 covers the fixing device 80 attached to the device body 1A. More specifically, when the door 20 is in the closed position, the upper cover portion 20b of the door 20 is located above the fixing device 80. The upper cover portion 20b of the door 20 functions as part of the exterior. The door 20 can move between the open position and the closed position while the fixing device 80 is supported by the device body 1A. In other words, the door 20 moves from the closed position to the open position so as to move away from the fixing device 80 supported by the device body 1A. Therefore, as shown in Figure 2(a), when the door 20 is in the open position, the door 20 is separated from the fixing device 80 supported by the main body 1A of the device.

[0024] The fixing device 80 is movable from the state shown in Figure 2(a) to the state shown in Figure 2(b) so that the opening 1A1 is widely exposed. More specifically, the fixing device 80 can be retracted in the +Z direction (upward) so that the opening 1A1 is widely exposed. With the door 20 and the fixing device 80 moved (Figure 2(b)), the transfer unit 40 and the tray unit 50 can move from the inside to the outside of the device body 1A through the opening 1A1, and after the movement, it will be in the state shown in Figure 3(a). In this way, because the fixing device 80 can be retracted upward, the transfer unit 40 and the tray unit 50 can be housed in the device body 1A diagonally rather than horizontally, as shown in Figure 1, etc. Reference numeral 85 denotes an arm for moving the fixing device 80 upward, and reference numeral 85A denotes the pivot axis of the arm 85.

[0025] With the tray unit 50 moved outside the main body 1A of the device (Figure 3(a)), it is permissible to remove cartridges PY, PM, PC, and PK from the tray 51 and to install cartridges PY, PM, PC, and PK onto the tray 51. This allows cartridges PY, PM, PC, and PK to be replaced with new cartridges PY, PM, PC, and PK. In Embodiment 1, cartridge P is detachable from the tray 51 in a direction intersecting (preferably perpendicular to) the rotation axis of the photosensitive drum 61.

[0026] Cartridges PY, PM, PC, and PK are removed from tray 51 by moving away from the transfer unit 40 relative to the tray 51. In other words, cartridges PY, PM, PC, and PK are removed from tray 51 by moving away from the transfer unit 40 relative to the tray 51. In Embodiment 1, the transfer unit 40 is located below the tray unit 50. Therefore, cartridges PY, PM, PC, and PK are removed from tray 51 by moving upward relative to the tray 51. Furthermore, the transfer unit 40 is removable from the apparatus body 1A independently of the tray unit 50 and can be replaced with a new transfer unit 40.

[0027] [Image Formation Process] The image formation operation of printer 1 will be explained using Figure 1. The control unit 3 of printer 1 starts the image formation operation on the sheet S based on the image signal received from the external host device 400. The external host device 400 is, for example, a personal computer, an image reader, and a facsimile machine.

[0028] When an image is formed on the sheet S, the fixing device 80 is in the use position, the tray unit 50 is in the first inner position, the transfer unit 40 is in the second inner position, and the door 20 is in the closed position. With the transfer unit 40 in the second inner position, the belt 41 can contact the photosensitive drum 61. At this time, the tray unit 50 is positioned above the transfer unit 40.

[0029] When an image is formed on the sheet S, a charging voltage is applied to the charging roller 62, causing the photosensitive drum 61 to rotate. A laser corresponding to the image information is emitted from the laser scanner 2 to the photosensitive drum 61, and the surface of the photosensitive drum 61, which has been charged by the charging roller 62, is exposed. As a result, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 61.

[0030] The developing roller 71 carries toner. A developing voltage is applied to the developing roller 71, and the electrostatic latent image formed on the photosensitive drum 61 is developed by the toner supplied from the developing roller 71, forming a toner image on the surface of the photosensitive drum 61. In Example 1, the developing roller 71 develops the electrostatic latent image while in contact with the photosensitive drum 61, but the developing roller 71 may develop the electrostatic latent image with a gap between the developing roller 71 and the photosensitive drum 61.

[0031] When a full-color image is formed, toner images of each color are formed on each photosensitive drum 61. In Embodiment 1, with the tray unit 50 in the first inner position, the developing roller 71 is movable between a contact position in contact with the photosensitive drum 61 and a separated position away from the photosensitive drum 61. Specifically, a switching device provided in the main body 1A switches between the developing roller 71 being in the contact position and the developing roller 71 being in the separated position. This allows the developing roller 71 to be kept away from the photosensitive drum 61 when no image forming operation is being performed.

