conveying device

Abstract

The present disclosure relates to a conveyance device. The conveyance device includes a motor, a gear, a first side plate configured to support the gear, a second side plate disposed inside the conveyance device with respect to the first side plate in a rotation axis direction of the gear, a detected portion connected to the gear and configured to rotate with the gear, and a sensor, wherein teeth of the gear are located between the first side plate and the second side plate in the rotation axis direction, wherein, in a case where a direction from the first side plate toward the second side plate along the rotation axis direction is defined as a first direction, the detected portion is located upstream of the first side plate in the first direction, and wherein at least a portion of the motor is located downstream of the detected portion in the first direction.

Description

Technical Field

[0001] This disclosure relates to a transmission apparatus for transmitting recording media. Background Technology

[0002] An image forming apparatus described in Japanese Patent Application Publication No. 2011-190922 includes a motor, a transmission unit for transmitting motor driving force, a detection unit that receives driving force from the transmission unit and rotates, a detection unit for detecting the rotation of the detection unit, and a side plate disposed outside the transmission unit. Furthermore, the detection unit is located outside the side plate, and the motor is located outside the detection unit.

[0003] In the image forming apparatus described in Japanese Patent Application Publication No. 2011-190922, the motor is located outside the detected part, and the space inside the detected part cannot be used as space for arranging the motor. Summary of the Invention

[0004] Therefore, this disclosure aims to use the space inside the detection section as a space for arranging a motor.

[0005] According to one aspect of this disclosure, a transmission device for transmitting a recording medium includes: a motor configured to generate a driving force; a gear configured to rotate by receiving the driving force; a first side plate configured to support the gear; a second side plate disposed inside the transmission device relative to the first side plate in the direction of rotation axis of the gear and configured to support the gear; a detection unit connected to the gear and configured to rotate with the gear; and a sensor configured to detect rotation of the detection unit, wherein, in the direction of rotation axis, the teeth of the gear are located between the first side plate and the second side plate, wherein, in a direction along the direction of rotation axis from the first side plate toward the second side plate is defined as a first direction, the detection unit is located upstream of the first side plate in the first direction, and wherein at least a portion of the motor is located downstream of the detection unit in the first direction.

[0006] The features of this disclosure will become clear from the following description of embodiments with reference to the accompanying drawings. The following description of the embodiments is by way of example. Attached Figure Description

[0007] Figure 1 This is a schematic diagram illustrating an image forming system according to a first embodiment.

[0008] Figure 2 This is a perspective view of an optional device according to the first embodiment.

[0009] Figure 3 This is a perspective view of the sheet feed box according to the first embodiment.

[0010] Figure 4A , Figure 4B as well as Figure 4C This is a schematic diagram of the right housing unit according to the first embodiment.

[0011] Figure 5 This is a plan view of the ratchet unit according to the first embodiment.

[0012] Figure 6A , Figure 6B as well as Figure 6C This is a perspective view of the flag and ratchet output gear according to the first embodiment.

[0013] Figure 7A and Figure 7B The figures are plan and perspective views of the baffle and ratchet output gear according to the first embodiment.

[0014] Figure 8 This is a block diagram illustrating an image forming system according to a first embodiment.

[0015] Figure 9A and Figure 9B This is a plan view of the second transmission unit according to the first embodiment.

[0016] Figures 10A to 10D This is a plan view showing the right housing unit according to the first embodiment.

[0017] Figure 11A and Figure 11B This is a perspective view of the conveying device according to the second embodiment.

[0018] Figure 12 This is a plan view of the encoder recording medium according to the second embodiment.

[0019] Figure 13A and Figure 13B These are plan and perspective views of the area surrounding the photosensitive drum according to the third embodiment. Detailed Implementation

[0020] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings.

[0021] [First Embodiment] Figure 1 This is a schematic diagram illustrating an image forming system 1 equipped with an optional device 300, according to the present disclosure. The image forming system 1 includes an image forming apparatus 100 and an optional device 300. The image forming apparatus 100 is an electrophotographic color laser printer. In this embodiment, an electrophotographic image forming apparatus is described as an example, but the present disclosure can be applied to inkjet printers, etc.

[0022] The structure of the image forming apparatus 100 is described. The image forming apparatus 100 includes a transport device 50 for transporting recording media. The transport device 50 includes a sheet feed cassette 11, a sheet feed unit 32, and a separation roller pair 33. The sheet feed cassette 11 is a storage unit for storing recording media. The sheet feed unit 32 is a pickup roller that feeds recording media S1 located on top of a stack of recording media Sa loaded in the sheet feed cassette 11. The separation roller pair 33 separates the recording media fed by the sheet feed unit 32 one by one. The image forming apparatus 100 includes a transfer roller pair 36 for transporting the recording media separated by the separation roller pair 33.

