The present invention relates to an image forming apparatus which forms an image on a recording material by electrophotography.
In general, an electrophotographic image forming apparatus (hereinafter simply as the “image forming apparatus”) requires toner refilling and maintenance of various processing units. In order to facilitate such toner refilling or maintenance, there is a commercially available cartridge including for example a photosensitive drum, charging unit, developing unit, and cleaning unit combined together in a frame, so that the cartridge is detachably mounted to the main body of the image forming apparatus. The cartridge type image forming apparatus has a detecting mechanism for detecting insertion of a cartridge such as a process cartridge. This prevents unwanted jam when a printing operation is carried out without inserting a cartridge. The mechanism is referred to as a cartridge presence/absence detecting mechanism. In other words, the image forming apparatus does not operate when the cartridge presence/absence detecting mechanism detects “cartridge absence,” and the image forming apparatus is allowed to operate when “cartridge presence” is detected.
As disclosed in Japanese Patent Application Publication No. 2002-323822, the image forming apparatus may be provided with a shutter member at the entrance of a fixing apparatus. This is for the purpose of protecting a user and keeping the user from touching a heat-generating portion for example during jam processing. Hereinafter, the shutter member will be referred to as the “fixing entrance shutter.” Examples of known mechanisms for driving the fixing entrance shutter include the mechanism operating in a manner in conjunction with opening/closing of the door as disclosed in Japanese Patent Application Publication No. 2002-323822 and the mechanism operating in a manner in conjunction with insertion/removal of the cartridge as disclosed in Japanese Patent Application Publication No. 2019-95643. These mechanisms are selected as appropriate depending on the structure of the apparatus main body or the structure of the cartridge.
Since the driving mechanism for the fixing entrance shutter and the cartridge presence/absence detecting mechanism are directed to different purposes, these mechanisms are individually provided as independent mechanisms from each other.
As described above, the cartridge presence/absence detecting mechanism and the mechanism for activating the fixing entrance shutter are separately provided in a conventional apparatus. In addition, the mechanisms each require an interface part which operates under direct influence of opening/closing operation of the door or the insertion/removal of the cartridge as a trigger for operation in conjunction with each other. This requires a large amount of space, which increases the size of the main body. Furthermore, the number of components for each mechanism increases, which increases the cost.
It is an object of the present invention to allow a shutter driving mechanism and a cartridge presence/absence detecting mechanism in an image forming apparatus to operate in a manner in conjunction with each other less costly and in a reduced space.
In order to solve the problem, an image forming apparatus according to the present invention includes:
a cartridge including an abutting portion; and
an apparatus main body, the apparatus main body comprising:
wherein in a state where the cartridge is moved toward the mounting portion in the mounting direction, the moving member is moved in the mounting direction by the abutting portion of the cartridge abutting with the abutted portion of the moving member, thereby, the acting member moving from the first position to the second position, and the shutter moving from the closed position to the open position.
In order to achieve the object, an image forming apparatus according to the present invention includes:
an apparatus main body;
an attachable/detachable unit that is attachable to/detachable from the apparatus main body;
a first moving member capable of moving between a first position in which the first moving member is not in contact with the recording material and a second position in which the first moving member is in contact with the recording material;
a second moving member positioned in a third position in a state where the attachable/detachable unit is not attached to the apparatus main body and in a fourth position in a state where the attachable/detachable unit is attached to the apparatus main body;
an optical sensor comprising a light-emitting portion and a light-receiving portion; and
a flag member capable of moving between a transmission position in which light from the light-emitting portion is allowed to be received by the light-receiving portion and a light-shielding position in which the light is not allowed to be received by the light-receiving portion, the flag member moving in conjunction with a movement of the first moving member from the first position to the second position, the flag member moving in conjunction with a movement of the second moving member from the third position to the fourth position.
According to the present invention, the shutter driving mechanism and the cartridge presence/absence detecting mechanism in the image forming apparatus can be operated in a manner in conjunction with each other less costly and in a reduced space.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Hereinafter, a description will be given, with reference to the drawings, of embodiments (examples) of the present invention. However, the sizes, materials, shapes, their relative arrangements, or the like of constituents described in the embodiments may be appropriately changed according to the configurations, various conditions, or the like of apparatuses to which the invention is applied. Therefore, the sizes, materials, shapes, their relative arrangements, or the like of the constituents described in the embodiments do not intend to limit the scope of the invention to the following embodiments.
