JP2021085889A - Power transmission device and image forming apparatus - Google Patents

Abstract

To provide a power transmission device that can prevent the generation of noise, and an image forming apparatus.SOLUTION: A power transmission device can transmit a driving force from a motor to a developing roller in an image forming apparatus, and comprises: a planetary gear mechanism 210 having a ring gear 212 that receives input of the driving force, a carrier 213 that outputs the driving force, and a sun gear 211 that can transmit the driving force when its rotation is restricted and does not transmit the driving force when its rotation is not restricted; a switching member 220 that can rotate integrally with the sun gear 211; an engagement member that is movable between a position where it is engaged with a convex part 222 of the switching member 220 to restrict the rotation of the sun gear 211 and a position where it is separated from the convex part 222 to not restrict the rotation of the sun gear 211; and a one-way clutch 240 that is located between the sun gear 211 and the switching member 220, and transmits the rotation of the sun gear 211 to the switching member 220 when the motor rotates normally and does not transmit the rotation of the sun gear 211 to the switching member 220 when the motor rotates reversely.SELECTED DRAWING: Figure 7

Description

The present invention relates to a power transmission device and an image forming apparatus used in an image forming apparatus.

Conventionally, as a power transmission device capable of transmitting the driving force from the motor to the driven body, a planetary gear mechanism having a sun gear, a ring gear, a carrier and a planetary gear is provided integrally with the sun gear, and the rotation is restricted to the ring gear. A ratchet part that can transmit the input driving force to the carrier and does not transmit the driving force input to the ring gear to the carrier because it becomes rotatable, a regulation arm having a claw part that meshes with the protrusion of the ratchet part, and a spring. A switching means for switching between a state in which the regulation arm engages the claw portion with the contact portion to restrict the rotation of the ratchet portion by an action and a state in which the regulation arm is separated from the protrusion portion by a solenoid to make the ratchet portion rotatable. It is known that the ratchet is provided (Patent Document 1).

In this technology, in both the case where the motor rotates in the forward direction and the case where the motor rotates in the reverse direction, the power transmission device is driven by the switching means to switch between the connected state and the disconnected state. Switching between driving and stopping a developing roller.

Japanese Unexamined Patent Publication No. 2013-113971

By the way, the surface of the ratchet portion that faces one of the rotation directions is defined as an inclined surface, and when the motor rotates in the reverse direction, the claw portion of the regulating arm slides on the inclined surface of the rotating ratchet portion to form the protruding portion. If it can be overcome, the ratchet part becomes rotatable. Then, when the motor rotates in the reverse direction, it is possible to realize a configuration in which the driving force input to the ring gear is not transmitted to the carrier without moving the regulation arm by the solenoid. On the other hand, in such a configuration, there is a possibility that a protruding portion of the rotating ratchet portion may generate a sound of popping the regulation arm, that is, noise.

The present invention has been made in view of the above background, and an object of the present invention is to provide a power transmission device and an image forming device capable of suppressing the generation of noise.

In order to achieve the above object, the power transmission device of the present invention is a power transmission device capable of transmitting a driving force from a motor to a driven body in an image forming device, and includes a planetary gear mechanism, a switching member, and the like. It includes an engaging member and a one-way clutch.
The planetary gear mechanism enables the input element to which the driving force is input from the motor, the output element to output the driving force to the driven body, and the driving force to be transmitted from the input element to the output element when the rotation is restricted. It has a transmission element that does not transmit driving force from the input element to the output element when rotation is not regulated.
The switching member has a convex portion and can rotate integrally with the transmission element.
The engaging member is movable between an engaging position that engages with the convex portion to regulate the rotation of the transmission element and a disengagement position that disengages from the convex portion and does not restrict the rotation of the transmission element.
The one-way clutch is located between the transmission element and the switching member, and transmits the rotation of the transmission element to the switching member when the motor rotates forward, and does not transmit the rotation of the transmission element to the switching member when the motor rotates in the reverse direction. ..
Then, in the power transmission device, when the engaging member is located at the disengaged position, the transmission element idles with respect to the output element in both the case where the motor rotates in the forward direction and the case where the motor rotates in the reverse direction. The driving force from the motor is not transmitted to the driven body.
Further, when the engaging member is located at the engaging position, the power transmission device transmits the driving force from the motor to the driven body when the motor rotates in the forward direction, and when the motor rotates in the reverse direction. , The transmission element idles with respect to the output element and the switching member, so that the driving force from the motor is not transmitted to the driven body.

According to such a configuration, even if the motor rotates in the reverse direction when the engaging member is located at the engaging position, the transmission element can idle without rotating the switching member. Therefore, while blocking the transmission of the driving force from the input element to the output element, the sound of the convex portion of the switching member flipping the engaging member is not generated. Thereby, the generation of noise can be suppressed.

In the power transmission device described above, the planetary gear mechanism has a sun gear, a ring gear, a carrier and a planetary gear, one of the sun gear, the ring gear and the carrier is an input element, one other than the input element is an output element, and the rest. One of the components can be a transmission element.

In the power transmission device described above, the sun gear may be a transmission element, the ring gear may be an input element, and the carrier may be an output element.

In the power transmission device described above, the driven body may be configured to be a developing roller.

In order to achieve the above object, the image forming apparatus of the present invention is an image forming apparatus including a roller, a motor, and a power transmission device capable of transmitting a driving force from the motor to the rollers, and is a power transmission device. Includes a planetary gear mechanism, a switching member, an engaging member, and a one-way clutch.
The planetary gear mechanism makes it possible to transmit the driving force from the input element to the output element when the rotation is restricted, the input element to which the driving force is input from the motor, the output element to output the driving force to the roller, and the rotation It has a transmission element that does not transmit driving force from the input element to the output element when not regulated.
The switching member has a convex portion and can rotate integrally with the transmission element.
The engaging member is movable between an engaging position that engages with the convex portion to regulate the rotation of the transmission element and a disengagement position that disengages from the convex portion and does not restrict the rotation of the transmission element.
The one-way clutch is located between the transmission element and the switching member, and transmits the rotation of the transmission element to the switching member when the motor rotates forward, and does not transmit the rotation of the transmission element to the switching member when the motor rotates in the reverse direction. ..
Then, in the power transmission device, when the engaging member is located at the disengaged position, the transmission element idles with respect to the output element in both the case where the motor rotates in the forward direction and the case where the motor rotates in the reverse direction. The driving force from the motor is not transmitted to the rollers.
Further, when the engaging member is located at the engaging position, the power transmission device transmits the driving force from the motor to the rollers when the motor rotates in the forward direction, and transmits the driving force from the motor to the rollers when the motor rotates in the reverse direction. The driving force from the motor is not transmitted to the roller because the element idles with respect to the output element and the switching member.