[0023] Image forming apparatus 100 includes image forming unit 21. Image forming unit 21 includes photosensitive drums 29Y, 29M, 29C, and 29K. In the following description, the four colors—yellow, magenta, cyan, and black—are represented by Y, M, C, and K, respectively, and components with the symbols Y, M, C, and K represent components corresponding to the toners of the four colors. Image forming unit 21 includes developing units 20Y, 20M, 20C, and 20K, primary transfer rollers 28Y, 28M, 28C, and 28K, intermediate transfer belt 27, and secondary transfer roller 23. The surface of photosensitive drum 29 is charged by a charging unit (not shown). Next, a scanner irradiates the surface of photosensitive drum 29 with a laser to form an electrostatic latent image. Next, the electrostatic latent image is developed using the toner by developing unit 20, which includes a developer (toner) and a developing roller, and a developer image is formed. The developer image on the surface of the photosensitive drum 29 is transferred once to the intermediate transfer belt 27 by the primary transfer roller 28. Next, the secondary transfer roller 23 transfers the developer image on the intermediate transfer belt 27 onto the recording medium fed from the transport device 50.

[0024] The image forming apparatus 100 includes a fixing unit 24, a sheet ejection roller 25, and an ejection tray 26. The fixing unit 24 applies heat and pressure to a recording medium S on which a developer image has been transferred by a secondary transfer roller 23, to fix the developer image onto the recording medium S. The recording medium S, on which toner has been fixed by the fixing unit 24, is ejected from the sheet ejection roller 25 onto the ejection tray 26.

[0025] Optional device 300 is a storage device connected to the bottom of image forming apparatus 100 and storing recording media. Furthermore, optional device 300 is a transport device for transferring the recording media stored therein to image forming apparatus 100. Optional device 300 includes a sheet feed cassette 22, a sheet feed unit 64, a separation roller pair 66, and a transport roller pair 72. The sheet feed cassette 22 is a storage unit for storing recording media. The sheet feed unit 64 is a pickup roller that feeds recording media S2 located on top of the stack of recording media Sb loaded in the sheet feed cassette 22. The separation roller pair 66 separates the recording media fed by the sheet feed unit 64 one by one. The transport roller pair 72 transports the recording media conveyed by the separation roller pair 66 toward the transport roller pair 36.

[0026] (Construction of optional device) First, refer to Figure 2 Describe the construction of optional device 300. Figure 2 This is a perspective view of optional device 300. Figure 2 Some components, such as the exterior of optional device 300, have been omitted. Furthermore, Figure 2 The dashed area in the diagram represents the area where the motor 205 is installed. Optional device 300 includes a housing 60 and a sheet feed cassette 22. The sheet feed cassette 22 can be pulled out of the housing 60. The sheet feed cassette 22 can also be mounted onto the housing 60. In other words, the sheet feed cassette 22 is detachably attached to the housing 60. The direction in which the sheet feed cassette 22 is mounted onto the housing 60 is called the mounting direction.

[0027] The sheet feed cassette 22 includes a recording medium support unit 122 for supporting the recording medium. The housing 60 includes a right housing unit 200 and a left housing unit 400. The right housing unit 200 and the left housing unit 400 extend in the mounting direction. The right housing unit 200 is one end of the housing 60 in a direction orthogonal to both the mounting direction and the vertical direction (orthogonal direction). The left housing unit 400 is the other end opposite to one end of the housing 60 in the orthogonal direction. When the sheet feed cassette 22 is mounted to the housing 60, the recording medium support unit 122 is located between the right housing unit 200 and the left housing unit 400 in the orthogonal direction.

[0028] Next, refer to Figure 3 Describe the structure of the sheet feed box 22. Figure 3This is a schematic diagram showing the sheet feed cassette 22. The sheet feed cassette 22 includes a rear guide unit 14, a pair of side guides 12, a lifter unit 13, and a first transfer unit 180. The direction in which the recording medium is fed to the sheet feed unit 32 is called the feed direction. The rear guide unit 14 is a guide that adjusts the position of the recording medium at its upstream end (rear end) in the feed direction. The side guides 12 are guides that adjust the position of the recording medium in the orthogonal direction, and include a right guide 102 and a left guide 101.

[0029] The lifting unit 13 forms part of the recording medium support unit 122 that supports the recording medium stack Sa. The lifting unit 13 also functions as a moving unit that lifts the recording medium stack Sa. The lifting unit 13 receives a driving force transmitted from the motor 205, described later, and thus rises to a position where the recording medium can be fed to the sheet feed unit 32. The lifting unit 13 includes an intermediate plate 120, an arm 121, and a rotation shaft 120a. The intermediate plate 120 is positioned above the arm 121 and supported by the rotation shaft 120a, thereby rotating about the rotation shaft 120a. The arm 121 receives the driving force transmitted from the motor 205 and lifts the intermediate plate 120, which rotates about the rotation shaft 120a. The rotation shaft 120a extends in an orthogonal direction, and the rotation axis direction of the lifting unit 13 is orthogonal.

