Patent Application
20240333850
This application claims priority to Japanese Patent Application No. 2023-057307 filed on Mar. 31, 2023, the entire contents of which are incorporated by reference herein.
The present disclosure relates to sheet conveying devices.
There is known an image reading device that performs shading compensation with high accuracy, for example, by moving a white reference member a specified amount in a main scanning direction in conjunction with rotation of a conveyance drive roller conveying a sheet, reading an image of the white reference member several times with an image sensor during the movement of the white reference member to read different locations on the white reference member, and averaging sets of white reference data obtained by the reading at the different locations to acquire accurate white reference data even in the presence of dirt somewhere on the reading surface of the white reference member.
A technique improved over the aforementioned technique is proposed as one aspect of the present disclosure.
A sheet conveying device according to an aspect of the present disclosure includes a drive device, a conveyance device, an optical unit, a white reference member, and a transmission device. The drive device generates a driving force. The conveyance device conveys a sheet by a rotary driving force of the drive device. The optical unit includes an image reading unit that extends in a longitudinal direction thereof along a widthwise direction orthogonal to a direction of conveyance of the sheet, applies light to the sheet, and reads light reflected from the sheet with an image sensor. The white reference member extends in the longitudinal direction of the image reading unit and is read by the image reading unit. The transmission device transmits the driving force generated by the drive device to rock the optical unit in the widthwise direction. The transmission device includes a rocking member that rocks the optical unit in a longitudinal direction of the optical unit.
Hereinafter, a description will be given of a sheet conveying device according to an embodiment as an aspect of the present disclosure with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are designated by the same reference characters and further description is omitted.
First, a multifunction peripheral 1 will be described with reference to
The cloud is a form of utility that provides computer resources via a computer network, such as the Internet, and includes, as an example, an application, a platform, and an infrastructure.
The server stores data and, upon request via a communication line, provides a requested piece of data.
The multifunction peripheral 1 includes a document reading apparatus 2 and an image forming apparatus 3.
First, the image forming apparatus 3 will be described with reference to
The image forming apparatus 3 includes a sheet tray 30, a sheet feed roller 31, an image forming device 32, a fixing device 33, a sheet output roller 34, and a sheet output tray 35.
The sheet tray 30 accommodates sheets. The sheet feed roller 31 picks up and feeds a sheet from the sheets accommodated in the sheet tray 30.
The image forming device 32 forms an image on a sheet by toner or ink. In the case where the image forming apparatus 3 forms an image electrophotographically, the image forming device 32 includes a photoconductor, a charging device, an exposure device, a developing device, a transfer device, a cleaning device, and a destaticizing device.
An example of the photoconductor is a photoconductive drum. The photoconductive drum has a photosensitive layer on the peripheral surface. Examples of the photoconductive drum include a selenium drum and an OPC (organic photoconductor).
The charging device charges the photosensitive layer of the photoconductor to a predetermined potential. An example of the charging device is a corona discharger.
The exposure device irradiates the photosensitive layer of the photoconductor with laser light to expose it to the laser light. The exposure device exposes the photosensitive layer of the photoconductor to light based on image data. As a result, an electrostatic latent image is formed on the photoconductor. An example of the exposure device is an LED (light-emitting diode).
The developing device contains, as an example, a two-component developer containing a carrier made of a magnetic material and a toner. The developing device develops by the toner the electrostatic latent image formed on the photoconductor, thus forming a toner image on the photoconductor. The transfer device transfers the toner image on the photoconductor to a sheet. The cleaning device cleans up residual toner remaining on the photoconductor after the transfer. The destaticizing device removes electrostatic charge from the photoconductor.
The fixing device 33 applies heat and pressure to the toner image developed on the sheet to fix the toner image on the sheet. The fixing device 33 includes, for example, a fixing roller, a heater, and a pressing roller.
The fixing roller is a hollow cylindrical roller. The fixing roller is pressed against the pressing roller. The pressing roller and the fixing roller form a nip between them. The pressing roller is driven into rotation by an unshown drive device and forms a nip together with the fixing roller to rotate the fixing roller.
The heater is supplied with power from an unshown power source to apply heat to the fixing roller. The heater is disposed in proximity to an inner peripheral surface of the fixing roller. The sheet conveyed to the fixing device 33 is heated by the heater when passing through the nip and, thus, the toner image is fixed on the sheet.