According to such a configuration, the generation of noise can be suppressed.

In the image forming apparatus described above, the planetary gear mechanism has a sun gear, a ring gear, a carrier and a planetary gear, one of the sun gear, the ring gear and the carrier is an input element, one other than the input element is an output element, and the rest. One of the components can be a transmission element.

In the image forming apparatus described above, the sun gear may be a transmission element, the ring gear may be an input element, and the carrier may be an output element.

The image forming apparatus described above may include a developing roller, and the roller may be a developing roller.

The image forming apparatus described above is one of a plurality of members constituting the image forming apparatus, and includes a first member capable of switching to a plurality of different states, and the first member is used when the motor rotates in the forward direction. The state can be switched by receiving the driving force from the motor, and the state can be switched by receiving the driving force from the motor when the motor rotates in the reverse direction.

According to this, it is possible to drive the developing roller and switch the state of the first member with one motor while suppressing the generation of noise when the motor rotates in the reverse direction.

The image forming apparatus described above includes a photosensitive drum, and the first member is a developing roller, which can move between a contact position in contact with the photosensitive drum and a separation position away from the photosensitive drum to form an image. The device moves the developing roller between the contact position and the separated position by receiving the driving force from the motor when the motor rotates in the forward direction, and develops by receiving the driving force from the motor when the motor rotates in the reverse direction. A moving mechanism for moving the roller between the contact position and the separated position can be provided.

The image forming apparatus described above includes a photosensitive drum and a developing roller, and the roller is a developing roller and can be moved between a contact position in contact with the photosensitive drum and a separated position away from the photosensitive drum. The image forming apparatus moves the developing roller between the contact position and the separated position by receiving the driving force from the motor when the motor rotates in the forward direction, and also receives the driving force from the motor when the motor rotates in the reverse direction. The structure can be configured to include a moving mechanism for moving the developing roller between the contact position and the separated position by receiving the developing roller.

In the image forming apparatus described above, the moving mechanism includes a cam having a first cam portion that moves the developing roller between the contact position and the separated position, and a second cam portion that rotates together with the first cam portion. The mating member can come into contact with the second cam portion, and can be configured to be positioned at the engaging position when separated from the second cam portion and at the disengaged position when contacting the second cam portion. ..

According to the present invention, the generation of noise can be suppressed.

It is a figure which shows the schematic structure of the image forming apparatus which concerns on embodiment. It is a perspective view which looked at the motor, the drive transmission mechanism and the moving mechanism from the upper right. It is the figure which looked at the motor, the drive transmission mechanism and the moving mechanism from the right side. It is the figure which looked at the drive transmission mechanism from the left side. It is a perspective view (a) and a side view (b) which show a cam, a cam follower, and an engaging member when a developing roller is in a contact position and a clutch is in a transmission state. It is a schematic view which looked at the periphery of the developing cartridge from the top, and shows when the cam follower is in a standby position (a), and when it is in a protruding position (b). It is a perspective view (a) which saw the planetary gear mechanism, a switching member and a one-way clutch from the sun gear side, and is a perspective view (b) which looked at from a carrier side. It is a perspective view (a) and a side view (b) which show the cam, the cam follower, and the engaging member when the developing roller is in a separated position and the clutch is in the disengaged state. It is a figure explaining the operation of the clutch when the engaging member is located in the disengagement position, and shows the case (a) when the motor rotates in the forward direction, and (b) when the motor rotates in the reverse direction. It is a figure explaining the operation of the clutch when the engaging member is located at the engaging position, and shows when the motor rotates forward (a) and when the motor rotates in the reverse direction (b).

As shown in FIG. 1, the image forming apparatus 1 according to the embodiment is a color printer, and includes a housing 10, a sheet supply unit 20, an image forming unit 30, and a control unit 2. In the present embodiment, the left side of FIG. 1 is the front, the right side is the rear, the top and bottom are the top and bottom as they are, the front side of the paper surface of FIG. 1 is the right side, and the back side of the paper surface is the left side.

The seat supply unit 20 includes a seat tray 21 on which the seat S is set and a supply mechanism 22. The seat tray 21 is arranged below the image forming portion 30, and is removable from the housing 10 by pulling it forward. The supply mechanism 22 includes a paper feed roller 23, a separation roller 24, a separation pad 25, a transfer roller 26, and a registration roller 27. The sheet S is a medium on which an image can be formed by the image forming apparatus 1, and includes plain paper, envelopes, postcards, thin paper, thick paper, glossy paper, resin sheets, stickers, and the like.

The sheet S housed in the sheet tray 21 is sent out by the paper feed roller 23, then separated one by one between the separation roller 24 and the separation pad 25, and is directed toward the registration roller 27 by the transfer roller 26. Be transported. After that, the seat S is supplied to the image forming unit 30 by rotating the registration roller 27 after the position of the front end is regulated by the registration roller 27 in a state where the rotation is stopped.

The image forming unit 30 includes an exposure device 40, a plurality of photosensitive drums 50, a plurality of developing cartridges 60, a transport device 70, and a fixing device 80.
The exposure apparatus 40 includes a laser diode, a deflector, a lens, and a mirror (not shown). The exposure apparatus 40 is configured to expose the surface of each photosensitive drum 50 by emitting a plurality of light beams shown by an alternate long and short dash line that exposes the plurality of photosensitive drums 50.

The plurality of photosensitive drums 50 include a Y photosensitive drum 50Y corresponding to yellow, an M photosensitive drum 50M corresponding to magenta, a C photosensitive drum 50C corresponding to cyan, and a K photosensitive drum 50K corresponding to black. In the present specification and the drawings, when the members provided corresponding to each color are indicated by different colors, Y, M, C, and K are added to the reference numerals, and the members will be described without distinguishing the colors. In this case, Y, M, C, and K are not added to the symbols.