[0030] Next, the first transmission unit 180 is described. The first transmission unit 180 receives driving force from the second transmission unit 600 (described later) and transmits it to the arm 121. The first transmission unit 180 includes an interface gear 181, an idler gear 182, and a sector gear 183. The interface gear 181, idler gear 182, and sector gear 183 can all be referred to as transmission units for transmitting driving force. In other words, the first transmission unit 180 includes multiple transmission units for transmitting driving force. The interface gear 181 meshes with the drive output gear 153 of the second transmission unit 600 (described later). Therefore, the interface gear 181 rotates along with the rotation of the drive output gear 153. The idler gear 182 meshes with the interface gear 181 and rotates along with the rotation of the interface gear 181. The sector gear 183 meshes with the idler gear 182 and rotates along with the rotation of the idler gear 182. The arm 121 is connected to the sector gear 183 and rotates along with the rotation of the sector gear 183. Arm 121 rotates to lift intermediate plate 120. The rotation axis of each of the interface gear 181, idler gear 182, sector gear 183, arm 121 and intermediate plate 120 is in an orthogonal direction, specifically an orthogonal direction.

[0031] (Drive force transmission structure of the right shell unit) Next, refer to Figure 2 , Figure 4A , Figure 4B as well as Figure 4C The second transmission unit 600 is described as a drive force transmission structure disposed in the right housing unit 200. As described above, the second transmission unit 600 is a transmission unit that transmits drive force from the motor 205 to the first transmission unit 180. Figure 4A , Figure 4B as well as Figure 4C The right housing unit 200 is shown. Figure 4A This is a perspective view of the right shell unit 200. Figure 4B and Figure 4C This is a plan view of the right shell unit 200.

[0032] The right housing unit 200 includes a motor 205 and a second transmission unit 600. The second transmission unit 600 includes a worm gear 206, a ratchet unit 207, a first reduction gear 208, a second reduction gear 209, and a drive output gear 153. The worm gear 206, ratchet unit 207, first reduction gear 208, second reduction gear 209, and drive output gear 153 transmit driving force, and therefore can be called a transmission unit. In other words, the second transmission unit 600 includes multiple transmission units that transmit driving force. For example... Figure 4C As shown, the worm gear 206, ratchet unit 207, first reduction gear 208, second reduction gear 209, and drive output gear 153 all include gears and gear rotation shafts. For example, ratchet unit 207 includes a rotation shaft 207c.

[0033] Motor 205 is a drive unit that converts electrical energy supplied from a power source (not shown) into mechanical energy to generate driving force. For example... Figure 4BAs shown, the motor 205 includes a shaft 205a that serves as an output shaft and transmits driving force. A worm gear 206 is press-fitted onto the shaft 205a. Therefore, the worm gear 206 rotates along with the shaft 205a. The worm gear 206 meshes with a ratchet input gear 207a on the drive input side of the ratchet unit 207. The ratchet input gear 207a and the ratchet output gear 207b are connected via a rotating shaft 207c. According to this embodiment, the rotating shaft 207c is constructed by connecting multiple components, but it can also be constructed by only one component. The ratchet output gear 207b on the output side of the ratchet unit 207 meshes with a large gear 208a disposed in the first reduction gear 208. The first reduction gear 208 is provided with a small gear 208b, which rotates about the rotation axis of the large gear 208a and meshes with a large gear 209a disposed in the second reduction gear 209. The second reduction gear 209 is equipped with a pinion 209b, which rotates around the rotation axis of the large gear 209a and meshes with the large gear 153a disposed in the drive output gear 153. In other words, the driving force generated by the motor 205 is transmitted sequentially to the worm gear 206, ratchet unit 207, first reduction gear 208, second reduction gear 209, and drive output gear 153. As described above, the drive output gear 153 meshes with the interface gear 181 and transmits driving force to it. More specifically, the pinion 153b disposed in the drive output gear 153 meshes with the interface gear 181. In this way, the second transmission unit 600 adjusts the reduction ratio by inserting multiple transmission units, thereby increasing the torque of the drive output gear 153.

