SHEET CONVEYING MECHANISM AND IMAGE FORMING APPARATUS

Abstract

Disclosed is a sheet conveying mechanism, including: a sheet feeder that conveys a sheet to a sheet conveying path; a conveying track that defines the sheet conveying path of the sheet; and a conveying roller pair that conveys the sheet along the sheet conveying path. The sheet conveying mechanism further includes: a conveying track separator that adjusts a height of the sheet conveying path, wherein the sheet conveying path has at least a first height and a second height, and the second height is greater than the first height; and a conveying roller separator that adjusts a clamping force of the conveying roller pair, wherein the conveying roller pair has at least a first clamping force and a second clamping force, and the second clamping force is smaller than the first clamping force.

Claims

1. A sheet conveying mechanism, comprising: a sheet feeder that conveys a sheet to a sheet conveying path; a conveying track that defines the sheet conveying path of the sheet; and a conveying roller pair that conveys the sheet along the sheet conveying path; wherein the sheet conveying mechanism further comprises: a conveying track separator that adjusts a height of the sheet conveying path, wherein the sheet conveying path has at least a first height and a second height, and the second height is greater than the first height; and a conveying roller separator that adjusts a clamping force of the conveying roller pair, wherein the conveying roller pair has at least a first clamping force and a second clamping force, and the second clamping force is smaller than the first clamping force.

2. The sheet conveying mechanism according to claim 1, wherein the sheet conveying mechanism further comprises: a hardware processor that has a sheet conveying mode and a sheet discharging mode, wherein in the sheet conveying mode, the sheet conveying path has the first height, and in the sheet discharging mode, the hardware processor switches the sheet conveying path from the first height to the second height.

3. The sheet conveying mechanism according to claim 2, wherein in the sheet discharging mode, the hardware processor further determines whether to switch the sheet conveying path from the first height to the second height based on a conveying abnormality of the sheet.

4. The sheet conveying mechanism according to claim 2, wherein in the sheet discharging mode, the hardware processor further determines whether to switch the sheet conveying path from the first height to the second height based on a sheet grammage of the sheet.

5. The sheet conveying mechanism according to claim 2, wherein in the sheet conveying mode, before a front end of the sheet enters the conveying roller pair, the conveying roller pair has the first clamping force, when the front end of the sheet enters the conveying roller pair, the conveying roller pair has the second clamping force, and after the front end of the sheet enters the conveying roller pair, the conveying roller pair has the first clamping force, wherein in the sheet discharging mode, the conveying roller pair has the first clamping force.

6. The sheet conveying mechanism according to claim 2, wherein the sheet conveying mechanism further comprises a sheet detector that detects the sheet, and the conveying roller pair comprises an upstream conveying roller pair and a downstream conveying roller pair located on two sides of the sheet detector, wherein in the sheet conveying mode, before a front end of the sheet enters the downstream conveying roller pair, the downstream conveying roller pair has the first clamping force, when the front end of the sheet enters the downstream conveying roller pair, the downstream conveying roller pair has the second clamping force, and after the front end of the sheet enters the downstream conveying roller pair, the downstream conveying roller pair has the first clamping force, before a rear end of the sheet leaves the upstream conveying roller pair, the upstream conveying roller pair has the first clamping force, when the rear end of the sheet leaves the upstream conveying roller pair, the upstream conveying roller pair has the second clamping force, and after the rear end of the sheet leaves the upstream conveying roller pair, the upstream conveying roller pair has the first clamping force, wherein in the sheet discharging mode, the upstream conveying roller pair and the downstream conveying roller pair both have the first clamping force.

7. The sheet conveying mechanism according to claim 6, wherein when the front end of the sheet reaches a first predetermined position, the clamping force of the downstream conveying roller pair is adjusted by the conveying roller separator, and when the rear end of the sheet reaches a second predetermined position, the clamping force of the upstream conveying roller pair is adjusted by the conveying roller separator.

8. The sheet conveying mechanism according to claim 7, wherein the sheet conveying mechanism further comprises a first detection sensor and a second detection sensor, wherein the first detection sensor detects whether the front end of the sheet has reached the first predetermined position, and the second detection sensor detects whether the rear end of the sheet has reached the second predetermined position.

9. The sheet conveying mechanism according to claim 1 wherein the conveying track separator comprises a first driving motor, a first driving belt and a first rotary cam, and the first driving motor drives the first rotary cam to rotate through the first driving belt to adjust the height of the sheet conveying path of the conveying track, and/or the conveying roller separator comprises a second driving motor, a second driving belt and a second rotary cam, and the second driving motor drives the second rotary cam to rotate through the second driving belt to adjust the clamping force of the conveying roller pair.