A sheet output device ejects the sheet to the outside of a body of the image forming apparatus 3. The sheet output device includes the sheet output roller 34 and the sheet output tray 35. The sheet output roller 34 ejects to the sheet output tray 35 the sheet conveyed from the fixing device 33 by the sheet conveying device. The sheet output tray 35 accommodates ejected sheets.
Although
The ink cartridge and the ink tank store, as an example, different types of water-based inks of different colors: Y (yellow). M (magenta), C (cyan), and Bk (black).
The pump supplies ink from the ink tank to the head.
Multiple nozzles forming pixels are disposed on the head. Based on image data, ink of color according to the image data is supplied from the ink tank to the head. The ink is discharged through the nozzles toward a sheet.
The electrode includes, as an example, a charging electrode and a deflection electrode. The charging electrode applies charge to the ink discharged from the nozzles.
The deflection electrode controls the direction of flight of the charged ink.
The conveying belt is opposed to the nozzles of the head and conveys a sheet. Image is formed, by the ink discharged from the nozzles of the head, on the sheet being conveyed by the conveying belt. In the case where the image forming apparatus 3 is an inkjet printer, no fixing device is needed.
Next, the document reading apparatus 2 will be described with reference to
The document reading apparatus 2 shown in
The document reading apparatus 2 includes a document sheet conveying device 4, a document feed roller 5, a document conveyance path 6, a document conveyance roller 7, a sheet conveying device 8, and a document conveyance roller 10.
The document reading apparatus 2 reads an image from an original document G and generates image data based on the read image. The document sheet conveying device 4 feeds the original document G. The document sheet conveying device 4 includes a feed tray 40 and an ejection tray 41. The feed tray 40 accommodates original documents G. The ejection tray 41 accommodates original documents G from which images have been read and which have then been ejected to the ejection tray 41.
The document feed roller 5 picks up and feeds an original document G on the feed tray 40. The document conveyance path 6 includes the document feed roller 5 disposed therein and allows the document sheet fed by the document feed roller 5 to be conveyed therealong. The document conveyance roller 7 is also disposed in the document conveyance path 6 and conveys the original document G along the document conveyance path 6.
The sheet conveying device 8 is disposed in the document conveyance path 6. The sheet conveying device 8 further conveys the original document G conveyed along the document conveyance path 6 by the document conveyance roller 7. In the sheet conveying device 8, the image of the original document G being conveyed is read by the optical unit 84.
A position at which the image of an original document G is read is referred to as a reading position 9. When the original document G is passing through the reading position 9, the image of the original document G is read by the optical unit 84.
The document conveyance roller 10 is disposed in the document conveyance path 6 and conveys the original document G toward the ejection tray 41.
Next, the sheet conveying device 8 according to this embodiment will be described in detail with reference to, in addition to
As shown in
The drive device 80 includes an unshown motor as an example of a drive source and a drive gear part 810. The drive device 80 supplies through the transmission device 81 a rotary driving force generated by the motor to the conveyance device 83. The drive gear part 810 is provided on a rotary shaft of the motor as a drive source to rotate simultaneously and coaxially with the rotary shaft and is rotated by the rotary driving force of the motor.
The transmission device 81 transmits the rotary driving force generated by the drive device 80 to the conveyance device 83. As shown in
The conveyance device 83 is rotated by the rotary driving force transmitted thereto through the transmission device 81 from the drive device 80 to convey a sheet (an original document G). As shown in
The conveying shaft 830 is bridged in the widthwise direction of the document conveyance path 6 described with reference to
The roller 831 is mounted on the conveying shaft 830 and rotates along with the rotation of the conveying shaft 830 to convey a sheet. By the rotary driving force transmitted from the drive device 80, the lock drive gear part 832 and the conveying shaft 830 are rotated in a direction for the roller 831 to convey the sheet in the direction of sheet ejection. When the drive device 80 transmits to the conveyance device 83 a rotary driving force opposite in the direction of rotation to the above-described rotary driving force, the lock drive gear part 832 and the conveying shaft 830 rotate in the same opposite direction according to the transmitted rotary driving force.
The lock drive gear part 832 rotates in response to the rotary driving force from the drive device 80. The lock drive gear part 832 will be described later in further detail with reference to
The optical unit 84 shown in
As shown in
The case 840 accommodates the image reading unit 842. The guide 841 is disposed at a position of abutment on a rocking portion 821 which is a portion of the rocking member 812.