[0034] (Drive structure of the ratchet unit) Next, refer to Figure 5 The drive structure of the ratchet unit 207 is described in detail. Figure 5This is a cross-sectional view of the ratchet unit 207. The ratchet unit 207 includes a ratchet input gear 207a, a ratchet output gear 207b, and a bias spring 213. The bias spring 213 is a biasing member that biases the ratchet input gear 207a toward the ratchet output gear 207b. Engagements 211 and 212 with protruding shapes are respectively disposed on the opposing surfaces of the ratchet input gear 207a and the ratchet output gear 207b. Each engagement has an inclined surface along the circumferential direction on both sides of the protrusion, and the connecting surfaces 211a and 212a are the surfaces that contact when driven by the motor 205. Engagements 211 and 212 also include sliding surfaces 211b and 212b. The connecting surfaces 211a and 212a and the sliding surfaces 211b and 212b have substantially the same inclination. In normal operation, the ratchet input gear 207a and ratchet output gear 207b rotate as a unit via the bias spring 213, thereby transmitting driving force from the motor 205. However, if an excessive load is applied to the ratchet output gear 207b, the connecting surfaces 211a and 212a rise against the force of the bias spring 213 while in contact with each other. When the connecting surfaces 211a and 212a pass the apex of the raised shape, the holding force in the rotational direction disappears, and the ratchet input gear 207a idles relative to the ratchet output gear 207b. The ratchet input gear 207a descends the sliding surface 212b while being pressed down again by the bias spring 213, stopping when the connecting surface 211a contacts the adjacent connecting surface 212a, and returning to a state where driving force can be transmitted again. This operation is repeated when the load continues to be applied. Thus, in the event of an unexpectedly large load, the ratchet unit 207 serves to prevent damage to the device by not transmitting driving force.

[0035] (Sheet quantity testing agency) Next, refer to Figure 6A , Figure 6B , Figure 6C , Figure 7A as well as Figure 7B The image forming apparatus 100 describes a sheet quantity detection mechanism that detects the number of recording media supported by the recording medium support unit 122. The image forming apparatus 100 calculates the number of recording media supported by the recording medium support unit 122, and if, as a result of the calculation, the number of recording media supported by the recording medium support unit 122 is low, it notifies the user that there is insufficient recording media. Figure 6A and Figure 6B These are perspective views of the baffle 202 (the part to be detected), which will be described later, as seen from the oblique front and oblique rear. Figure 6C This is a 3D view of the ratchet output gear 207b. Figure 7A and Figure 7B The ratchet output gear 207b and the baffle 202 are shown in their engaged states.

[0036] First, the engagement between the ratchet output gear 207b and the baffle 202 is described. For example... Figure 2 As shown, the right housing unit 200 includes a baffle 202. (As indicated...) Figure 6A and Figure 6B As shown, the baffle 202 is an encoder disk. The baffle 202 includes a light-blocking portion 220 and a light-transmitting portion 221. The light-blocking portion 220 blocks light from the light-emitting portion 201a of the sensor 201, which will be described later, while the light-transmitting portion 221 does not block light from the light-emitting portion 201a. Furthermore, the baffle 202 includes a rotation stop groove 231, a baffle mounting shaft 232, a connecting claw 234, and a connecting claw operating portion 235. On the other hand, as... Figure 6C As shown, the ratchet output gear 207b includes an engagement hole 243 and a rotation stop rib 242. A baffle mounting hole 241 is formed in the ratchet output gear 207b, and a baffle mounting shaft 232 is fitted into the baffle mounting hole 241. Furthermore, the side surface of the rotation stop rib 242 and the side surface of the rotation stop groove 231 of the baffle 202 are fitted together. The baffle 202 is attached from the opposite side of the ratchet unit 207 to the first side plate 203. When the baffle 202 is inserted into the ratchet output gear 207b, the engagement pawl 234 engages with the engagement hole 243. The engagement pawl operating part 235 is a component for releasing the engagement between the engagement pawl 234 and the engagement hole 243. The user can release the engagement between the engagement pawl 234 and the engagement hole 243 by grasping the engagement pawl operating part 235 and pulling the engagement arm 244 inward. As described above, the baffle 202 is attached to the ratchet output gear 207b and rotates along with the ratchet output gear 207b. Specifically, the ratchet output gear 207b, which receives driving force from the motor 205, transmits it to the baffle 202, causing the baffle 202 to rotate. In other words, the baffle 202 is connected to the ratchet output gear 207b, and when the ratchet output gear 207b receives driving force from the motor 205, the baffle 202 rotates together with the ratchet output gear 207b. The baffle 202 and the ratchet output gear 207b rotate about a common axis of rotation.

[0037] Here, the ratchet output gear 207b has teeth 207ba. Teeth 207ba are gear teeth that mesh with other gears, and according to this embodiment, they mesh with the large gear 208a disposed in the first reduction gear 208.