A first embodiment of the present invention will be described. Examples of an electrophotographic image forming apparatus to which the present invention is applied (hereinafter referred to as the image forming apparatus) include an electrophotographic copier, an electrophotographic printer (such as an LED printer and a laser printer), a facsimile device, and a word processor. Examples of a recording material onto which an image is formed by the image forming apparatus according to the embodiment include a recording paper sheet and a plastic sheet.
In the following description, the positional relation among components is defined with respect to the direction of a rotation axis of an electrophotographic photosensitive drum as the lengthwise direction. In the lengthwise direction, the side on which the electrophotographic photosensitive drum receives driving force from the main body of the image forming apparatus is the driving side, while the opposite side is the non-driving side. That schematic cross section of the image forming apparatus for example in
Overall Structure of Electrophotographic Image Forming Apparatus
The image forming apparatus shown in
The apparatus main body A includes a pickup roller 5a, a feed roller pair 5b, a conveying roller pair 5c, a transfer roller 7, a fixing apparatus 9, a discharge roller pair 10, and a discharge tray 11 sequentially arranged in the conveying direction D of the sheet PA.
Image Forming Process
The following is an outline of an image forming process. The electrophotographic photosensitive drum 62 (hereinafter simply referred to as the photosensitive drum 62) is driven to rotate at a prescribed peripheral speed (a process speed) in the direction of the arrow R in response to a printing start signal. A charging roller (a charging member) 66 provided with biasing voltage contacts the outer peripheral surface of the photosensitive drum 62 and uniformly charges the outer peripheral surface of the photosensitive drum 62. The exposure device 3 outputs laser light L according to image information. The laser light L passes through the laser opening of the cartridge B, so that the outer peripheral surface of the photosensitive drum 62 is exposed to and scanned with the light. In this way, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the photosensitive drum 62. In the meantime, the toner in the cartridge B is carried by a developing roller 32 and supplied to the photosensitive drum 62 according to the electrostatic latent image to form a latent image. In this way, the latent image is made visible as a toner image (a developer image).
As shown in
The sheet PA having that toner image transferred thereon is separated from the photosensitive drum 62 and conveyed to the fixing apparatus 9 (fixing portion). The sheet PA is subjected to pressing/heating fixing processing at a nip portion as a part of the fixing apparatus 9, and the toner image is fixed on the sheet PA. The sheet PA after the toner image fixing processing is conveyed to the discharge roller pair 10 and discharged onto the discharge tray 11.
Mounting Cartridge
With reference to
The state of the apparatus main body A while the opening/closing door 13 is opened will be described. As shown in
Now, how to mount the cartridge B will be described. As shown in
As shown in
The cartridge B is mounted to the apparatus main body A in a direction substantially orthogonal to the axis of photosensitive drum 62. The upstream or downstream in the mounting direction refer to the upstream or downstream in the moving direction of the cartridge immediately before the cartridge B is mounted to the apparatus main body A.
When the cartridge B is mounted from the cartridge insert opening 17 of the apparatus main body A, the rotation stopper target portion 73c of the cartridge B is guided to the upper guide rail 15g of the apparatus main body A on the driving side of the cartridge B. The positioning target portion 71d and the rotation stopper target portion 71g of the cartridge B are guided to the guide rails 16d and 16e of the apparatus main body A on the non-driving side of the cartridge B. In this way, the cartridge B is mounted to the apparatus main body A.