The image reading unit 842 irradiates a sheet or a reflectance standard (a white reference member) with light and reads reflected light with an image sensor. The reflectance standard has a shape extending in a direction of extension of the image reading unit 84. The reflectance standard is provided separately from and independently of the image reading unit 842 at a location opposed to an image reading surface of the image sensor of the image reading unit 842. The reflectance standard has such a length that it keeps facing opposite to the image reading surface even when the image reading unit 842 moves to either an initial position or a reading position to read the reflectance standard both of which will be described hereinafter. Image data generated from reflected light of the light applied from the image reading unit 842 to the reflectance standard is used, for example, as white reference data for shading compensation.
An example of the image reading unit 842 is a CIS (contact image sensor) type sensor.
The spring 843 shown in
Next, the transmission device 81 will be described in detail. As described previously, the transmission device 81 includes the planet gear part 811, the rocking member 812, and the lock member 813. As shown in
As shown in
The rocking member 812 includes a second cam 820, a rocking shaft 819, and a rocking portion 821. The second cam 820 is formed integrally with the rocking shaft 819 and the rocking portion 821 and rotates simultaneously with the rocking shaft 819 and the rocking portion 821.
As shown in
In a state where the second cam 820 and a first cam 8160 of an internal gear member 816 to be described hereinafter mesh with each other, the case 840 accommodating the image reading unit 842 is biased by the spring 843 to push the rocking portion 821 toward the first cam 8160 and thus located at a reading position to read a sheet in the direction of extension of the rocking portion 821 (the direction of extension of the case 840).
When the rocking portion 821 and the second cam 820 rotate and the second cam 820 is thus displaced and released from meshing engagement with the first cam 8160, the rocking portion 821 moves in the direction of extension thereof and the case 840 moves in a direction away from the first cam 8160 along the direction of extension of the rocking portion 821 against the bias of the spring 843. Hereinafter, this movement of the case 840 is referred to as rocking.
When the rocking portion 821 and the second cam 820 further rotate and the second cam 820 is thus returned to meshing engagement with the first cam 8160, the rocking portion 821 is returned, by the bias of the spring 843, in the direction of extension thereof to a position when the second cam 820 and the first cam 8160 mesh with each other, and the case 840 is returned in the direction of extension of the rocking portion 821 to the above reading position.
The transmission device 81 is designed to keep the rocking member 812 from moving in the above manner when the drive device 80 rotates the conveyance device 83 in the direction of conveyance of a sheet, and allow the rocking member 812 to move in the above manner when the drive device 80 rotates the conveyance device 83 in a direction opposite to the direction of conveyance of a sheet.
The lock member 813 allows the sun gear member 814 to rotate in one direction (a direction of its rotation during conveyance of a sheet), but restrains the rotation of the sun gear member 814 in the direction opposite to the one direction by meshing engagement into the sun gear member 814. An internal gear 8162 of an internal gear member 816 meshes with the lock drive gear part 832.
Specifically, the lock member 813 is designed so that, as shown in
Furthermore, the lock member 813 is designed so that, as shown in
Next, a detailed description will be given of the structure of the planet gear part 811 with reference to
The planet gear part 811 shown in
As shown in
The through hole 8140 of the sun gear member 814 is passed through by the rocking shaft 819 of the rocking member 812 shown in
The internal gear member 816 includes an internal gear 8162, the first cam 8160, and a through hole 8161.
The first cam 8160 shown in
As shown in
The first declivity 8160A inclines in a direction toward the internal gear 8162. More specifically, the first declivity 8160A inclines toward the internal gear 8162 from the first peak 8160D and inclines toward the first bottom 8160B.
At the first bottoms 8160B, the first declivities 8160A come closest to the internal gear 8162.
The first acclivity 8160C inclines, starting with the first bottom 8160B, in a direction away from the internal gear 8162. In other words, the first acclivity 8160C inclines, starting with the first bottom 8160B, toward the first peak 8160D.
At the first peaks 8160D, the first acclivities 8160C come farthest away from the internal gear 8162.
The planet carrier member 817 shown in
The shaft portion 8141 of the sun gear member 814 is inserted through the respective through holes 8161, 8171 of the internal gear member 816 and the planet carrier member 817 and the internal gear member 816 and the planet carrier member 817 are fitted with play around the shaft portion 8141. The planet gear members 815 shown in
When the rotation of the sun gear member 814 is restrained by the lock member 813, the internal gear member 816 is rotated through the planet carrier member 817 and the planet gear members 815 by the driving force of the drive device 80.