[0038] Next, the construction of the sensor 201 that detects the rotation of the baffle 202 will be described. Figure 7A and Figure 7BIn this sensor, 201 is a light-emitting part 201a that emits light 218 and a light-receiving part 201b that receives the light 218 emitted from the light-emitting part 201a. A baffle 202 rotates so that a light-blocking part 220 and a light-transmitting part 221 pass between the light-emitting part 201a and the light-receiving part 201b. When the light-blocking part 220 is located between the light-emitting part 201a and the light-receiving part 201b, it blocks the light 218, thereby reducing the amount of light received by the light-receiving part 201b. On the other hand, when the light-transmitting part 221 is located between the light-emitting part 201a and the light-receiving part 201b, the amount of light received by the light-receiving part 201b is not reduced by the light-transmitting part 221. The sensor 201 alternately detects the light-blocking state and the light-transmitting state based on the received light amount and outputs a signal to an optional control unit 48, described later.

[0039] Next, the control structure of the sheet quantity detection mechanism will be described. First, refer to... Figure 8 Describe the control structure of image forming system 1. Figure 8 This is a block diagram showing the control structure of the image forming system 1.

[0040] The image forming apparatus 100 includes an engine control unit 111, a communication unit 130, and a display unit 140. The engine control unit 111 includes a central processing unit (CPU) 80, a read-only memory (ROM) 81, and a random access memory (RAM) 82. The communication unit 130 receives print jobs from a host computer and communicates with the engine control unit 111 to perform image forming operations on a recording medium based on the received print jobs. The display unit 140 is a display capable of displaying information. The engine control unit 111 controls the image forming operation. The CPU 80 loads programs and various data into the ROM 81 and uses the RAM 82 as a working area to execute the program. The ROM 81 is a storage component for storing data. Furthermore, the engine control unit 111 communicates with an optional control unit 48 of the optional device 300 via a serial communication capable of bidirectional communication. The optional control unit 48 controls the sheet feed operation of the optional device 300. The optional control unit 48 includes an optional CPU 83, an optional ROM 84, and an optional RAM 85. The optional ROM 84 is a storage unit for storing data. An optional CPU 83 loads programs and various data into an optional ROM 84 and uses an optional RAM 85 as the working area to execute the program. Additionally, an optional control unit 48 receives a signal output from the sensor 201 when rotation of the baffle 202 is detected.

[0041] When the image forming system 1 detects the rotation of the baffle 202, it determines the number of recording media supported by the sheet feed cassette 22 (intermediate plate 120) based on the signal output by the sensor 201. During the period when the intermediate plate 120 is raised, the baffle 202 rotates together with the ratchet output gear 207b. During the period when the baffle 202 rotates, the light-blocking part 220 and the light-transmitting part 221 alternately pass between the light-emitting part 201a and the light-receiving part 201b. Therefore, the signal output by the sensor 201 alternates between ON and OFF, and the optional control unit 48 receives the output signal from the sensor 201. The optional control unit 48 transmits information to the engine control unit 111 based on the received signal. The CPU 80 of the engine control unit 111 counts the number of switching pulses of the signal from the sensor 201 and determines the number of recording media supported by the recording medium support unit 122.

[0042] If the number of recording media determined by the CPU 80 is lower than a predetermined threshold, the communication unit 130 notifies the display unit 140 to display information about the number of recording media. For example, the display unit 140 displays information prompting the user to set / supply recording media in the recording media support unit 122.

[0043] (The positional relationship of the components) Next, refer to Figure 2 , Figures 4A to 4C , Figure 9A , Figure 9B as well as Figures 10A to 10D Describe the positional relationship of the components according to this embodiment. Figure 9A This is a top view showing the second transmission unit 600. Figures 10A to 10D This is a plan view of the right shell unit 200. Figure 9B This is a schematic diagram of the ratchet unit 207. Furthermore, Figure 9A The dashed line shown indicates the area where motor 205 is installed.

[0044] First, the positional relationship between the first side plate 203 and the second side plate 204 is described. The right housing unit 200 includes the first side plate 203 and the second side plate 204. The longitudinal direction of the first side plate 203 and the second side plate 204 is the mounting direction. In other words, the first side plate 203 and the second side plate 204 extend in the mounting direction. Alternatively, the first side plate 203 and the second side plate 204 extend in a direction that intersects (or is orthogonal to) the rotation axis direction of the baffle 202. Here, the direction in which the rotation axis of the baffle 202 extends from the first side plate 203 toward the second side plate 204 is referred to as the first direction. The first direction is also the direction extending from one end 207c1 to the other end 207c2, which will be described later. Figure 2 The center M shown represents the center of the optional device 300 in the orthogonal direction. For example... Figure 2As shown, the second side plate 204 is disposed inside the optional device 300 (conveyor) relative to the first side plate 203 in the first direction (orthogonal direction). In other words, in the first direction, the shortest distance between the second side plate 204 and the center M is less than the shortest distance between the first side plate 203 and the center M. Alternatively, the second side plate 204 can be described as being downstream of the first side plate 203 in the first direction.