One development cartridge 60 is provided for each of the plurality of photosensitive drums 50. The plurality of developing cartridges 60 include a Y developing cartridge 60Y having a Y developing roller 61Y for supplying toner to the Y photosensitive drum 50Y, an M developing cartridge 60M having an M developing roller 61M for supplying toner to the M photosensitive drum 50M, and C. A C developing cartridge 60C having a C developing roller 61C for supplying toner to the photosensitive drum 50C and a K developing cartridge 60K having a K developing roller 61K for supplying toner to the K photosensitive drum 50K are included.

Each developing roller 61 corresponds to a "driven body", a "first member", and a "roller", and is one of a plurality of members constituting the image forming apparatus 1. The developing roller 61 can be switched to a plurality of different states. Specifically, the developing roller 61 has a contact position in contact with the corresponding photosensitive drum 50 among the plurality of photosensitive drums 50 shown by a solid line in FIG. 1, and a corresponding photosensitive drum 50 shown by a virtual line in FIG. It is possible to move to and from a separation position away from. Further, the developing roller 61 switches its state by receiving a driving force from the motor 3 when the motor 3 to be described later rotates in the forward direction, and changes its state by receiving the driving force from the motor 3 when the motor 3 rotates in the reverse direction. Switch. Specifically, the developing roller 61 moves between the contact position and the separated position by receiving a driving force from the motor 3 when the motor 3 rotates in the forward direction, and is driven by the motor 3 when the motor 3 rotates in the reverse direction. By receiving a force, it moves between the contact position and the separation position.

Each developing cartridge 60 is at a position where the developing roller 61 is in contact with the corresponding photosensitive drum 50 (see the solid line) and a position where the developing roller 61 is separated from the corresponding photosensitive drum 50 (see the virtual line). ) And can be moved.

The plurality of photosensitive drums 50 are rotatably supported by the support member 90. The support member 90 is provided with a charger 52 for charging the photosensitive drum 50, which is arranged corresponding to each photosensitive drum 50. The support member 90 is removable from the housing 10 through an opening formed by opening the front cover 11 of the housing 10. Further, the support member 90 supports the plurality of developing cartridges 60 in a detachable manner.

The transport device 70 is provided between the sheet tray 21 and the plurality of photosensitive drums 50. The transfer device 70 includes a drive roller 71, a driven roller 72, a transfer belt 73 including an endless belt, and four transfer rollers 74. The transport belt 73 is stretched between the drive roller 71 and the driven roller 72, and the outer surface is arranged so as to face each photosensitive drum 50. Each transfer roller 74 is arranged inside the transfer belt 73 so as to sandwich the transfer belt 73 with each photosensitive drum 50.

The fuser 80 is provided behind the plurality of photosensitive drums 50 and the conveying device 70. The fuser 80 includes a heating roller 81 and a pressure roller 82 arranged so as to face the heating roller 81. A transport roller 15 and a discharge roller 16 are provided on the downstream side of the fuser 80 in the transport direction of the sheet S.

In the image forming unit 30, the surface of the photosensitive drum 50 is uniformly charged by the charger 52, and then exposed by the light beam emitted from the exposure apparatus 40. As a result, an electrostatic latent image based on the image data is formed on the photosensitive drum 50. Further, the toner contained in the developing cartridge 60 is supported on the surface of the developing roller 61 and is supplied from the developing roller 61 located at the contact position to the electrostatic latent image formed on the photosensitive drum 50. As a result, a toner image is formed on the photosensitive drum 50. Next, the sheet S supplied on the transfer belt 73 is conveyed on the transfer belt 73 and passes between the photosensitive drum 50 and the transfer roller 74, so that the toner image on the photosensitive drum 50 is transferred to the sheet S. Will be done. Then, the sheet S passes between the heating roller 81 and the pressure roller 82, so that the toner image is heat-fixed to the sheet S. After that, the sheet S is discharged onto the paper discharge tray 13 by the transport roller 15 and the discharge roller 16.

Next, a configuration for driving / stopping the developing roller 61 and a configuration for contacting / separating the developing roller 61 with the corresponding photosensitive drum 50 will be described.
As shown in FIG. 2, the image forming apparatus 1 includes a motor 3, a drive transmission mechanism 100, and a moving mechanism 5.

The motor 3 is a motor for driving the developing roller 61 and the cam 150 described later of the moving mechanism 5. The motor 3 is a motor capable of forward and reverse rotation. In the present embodiment, the rotation direction of the motor 3 when the image forming apparatus 1 forms an image is a forward rotation, and the case where the motor 3 rotates in the opposite direction to the forward rotation is a reverse rotation. The motor 3 has an output shaft 3A that is rotationally driven, and the output shaft 3A is provided with a gear (not shown). The drive of the motor 3 is controlled by the control unit 2.

The drive transmission mechanism 100 is a mechanism for transmitting the driving force from the motor 3 to the developing roller 61 and the cam 150. As shown in FIGS. 3 and 4, the drive transmission mechanism 100 includes a first gear row 100D for transmitting the driving force to the developing roller 61 and a second gear row 100C for transmitting the driving force to the cam 150. have. In FIGS. 3 and 4, the meshing of the gears constituting the first gear row 100D is shown by a thick solid line, and the meshing of the gears constituting the second gear row 100C is shown by a thick broken line.

As shown in FIG. 4, the first gear train 100D includes idle gears 110, 113A, 113B, 113C, 115, a clutch 200 as a power transmission device, and a coupling gear 117.
The coupling gear 117 has a coupling shaft 119 (see FIG. 2) that meshes with the clutch 200 and rotates integrally. The coupling shaft 119 can move in the axial direction of the developing roller 61 in conjunction with the opening and closing of the front cover 11 (see FIG. 1), and when the front cover 11 is closed, it engages with a coupling (not shown) of the developing cartridge 60. The driving force from the motor 3 can be transmitted to the developing roller 61.

The driving force of the yellow coupling gear 117Y is transmitted from the motor 3 via the idle gears 110A, 113A, 115Y and the clutch 200. The driving force of the magenta coupling gear 117M is transmitted from the motor 3 via the idle gears 110A, 113A, 115M and the clutch 200. The driving force of the cyan coupling gear 117C is transmitted from the motor 3 via the idle gears 110B, 113B, 115C and the clutch 200. The driving force of the black coupling gear 117K is transmitted from the motor 3 via the idle gears 110B, 113B, 115C, 113C, 115K and the clutch 200. The detailed configuration of the clutch 200 will be described later.