[0032] Furthermore, printer 1 can perform monochrome printing with the developing roller 71 and photosensitive drum 61 corresponding to cartridge PK in contact, and with the developing roller 71 and photosensitive drum 61 corresponding to cartridges PY, PM, and PC separated. In addition, printer 1 can perform full-color printing with the photosensitive drum 61 and belt 41 corresponding to cartridges PY, PM, PC, and PK in contact. The toner images formed on each photosensitive drum 61 are transferred in the primary transfer section by the primary transfer roller 42 onto the belt 41 and then transported toward the secondary transfer section formed by the belt 41 and the secondary transfer roller 45.

[0033] Meanwhile, the main body 1A of the device has a transport path (first path, first transport path) 1c through which the sheet S heading toward the fixing device 80 passes. The door 20 also has a double-sided transport path (second path, second transport path) 20a through which the sheet S that has passed through the fixing device 80 passes. When the door 20 is closed, it covers the transport path 1c. When the door 20 is opened, the transport path 1c and the double-sided transport path 20a are exposed (see Figure 2(a)).

[0034] In the sheet feeding unit 30, one sheet S is separated and fed at a predetermined timing by the supply roller 32 from among the multiple sheets S loaded on the loading tray 31, and is transported through the transport path 1c toward the secondary transfer unit and the fixing device 80. In the secondary transfer unit, the toner image is transferred from the belt 41 to the sheet S. Toner that was not transferred to the sheet S is removed from the belt 41 by a cleaning blade (cleaning member) 43A provided in the cleaning unit 43.

[0035] In the secondary transfer section, the sheet S onto which the toner image has been transferred is transported toward the fuser unit 80. In the fuser unit 80, the sheet S is heated and pressurized in the fuser unit 81, and the unfixed toner image is fixed to the sheet S. The sheet S with the fixed toner image is transported toward the flapper 5, which acts as a path switching unit. The flapper 5 is movable between an discharge position that guides the sheet S that has passed through the fuser unit 80 toward the discharge path 1d and a reversal position that guides it toward the reversal path 1e. When single-sided printing is performed, in which an image is formed on one side of the sheet S, the sheet S is guided toward the discharge path 1d by the flapper 5 and discharged into the discharge tray 1f formed on the upper part of the main body 1A of the device.

[0036] On the other hand, when double-sided printing is performed in which an image is printed on one side and the other side of the sheet S, the sheet S is guided to the reversal path 1e by the flapper 5. After the sheet S is guided to the reversal path 1e, the transport direction of the sheet S is reversed, and the sheet S is transported through the double-sided transport path 20a formed in the door 20 toward the secondary transfer section. In the secondary transfer section, after the toner image is transferred to the back side of the sheet S, the sheet S passes through the fuser 80, is guided to the discharge path 1d by the flapper 5, and is discharged into the discharge tray 1f of the main body 1A.

[0037] [Shutter operation based on door opening / closing and the attachment / detachment status of the fixing device] As described above, the photosensitive drum 61, which is charged by the charging roller 62, is irradiated with lasers 2Y, 2M, 2C, and 2K (see Figure 4) from the laser scanner 2 to form an electrostatic latent image. These lasers 2Y, 2M, 2C, and 2K must be reliably shielded by the exterior, including the door 20, from the standpoint of user safety. Therefore, it is necessary to control the laser irradiation state from the laser scanner 2 by operating the openable and closable door 20. In addition, it is necessary to shield the lasers 2Y, 2M, 2C, and 2K depending on the mounting state of the main body 1A of the device, which includes the tray unit 50 containing the user-replaceable cartridges PY, PM, PC, and PK, the transfer unit 40, and the fixing device 80.

[0038] Figure 4 shows the state in which the fuser unit 80 is mounted on the device body 1A when the tray unit 50 containing cartridges PY, PM, PC, and PK, and the transfer unit 40 are not mounted on the device body 1A. Figure 4(a) shows the fuser unit 80 mounted on the device body 1A, and the lasers 2Y, 2M, 2C, and 2K are shielded regardless of whether the door 20 is open or closed. Here, Ls is a virtual line representing the user's line of sight, and will be referred to as virtual line Ls below. Even if the door 20 were open in Figure 4(a), the virtual line Ls intersects with the fuser unit 80, so the lasers 2Y, 2M, 2C, and 2K, especially the laser 2Y which is closest to the viewer from the door 20 side, are shielded by the fuser unit 80.