[0045] Next, the positional relationship between the first side plate 203, the second side plate 204, and the ratchet unit 207 will be described. For example... Figure 9B As shown, the first side plate 203 supports one end 207c1 of the rotating shaft 207c. Furthermore, the second side plate 204 supports the other end 207c2 opposite to end 207c1. In other words, the ratchet unit 207 (transmission unit) has one end 207c1 supported by the first side plate 203 in the first direction, and the other end 207c2 opposite to end 207c1 supported by the second side plate 204. Moreover, both the first side plate 203 and the second side plate 204 face the ratchet input gear 207a. Figure 9B As shown, the shortest distance between one end 207c2 and the center M is less than the shortest distance between the other end 207c1 and the center M. Figure 9A As shown, the teeth 207ba of the ratchet output gear 207b are located between the first side plate 203 and the second side plate 204 in the direction of the rotation axis (first direction) of the ratchet output gear 207b.

[0046] Next, the positional relationship between the baffle 202, the motor 205, the first side plate 203, and the second side plate 204 will be described. For example... Figure 4A As shown, the first side plate 203 is provided with a sensor attachment portion 214, which is arranged to protrude upstream from the first side plate 203 in a first direction. Figure 7A and Figure 7B As shown, the sensor 201 is fixed by inserting the attachment portion 216 of the sensor 201 into the hole formed in the sensor attachment portion 214. The light-emitting portion 201a is located outside the baffle 202 and the first side plate 203 in the first direction. Figure 7A The long double-short dashed line A shown is a virtual line indicating the position of a portion of the surface of the first side plate 203. Thus, at least a portion of the sensor 201 is located outside the first side plate 203 covering the second transmission unit 600. Similarly, as... Figure 2As shown, the baffle 202 is located upstream of the first side plate 203 in the first direction. In other words, the first side plate 203 is located between the baffle 202 and the second side plate 204 in the first direction. This configuration prevents lubricating oil applied to the gear train from spilling onto the sensor 201 and the baffle 202, and reduces false detections and malfunctions caused by dirt. Furthermore, since various components, such as the second transmission unit 600, are located inside the first side plate 203, the space for arranging the sensor 201 is small, resulting in low design flexibility. Arranging the sensor 201 outside the first side plate 203 increases the design flexibility of the sensor 201. On the other hand, according to this embodiment, the light receiving part 201b is located downstream of the first side plate 203 in the first direction. This configuration can reduce the size of the second transmission unit 600 in the first direction. In other words, by arranging a portion of the sensor 201 downstream of the first side plate 203 in the first direction and arranging another portion of the sensor 201 upstream of the first side plate 203, design flexibility and size reduction can be achieved.

[0047] Next, the construction of the motor 205 will be described. For example... Figure 4A and Figure 9A As shown, at least a portion of the motor 205 is located downstream of the first side plate 203 and the baffle 202 in a first direction. In other words, the optional device 300 according to this embodiment utilizes the space inside the baffle 202 as a space for arranging the motor 205. Furthermore, as... Figure 2 and Figure 9A As shown, at least a portion of the motor 205 is located upstream of the second side plate 204 in a first direction. In other words, in the first direction, the motor 205 is located between the first side plate 203 and the second side plate 204. Figure 10C This is a plan view of the right housing unit 200 of the motor 205. The rotation axis direction of the shaft 205a extends in a direction intersecting the first direction. For example, the rotation axis direction of the shaft 205a can be referred to as the second direction. The longitudinal direction of the motor 205 is the second direction. In this way, by setting the longitudinal direction of the motor 205 as the second direction, the size of the right housing unit 200 can be reduced.

[0048] The right housing unit 200 includes a cover member 210 that covers the motor 205. The cover member 210 is disposed upstream of the motor 205 in a first direction. Furthermore, the cover member 210 is located downstream of the baffle 202 in the first direction. In other words, the cover member 210 is located between the motor 205 and the baffle 202 in the first direction.

[0049] (Motor replacement) Next, refer to Figure 7A , Figure 7B as well as Figures 10A to 10D Describe the construction of the replacement motor 205. Figure 10A The state of the cover member 210 covering the motor 205 is shown. Figure 10B It shows from Figure 10A Remove the baffle 202 from the state. Figure 10C It shows from Figure 10B The state of removing cover component 210 in the state. Figure 10D It shows from Figure 10C Remove the state of motor 205 from the current state. Figures 10A to 10D It is a plan view viewed along the first direction. Figure 10A and Figure 10B The dashed lines shown schematically indicate the area where motor 205 is located.