10. An image forming apparatus, comprising: a sheet conveying mechanism according to claim 1, that conveys a sheet; and an image former that forms an image on the sheet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Other features and advantages of the present disclosure will be better understood from the following detailed description of specific embodiments with reference to the accompanying drawings, where the same reference numerals identify the same or similar parts, wherein:

[0012] FIG. 1 illustrates a schematic structural view of a sheet conveying mechanism according to an embodiment of the present disclosure;

[0013] FIG. 2 illustrates a schematic structural view of a sheet feeding unit and a sheet detection unit of a sheet conveying mechanism according to an embodiment of the present disclosure;

[0014] FIG. 3 illustrates a flow chart diagram of a control unit of a sheet conveying mechanism according to an embodiment of the present disclosure;

[0015] FIG. 4 illustrates a flow chart diagram of a control unit of a sheet conveying mechanism according to another embodiment of the present disclosure;

[0016] FIG. 5 illustrates a flow chart diagram of a control unit of a sheet conveying mechanism according to another embodiment of the present disclosure;

[0017] FIG. 6 illustrates a flow chart diagram of a control unit of a sheet conveying mechanism according to another embodiment of the present disclosure;

[0018] FIG. 7 illustrates a working timing diagram of a control unit of a sheet conveying mechanism according to another embodiment of the present disclosure;

[0019] FIG. 8 illustrates a flow chart diagram of a control unit of a sheet conveying mechanism according to another embodiment of the present disclosure;

[0020] FIG. 9 illustrates a schematic structural view of a conveying track separation device of a sheet conveying mechanism according to an embodiment of the present disclosure; and

[0021] FIG. 10 illustrates a schematic structural view of a conveying roller separation device of a sheet conveying mechanism according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

[0022] The implementation and application of specific embodiments will be discussed in detail below. However, it should be understood that the specific embodiments discussed only exemplarily illustrate specific ways of implementing and applying the present disclosure, and are not limiting the scope of the present disclosure. In the following description, some directional representations, such as left, right, top, bottom, front, back, are used with reference to the directions shown in the drawings. When the components are arranged as shown in the drawings, these directional representations are appropriate, but when the positions of the components in the drawings change, these directional representations also change accordingly.

[0023] In an image forming apparatus (i.e., image former), a sheet detection unit (i.e., sheet detector) is configured to scan an external dimension and a surface of a sheet. In a sheet conveying mode, the sheet is conveyed from a sheet feeding unit (i.e., sheet feeder) to an image forming unit through the sheet detection unit. When there is a conveying abnormality of the sheet, such as a sheet multi-feed, in the sheet feeding unit, the apparatus switches to a sheet discharging mode and an abnormal sheet is discharged to a sheet discharging tray through a sheet discharging channel.

[0024] The existing image forming apparatus has following problems: (1) the image detection performance requires the sheet conveying path of the conveying track to be less than 1 mm, while the sheet multi-feeding performance requires the sheet conveying path of the conveying track to be greater than 2 mm; (2) the image detection performance requires a low conveying pressure of the conveying roller pair, while the sheet multi-feeding performance requires a high conveying pressure of the conveying roller pair.

[0025] Accordingly, an embodiment of the present disclosure provides a sheet conveying mechanism. The sheet conveying mechanism includes: a sheet feeding unit configured to convey a sheet to a sheet conveying path; a conveying track configured to define the sheet conveying path of the sheet; and a conveying roller pair configured to convey the sheet along the sheet conveying path. The sheet conveying mechanism further includes: a conveying track separation device (i.e., conveying track separator) configured to adjust a height of the sheet conveying path, wherein the sheet conveying path has at least a first height and a second height, and the second height is greater than the first height; and a conveying roller separation device (i.e., conveying roller separator) configured to adjust a clamping force of the conveying roller pair, wherein the conveying roller pair has at least a first clamping force and a second clamping force, and the second clamping force is smaller than the first clamping force.

[0026] In order to simultaneously ensure the image detection performance and the sheet multi-feeding performance, the embodiment of the present disclosure provides a conveying track separation device and a conveying roller separation device. An optimal design based on sheet type, sheet size, scheduled time and sheet conveying mode can ensure an appropriate height of the sheet conveying path and the clamping force of the conveying roller pair. By optimizing the height of the sheet conveying path and the clamping force of the conveying roller pair, the image detection performance of the image forming apparatus can be improved, the sheet multi-feeding performance can be ensured, and the sheet handling capability of the image forming apparatus can be enhanced.