[0039] On the other hand, in Figure 4(b), the fixing device 80 is not mounted on the main body 1A, and when the door 20 is opened, lasers 2Y, 2M, 2C, and 2K are not shielded. In other words, if the door 20 were open in Figure 4(b), lasers 2Y, 2M, 2C, and 2K, especially laser 2Y which is closest to the door 20, would not be shielded by the fixing device 80. Therefore, it is necessary to control the laser shielding state according to the state in which the fixing device 80 is mounted on the main body 1A.

[0040] To achieve this requirement, a shutter 2S that shields the laser, a fixing link 80L that is linked to the attachment and detachment of the fixing device 80, and a shutter link 90 are required, as shown in Figure 5. The shutter 2S is a shielding member that can block the optical path of the laser light emitted from the laser scanner 2. Figure 5(a) shows the fixing device 80 mounted on the device body 1A and the door 20 closed. In this state, the fixing link 80L inside the fixing device 80 moves due to the pressing member 20P (pressing part) located on the door 20. More specifically, the fixing link 80L moves when one end 80La (pressed part) of the fixing link 80L is pressed by the pressing member 20P.

[0041] The shutter link 90 moves in accordance with the movement of the fixing link 80L. More specifically, the shutter link 90 moves when one end 90a of the shutter link 90 is pressed against the other end 80Lb of the fixing link 80L. At this time, as the shutter link 90 moves, the shutter 2S rotates in a counterclockwise direction (hereinafter referred to as the CCW direction) when viewed from the side of the regulating wall 2S4, which will be described later, so that the lasers 2Y, 2M, 2C, and 2K can be irradiated. That is, the shutter 2S moves to the transmission position when the pressing member 20P is pressing against the end 80La of the fixing link 80L.

[0042] Figure 5(b) shows the state in which the fixing device 80 is attached to the main body 1A and the door 20 has begun to open. As the door 20 moves from the state in Figure 5(b) to the open state in Figure 2(a), the pressing member 20P moves away from the end 80La of the fixing link 80L. The fixing link 80L is biased by an elastic member (not shown) to follow the movement of the pressing member 20P. The shutter link 90 is also biased by an elastic member (not shown) to follow the movement of the fixing link 80L. As the door 20 opens in this way, the shutter link 90 moves away, and the shutter 2S rotates clockwise (hereinafter referred to as the CW direction) when viewed from the side of the regulating wall 2S4, thereby shielding the lasers 2Y, 2M, 2C, and 2K. In other words, the shutter 2S moves to the shielding position when the pressing member 20P moves away from the end 80La.

[0043] As shown in Figure 5(c), when the fixing device 80 is detached from the main body 1A, the fixing link 80L does not exist. Therefore, the shutter link 90 moves apart and the shutter 2S rotates in the CW direction, so that the lasers 2Y, 2M, 2C, and 2K are always shielded by the shutter 2S regardless of whether the door 20 is open or closed.

[0044] [Screenshot operation to control laser shielding and irradiation] Next, the laser shielding configuration associated with the shutter operation described above will be explained in detail. Figure 6 shows a schematic perspective view of the shutter 2S of Embodiment 1. The shutter 2S is movable between a shielding position in which the laser light is shielded when the fixing device 80 is detached from the main body 1A, and a transmission position in which the laser light is not shielded when the fixing device 80 is attached to the main body 1A and the door 20 is closed.

[0045] As shown in Figure 6, the shutter 2S consists of a rotating shaft 2S1, a laser beam shielding wall 2S2, a rotating boss 2S3, a regulating wall 2S4, and a positioning projection 2S5 (first engaging part). Figure 7(a) shows a bottom view of the shutter 2S installed on the laser scanner 2 (view of the laser scanner 2 from the bottom side of the device body 1A), and Figure 7(b) shows a cross-sectional view. First, the center CL of the rotating shaft 2S1 of the shutter 2S is located below the rotating polyhedron mirror 210 of the laser scanner 2, and is positioned on the bisector E of the lasers 2K, 2C and 2M, 2Y incident from a semiconductor laser (not shown) onto the rotating polyhedron mirror 210. The direction of the rotating shaft 2S1 is the Y direction, and the direction of the rotation axis of the rotating polyhedron mirror 210 is the Z direction.