[0050] Viewed from the first direction, the baffle 202 and the first side plate 203 overlap. Furthermore, viewed from the first direction, the baffle 202 and the motor 205 overlap. The reason for the overlap between the baffle 202 and the motor 205 is explained. As the number of transmission units inserted between the motor 205 and the baffle 202 increases, the influence of tolerances becomes greater, making it more difficult to accurately detect the rotational speed of the motor 205. Therefore, according to this embodiment, the baffle 202 is connected to the ratchet unit 207 to reduce the number of transmission units inserted between the motor 205 and the baffle 202. Therefore, the fact that the baffle 202 is connected to the ratchet unit 207 near the motor 205 is one of the reasons for the overlap between the baffle 202 and the motor 205. It can also be said that overlapping the baffle 202 and the motor 205 allows for accurate detection of the rotational speed of the motor 205. Viewed from the first direction, the cover member 210 overlaps with the motor 205. Furthermore, viewed from the first direction, the baffle 202 overlaps with the cover member 210.

[0051] To replace the motor 205, firstly, remove the retainer 202 from the ratchet output gear 207b. As described above, when the user grips the engagement pawl operating part 235 and pulls the engagement arm 244 inward, the engagement of the engagement pawl 234 is released, and the retainer 202 can be removed from the ratchet output gear 207b. Next, remove the cover member 210. The cover member 210 is secured to the right housing unit 200 by inserting screws 230a and 230b into holes formed in the cover member 210. In other words, the screws 230a and 230b can be referred to as fixing members for securing the cover member 210. Figure 10BAs shown, the fixing member is arranged so as not to overlap with the first side plate 203 when viewed in the first direction. In other words, the fixing member protrudes from the first side plate 203. Therefore, the first side plate 203 is unlikely to become an obstacle to removing the fixing member, thus allowing for easy removal. The fixing member is removed, and then the cover member 210 is removed. The cover member 210 is arranged so as not to overlap with the first side plate 203 when viewed along the first direction, thus allowing for easy removal. After the cover member 210 is removed, the motor 205 is removed. During the above removal process, the baffle 202, the cover member 210, and the motor 205 can be removed without removing the first side plate 203, which is not easily removed from the right housing unit 200.

[0052] [Second Embodiment] Next, we will refer to Figure 11A , Figure 11B as well as Figure 12 A second embodiment of this disclosure is described. The second embodiment illustrates the application of this disclosure to the transmission device 50 of the image forming apparatus 100 according to the first embodiment. Descriptions of configurations identical to those in the first embodiment are omitted. Figure 11A and Figure 11B This is a perspective view of the sheet feeding unit 32 according to the second embodiment. Figure 12 This is a plan view of the encoder recording medium 263, which will be described later.

[0053] The conveying device 50 includes a pair of separating rollers 33, a rotary transmission shaft 261, a side plate 262, an encoder recording medium 263, and a rotation detection sensor 264. The separating roller pair 33 includes a separating roller 33a and a separating roller 33b opposite to the separating roller 33a. In addition, the conveying device 50 includes a motor 274, a rotation detection gear 265, and a rotation transmission gear 266.

[0054] A rotary transmission shaft 261 is inserted into the rotary shaft of the separating roller 33b. A rotary transmission gear 266 is attached to the other end of the rotary transmission shaft 261. A rotary detection gear 265 meshes with the rotary transmission gear 266. A side plate 262 includes a bearing hole 273 through which the shaft of the rotary detection gear 265 is inserted. An encoder recording medium 263 and a rotary detection sensor 264 are disposed on the side of the side plate 262 opposite to the rotary transmission gear 266. The rotary detection sensor 264 has the same construction as the sensor 201 according to the first embodiment, and therefore its description is omitted.

[0055] According to the second embodiment, the encoder recording medium 263 is a transparent polyethylene terephthalate (PET) recording medium on which a print is applied to block light from the light blocker. Figure 12As shown, the encoder recording medium 263 includes a strip of printed portions 267 and non-printed portions 268. The printed portions 267 block light, while the non-printed portions 268 transmit light. According to this embodiment, 120 printed portions 267 are printed uniformly, but the number of printed portions can be appropriately selected according to the required resolution.

[0056] Motor 274 is arranged inside side plate 262 and transmits driving force to separation roller 33a. When driving force is transmitted to separation roller 33a, separation roller 33b is driven to rotate. The rotation of separation roller 33b is transmitted to encoder recording medium 263 via rotation transmission shaft 261, rotation transmission gear 266, and rotation detection gear 265. When encoder recording medium 263 rotates, printing section 267 and non-printing section 268 alternately block and transmit light, generating pulse signals. Engine control unit 111 calculates the rotational speed of separation roller 33b based on the frequency of the generated pulse signals and controls the timing of stopping the conveying drive of separation roller 33a.

[0057] As described above, the motor 274 is located in the space inside the encoder recording medium 263 (the detected part). Therefore, the image forming apparatus 100 according to this embodiment utilizes the space inside the encoder recording medium 263 as the arrangement space.