As shown in FIG. 3, the second gear train 100C includes idle gears 131 to 137, a YMC clutch 140A, and a K clutch 140K.
The YMC clutch 140A switches between rotation and stop of the cams 150Y, 150M, and 150C by switching between transmission and disconnection of the driving force. The YMC clutch 140A has a large-diameter gear 140L and a small-diameter gear 140S, the large-diameter gear 140L meshes with the idle gear 132A, and the small-diameter gear 140S meshes with the idle gear 133A.

The K clutch 140K switches between rotation and stop of the cam 150K by switching between transmission and disconnection of the driving force. The K clutch 140K has the same configuration as the YMC clutch 140A, the large diameter gear 140L meshes with the idle gear 132B, and the small diameter gear 140S meshes with the idle gear 133B.

The YMC clutch 140A and the K clutch 140K are electromagnetic clutches, and when the power is turned on, the large-diameter gear 140L and the small-diameter gear 140S rotate integrally, and when the power is stopped and turned off, the large-diameter gear 140L is turned on. The small diameter gear 140S slips and does not rotate. ON / OFF of the YMC clutch 140A and the K clutch 140K is controlled by the control unit 2.

The driving force of the yellow cam 150Y is transmitted from the motor 3 via the idle gears 110A, 131A, 132A, the YMC clutch 140A, and the idle gears 133A, 134. The driving force of the magenta cam 150M is transmitted from the cam 150Y via the idle gear 135. The driving force of the cyan cam 150C is transmitted from the cam 150M via the idle gear 136. The cams 150Y, 150M, and 150C rotate at the same time when the YMC clutch 140A is turned on, and stop when the YMC clutch 140A is turned off.

The driving force of the black cam 150K is transmitted from the motor 3 via the idle gears 110B, 131B, 132B, the K clutch 140K, and the idle gears 133B, 137. The cam 150K rotates when the K clutch 140K is turned on, and stops when the K clutch 140K is turned off.

The moving mechanism 5 is a mechanism for moving the developing roller 61 between the contact position and the separated position. The moving mechanism 5 moves the developing roller 61 between the contact position and the separated position by receiving a driving force from the motor 3 when the motor 3 rotates in the forward direction, and also when the motor 3 rotates in the reverse direction. The developing roller 61 is configured to move between the contact position and the separated position by receiving the driving force from the developing roller 61. The moving mechanism 5 includes a plurality of cams 150 (150Y, 150M, 150C, 150K) and a plurality of cam followers 170 provided corresponding to each of the plurality of cams 150.

The cam 150 is a member that moves the corresponding developing roller 61 between the contact position and the separated position by rotating. As shown in FIG. 5, the cam 150 includes a disk portion 151, a gear portion 150G formed on the outer circumference of the disk portion 151, a first cam portion 152, a second cam portion 153, and a detected portion 154. And have.

The first cam portion 152 is a portion that moves the developing roller 61 between the contact position and the separated position, and protrudes from the disc portion 151 in the axial direction of the developing roller 61. The first cam portion 152 has a cam surface 152F on an end surface in the axial direction. The cam surface 152F has a first holding surface F11, a second holding surface F12, a first guide surface F13, and a second guide surface F14. The first holding surface F11 is a surface for holding the cam follower 170 at a standby position described later, and the second holding surface F12 is a surface for holding the cam follower 170 at a protruding position described later. The first guide surface F13 is a surface inclined with respect to the first holding surface F11 connecting the first holding surface F11 and the second holding surface F12, and the second guide surface F14 is the second holding surface F12 and the first. It is a surface inclined with respect to the first holding surface F11, which connects the holding surfaces F11. In FIG. 5 and the like, the dot hatch attached to the first cam portion 152 represents the second holding surface F12.

The second cam portion 153 is a portion that switches transmission and disengagement of the clutch 200 in cooperation with the engaging member 230 described later, and is a side surface of the disk portion 151 on which the first cam portion 152 is arranged. Projects from the opposite side surface in the axial direction of the developing roller 61. The second cam portion 153 extends in a substantially arc shape when viewed from the axial direction. The second cam portion 153 is formed integrally with the disk portion 151 together with the first cam portion 152. Therefore, the second cam portion 153 rotates together with the first cam portion 152.

The detected portion 154 is a portion showing the phase of the cam 150 in the rotation direction, and protrudes from the disk portion 151 in the axial direction of the developing roller 61 at a position closer to the rotation center than the first cam portion 152. The detected portion 154 of the cyan and black cams 150C and 150K is detected by the separation sensors 4C and 4K described later.

As shown in FIG. 2, the cams 150Y, 150M, and 150C are almost the same in other configurations except that the length of the cam 150 of the first cam portion 152 in the rotation direction is longer than the others. Is. Further, the black cam 150K is provided with two first cam portions 152 that are short in the rotation direction.

Returning to FIG. 5, the cam follower 170 has a slide shaft portion 171, a contact portion 172, and a spring hook portion 174.
The slide shaft portion 171 is supported by a support shaft 179 (see FIG. 6B) provided in the housing 10 so as to be slidable in the axial direction of the developing roller 61. As a result, the cam follower 170 can slide and move in the axial direction.

The contact portion 172 is a portion that can come into contact with the cam surface 152F of the first cam portion 152, and is provided so as to extend from the slide shaft portion 171. The cam follower 170 has a protruding position in which the contact portion 172 contacts the second holding surface F12 to position the developing roller 61 at a separated position as shown in FIG. 6 (b), and a contact portion 172 shown in FIG. 6 (a). The developing roller 61 can be slidably moved to and from the standby position where it comes into contact with the first holding surface F11 and is positioned at the contact position.

As shown in FIG. 5, the spring hooking portion 174 is a portion on which one end of the spring 176 is hooked, and is provided so as to extend from the slide shaft portion 171 in a direction different from that of the contact portion 172. The spring 176 is a tension spring, and the other end thereof is hooked on a spring hooking portion (not shown) provided at a position below the spring hooking portion 174 of the housing 10. As a result, the spring 176 urges the cam follower 170 from the protruding position to the standby position.

As shown in FIG. 6, the developing cartridge 60 is supported by the support member 90 so as to be movable back and forth. The support member 90 has a contacted portion 94 and a pressing member 95. The contacted portion 94 is a portion to which the slide member 64, which will be described later, comes into contact with the contacted portion 94, and is composed of a roller that can rotate about an axis along the vertical direction. The pressing member 95 is urged rearward by the spring 95A, and when the developing cartridge 60 is mounted on the supporting member 90, the pressing member 95 presses the developing cartridge 60 and brings the developing roller 61 into contact with the corresponding photosensitive drum 50. Move to the contact position.