[0046] Next, the positional restrictions of the shutter 2S relative to the laser scanner 2 will be explained. As shown in Figure 7(a), the X direction is restricted by the rotation axis 2S1 provided on the laser scanner 2, specifically by the first restricting wall 201 and the second restricting wall 202. The Y direction is restricted by the shielding wall 2S2 and the restricting wall 2S4 sandwiching the first restricting wall 201 and the second restricting wall 202. As shown in Figure 7(b), the Z direction is restricted by the rotation axis 2S1 provided on the laser scanner 2, specifically by the third restricting wall 203 and the fourth restricting wall 204, and by the fifth restricting wall 205 and the sixth restricting wall 206, which are positioned opposite the third restricting wall 203 and the fourth restricting wall 204, respectively.

[0047] More specifically, on the side of the rotating shaft 2S1 where the shielding wall 2S2 is provided, movement in the Z direction is restricted by the third restricting wall 203 and the fifth restricting wall 205, which is provided opposite the third restricting wall 203. On the side of the rotating shaft 2S1 where the restricting wall 2S4 is provided, movement in the Z direction is restricted by the fourth restricting wall 204 and the sixth restricting wall 206, which is provided opposite the fourth restricting wall 204. In addition, clearances are provided between each restricting part to allow the shutter 2S to operate smoothly.

[0048] Next, the operation of the shutter 2S in Example 1 will be explained with reference to Figure 8. Figure 8(a) shows the positional relationship between the shutter 2S, lasers 2K, 2C, 2M, 2Y and the rotating polyhedron mirror 210 when the door 20 is open or the fixing device 80 has been removed. Figure 8(b) shows the positional relationship between the shutter 2S, lasers 2K, 2C, 2M, 2Y and the rotating polyhedron mirror 210 when the fixing device 80 is installed and the door 20 is closed.

[0049] As shown in Figure 8(a), when the door 20 is open or the fixing device 80 is removed, the lasers 2K, 2C, 2M, and 2Y are prevented from leaking outside the laser scanner 2. That is, the optical paths of the lasers 2K, 2C, 2M, and 2Y from the semiconductor laser (not shown) to the rotating polyhedron mirror 210 are blocked by the shielding wall 2S2. At this time, as viewed from the side of the restricting wall 2S4, the shutter 2S rotates in the CW direction, and the positioning projection 2S5 engages (contacts) with the engaging portion 90e of the shutter link 90 to maintain its position. As shown in Figure 8(b), when the door 20 is closed and the fixing device 80 is installed, as viewed from the side of the restricting wall 2S4, the shutter 2S rotates in the CCW direction. This opens the optical paths of the lasers 2K, 2C, 2M, and 2Y from the semiconductor laser (not shown) to the rotating polyhedron mirror 210, allowing the electrostatic latent image described above to be formed.

[0050] In Example 1, the fixing link 80L and the shutter link 90 are configured to operate linearly, but the method of operation is not limited to linear motion. Also, the shutter 2S rotates to irradiate / shield the laser, but the operation of the shutter 2S is not limited to rotation; it may also irradiate / shield the laser linearly. In this way, the fixing link 80L, shutter link 90, and shutter 2S, which are linked to the attachment and detachment of the fixing device 80, ensure that the lasers 2Y, 2M, 2C, and 2K are reliably shielded regardless of the state in which the user opens the door 20.

[0051] As described above, according to Example 1, the laser light can be reliably blocked even when the cover is opened and closed when attaching or detaching replacement units other than the cartridge. [Examples]

[0052] <Electric shutter> Example 2 is a configuration in which the shielding state of lasers 2Y, 2M, 2C, and 2K is controlled by means of detecting the state in which the fixing device 80 is attached to the device body 1A, without using the fixing link 80L and shutter link 90 described in Example 1 above.

[0053] As shown in Figure 9, the printer 1 is equipped with a fuser switch 80S that detects whether the fuser unit 80 is mounted on the main unit 1A, and a door switch 20S (second detection means) that detects whether the door 20 is open or closed. The door 20 has a pressing portion 20c that presses against the door switch 20S. The fuser unit 80 has a pressing portion 80a that presses against the fuser switch 80S. The pressing portion 80a may be the bottom of the fuser unit 80. The fuser switch 80S functions as a first detection means (detection means) that detects whether or not the fuser unit 80 is mounted on the main unit 1A. The control unit 3 functions as a control means that controls the laser scanner 2 based on the detection result from the fuser switch 80S.