[0027] As shown in FIG. 1, an image forming apparatus 100 includes a sheet conveying mechanism 10 and an image forming unit 20. The sheet conveying mechanism 10 is configured to convey a sheet, and the image forming unit 20 may be a printing body, configured to form an image on the sheet.

[0028] The sheet conveying mechanism 10 includes a sheet feeding unit 11, a conveying track, a conveying roller pair, a conveying track separation device and a conveying roller separation device. The sheet feeding unit 11 is configured to convey a sheet to a sheet conveying path. The conveying track is configured to define the sheet conveying path of the sheet. The conveying roller pair is configured to convey the sheet along the sheet conveying path. The conveying track separation device is configured to adjust a height of the sheet conveying path. The sheet conveying path has at least a first height and a second height, and the second height is greater than the first height. The conveying roller separation device is configured to adjust a clamping force of the conveying roller pair. The conveying roller pair has at least a first clamping force and a second clamping force, and the second clamping force is smaller than the first clamping force.

[0029] In some embodiments, the sheet conveying mechanism further includes a control unit (i.e., hardware processor) configured to have a sheet conveying mode and a sheet discharging mode. In a normal conveying state, the control unit is in the sheet conveying mode, and the sheet is conveyed to the image forming unit 20 and then an image is printed on the sheet. When a conveying abnormality occurs, the control unit switches to the sheet discharging mode and the abnormal sheet is discharged through a vertical conveying path 31 to a sheet discharging tray 30.

[0030] In some embodiments, during a sheet conveying process, a sheet grammage and/or a size of each sheet are automatically detected by a sheet detection sensor. When there is a significant difference between a real-time detection results and parameters set for printing, it is determined that the sheet is an incorrect sheet and needs to be automatically discharged, and the sheet conveying mechanism switches to the sheet discharging mode.

[0031] As shown in FIG. 2, the sheet feeding unit 11 is provided with a sheet multi-feeding detection sensor 111 configured to detect whether a sheet multi-feed has occurred in the sheet feeding unit 11. When the sheet multi-feeding detection sensor 111 detects a sheet multi-feed in the sheet feeding unit 11, the control unit switches from the sheet conveying mode to the sheet discharging mode, and the abnormal sheet is discharged through the vertical conveying path 31 to the sheet discharging tray 30.

[0032] In some embodiments, the sheet conveying mechanism 10 further includes a sheet detection unit 12 configured to detect the sheet. The sheet detection unit 12 may be a sheet image scanner based on a contact image sensor (CIS) 121. The conveying roller pair includes an upstream conveying roller pair 122 and a downstream conveying roller pair 123 located on two sides of the contact image sensor 121. During continuous sheet conveying process, the sheet is scanned by the contact image sensor 121 to obtain an image of an external shape of the sheet, and an external dimension of the sheet are calculated by scanning the image.

[0033] In some embodiments, the sheet conveying mechanism 10 further includes multiple position detection sensors PS1, PS2, PS3, PS4 and PS5 configured to detect whether the sheet has arrived or passed through a conveying roller pair adjacent to the position detection sensors. For example, the position detection sensors PS3 and PS4 are located on two sides of the upstream conveying roller pair 122, and the position detection sensor PS5 is located at downstream of the downstream conveying roller pair 123.

[0034] In some embodiments, in the sheet conveying mode, the sheet conveying path has the first height, and in the sheet discharging mode, the control unit is configured to switch the sheet conveying path from the first height to the second height.

[0035] In some embodiments, in the sheet discharging mode, the control unit is configured to further determine whether to switch the sheet conveying path from the first height to the second height based on a conveying abnormality of the sheet.

[0036] Specifically, in the sheet discharging mode, when a sheet multi-feed is detected, the control unit is configured to switch the sheet conveying path from the first height to the second height.

[0037] In some embodiments, in the sheet discharging mode, the control unit is configured to further determine whether to switch the sheet conveying path from the first height to the second height based on a sheet grammage of the sheet.

[0038] Specifically, in the sheet discharging mode, when the sheet grammage of the sheet exceeds 300 gsm or a thickness of the sheet exceeds 0.3 mm, the sheet conveying path is switched from the first height to the second height.

[0039] In some embodiments, in the sheet discharging mode, when a sheet multi-feed is detected, the control unit is configured to further determine whether to switch the sheet conveying path from the first height to the second height based on the sheet grammage of the sheet.