As shown in
Now, the state in which the opening/closing door 13 is closed will be described. As shown in
The cartridge pressing members 1 and 2 are provided at opposed ends of the opening/closing door 13 in the lengthwise direction. The cartridge pressing springs 19 and 21 are attached to the cartridge pressing members 1 and 2. The cartridge B has a pressing target portion 73e as a biasing force receiving portion on the driving side and a pressing target portion 710 on the non-driving side. As the opening/closing door 13 is closed, the pressing target portions 73e and 710 of the cartridge B are pressed by the cartridge pressing members 1 and 2 biased by the cartridge pressing springs 19 and 21 of the apparatus main body A (see
In this way, on the driving side, the upper positioning target portion 73d, the lower positioning target portion 73f, and the rotation stopper target portion 73c of the cartridge B abut against the upper positioning portion 91a, the lower positioning portion 91b, and rotation stopper portion 15c of the apparatus main body A, respectively. As a result, the cartridge B and the photosensitive drum 62 are positioned on the driving side. On the non-driving side, the positioning target portion 71d and the rotation stopper target portion 71g of the cartridge B abut against the positioning portion 91c and the rotation stopper portion 16c of the apparatus main body A, respectively. In this way, the cartridge B and the photosensitive drum 62 are positioned on the non-driving side. Hereinafter, this state in which the cartridge B is positioned with respect to the apparatus main body A in the mounting direction is defined as a state in which the cartridge B is mounted in the mounting portion of the apparatus main body A.
Configuration of Cartridge Presence/absence Detecting Mechanism and Fixing Entrance Shutter Mechanism
With reference to
The cartridge B in the embodiment has a cartridge-side protruding portion 102 on the non-driving side which protrudes in the inserting direction of the cartridge B beyond the photosensitive drum 62. That is, the cartridge-side protruding portion 102 is positioned at the downstream side from the photosensitive drum 62 in the mounting direction. Further, the cartridge-side protruding portion 102 is positioned at the end in the direction of the rotation axis of the photosensitive drum 62.
In the embodiment, the cartridge-side protruding portion 102 also serves as a protective member (an abutting portion) which prevents the photosensitive drum 62 from contacting a floor surface and getting stains and scratches when the cartridge B taken out from the main body A is placed on the floor and comes into abutment against the floor surface.
The conveying guide 91 of the apparatus main body A has the interface member 120 (moving member) which can move substantially linearly (linearly move) with respect to the direction in which the cartridge B is inserted. The interface member 120 has a main body side abutting portion 122 (abutted portion) to be abutted against the cartridge-side protruding portion 102 (abutting portion) (
The conveying guide 91 has a cartridge presence/absence detecting lever 130 (link member) which can be rotated and a sensor link member 131 (acting member) operated in conjunction with the cartridge presence/absence detecting lever 130. The sensor link member 131 has a light-shielding portion 132 (acting portion) as a light-shielding member. The sensor link member 131 has a photo-interrupter 133 as an optical sensor which allows detection light from the light-emitting portion to the light-receiving portion to be switched between a transmission state and a light-shielding state in response to change in the position of the light-shielding portion 132 caused by change in the position of the sensor link member 131. This part is referred to as the cartridge presence/absence detecting mechanism. The light-emitting portion is a portion that emits light, and the light-receiving portion is a portion that is configured to receive the light emitted from the light-emitting portion. The sensor link member 131 is configured to be movable between a first position in which the photo-interrupter 133 is made the transmission state and a second position in which the photo-interrupter 133 is made the light-shielding state by the light-shielding portion 132. The cartridge presence/absence detecting mechanism has the photo-interrupter 133 (sensor) and the sensor link member 131 provided with the light-shielding portion 132 that acts on the photo-interrupter 133. The cartridge presence/absence detecting lever 130 and the sensor link member 131 may be integrally configured.
The cartridge presence/absence detecting mechanism in the embodiment also has the function of detecting whether the width of the conveyed sheet PA is larger or smaller than a prescribed size. In other words, the sensor link member 131 is operated in conjunction with the paper width detecting mechanism, which is not shown in
The conveying guide 91 has a fixing entrance shutter 140 which opens and closes the fixing entrance portion 141 as the entrance to the fixing apparatus 9 in the recording material conveyance path and a shutter link member 142 at the fixing entrance portion 141 through which the sheet PA is conveyed to the fixing apparatus 9. The fixing entrance shutter 140 is provided pivotably around the y-axis about a shutter pivot center 146 extending in the y-axis direction. The shutter link member 142 opens/closes the fixing entrance shutter 140 in conjunction with the interface member 120. The shutter link member 142 can move linearly only in the vertical direction (the z-axis direction) in
The interface member 120 has an engagement groove 123 (engaged portion) for operating in conjunction with the cartridge presence/absence detecting lever 130, and is connected to the cartridge presence/absence detecting lever 130 as the engagement boss 134 (engaging portion) of the cartridge presence/absence detecting lever 130 is engaged with the engagement groove 123. The interface member 120 has a sliding surface 124 (inclined surface) including a slope portion for operating in conjunction with the shutter link member 142. The shutter link member 142 has a sliding surface abutting portion 143 which abut against the sliding surface 124. The sliding surface 124 is an inclined surface that extends downward toward the mounting direction of the cartridge B
The interface member 120 is constantly pressed in the direction opposite to the direction in which the cartridge B is inserted by biasing member 125 such as a spring. The fixing entrance shutter 140 is constantly biased in the direction of the arrow R1 by a biasing member which is not shown.