The developing cartridge 60 has a case 63 for accommodating toner and a slide member 64. The slide member 64 is a member that can slide and move in the axial direction of the developing roller 61 with respect to the case 63, and slides and moves in the axial direction when pressed by the cam follower 170. The slide member 64 includes a shaft 191 supported by the case 63 so as to be slidable, a first contact member 192 provided at one end of the shaft 191 and a second contact member 193 provided at the other end of the shaft 191. And have.

The first contact member 192 has a pressing surface 192A and a slope 192B inclined with respect to the axial direction, and the second contact member 193 has a slope 193B inclined in the same manner as the slope 192B. The pressing surface 192A is pressed by the cam follower 170. When the slide member 64 is pressed by the cam follower 170, the slopes 192B and 193B abut on the contacted portion 94 to urge the developing cartridge 60 in a direction orthogonal to the axial direction, and the developing roller 61 is subjected to the corresponding photosensitivity. It is moved to a separation position away from the drum 50. A spring 194 for urging the slide member 64 toward the left side is arranged between the first contact member 192 and the case 63.

As shown in FIG. 2, the image forming apparatus 1 includes separation sensors 4C and 4K provided corresponding to the cyan and black cams 150C and 150K. The separation sensors 4C and 4K are phase sensors capable of detecting the origin of the phase of the cams 150C and 150K. A signal is output when it is located in the range, and no signal is output when the cams 150C and 150K are not located in the predetermined phase range. In the following, the case where the separation sensors 4C and 4K output a signal is referred to as ON, and the case where the signal is not output is referred to as OFF.

The separation sensors 4C and 4K have a light emitting unit that emits detection light and a light receiving unit that can receive the detection light from the light emitting unit. The separation sensors 4C and 4K output an ON signal to the control unit 2 when the detected unit 154 is inserted between the light emitting unit and the light receiving unit to block the detection light of the light emitting unit and the light receiving unit does not receive the detected light. When the detected unit 154 is disengaged from between the light emitting unit and the light receiving unit and the light receiving unit receives the detected light of the light emitting unit, an OFF signal is output to the control unit 2. Although the cams 150Y and 150M are also provided with the detected portion 154, since the separation sensor corresponding to the cams 150Y and 150M is not provided, these do not function as the portions detected by the separation sensor.

Next, the detailed configuration of the clutch 200 will be described.
As shown in FIGS. 5 and 7, the clutch 200 is a mechanism capable of transmitting the driving force from the motor 3 to the developing roller 61 in the image forming apparatus 1. Specifically, the clutch 200 is configured to be switchable between a transmission state in which the driving force from the motor 3 is transmitted to the developing roller 61 and a cutting state in which the driving force from the motor 3 is not transmitted to the developing roller 61. The clutch 200 includes a planetary gear mechanism 210, a switching member 220, an engaging member 230, and a one-way clutch 240.

As shown in FIG. 7, the planetary gear mechanism 210 has a sun gear 211, a ring gear 212, and a carrier 213 that can rotate around one axis, and a planetary gear 214 supported by the carrier 213. In the planetary gear mechanism 210, one of the sun gear 211, the ring gear 212, and the carrier 213 is an input element to which the driving force is input from the motor 3, and one other than the input element is an output element to output the driving force to the developing roller 61. The remaining one is a transmission state in which the driving force can be transmitted from the input element to the output element when the rotation is regulated, and a disconnection state in which the driving force is not transmitted from the input element to the output element when the rotation is not regulated. It is a transmission element to be used. In this embodiment, the sun gear 211 is a transmission element, the ring gear 212 is an input element, and the carrier 213 is an output element.

The sun gear 211 has a shaft portion 211A and a gear portion 211B that rotates integrally with the shaft portion 211A.
The ring gear 212 has an inner gear 212A provided on the inner peripheral surface. An input gear 212B is provided on the outer peripheral surface of the ring gear 212, and the input gear 212B meshes with an idle gear 115 (see FIG. 4) constituting the drive transmission mechanism 100.

The carrier 213 has four shaft portions 213A that rotatably support the planetary gear 214. An output gear 213B is provided on the outer peripheral surface of the carrier 213, and the output gear 213B meshes with the coupling gear 117 (see FIG. 5).
Four planetary gears 214 are provided, and each is rotatably supported by a shaft portion 213A of the carrier 213. The planetary gear 214 meshes with the gear portion 211B of the sun gear 211 and also meshes with the inner gear 212A of the ring gear 212.

The planetary gear mechanism 210 is in a transmission state in which the driving force input to the input gear 212B can be transmitted to the output gear 213B when the sun gear 211 is stopped so as not to rotate. On the other hand, when the sun gear 211 can rotate, the driving force input to the input gear 212B cannot be transmitted to the output gear 213B, resulting in a disconnection state. In the planetary gear mechanism 210, when a driving force is input to the input gear 212B in a disconnected state and a load is applied to the output gear 213B, the carrier 213 does not rotate and the sun gear 211 idles with respect to the carrier 213.

The switching member 220 is a member that can rotate integrally with the sun gear 211, and has a ring portion 221 and a plurality of convex portions 222 provided on the outer periphery of the ring portion 221. The convex portion 222 protrudes from the outer circumference of the ring portion 221 in the radial direction of the ring portion 221.

As shown in FIG. 5, the engaging member 230 extends in a direction different from that of the rotation support portion 231 and the first arm 232 provided so as to extend from the rotation support portion 231 and the rotation support portion 231 to the first arm 232. It has a second arm 233.
The rotary support portion 231 is rotatably supported by a support shaft 239 provided on the housing 10.

The tip of the second arm 233 extends toward the outer peripheral surface of the switching member 220. The engaging member 230 is provided with a spring hooking portion 234 on the second arm 233, and one end of the spring 250 as an urging member is hooked on the spring hooking portion 234. The spring 250 is a tension spring, and the other end is hooked on a spring hooking portion (not shown) provided at a position in front of the spring hooking portion 234 of the housing 10. As a result, the spring 250 urges the engaging member 230 from the disengagement position, which will be described later, toward the engaging position.