[0040] In some embodiments, as shown in FIG. 3, the control unit is configured to perform the following operations: [0041] S11: Start. [0042] S13: Determine whether to use the sheet discharging mode. If yes, execute step S15: increase the height of the sheet conveying path through the conveying track separation device, so as to switch the sheet conveying path from the first height to the second height; If not, execute step S12: the conveying track separation device does not act.

[0043] In some embodiments, as shown in FIG. 4, the control unit is configured to perform the following operations: [0044] S21: Start. [0045] S23: Determine whether to use the sheet discharging mode; If yes, execute step S25: determine whether a multi-feed sheet can be discharged; If not, execute step S22: the conveying track separation device does not act. [0046] S25: Determine whether the multi-feed sheet can be discharged; If yes, execute step S27: increase the height of the sheet conveying path through the conveying track separation device, so as to switch the sheet conveying path from the first height to the second height; If not, execute step S22: the conveying track separation device does not act. The determination of whether the multi-feed sheet can be discharged is based on the sheet grammage and the size of the multi-feed sheet. If the sheet grammage and the size of the multi-feed sheet exceed the conveying capacity of the conveying track, it will be determined that the multi-feed sheet cannot be discharged. The mechanism will directly report JAM abnormal stop and the multi-feed sheet is removed manually.

[0047] In some embodiments, as shown in FIG. 5, the control unit is configured to perform the following operations: [0048] S31: Start. [0049] S33: Determine whether to use the sheet discharging mode; If yes, execute step S35: determine whether a multi-feed sheet can be discharged; If not, execute step S32: the conveying track separation device does not act. [0050] S35: Determine whether the multi-feed sheet can be discharged; If yes, execute step S37: determine whether the sheet grammage is greater than 300 gsm; if not, execute step S32: the conveying track separation device does not act. The determination of whether the multi-feed sheet can be discharged is based on the sheet grammage and the size of the multi-feed sheet. If the sheet grammage and the size of the multi-feed sheet exceed the conveying capacity of the conveying track, it will be determined that the multi-feed sheet cannot be discharged. The mechanism will directly report JAM abnormal stop and the multi-feed sheet is removed manually. [0051] S37: Determine whether the sheet grammage is greater than 300 gsm; If yes, execute step S39: increase the height of the sheet conveying path through the conveying track separation device, so as to switch the sheet conveying path from the first height to the second height; If not, execute step S32: the conveying track separation device does not act.

[0052] In some embodiments, when starting to convey the sheet from the sheet feeding unit, if a conveying abnormality occurs, the sheet will conveyed to a designated position and wait for a clearing operation. When it is determined that a sheet multi-feed occurs, it is necessary to determine whether to increase the height of the sheet conveying path by the conveying track separation device.

[0053] In some embodiments, as shown in FIG. 6, the control unit is configured to perform the following operations: [0054] S41: Start. [0055] S42: Determine whether to stop conveying. When there is a conveying abnormality of the sheet, determine whether to stop conveying based on whether the sheet has reached furthest downstream conveying roller in the sheet feeding unit. If a front end of the sheet has reached the furthest downstream conveying roller, the conveying is stopped; If yes, execute S43: immediately stop conveying and manually handle the fault; If not, execute step S44. [0056] S44: Temporary stop conveying. [0057] S45: Determine whether a multi-feed sheet can be discharged; If not, execute step S48: clear a conveying operation; If yes, execute step S46. The determination of whether the multi-feed sheet can be discharged is based on the sheet grammage and the size of the multi-feed sheet. If the sheet grammage and the size of the multi-feed sheet exceed the conveying capacity of the conveying track, it will be determined that the multi-feed sheet cannot be discharged. The mechanism will directly report JAM abnormal stop and the multi-feed sheet is removed manually. [0058] S46: Determine whether to increase the height of the sheet conveying path, for example, based on the embodiments shown in FIGS. 3 to 5 to determine whether to increase the height of the sheet conveying path; If not, execute step S48: clear the conveying operation; If yes, execute step S47. [0059] S47: Determine whether the height of the sheet conveying path has been increased. If yes, execute step S48: clear the conveying operation.

[0060] In some embodiments, a status of the multi-feed sheet when starting multi-feeding inspection is determined by determining whether the sheet has reached the conveying roller. If the front end of the multi-feed sheet is greatly offset, the front end of the multi-feed sheet has already reached the furthest downstream conveying roller when starting the multi-feeding inspection. The multi-feed sheet in this state is not suitable for automatic discharging, and it is safer to manually deal with the fault.