Since the planet carrier member 817 and the internal gear member 816 are fitted with play around the shaft portion 8141 of the sun gear member 814, the sun gear member 814 holds the planet carrier member 817 and the internal gear member 816 freely rotatable with respect to the shaft portion 8141. In other words, the planet carrier member 817 and the internal gear member 816 rotate independently of the sun gear member 814.
Next, the rocking member 812 will be described in detail with reference to
The rocking member 812 presses against the guide 841 of the optical unit 84 and moves in the direction of extension of the case 840 together with the guide 841 of the optical unit 84.
As shown in
The rocking member 812 includes the second cam 820 facing opposite to the first cam 8160 disposed coaxially with the rocking shaft 819. The second cam 820 is formed integrally with the rocking shaft 819 of the rocking member 812. The rocking shaft 819 of the rocking member 812 passes through the through hole 8140 of the sun gear member 814 constituting part of the planet gear part 811 and is fitted and mounted in the through hole 8140. Thus, the rocking member 812 rotates simultaneously with the sun gear member 814.
The second cam 820 faces opposite to the first cam 8160 (see
The second cam 820 of the rocking member 812 includes second acclivities 8200, second peaks 8201, second declivities 8202, and second bottoms 8203.
The second acclivity 8200 inclines in a direction toward the gear-side end portion 822. The second acclivity 8200 of the second cam 820 is formed to extend while inclining, starting with the second bottom 8203 to the second peak 8201, in a direction toward the gear-side end portion 822.
The second peaks 8201 are located where the second acclivities 8200 come closest to the gear-side end portion 822. More specifically, the second peaks 8201 are located where the second acclivities 8200 come closest to the gear-side end portion 822 in the axial direction of the rocking shaft 819.
The second declivity 8202 inclines, starting with the second peak 8201, in a direction toward the guide-side end portion 823. The second declivity 8202 of the second cam 820 is formed to extend while inclining, starting with the second peak 8201 to the second bottom 8203, in a direction toward the guide-side end portion 823.
The second bottoms 8203 are located where the second declivities 8202 come closest to the guide-side end portion 823. More specifically, the second bottoms 8203 are located where the second declivities 8202 come closest to the guide-side end portion 822 in the axial direction of the rocking shaft 819.
When the internal gear member 816 of the planet gear part 811 rotates while, as described above, the pawl 8132A of the lock member 813 bites into the sun gear member 814 to restrain the rotation of the sun gear member 814, the rocking member 812 does not rotate, but the internal gear member 816 rotates, which displaces the meshing engagement between the second cam 820 and the first cam 8160. Therefore, the rocking member 812 moves in a direction toward the guide 841 to allow the rocking portion 821 to push the guide 841 in the direction of extension of the rocking portion 821 and the rocking shaft 819, which causes the optical unit 84 to rock in this direction.
In this embodiment, the sum of the axial distance from the first bottom 8160B of the first cam 8160 of the internal gear member 816 to the first peak 8160D thereof and the axial distance from the second bottom 8203 of the second cam 820 of the rocking member 812 to the second peak 8201 thereof is set at 4 mm or less. This sum corresponds to the amount of rocking of the optical unit 84. By specifying the figures of the first cam 8160 and the second cam 820 as so far described, the amount of rocking of the optical unit 84 can be adjusted.
When the conveyance device 83 is rotated in the direction of conveyance of a sheet by the rotary driving force from the drive device 80, the first declivities 8160A, the first bottoms 8160B, the first acclivities 8160C, and the first peaks 8160D of the first cam 8160 mesh with the second acclivities 8200, the second peaks 8201, the second declivities 8202, and the second bottoms 8203, respectively, of the second cam 820.
Next, the lock member 813 will be described in detail with reference to
The lock member 813 shown in
As shown in
The washer 8131 is incorporated into the lock gear 8130. The washer 8131 functions as a resistant for the lock gear 8130 against the connector 8132. The connector 8132 is assembled with the lock gear 8130 and the washer 8131 by the screw 8133.
The connector 8132 includes a pawl 8132A. When, as shown in
Next, the movement of the sheet conveying device 8 will be described with reference to, in addition to
As shown in
At this time, as shown in
Thus, the lock member 813 moves away in the direction of the arrow B from the planet gear part 811 (see
Next, a description will be given of movement in performing shading compensation for the image reading unit 842 while no sheet is conveyed. In this case, a rotary driving force in a direction reverse to the forward rotation is supplied from the drive device 80 through the drive gear part 810 to the planet carrier member 817 and thus causes the planet carrier member 817 and the internal gear member 816 to rotate reversely to the direction of rotation during conveyance of a sheet. At the start of this reverse rotation, in the planet gear part 811, the sun gear member 814, the planet gear members 815, the planet carrier member 817, and the internal gear member 816 rotate reversely to the direction of rotation during conveyance of a sheet.