The engaging member 230 has an engaging position in which the tip of the second arm 233 engages with the convex portion 222 of the switching member 220 to regulate the rotation of the sun gear 211, and the tip of the second arm 233 is separated from the convex portion 222. The sun gear 211 can be moved to and from a detached position (see FIG. 8) that does not restrict the rotation of the sun gear 211. Specifically, the engaging member 230 can swing between the engaging position and the disengaging position.

In the engaging member 230, the tip end portion of the first arm 232 can come into contact with the second cam portion 153. The engaging member 230 is positioned at the engaging position by the urging force of the spring 250 when the tip of the first arm 232 is separated from the second cam 153, and the tip of the first arm 232 is the second cam 153. When it comes into contact with (see FIG. 8), it swings against the urging force of the spring 250 and is located at the detached position.

As shown in FIG. 7, the one-way clutch 240 is located between the shaft portion 211A of the sun gear 211 and the ring portion 221 of the switching member 220. The one-way clutch 240 has an inner ring 241 that rotates integrally with the sun gear 211, an outer ring 242 that rotates integrally with the switching member 220, and a one-way clutch mechanism including a roller (not shown) or the like.

The one-way clutch 240 transmits the rotation of the inner ring 241 rotating in one rotation direction to the outer ring 242, the inner ring 241 and the outer ring 242 rotate integrally, and the inner ring 241 rotates in the other rotation direction opposite to the one rotation direction. The inner ring 241 is configured to idle with respect to the outer ring 242 without transmitting the rotation of the outer ring 242 to the outer ring 242. Therefore, the one-way clutch 240 transmits the rotation of the sun gear 211 to the switching member 220 when the motor 3 rotates forward to enable the sun gear 211 and the switching member 220 to rotate integrally, and when the motor 3 rotates in the reverse direction, the sun gear The sun gear 211 is idled with respect to the switching member 220 without transmitting the rotation of the 211 to the switching member 220.

When the engaging member 230 is located at the disengaged position, the clutch 200 is caused by the sun gear 211 idling with respect to the carrier 213 in both the case where the motor 3 rotates in the forward direction and the case where the motor 3 rotates in the reverse direction. The driving force from the motor 3 is not transmitted to the developing roller 61. Further, in the clutch 200, when the engaging member 230 is located at the engaging position, when the motor 3 rotates in the forward direction, the driving force from the motor 3 is transmitted to the developing roller 61, and the motor 3 rotates in the reverse direction. In this case, the sun gear 211 idles with respect to the carrier 213 and the switching member 220, so that the driving force from the motor 3 is not transmitted to the developing roller 61.

The control unit 2 is a device that controls the operation of the image forming device 1. The control unit 2 has a CPU, a ROM, a RAM, an input / output unit, and the like, and executes each process by executing a program stored in advance. The control unit 2 controls the drive of the motor 3 and controls the ON / OFF of the YMC clutch 140A and the K clutch 140K to control the operation of the cam 150, thereby driving / stopping the developing roller 61 and. The contact / separation of the developing roller 61 with respect to the corresponding photosensitive drum 50 is controlled.

Here, an example of the processing of the control unit 2 will be described.
In the image forming apparatus 1, all the developing rollers 61 are located at separated positions in the standby state before executing the image forming. At this time, as shown in FIG. 8, the cam follower 170 is located at a protruding position where the contact portion 172 comes into contact with the second holding surface F12 of the cam 150.

When a print job is input and image formation is executed, the control unit 2 rotates the motor 3 in the forward direction and sets the YMC clutch 140A and the K clutch 140K to ON according to the color of the toner used for image formation to plot the cam 150. Rotate clockwise. As a result, the contact portion 172 of the cam follower 170 is guided from the second holding surface F12 to the second guide surface F14, slides on the second guide surface F14, and is brought into contact with the first holding surface F11 as shown in FIG. Contact. As a result, the cam follower 170 slides from the protruding position to the standby position by the urging force of the spring 176, and the developing roller 61 moves from the separated position to the contact position. When the developing roller 61 moves to the contact position, the control unit 2 turns off the YMC clutch 140A and the K clutch 140K and stops the cam 150.

When the development by the developing roller 61 is completed, the control unit 2 turns on the YMC clutch 140A and the K clutch 140K and rotates the cam 150 again. As a result, the contact portion 172 is guided from the first holding surface F11 to the first guide surface F13, slides on the first guide surface F13, and comes into contact with the second holding surface F12 as shown in FIG. As a result, the cam follower 170 slides from the standby position to the protruding position, and the developing roller 61 moves from the contact position to the separated position. After that, when the separation sensors 4C and 4K are turned on, the control unit 2 turns off the YMC clutch 140A and the K clutch 140K and stops the cam 150.

On the other hand, when the open front cover 11 (see FIG. 1) is closed, the control unit 2 rotates the motor 3 in the reverse direction in order to position the developing roller 61 at a separated position (position in the standby state). , YMC clutch 140A and K clutch 140K are turned ON, and the cam 150 is rotated counterclockwise in the figure. After that, when the separation sensors 4C and 4K are turned on twice, the control unit 2 turns off the YMC clutch 140A and the K clutch 140K and stops the cam 150.

During this time, the contact portion 172 is guided from the first holding surface F11 to the second guide surface F14, slides on the second guide surface F14 and comes into contact with the second holding surface F12, so that the cam follower 170 protrudes from the standby position. The developing roller 61 slides to the position and moves from the contact position to the separated position. Further, the contact portion 172 is guided from the second holding surface F12 to the first guide surface F13, slides on the first guide surface F13 and comes into contact with the first holding surface F11, so that the cam follower 170 stands by from the protruding position. The developing roller 61 slides to the position and moves from the separated position to the contact position.

After stopping the cam 150, the control unit 2 rotates the motor 3 in the forward direction and turns on the YMC clutch 140A and the K clutch 140K to rotate the cam 150. Then, when the separation sensors 4C and 4K are turned on, the control unit 2 turns off the YMC clutch 140A and the K clutch 140K and stops the cam 150. As a result, the developing roller 61 is positioned at a separated position (position in the standby state).

Next, the operation of the clutch 200 will be described.
As shown in FIG. 5, when the tip end portion of the first arm 232 is separated from the second cam portion 153 of the cam 150, the engaging member 230 is positioned at the engaging position by the urging force of the spring 250. The tip of the 2 arm 233 engages with the convex portion 222 of the switching member 220. At this time, the rotation of the switching member 220 is restricted by the engaging member 230.