[0061] In some embodiments, in the sheet conveying mode, before a front end of the sheet enters the conveying roller pair, the conveying roller pair has the first clamping force, when the front end of the sheet enters the conveying roller pair, the conveying roller pair has the second clamping force, and after the front end of the sheet enters the conveying roller pair, the conveying roller pair has the first clamping force. In the sheet discharging mode, the conveying roller pair has the first clamping force.

[0062] In some embodiments, in the sheet conveying mode, before a rear end of the sheet leaves the conveying roller pair, the conveying roller pair has the first clamping force, when the rear end of the sheet leaves the conveying roller pair, the conveying roller pair has the second clamping force, and after the rear end of the sheet leaves the conveying roller pair, the conveying roller pair has the first clamping force. In the sheet discharging mode, the conveying roller pair has the first clamping force.

[0063] In practical applications, whether the front end of the sheet enters the conveying roller pair and whether the rear end of the sheet leaves the conveying roller pair are detected by position detection sensors, such as multiple position detection sensors PS1, PS2, PS3, PS4 and PS5. By switching the clamping force of the conveying roller pair from the first clamping force to the second clamping force when the sheet enters and leaves the conveying roller pair, an impact on the sheet is reduced.

[0064] In some embodiments, the sheet conveying mechanism 10 further includes a sheet detection unit 12 configured to detect the sheet. The sheet detection unit 12 includes a contact image sensor 121. The conveying roller pair includes an upstream conveying roller pair 122 and a downstream conveying roller pair 123 located on two sides of the contact image sensor 121. In the sheet conveying mode, before the front end of the sheet enters the downstream conveying roller pair 123, the downstream conveying roller pair 123 has the first clamping force. When the front end of the sheet enters the downstream conveying roller pair 123, the downstream conveying roller pair 123 has the second clamping force. After the front end of the sheet enters the downstream conveying roller pair 123, the downstream conveying roller pair 123 has the first clamping force. Before the rear end of the sheet leaves the upstream conveying roller pair 122, the upstream conveying roller pair 122 has the first clamping force. When the rear end of the sheet leaves the upstream conveying roller pair 122, the upstream conveying roller pair 122 has the second clamping force, and after the rear end of the sheet leaves the upstream conveying roller pair 122, the upstream conveying roller pair 122 has the first clamping force. When the rear end of the sheet leaves the upstream conveying roller pair 122, if the pressure of the conveying roller pair is small, the posture of the rear end of the sheet is more stable, which is more conducive to scanning the image of the sheet.

[0065] In the sheet discharging mode, the upstream conveying roller pair 122 and the downstream conveying roller pair 123 have the first clamping force.

[0066] In some embodiments, when the front end of the sheet reaches a first predetermined position, the conveying roller separation device adjusts the clamping force of the downstream conveying roller pair, and when the rear end of the sheet reaches a second predetermined position, the conveying roller separation device adjusts the clamping force of the upstream conveying roller pair.

[0067] In some embodiments, the sheet conveying mechanism further includes a first detection sensor and a second detection sensor. The first detection sensor is configured to detect whether the front end of the sheet has reached the first predetermined position, and the second detection sensor is configured to detect whether the rear end of the sheet has reached the second predetermined position.

[0068] FIG. 7 illustrates a working timing diagram of a control unit of a sheet conveying mechanism according to another embodiment of the present disclosure.

[0069] t1: When the front end of the sheet reaches PS4 for a certain time t1, the front end of the sheet reaches the CIS detection sensor, and the sheet image scanner begins to detect.

[0070] t2: When the front end of the sheet reaches PS4 for a certain time t2, the front end of the sheet reaches the downstream conveying roller pair 123, and the conveying track separation device of the downstream conveying roller pair 123 acts to switch the clamping force of the downstream conveying roller pair 123 from the first clamping force to the second clamping force.

[0071] t3: When the front end of the sheet protrudes into the downstream conveying roller pair 123 for a certain time t3, the conveying track separation device of the downstream conveying roller pair 123 acts to switch the clamping force of the downstream conveying roller pair 123 from the second clamping force to the first clamping force.

[0072] t4: When the rear end of the sheet leaves PS3 for a certain time t4, the rear end of the sheet leaves the upstream conveying roller pair 122, and the conveying track separation device of the upstream conveying roller pair 122 acts to switch the clamping force of the upstream conveying roller pair 122 from the first clamping force to the second clamping force.