At this time, as shown in
Thus, the lock member 813 moves in the direction of the arrow A and close to the planet gear part 811 and, as shown in
Since the internal gear member 816 rotates as just described, as shown in
At the time when the internal gear member 816 rotates in the above manner, as shown in
Suppose that, in the planet gear part 811, the planet gear members 815, the internal gear member 816, and the planet carrier member 817 continue to rotate. The rotation of the sun gear member 814 remains restrained.
At this time, since the conveying shaft 830 and the lock drive gear part 832 continue to be rotated in the direction of reverse conveyance D by the rotary driving force of reverse rotation supplied from the drive device 80, they move closer to the planet gear part 811.
Thus, as shown in
At this time, the spring 843 always biases the guide 841 of the optical unit 84 against the guide-side end portion 823 of the conveying shaft 830, but the rocking portion 821 and the rocking shaft 819 of the rocking member 812 are moved toward the guide 841 against the bias of the spring 843 by the above rotation of the first cam 8160 while abutting on the guide 841 of the optical unit 84, thus presses the guide 841, and moves it in the direction of pressing.
Therefore, as shown in
A description will be given below of the case where, in the planet gear part 811, the planet gear members 815, the internal gear member 816, and the planet carrier member 817 further continue to rotate from the above state.
The rotation of the sun gear member 814 remains restrained. As shown in
As shown in
In this embodiment, as shown in
A description will be given below of the case where, in the planet gear part 811, the planet gear members 815, the internal gear member 816, and the planet carrier member 817 further continue to rotate from the above state.
The rotation of the sun gear member 814 remains restrained. As shown in
At this time, as shown in
Thus, the rocking portion 821 and the rocking shaft 819 of the rocking member 812 start to move in a direction away from the guide 841 of the optical unit 84 and the guide 841 is moved, by the bias of the spring 843, in a direction of movement of the rocking portion 821 and the rocking shaft 819 together with the rocking portion 821 and the rocking shaft 819.
Therefore, the image reading unit 842 of the optical unit 84 moves from the position to read the reflectance standard toward the sheet reading position. In this embodiment, as shown in
A description will be given below of the case where, in the planet gear part 811, the planet gear members 815, the internal gear member 816, and the planet carrier member 817 further continue to rotate from the above state.
The rotation of the sun gear member 814 remains restrained. As shown in
At this time, as shown in
Thus, the rocking portion 821 and the rocking shaft 819 of the rocking member 812 further move along their axis in a direction away from the guide 841 of the optical unit 84 and the guide 841 is moved, by the bias of the spring 843, in the direction of movement of the rocking portion 821 and the rocking shaft 819 together with the rocking portion 821 and the rocking shaft 819.
At this time, the image reading unit 842 of the optical unit 84 returns to the sheet reading position. As shown in
In accordance with this embodiment, the optical unit 84 is rocked with respect to the reflectance standard and the image reading unit 842 reads the reflectance standard at the position to read the reflectance standard. Therefore, although reading of the reflectance standard at the initial position might cause dirt or the like on the reflectance standard to be read, resulting in failure to acquire proper white reference data, the reflectance standard can be read away from its region where dirt or the like is present and thus acquire proper white reference data.
In accordance with this embodiment, by changing the direction of rotation of the rotary driving force supplied from the drive device 80, the image reading unit 842 can be moved between the initial position and the position to read the reflectance standard. Therefore, in this embodiment, the image reading unit 842 can be returned to the initial position (sheet reading position) after shading compensation.
The description of the embodiment of the present disclosure has so far been given with reference to the drawings. However, the present disclosure is not limited to the above embodiment and can be implemented in various forms without departing from the gist of the present disclosure. For the sake of ease of understanding, the drawings may be schematic representation, primarily of components. The number of components and so on shown in the drawings may be different from those of actual components for convenience of creation of the drawings. The components described in the above embodiment are merely illustrative, not particularly limited, and can be changed variously without substantially departing from the effects of the present disclosure.
The present disclosure is applicable to the field of sheet conveying devices.
While the present disclosure has been described in detail with reference to the embodiments thereof, it would be apparent to those skilled in the art the various changes and modifications may be made therein within the scope defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-057307 | Mar 2023 | JP | national |