As shown in FIG. 8, when the second cam portion 153 comes into contact with the tip end portion of the first arm 232 due to the rotation of the cam 150 and the first arm 232 is pushed and moved by the second cam portion 153, the engaging member 230 is moved. It swings to the detached position against the urging force of the spring 250, and the tip of the second arm 233 is detached from the convex portion 222 of the switching member 220. At this time, the rotation of the switching member 220 is not restricted by the engaging member 230.

As shown in FIG. 9A, when the engaging member 230 is located at the disengaged position and the motor 3 rotates in the forward direction, a driving force is input from the motor 3 to the ring gear 212 via the idle gear 115 or the like. The ring gear 212 rotates counterclockwise in the figure. Then, since the carrier 213 is stopped from rotating due to the load applied from the coupling gear 117 or the like, the planetary gear 214 rotates counterclockwise in the figure on the spot, and the sun gear 211 rotates clockwise in the figure. Rotate. At this time, the driving force from the motor 3 is not transmitted to the developing roller 61. At this time, the switching member 220 rotates together with the sun gear 211 by the function of the one-way clutch 240. The sun gear 211 will idle with respect to the carrier 213.

As shown in FIG. 9B, when the engaging member 230 is located at the disengaged position and the motor 3 rotates in the reverse direction, the ring gear 212 rotates clockwise in the figure. Then, since the rotation of the carrier 213 is stopped, the planetary gear 214 rotates clockwise on the spot, and the sun gear 211 rotates counterclockwise in the figure. Also at this time, the driving force from the motor 3 is not transmitted to the developing roller 61. The rotation of the sun gear 211 when the motor 3 rotates in the reverse direction is not transmitted to the switching member 220 due to the function of the one-way clutch 240, but the rotation of the switching member 220 is not regulated, so that due to friction in the one-way clutch 240. It may rotate with the sun gear 211. The sun gear 211 will idle with respect to the carrier 213.

As shown in FIG. 10A, when the engaging member 230 is located at the engaging position and the motor 3 rotates in the forward direction, the ring gear 212 rotates counterclockwise in the drawing. Then, the switching member 220 and the sun gear 211 can rotate integrally by the function of the one-way clutch 240, and the rotation is regulated by the engaging member 230, so that the planetary gear 214 rotates counterclockwise in the figure. While revolving around the sun gear 211 in the counterclockwise direction shown in the figure. As a result, the carrier 213 rotates counterclockwise in the drawing, so that the driving force from the motor 3 is transmitted to the developing roller 61 via the coupling gear 117 or the like.

As shown in FIG. 10B, when the engaging member 230 is located at the engaging position and the motor 3 rotates in the reverse direction, the ring gear 212 rotates clockwise in the figure. Then, the rotation of the carrier 213 is stopped, and the sun gear 211 can rotate independently of the switching member 220 by the function of the one-way clutch 240, so that the planetary gear 214 rotates clockwise on the spot. At the same time, the sun gear 211 rotates counterclockwise in the figure. At this time, the driving force from the motor 3 is not transmitted to the developing roller 61. Further, at this time, the switching member 220 does not rotate because the rotation of the sun gear 211 is not transmitted by the function of the one-way clutch 240 and the rotation is restricted by the engaging member 230. Therefore, the sun gear 211 will idle with respect to both the carrier 213 and the switching member 220.

According to the present embodiment described above, even if the motor 3 rotates in the reverse direction when the engaging member 230 is located at the engaging position, the sun gear 211 can idle without rotating the switching member 220. Therefore, while blocking the transmission of the driving force from the ring gear 212 to the carrier 213, the sound of the convex portion 222 of the switching member 220 flipping the engaging member 230 is not generated. Thereby, the generation of noise can be suppressed.

Further, according to the present embodiment, while suppressing the generation of noise when the motor 3 rotates in the reverse direction, one motor 3 can drive / stop the developing roller 61 and switch the state of the developing roller 61, specifically. The developing roller 61 can be brought into contact with and separated from the developing roller 61.

Although one embodiment of the invention has been described above, the present invention is not limited to the above-described embodiment, and can be appropriately modified and implemented as illustrated below.
For example, in the above-described embodiment, the switching member 220 and the one-way clutch 240 are provided separately, but the present invention is not limited to this, and the switching member 220 and the one-way clutch 240 may be provided integrally. As an example, the convex portion of the switching member may be provided on the outer circumference of the outer ring of the one-way clutch.

Further, in the above-described embodiment, the first member capable of switching to a plurality of different states is the developing roller 61, which can move between the contact position and the separated position, but is not limited thereto. For example, the first member is a fuser, and the nip pressure of the heating portion such as a heating roller and the pressurizing portion such as a pressurizing roller is set to the first nip pressure and the second nip pressure smaller than the first nip pressure. It may be possible to switch between. In this case, for example, the image forming apparatus switches the nip pressure from the second nip pressure to the first nip pressure by receiving a driving force from the motor when the motor rotates in the forward direction, and also from the motor when the motor rotates in the reverse direction. A nip pressure adjusting mechanism for switching the nip pressure from the first nip pressure to the second nip pressure by receiving the driving force may be provided.

Further, the first member is a roller that conveys the sheet on which the image is formed on the front surface again toward the image forming portion in order to form an image on the back surface of the sheet S on which the image is formed on the front surface. It may be possible to switch between a state of rotating in the rotation direction and a state of rotating in the second rotation direction opposite to the first rotation direction. In this case, for example, when the motor rotates in the forward direction, the roller rotates in the first rotation direction by receiving a driving force from the motor to convey the sheet from the image forming unit toward the output tray, and the motor reverses. By receiving a driving force from the motor when rotating, the sheet can be rotated in the second rotation direction and the sheet can be conveyed again toward the image forming unit.

Further, in the above embodiment, the image forming apparatus 1 in which the driven body is the developing roller 61 is illustrated, but the driving body (roller) is not limited to this, and may be, for example, a photosensitive drum. In addition, the driven body picks up a supply roller for supplying toner to the developing roller, a charging roller for charging the photosensitive drum, a cleaning roller for collecting transfer residual toner from the photosensitive drum, and a sheet from the sheet tray. Rollers other than the developing roller, such as a paper feed roller (pickup roller) for the function and a roller for transporting the sheet, may be used.

Further, in the above embodiment, the rotating driven body and the moving first member are the same member (development roller 61), but the driven body and the first member may be different members. For example, the rotating driven body may be a photosensitive drum, and the moving first member may be a developing roller.