Interlocking Operation Between Cartridge Presence/Absence Detecting Mechanism and Fixing Entrance Shutter Mechanism
With reference to
With reference to
The cartridge presence/absence detecting mechanism will be described. The interface member 120 is biased in the direction opposite to the direction in which the cartridge B is inserted by the biasing member 125, and the main body side abutting portion 122 is positioned to protrude into the mounting space for the cartridge B. At the time, the position of the cartridge presence/absence detecting lever 130 is uniquely determined by engagement between the engagement groove 123 with the engagement boss 134. The cartridge presence/absence detecting lever 130 has a lever-side abutting portion 135, and the sensor link member 131 has a sensor link-side abutting portion 136. The sensor link member 131 is biased in the direction of the arrow R2 around the y-axis by a biasing member which is not shown. Here, the biasing force by the biasing member, which is not shown, for biasing the sensor link member 131 is smaller than the biasing force by the biasing member 125 for biasing the interface member 120. Therefore, the sensor link-side abutting portion 136 is in abutment against the lever-side abutting portion 135, the position of which is uniquely determined, so that the sensor link-side abutting portion 136 follows the lever-side abutting portion 135. In this way, the sensor link member 131 operates in a manner in conjunction with the cartridge presence/absence detecting lever 130, and the position of the sensor link member 131 is determined as the position of the cartridge presence/absence detecting lever 130 is determined.
As mentioned above, the sensor link member 131 has the light-shielding portion 132 for switching between transmission and shielding through the optical axis (not shown) of the photo-interrupter 133. According to the embodiment, in the state shown in
Now, the fixing entrance shutter mechanism will be described. In the state in
Next, the state in which the cartridge B is inserted in the apparatus main body A (the state in which the cartridge is mounted in the mounting portion) will be described with reference to
The cartridge presence/absence detecting mechanism will be described. When the cartridge B is inserted in the apparatus main body A, the position of the cartridge-side protrusion 102 is uniquely determined by the positioning portions, the rotation stopper portions, the pressing portions (71d, 71g, 71o, 73c, 73d, 73f, and 73e), and the pressing members (1 and 2) as described above. Therefore, the cartridge-side protrusion 102 pushes in the main body side abutting portion 122, and the interface member 120 moves in the inserting direction of the cartridge B.
As described above, the interface member 120 and the cartridge presence/absence detecting lever 130 are connected by engagement between the engagement boss 134 of the cartridge presence/absence detecting lever 130 and the engagement groove 123 of the interface member 120. The interface member 120 moves substantially linearly (linearly move), while the cartridge presence/absence detecting lever 130 pivots (rotational move). In order to operate in conjunction with these two components, the engagement groove 123 according to the embodiment has a gap substantially orthogonal to the direction in which the cartridge B is inserted (the mounting direction). In other words, when the cartridge presence/absence detecting lever 130 pivots, the engagement boss 134 is displaced in the vertical direction as shown in
As the engagement allows the interface member 120 to move in the direction in which the cartridge B is inserted, the cartridge presence/absence detecting lever 130 pivots around the lever pivot center 137 in the direction of the arrow R3. Accordingly, the lever-side abutting portion 135 also pivots in the direction of the arrow R3. Here, the sensor link member 131 is biased in the direction of the arrow R2 by the biasing member which is not shown. More specifically, the sensor link member 131 pivots in the direction of the arrow R2 while the lever-side abutting portion 135 and the sensor link-side abutting portion 136 are kept in abutment. Accordingly, the light-shielding portion 132 also pivots, so that light is shielded with respect to the optical axis (not shown) of the photo-interrupter 133 in the embodiment. That is, in the state in which the cartridge B is inserted in the apparatus main body A (the state in which the cartridge is mounted in the mounting portion), the sensor link member 131 is positioned in the second position.