[0054] The control unit 3 receives detection signals from the fixing switch 80S and the door switch 20S. The control unit 3 determines that the fixing device 80 is installed when the pressing part 80a is pressing the fixing switch 80S, and determines that the fixing device 80 is removed when the pressing part 80a is not pressing the fixing switch 80S. The control unit 3 also determines that the door 20 is closed when the pressing part 20c is pressing the door switch 20S, and determines that the door 20 is open when the pressing part 20c is not pressing the door switch 20S.

[0055] If the control unit 3 detects, based on the detection result of the fixing switch 80S, that the fixing device 80 has been removed from the main unit 1A, it controls the laser scanner 2 so as not to emit (remove) lasers 2Y, 2M, 2C, and 2K. On the other hand, if the control unit 3 detects, based on the detection result of the fixing switch 80S, that the fixing device 80 has been attached to the main unit 1A, it further detects, based on the detection result of the door switch 20S, that the door 20 has been closed, and then emits lasers 2Y, 2M, 2C, and 2K.

[0056] In Figure 9(a), the door 20 is closed and the fixing device 80 is installed, so the control unit 3 is in a state where it can emit a laser from the laser scanner 2 (ready to emit). On the other hand, in Figure 9(b), the fixing device 80 is installed but the door 20 is open, so the control unit 3 does not emit a laser from the laser scanner 2. In Figure 9(c), the door 20 is closed but the fixing device 80 is not installed, so the control unit 3 does not emit a laser from the laser scanner 2.

[0057] In this way, the control unit 3 controls the irradiation / shielding of lasers 2Y, 2M, 2C, and 2K based on the detection signals from the fixing switch 80S and the door switch 20S. This ensures that lasers 2Y, 2M, 2C, and 2K are reliably shielded regardless of the user's circumstances when opening the door 20.

[0058] Alternatively, the printer 1 may be equipped with the shutter 2S of Embodiment 1, and the control unit 3 may control the shutter 2S based on the detection results of the fuser switch 80S and the door switch 20S. That is, the control unit 3 may control the shutter 2S to move to the transparent position when the fuser device 80 is installed and the door 20 is closed, based on the detection results of the fuser switch 80S and the door switch 20S. Alternatively, the control unit 3 may control the shutter 2S to move to the shielding position when the fuser device 80 is removed or the door 20 is open, based on the detection results of the fuser switch 80S and the door switch 20S.

[0059] As described above, according to Example 2, the laser light can be reliably blocked even when the cover is opened and closed when attaching or detaching replacement units other than the cartridge. [Examples]

[0060] <Interlock shutter> In Example 3, the interlock switch 101 is controlled by the other end 90b of the shutter link 90 pressing against the arm 101a of the interlock switch 101, as described in Example 1 above. This interlock switch 101 is an electrical component that controls the supply of power to the main unit 1A of the device. The interlock switch 101 can switch between a power-off state in which no power is supplied to the printer 1 and a power-supply state in which power is supplied to the printer 1. The interlock switch 101 is in a power-off state when the fuser unit 80 is removed from the main unit 1A of the device, and in a power-supply state when the fuser unit 80 is attached to the main unit 1A and the door 20 is closed.

[0061] As shown in Figure 10, the fixing device 80 is mounted on the main body 1A by the operation of the fixing link 80L and the shutter link 90, similar to Embodiment 1, and when the door 20 is closed, the interlock switch 101 is driven. Similar to Embodiment 1, the fixing device 80 has an end portion 80La (pressed portion) of the fixing link 80L that is pressed by the pressing member 20P (pressing portion) of the door 20. The interlock switch 101 is powered when the pressing member 20P is pressing the end portion 80La (Figure 10(a)). Power is supplied to the main body 1A, and lasers 2Y, 2M, 2C, and 2K are irradiated.

[0062] On the other hand, when the door 20 is open, or when the fixing device 80 is detached from the main body 1A, the interlock switch 101 is not driven (Figures 10(b) and 10(c)). The interlock switch 101 enters a power-off state when the pressing member 20P separates from the end 80La. Since no power is supplied to the main body 1A, the lasers 2Y, 2M, 2C, and 2K are not emitted, which is equivalent to the lasers 2Y, 2M, 2C, and 2K being shielded.