Further, in the above-described embodiment, regarding the planetary gear mechanism 210, the sun gear 211 is a transmission element, the ring gear 212 is an input element, and the carrier 213 is an output element. It may be a combination.

Further, in the above embodiment, the image forming apparatus 1 capable of forming an image using four color toners has been exemplified, but for example, an image using two colors, three colors, or five or more colors of toner can be formed. It may be an image forming apparatus. Further, it may be an image forming apparatus that forms an image using only one color of toner. Further, the image forming apparatus is not limited to a printer, and may be a multifunction device, a copying machine, or the like.

In addition, the elements described in the above-described embodiments and modifications can be combined and implemented as appropriate.

1 Image forming device 3 Motor 5 Moving mechanism 50 Photosensitive drum 61 Development roller 150 Cam 152 1st cam part 153 2nd cam part 200 Clutch 210 Planetary gear mechanism 211 Sun gear 212 Ring gear 213 Carrier 214 Planetary gear 220 Switching member 222 Convex part 230 Engagement Member 240 One-way clutch

Claims (12)

In an image forming apparatus, it is a power transmission device capable of transmitting a driving force from a motor to a driven body.
An input element in which a driving force is input from the motor, an output element that outputs a driving force to the driven body, and a driving force that can be transmitted from the input element to the output element when rotation is restricted, and rotation A planetary gear mechanism having a transmission element that does not transmit driving force from the input element to the output element when is not regulated.
A switching member having a convex portion and rotatable integrally with the transmission element,
An engaging member that can move between an engaging position that engages with the convex portion and regulates the rotation of the transmission element and an engaging position that disengages from the convex portion and does not restrict the rotation of the transmitting element.
Located between the transmission element and the switching member, the rotation of the transmission element is transmitted to the switching member when the motor rotates forward, and the rotation of the transmission element is switched when the motor rotates in the reverse direction. Equipped with a one-way clutch that does not transmit to the member,
When the engaging member is located at the disengagement position, the transmission element idles with respect to the output element in both the case where the motor rotates in the forward direction and the case where the motor rotates in the reverse direction. The driving force from the motor is not transmitted to the driven body,
When the engaging member is located at the engaging position, the driving force from the motor is transmitted to the driven body when the motor rotates in the forward direction, and when the motor rotates in the reverse direction, the driving force is transmitted to the driven body. A power transmission device characterized in that the driving force from the motor is not transmitted to the driven body by idling with respect to the output element and the switching member. The planetary gear mechanism includes a sun gear, a ring gear, a carrier, and a planetary gear.
The first aspect of claim 1, wherein one of the sun gear, the ring gear and the carrier is the input element, one other than the input element is the output element, and the other one is the transmission element. The power transmission device described. The power transmission device according to claim 2, wherein the sun gear is the transmission element, the ring gear is the input element, and the carrier is the output element. The power transmission device according to any one of claims 1 to 3, wherein the driven body is a developing roller. With Laura
With the motor
An image forming apparatus including a power transmission device capable of transmitting a driving force from the motor to the rollers.
The power transmission device is
An input element in which a driving force is input from the motor, an output element that outputs a driving force to the roller, and a driving force that can be transmitted from the input element to the output element when rotation is restricted, so that rotation is restricted. A planetary gear mechanism having a transmission element that does not transmit a driving force from the input element to the output element when the input element is not provided.
A switching member having a convex portion and rotatable integrally with the transmission element,
An engaging member that can move between an engaging position that engages with the convex portion and regulates the rotation of the transmission element and an engaging position that disengages from the convex portion and does not restrict the rotation of the transmitting element.
Located between the transmission element and the switching member, the rotation of the transmission element is transmitted to the switching member when the motor rotates forward, and the rotation of the transmission element is switched when the motor rotates in the reverse direction. Equipped with a one-way clutch that does not transmit to the member,
When the engaging member is located at the disengagement position, the transmission element idles with respect to the output element in both the case where the motor rotates in the forward direction and the case where the motor rotates in the reverse direction. The driving force from the motor is not transmitted to the roller,
When the engaging member is located at the engaging position, the driving force from the motor is transmitted to the roller when the motor rotates forward, and the transmission when the motor rotates in the reverse direction. An image forming apparatus, characterized in that the driving force from the motor is not transmitted to the roller by idling the element with respect to the output element and the switching member. The planetary gear mechanism includes a sun gear, a ring gear, a carrier, and a planetary gear.
5. The fifth aspect of the present invention, wherein one of the sun gear, the ring gear, and the carrier is the input element, one other than the input element is the output element, and the other one is the transmission element. The image forming apparatus according to the description. The image forming apparatus according to claim 6, wherein the sun gear is the transmission element, the ring gear is the input element, and the carrier is the output element. Equipped with a developing roller
The image forming apparatus according to any one of claims 5 to 7, wherein the roller is the developing roller. It is one of a plurality of members constituting the image forming apparatus, and includes a first member capable of switching to a plurality of different states.
The state of the first member is switched by receiving a driving force from the motor when the motor rotates in the forward direction, and the state is switched by receiving the driving force from the motor when the motor rotates in the reverse direction. The image forming apparatus according to claim 8. Equipped with a photosensitive drum
The first member is the developing roller and is movable between a contact position in contact with the photosensitive drum and a separation position away from the photosensitive drum.
The image forming apparatus moves the developing roller between the contact position and the separated position by receiving a driving force from the motor when the motor rotates in the forward direction, and when the motor rotates in the reverse direction. The image forming apparatus according to claim 9, further comprising a moving mechanism for moving the developing roller between the contact position and the separated position by receiving a driving force from the motor. Photosensitive drum and
With a developing roller,
The roller is the developing roller and can move between a contact position in contact with the photosensitive drum and a separation position away from the photosensitive drum.
The image forming apparatus moves the developing roller between the contact position and the separated position by receiving a driving force from the motor when the motor rotates in the forward direction, and when the motor rotates in the reverse direction. The image forming apparatus according to claim 6, further comprising a moving mechanism for moving the developing roller between the contact position and the separated position by receiving a driving force from the motor. The moving mechanism includes a cam having a first cam portion that moves the developing roller between the contact position and the separated position, and a second cam portion that rotates together with the first cam portion.
The engaging member is in contact with the second cam portion, is located at the engaging position when separated from the second cam portion, and is located at the disengaged position when contacting the second cam portion. The image forming apparatus according to claim 10 or 11.

Images