Here, the sensor link member 131 in the embodiment is operated in conjunction with the paper width detecting mechanism (not shown) as described above. The sensor link member 131 pivots by a certain amount in the direction of the arrow R2 and then abuts against the paper width detecting mechanism (not shown) to stop pivoting. At the time, the sensor link member 131 keeps the light-shielding portion 132 to block light with respect to the optical axis (not shown) of the photo-interrupter 133. According to the embodiment, when the cartridge B is completely inserted, the cartridge presence/absence detecting lever 130 is in a further pivoted position, so that the lever-side abutting portion 135 is in a position away from the sensor link-side abutting portion 136 as shown in
Here, with reference to
With reference to
In
Thereafter, when the rear end of the sheet PA exits the paper width detecting portion 153, the paper width detecting lever 150 returns to the state in
On the basis of the size detection result about the sheet PA from the paper width detecting mechanism described above, an engine controller (not shown) carries out such a control that the fixing temperature control is lowered when it is determined that the sheet size is smaller than the prescribed size.
According to the embodiment, the rotation phase in which the light-shielding portion 132 causes the photo-interrupter 133 to attain the transmission state in the cartridge presence/absence detecting mechanism is different from the rotation phase in which the light-shielding portion 132 causes the photo-interrupter 133 to attain the transmission state in the paper width detecting mechanism. More specifically, in the cartridge presence/absence detecting mechanism, when the photo-interrupter 133 changes from the light-shielding state to the transmission state (when the cartridge B is removed), the direction of rotation of the light-shielding portion 132 is one rotation direction. In the paper width detecting mechanism, when the photo-interrupter 133 changes from the light-shielding state to the transmission state (when the passage of a recording material is detected), the direction of rotation of the light-shielding portion 132 is the other direction, which is the opposite of the above-mentioned direction. From a different point of view, in the flow of events from mounting of the cartridge B in the apparatus main body A to detection of the width for conveying the recording material, the direction in which the light-shielding portion 132 rotates with respect to the photo-interrupter 133 is one direction (the other rotation direction). Similarly, the direction in which the light-shielding portion 132 rotates with respect to the photo-interrupter 133 is one direction (one rotation direction) in the flow of events until when the passage of the recording material is no longer detected and the cartridge B is removed from the apparatus main body A.
Next, the fixing entrance shutter mechanism will be described. As described above, the interface member 120 has a sliding surface 124 including a slope. In other words, when the interface member 120 moves in the insertion direction of the cartridge B, the sliding surface 124 also moves in the insertion direction of the cartridge B. The sliding surface abutting portion 143 of the shutter link member 142 is constantly in abutment against the sliding surface 124 and can move linearly only in the vertical direction (the z-axis direction) in
Here, the operation of the interface member 120, the shutter link member 142, and the fixing entrance shutter when the cartridge B is inserted in the embodiment is shown in
As described above, the manner of switching the contact between the shutter push-up portion 144 and the shutter side abutting portion 145 in the embodiment is for the purpose of further reducing the size of the apparatus main body A. Therefore, when there is a sufficient space for the interface member 120 and the shutter link member 142 to operate, or when the shutter push-up portion 144 of the shutter link member 142 can be raised to a sufficient level to contact the tip end side of the shutter side abutting portion 145 of the fixing entrance shutter 140 in
As in the foregoing, by operating in conjunction with the cartridge presence/absence detecting mechanism and the fixing entrance shutter mechanism by the single interface member, the space can be saved and the number of components can be reduced, so that the cost can be reduced.
According to the embodiment, the interface member 120 moves linearly, the cartridge presence/absence detecting mechanism is a link mechanism capable of linear and pivoting movement using an engagement groove, and the fixing entrance shutter mechanism is a link mechanism using a sliding surface. However, the interlocking mechanism through a single interface member is not limited by the configuration according to the described embodiment. The operation of the mechanisms when the cartridge B is detached from the mounted state corresponds to operation carried out in the reversed order from the above. The operation will not be described.