[0063] In this way, the drive of the interlock switch 101 is controlled by the fixing link 80L and the shutter link 90, which are linked to the attachment and detachment of the fixing device 80. As a result, lasers 2Y, 2M, 2C, and 2K can be reliably shielded regardless of the state in which the user opens the door 20.

[0064] As described above, according to Example 3, the laser light can be reliably blocked even when the cover is opened and closed when attaching or detaching replacement units other than the cartridge.

[0065] This embodiment includes the following configuration. (Composition 1) A cartridge having an image carrier and being detachable from the main body of the device, A scanner that emits laser light to form a latent image on the image carrier, A fixing device that is detachable from the main body of the device and fixes the toner image onto a sheet onto which a toner image has been transferred, which is a toner image developed from a latent image formed on the image carrier, A shielding member capable of blocking the optical path of the laser light emitted from the scanner, An opening / closing member that can be opened and closed relative to the main body of the device in order to attach and detach the cartridge and the fixing device, Equipped with, The shielding member is movable between a shielding position that shields the laser light when the fixing device is detached from the main body of the device, and a transmission position that does not shield the laser light when the fixing device is attached to the main body of the device and the opening / closing member is closed. An image forming apparatus characterized by the following features. (Configuration 2) When the shielding member is in the transmission position, the fixing device shields the laser beam from the opening / closing member at the upstream position with respect to the projection direction of the laser beam and the opening / closing member. The image forming apparatus according to configuration 1, characterized in that... (Composition 3) The opening / closing member has a pressing portion, The fixing device has a part to be pressed by the pressing part, The shielding member is in the transparent position when the pressing portion is pressing the pressed portion, and moves to the shielding position when the pressing portion moves away from the pressed portion. The image forming apparatus according to configuration 1, characterized in that it is a picture forming apparatus. (Composition 4) A detection means for detecting whether the fixing device is attached to the main body of the device, A control means for controlling the shielding member to switch the shielding member to the shielding position or the transparent position based on the detection result by the detection means, Equipped with, The image forming apparatus according to configuration 1, characterized in that... (Composition 5) A cartridge having an image carrier and being detachable from the main body of the device, A scanner that emits laser light to form a latent image on the image carrier, A fixing device that is detachable from the main body of the device and fixes the toner image onto a sheet onto which a toner image has been transferred, which is a toner image developed from a latent image formed on the image carrier, An opening / closing member that can be opened and closed relative to the main body of the device in order to attach and detach the cartridge and the fixing device, A first detection means for detecting whether the fixing device is attached to the main body of the device, A second detection means for detecting the open or closed state of the opening / closing member, A control means that enables the scanner to emit laser light or controls the scanner so as not to emit laser light based on the detection results from the first detection means and the second detection means, Equipped with, An image forming apparatus characterized by the following features. (Composition 6) The control means enables the scanner to emit laser light when the first detection means detects that the fixing device is mounted on the device body and the second detection means detects that the opening / closing member is in the closed state, and controls the scanner so as not to emit laser light when the first detection means detects that the fixing device has been removed or the second detection means detects that the opening / closing member is in the open state. The image forming apparatus according to configuration 5, characterized by the features described herein. (Composition 7) A cartridge having an image carrier and being detachable from the main body of the device, A scanner that emits laser light to form a latent image on the image carrier, A fixing device that is detachable from the main body of the device and fixes the toner image onto a sheet onto which a toner image has been transferred, which is a toner image developed from a latent image formed on the image carrier, An interlock switch that can switch between a power-off state in which no power is supplied to the main body of the device and a power-supply state in which power is supplied to the main body of the device, An opening / closing member that can be opened and closed relative to the main body of the device in order to attach and detach the cartridge and the fixing device, Equipped with, The interlock switch enters the power-off state when the fixing device is detached from the main body of the device, and enters the power-supply state when the fixing device is attached to the main body of the device and the opening / closing member is closed. An image forming apparatus characterized by the following features. (Composition 8) The scanner does not emit laser light when the interlock switch is powered off, and emits laser light when the interlock is powered. The image forming apparatus according to configuration 5, characterized in that... (Composition 9) The fixing device, when the scanner is emitting laser light, shields the laser light from the opening / closing member at the upstream end with respect to the projection direction of the laser light and the opening / closing member. The image forming apparatus according to configuration 5, characterized in that... (Composition 10) The opening / closing member has a pressing portion, The fixing device has a part to be pressed by the pressing part, The interlock switch is in the power supply state when the pressing part is pressing the pressed part, and in the power deactivation state when the pressing part releases from the pressed part. The image forming apparatus according to configuration 5, characterized by the features described herein. [Explanation of Symbols]