[0058] [Third Embodiment] Next, refer to Figure 13A and Figure 13B A third embodiment of this disclosure is described. The third embodiment illustrates the application of this disclosure to a drive unit that drives a photosensitive drum 29. Figure 13A This is a plan view of the area surrounding the drive unit of the photosensitive drum 29. Furthermore, Figure 13B This is a perspective view of a portion of the drum drive gear 280. The drum drive gear 280 has a drum connector 286 at one end of its shaft, which engages with a driven connector (not shown) disposed inside the photosensitive drum 29 to transmit driving force. A drum drive side plate 281 has a burring 287 and rotatably supports the shaft at the other end of the drum drive gear 280. The leading edge of the shaft of the drum drive gear 280, protruding from the burring 287, has a cylindrical portion 284. A notch 285 is formed on a portion of the cylindrical portion 284. A drum rotation detection sensor 282 is disposed on the outside of the drum drive side plate 281, and its detection unit 283 is attached to clamp the cylindrical portion 284. When the notch 285 is present at the detection unit 283 of the drum rotation detection sensor 282, the drum rotation detection sensor 282 is in a non-detection state.

[0059] The motor 289 is located inside the cylindrical part 284 and drives the photosensitive drum 29.

[0060] When the photosensitive drum 29 drives the drum drive gear 280, the notch 285 rotates relative to the drum rotation detection sensor 282. When the cylindrical portion 284 reaches the detection unit 283 of the drum rotation detection sensor 282, the drum rotation detection sensor 282 enters a detection state. When the drum drive gear 280 rotates once and the notch 285 reaches the detection unit 283 of the drum rotation detection sensor 282 again, the drum rotation detection sensor 282 enters a non-detection state and detects that the drum has rotated once. By repeating this process, the rotation state of the photosensitive drum 29 is monitored and the printing operation is controlled. As described above, the motor 289 is located in the space inside the cylindrical portion 284 (the detected portion). Therefore, the space inside the cylindrical portion 284 is used as a space for arranging the motor 289.

[0061] According to this disclosure, the space inside the tested part can be used as a space for arranging a motor.

[0062] Although this disclosure has been described with reference to embodiments, it is to be understood that this disclosure is not limited to the disclosed embodiments. The scope of the appended claims is to be given the broadest description to include all such modifications and equivalent structures and functions.

Claims

1. A transmission apparatus for transmitting a recording medium, the transmission apparatus comprising: An electric motor is constructed to generate driving force; A gear, which is configured to rotate by receiving the driving force; A first side plate is configured to support the gear; A second side plate is disposed inside the transmission device relative to the first side plate in the direction of rotation axis of the gear and is configured to support the gear. The part to be detected, which is connected to the gear and configured to rotate with the gear, and A sensor configured to detect the rotation of the detected part. In the direction of the rotation axis, the teeth of the gear are located between the first side plate and the second side plate. Wherein, if the direction along the rotation axis from the first side plate toward the second side plate is defined as the first direction, the detected part is located upstream of the first side plate in the first direction, and Wherein, at least a portion of the motor is located downstream of the detected part in the first direction.

2. The conveying device according to claim 1, wherein, The motor is located between the first side plate and the second side plate in the first direction.

3. The conveying device according to claim 1, wherein, When viewed from the first direction, the detected part overlaps with the motor.

4. The conveying device according to claim 3, further comprising: A cover component, configured to cover the motor. Wherein, the cover member is located between the motor and the detected part in the first direction, and When viewed from the first direction, the cover component overlaps with the detected part and the motor.

5. The conveying device according to claim 4, further comprising: A fixing member, configured to fix the cover member. When viewed from the first direction, the fixing member is arranged in a position that does not overlap with the first side plate.

6. The conveying device according to claim 1, in, The motor includes a shaft configured to transmit driving force. Wherein, the rotation axis direction of the shaft is a second direction intersecting the first direction, and The longitudinal direction of the motor is the second direction.

7. The conveying device according to any one of claims 1 to 6, in, The sensor includes a light-emitting part configured to emit light and a light-receiving part configured to receive light from the light-emitting part. The detected part rotates to pass between the light-emitting part and the light-receiving part.

8. The conveying device according to any one of claims 1 to 6, wherein, The part being detected is an coded disk.

9. The conveying device according to any one of claims 1 to 6, wherein, The transmission device is connected to the image forming apparatus to transmit the recording medium to the image forming apparatus.

10. The conveying device according to claim 9, further comprising: A support unit configured to support the recording medium; as well as An arm is configured to move the support unit by receiving a driving force transmitted from the gear.

11. The conveying device according to any one of claims 1 to 6, further comprising: An image forming unit is configured to form an image on a recording medium.

Images