Hereinafter, a second embodiment of the present invention will be described in detail in conjunction with the drawings. In the following case according to the second embodiment, the operation in conjunction with the paper width detecting mechanism (not shown) is not necessary. Since the configurations of the image forming apparatus main body A and the cartridge B, the image forming process, and the operation of inserting and removing the cartridge B are the same as those according to the first embodiment, a description thereof will not be provided. The matters not specifically described in the description of the second embodiment are the same as those according to the first embodiment.
Configurations of Cartridge Presence/Absence Detecting Mechanism and Fixing Entrance Shutter Mechanism
The configuration of the cartridge presence/absence detecting mechanism will be described with reference to
The conveying guide 91 of the apparatus main body A has the interface member 220 capable of substantially linear motion with respect to the direction in which the cartridge B is inserted. The interface member 220 has a main body side abutting portion 222 for abutting against the cartridge-side protrusion 102.
The interface member 220 has a light-shielding portion 223. The apparatus main body A is also provided with a photo-interrupter 233, the optical axis of which is switched between transmission and shielding (not shown) by the light-shielding portion 223. The part is the cartridge presence/absence detecting mechanism in the embodiment.
The conveying guide 91 has a fixing entrance shutter mechanism at a fixing entrance 141 through which a sheet PA is conveyed to the fixing apparatus 9. The fixing entrance shutter mechanism is the same as that according to the first embodiment including the sliding surface 224 provided in the interface member 220, and therefore a description thereof will not be provided.
Similarly to the first embodiment, the interface member 220 according to the embodiment is constantly biased by the biasing member 125 such as a spring in the direction opposite to the direction in which the cartridge B is inserted.
Similarly to the first embodiment, the fixing entrance shutter 140 according to the embodiment is constantly biased in the direction of the arrow R1 by biasing member which is not shown.
Interlocking Operation between Cartridge Presence/Absence Detecting Mechanism and Fixing Entrance Shutter Mechanism
Interlocking between the cartridge presence/absence detecting mechanism and the fixing entrance shutter mechanism will be described in detail with reference to
To start with, the state in which the cartridge B is not inserted in the apparatus main body A will be described with reference to
Next, the state in which the cartridge B is inserted into the apparatus main body A will be described with reference to
When the cartridge B is inserted into the apparatus main body A, the protrusion 102 on the cartridge side pushes in the main body side abutting portion 222, and the interface member 220 moves in the direction in which the cartridge B is inserted similarly to the first embodiment described above.
As described above, the interface member 220 is provided with a light-shielding portion 223, and as the cartridge B is inserted, the light-shielding portion 223 also moves. When the cartridge B is completely inserted (
As described above, the fixing entrance shutter mechanism is the same as that according to the first embodiment including the sliding surface 224 of the interface member 220. Similarly to the first embodiment described above, when the cartridge B is inserted, the fixing entrance shutter 140 rotates and the fixing entrance 141 attains a completely open state.
As described above, according to the embodiment, even when operation in conjunction with the paper width detecting mechanism is not necessary, the cartridge presence/absence detecting mechanism and the fixing entrance shutter mechanism can be operated in a manner in conjunction with each other by a single interface member, so that the space can be saved and the number of components can be reduced, so that the cost can be reduced.
According to the embodiment, the interface member 220 is capable of linear motion, and the fixing entrance shutter mechanism is a cam mechanism using a sliding surface. However, the interlocking mechanism through the single interface member is not limited by the configuration according to the described embodiment.
According to the embodiment, the interface member 220 is provided with the light-shielding portion 223, but the shutter link member 142 or the fixing entrance shutter 140 may be provided with the light-shielding portion.
A third embodiment of the present invention will be described according to the drawings. The feature of the third embodiment is the operating in conjunction with the cartridge presence/absence detecting mechanism and the paper width detecting mechanism.