[0066] 1A Main unit of the device 2. Laser scanner 2S shutter 20 doors 40 Transfer Units 50 tray units 80 Fixing device

Claims

1. A cartridge having an image carrier and being detachable from the main body of the device, A scanner that emits laser light to form a latent image on the image carrier, A fixing device that is detachable from the main body of the device and fixes the toner image onto a sheet onto which a toner image has been transferred, which is a toner image developed from a latent image formed on the image carrier, A shielding member capable of blocking the optical path of the laser light emitted from the scanner, An opening / closing member that can be opened and closed relative to the main body of the device in order to attach and detach the cartridge and the fixing device, Equipped with, The shielding member is movable between a shielding position that shields the laser light when the fixing device is detached from the main body of the device, and a transmission position that does not shield the laser light when the fixing device is attached to the main body of the device and the opening / closing member is closed. An image forming apparatus characterized by the following:

2. When the shielding member is in the transmission position, the fixing device shields the laser beam from the opening / closing member at the upstream end with respect to the projection direction of the laser beam and the opening / closing member. The image forming apparatus according to claim 1, characterized in that...

3. The opening / closing member has a pressing portion, The fixing device has a pressed portion that is pressed by the pressing portion, The shielding member is in the transparent position when the pressing portion is pressing the pressed portion, and moves to the shielding position when the pressing portion moves away from the pressed portion. The image forming apparatus according to feature 1.

4. A detection means for detecting whether the fixing device is attached to the main body of the device, A control means for controlling the shielding member to switch the shielding member to the shielding position or the transparent position based on the detection result by the detection means, Equipped with, The image forming apparatus according to claim 1, characterized in that...

5. A cartridge having an image carrier and being detachable from the main body of the device, A scanner that emits laser light to form a latent image on the image carrier, A fixing device that is detachable from the main body of the device and fixes the toner image onto a sheet onto which a toner image has been transferred, which is a toner image developed from a latent image formed on the image carrier, An opening / closing member that can be opened and closed relative to the main body of the device in order to attach and detach the cartridge and the fixing device, A first detection means for detecting whether the fixing device is attached to the main body of the device, A second detection means for detecting the open or closed state of the opening / closing member, A control means that enables the scanner to emit laser light or controls the scanner so as not to emit laser light based on the detection results from the first detection means and the second detection means, Equipped with, An image forming apparatus characterized by the following:

6. The control means enables the scanner to emit laser light when the first detection means detects that the fixing device is mounted on the device body and the second detection means detects that the opening / closing member is in the closed state, and controls the scanner so as not to emit laser light when the first detection means detects that the fixing device has been removed or the second detection means detects that the opening / closing member is in the open state. The image forming apparatus according to feature 5.

7. A cartridge having an image carrier and being detachable from the main body of the device, A scanner that emits laser light to form a latent image on the image carrier, A fixing device that is detachable from the main body of the device and fixes the toner image onto a sheet onto which a toner image has been transferred, which is a toner image developed from a latent image formed on the image carrier, An interlock switch capable of switching between a power-off state in which no power is supplied to the device body and a power-supply state in which power is supplied to the device body, An opening / closing member that can be opened and closed relative to the main body of the device in order to attach and detach the cartridge and the fixing device, Equipped with, The interlock switch enters the power-off state when the fixing device is detached from the main body of the device, and enters the power-supply state when the fixing device is attached to the main body of the device and the opening / closing member is closed. An image forming apparatus characterized by the following:

8. The scanner does not emit laser light when the interlock switch is powered off, and emits laser light when the interlock is powered. The image forming apparatus according to claim 7, characterized in that...

9. The fixing device, when the scanner is emitting laser light, shields the laser light from the opening / closing member at the upstream end with respect to the projection direction of the laser light and the opening / closing member. The image forming apparatus according to claim 7, characterized in that...

10. The opening / closing member has a pressing portion, The fixing device has a pressed portion that is pressed by the pressing portion, The interlock switch is in the power supply state when the pressing part is pressing the pressed part, and in the power deactivation state when the pressing part moves away from the pressed part. The image forming apparatus according to feature 7.

Images