A sheet width and attachable/detachable unit presence/absence detecting mechanism provided in an image forming apparatus according to a third embodiment of the present invention will be described with reference to
Image Forming Apparatus
With reference to
As shown in
Sheet Width and Detachable Unit Presence/Absence Detecting Mechanism
With reference to
In
A first lever 210 and a second lever 211 in
In
With reference to
When the large-size sheet L2 is conveyed in the conveyance path P1, the tip end of the sheet PA contacts the contact portions 210a and 211a of the first and second levers 210 and 211. This causes both the first and second levers 210 and 211 to rotate in the opposite direction to the arrow a1, and the rotation force of the sensor flag 212 which has been stopped at the arms 212a and 212b is released. At the time, the sensor flag 212 rotates in the direction of the arrow b1 together with the first and second levers 210 and 211 by the biasing force of the sensor flag spring 215. The rotation force of the sensor flag 212 in the direction of the arrow b1 due to the biasing force of the sensor flag spring 215 is smaller than both the rotation force of the first lever 210 in the direction of the arrow a1 and the rotation force of the second lever 211 in the direction of the arrow a1 due to the biasing force of the lever springs 214.
Therefore, the sensor flag 212 can be rotated in the direction of the arrow b1 only when both the first lever 210 and the second lever 211 are rotated in the direction opposite to the arrow a1, and when only one of the first lever 210 and the second lever 211 is rotated in the direction opposite to the arrow a1, one of the arms 212a and 212b is kept stopped with the engagement portion 210b of the first lever 210 or the engagement portion 211b of the second lever 211, and therefore the sensor flag 212 is not rotated in the direction of the arrow b1.
In
While the large-size sheet L2 is passed through, the contact part 210a of the first lever 210 and the contact part 211a of the second lever 211 continue to contact the sheet PA, so that the rotation state of the first lever 210 and the second lever 211 is maintained, and the signal from the photo-interrupter 216 maintains the “transmission (ON)” state. In this way, it can be determined that the large-size sheet L2 is conveyed on the basis of the transition of the signal from the photo-interrupter 216 from the “light shielding (OFF)” state to the “transmission (ON)” state.
When the first and second levers 210 and 211 return to the standby position from the paper passing position after the large-size sheet L2 has been passed through, the sensor flag 212 returns from the paper passing position in
With reference to
As shown in
When the cartridge B is inserted into the image forming apparatus 100, the pressing part 29a of the cartridge B contacts and pushes the detection part 217a of the third lever 217 in the direction of the arrow D1, which causes the third lever 217 to rotate in the direction of the arrow dl, which is opposite to arrow c1. As a result, the contact portion 217b moves to a retreated position, which is separated from the arm 212b in the direction of the arrow b1 (the first rotation direction). At the time, since the arm 212b of the sensor flag 212 and the contact part 217b of the third lever 217 do not contact each other, the sensor flag 212 rotates in the direction of the arrow b1 by the biasing force of the sensor flag spring 215. As a result, the sensor flag 212 stops in the standby position and the signal from the photo-interrupter 216 attains a “light shielding (OFF)” state because the sensor flag 212 is engaged with the contact part 210a of the first lever 210 and the contact part 211a of the second lever 211.
Next, the operation of the sensor flag 212 and the third lever 217 when the cartridge B is not inserted will be described with reference to
When the cartridge B is not inserted, no pressing force from the pressing portion 29a of the cartridge B is applied to the detection part 217a of the third lever 217, and therefore the third lever 217 rotates in the direction of the arrow c1 by the biasing force of the third lever spring 218. At the time, the third lever 217 contacts the arm 212b of the sensor flag 212 at the arm 212a, which causes the sensor flag 212 to rotate in the direction of the arrow el (the second rotation direction), which is opposite to the direction of arrow b1.
When the sensor flag 212 contacts the rotation stopper 213f of the conveying guide 213 shown in
With reference to
When the power supply of the image forming apparatus 100 is turned on in (1) in
Cartridge not Inserted
The cartridge B is not inserted in the image forming apparatus 100, and the third lever 217 is in the detection position, which causes the sensor flag 212 to rotate to the detection position (
Sheet Remaining in Image Forming Apparatus
When the image forming apparatus 100 stops operating during conveyance of a sheet PA because of any extraneous factor or an operation failure, and the sheet PA remains or stops in the conveyance path P1, the first lever 210 and the second lever 211 may be pushed by the sheet PA to rotate in the direction opposite to the direction of the arrow a1 in
As described above, when the image forming apparatus 100 recognizes the state (3) in
In the image forming apparatus 100 with a C-path shape as shown in
When the state of the signal from the photo-interrupter 216 is checked in (2) in
Therefore, it can be determined that the cartridge B is inserted in the image forming apparatus 100 and that the sheet PA remaining in the apparatus is at least not in the range of the rotation trajectory of the first lever 210 and the second lever 211. In this situation, the image forming apparatus 100 determines for the first time that printing preparation (preparation for image forming operation) has been completed. After the state (4), when printing starts and the sheet PA reaches the conveyance path P1, the state of the signal from the photo-interrupter 216 is checked again. At the time, when the signal from the photo-interrupter 216 remains in the “light shielding (OFF)” state even though a sufficient time period has passed for the sheet PA to reach the positions of the first and second levers 210 and 211, the image forming apparatus 100 determines that the passed sheet PA is a small-size sheet L1.
On the other hand, in (5), when the signal from the photo-interrupter 216 is in the “transmission (ON)” state, the first lever 210 and the second lever 211 contact the sheet PA and rotate, and the disengaged sensor flag 212 rotates to the paper-passing position (
According to the embodiment, the following advantages are provided in the sheet width and attachable/detachable unit presence/absence detecting mechanism in the image forming apparatus.
In an image forming apparatus provided with a sheet width detecting mechanism and a photo-interrupter corresponding to the sheet width detection, a lever member is provided to detect the presence or absence of an attachable/detachable unit such as a toner cartridge that can be attached to or detached from the main body of the apparatus, and by operating the member in conjunction with the sheet width detecting mechanism, the presence or absence of the attachable/detachable unit can be detected without providing a new dedicated photo-interrupter. In this way, the configuration of the image forming apparatus can be simplified and the cost can be reduced.
According to the embodiment, it cannot be determined whether printing preparation is not complete in state (3) in
For example, many image forming apparatuses are provided with a sheet tip end detecting lever for detecting the tip end position of a sheet PA and a corresponding photo-interrupter in the range in which the first lever 210 and the second lever 211 are provided in the conveyance path P1. In the state in (3), when the signal from the photo-interrupter for detecting the tip end position of the sheet is a signal corresponding to the paper-passing position of the sheet tip end detecting lever, the sheet tip end detecting lever contacts the sheet PA to move, indicating that the lever is in the paper-passing position. Therefore, it can be determined that the signal from photo-interrupter 216 is in the “transmission (ON)” state, not because the cartridge B is not inserted, but because the sheet PA remains in the conveyance path P1.
Meanwhile, in the state (3), when the signal from the photo-interrupter for detecting the sheet tip end position is a signal corresponding to the standby position of the sheet tip end detecting lever, it is unlikely that there is any sheet PA remaining in the conveyance path P1, and it can be determined that the cartridge B is not inserted.
According to the embodiment, the signal from the photo-interrupter 216 in the standby position as one position is in the “light shielding (OFF)” state and the signal from the photo-interrupter 216 in the paper passing position and detection position as the other position is in the “transmission (ON)” state, but the invention is not limited by this. When the shape of the light-shielding portion 212c of the sensor flag 212 is changed, the standby position as the other position may be set to correspond to the “transmission (ON)” state and the paper-threading position and the detection position to one position to the “light-shielding (OFF)” state.
According to the embodiment, the cartridge B is used as an example of the attachable/detachable unit to be attached to and detached from the image forming apparatus 100, and detection of the detached/attached state of the cartridge B has been described, but the attachable/detachable unit according to the present invention is not limited to the cartridge B. For example, the invention can be applied to detection of the insertion/withdrawal state of the sheet tray 4, which is loaded with sheets PA and can be inserted to and removed from the image forming apparatus 100. Furthermore, the invention can be applied to detection of any detection state other than the detection of the detached/attached state of the attachable/detachable unit. For example, the invention can be applied to detection of the open/closed state of a door member that can be opened and closed with respect to the image forming apparatus 100.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2020-102724, filed on Jun. 12, 2020, No. 2020-102666, filed on Jun. 12, 2020 which are hereby incorporated by reference herein in their entirety.
Number | Date | Country | Kind |
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JP2020-102666 | Jun 2020 | JP | national |
JP2020-102724 | Jun 2020 | JP | national |
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Number | Date | Country | |
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20210389692 A1 | Dec 2021 | US |