[0073] t5: When the conveying track separation device of the upstream conveying roller pair 122 acts for a certain time t5, the rear end of the sheet leaves the upstream conveying roller pair 122, and the conveying track separation device of the upstream conveying roller pair 122 acts to switch the clamping force of the upstream conveying roller pair 122 from the second clamping force to the first clamping force.

[0074] t6: When the rear end of the sheet leaves PS4 for a certain time t6, the rear end of the sheet leaves the CIS detection sensor, and the detection of the sheet image scanner ends.

[0075] In some embodiments, as shown in FIG. 8, the control unit is configured to perform the following operations: [0076] S51: Start. [0077] S52: Determine whether to use the sheet discharging mode; If not, execute step S54: the conveying roller separation device does not act; If yes, execute step S53. [0078] S53: Determine whether the CIS detection sensor is turned on; If not, execute step S54: the conveying roller separation device does not act; If yes, execute step S55. [0079] S55: Determine whether the conditions for separating the conveying rollers are met. If not, execute step S54: the conveying roller separation device does not act; If yes, execute step S56. [0080] S56: The conveying roller separation device acts.

[0081] In some embodiments, as shown in FIG. 9, the conveying track separation device 40 includes a first driving motor 41, a first driving belt 42 and a first rotary cam 43. The first driving motor 41 drives the first rotary cam 43 to rotate through the first driving belt 42. When the first rotary cam 43 rotates, the first rotary cam 43 drives a track mounting plate 44 to move up and down to adjust the height of the sheet conveying path of the conveying track. For example, an upper track of the conveying track is installed on the track mounting plate 44, which drives the upper track to move up and down to adjust a distance between the upper track and a lower track, so as to adjust the height of the sheet conveying path. The first driving motor 41 may adopt a high-precision stepper motor, a servo motor, etc. The driving transmission method may adopt a driving belt, a driving gear, a rack, etc. The separation action may be achieved by sliding the rotary cam up and down, or by rotating the rotary cam and a rotary shaft.

[0082] In some embodiments, as shown in FIG. 10, the conveying roller separation device 50 includes a second driving motor 51, a second driving belt 52 and a second rotary cam 53. The second driving motor 51 drives the second rotary cam 53 to rotate through the second driving belt 52. When the second rotary cam 53 rotates, the second rotary cam 53 drives a rotary shaft 54 to move, and the rotary shaft 54 drives a lifting rod 55 to move, so as to adjust the clamping force of the conveying roller pair. For example, the lifting rod 55 is connected to a driven roller of the conveying roller pair, and the lifting rod 55 drives the driven roller to move to adjust a gap between a driving roller and the driven roller, so as to adjust the clamping force of the conveying roller pair. The second driving motor 51 may adopt a high-precision stepper motor, servo motor, etc. The driving transmission method may adopt a driving belt, a driving gear, a rack, etc. The separation action can be achieved by sliding the rotary cam up and down, or by rotating the rotary cam and the rotary shaft.

[0083] According to some embodiments of the present disclosure, a conveying track separation device is configured to adjust a height of the sheet conveying path. The sheet conveying path has at least a first height and a second height, and the second height is greater than the first height. By adjusting the height of the sheet conveying path, the height of the sheet conveying path can not only meet the requirements of the image detection performance of the sheet, but also meet the requirements of the sheet multi-feeding performance.

[0084] According to some embodiments of the present disclosure, a conveying roller separation device is configured to adjust a clamping force of the conveying roller pair. The conveying roller pair has at least a first clamping force and a second clamping force, and the second clamping force is smaller than the first clamping force. By adjusting the clamping force of the conveying roller pair, the clamping force of the conveying roller pair can not only meet the requirements of the image detection performance of the sheet, but also meet the requirements of the sheet multi-feeding performance.

[0085] Compared with conventional technologies, the embodiments of the present disclosure have following beneficial effects.

[0086] In the sheet conveying mechanism according to the present disclosure, a conveying track separation device is configured to adjust a height of the sheet conveying path. The sheet conveying path has at least a first height and a second height, and the second height is greater than the first height. By adjusting the height of the sheet conveying path, the height of the sheet conveying path can not only meet the requirements of the image detection performance of the sheet, but also meet the requirements of the sheet multi-feeding performance.

[0087] In the sheet conveying mechanism according to the present disclosure, a conveying roller separation device is configured to adjust a clamping force of the conveying roller pair. The conveying roller pair has at least a first clamping force and a second clamping force, and the second clamping force is smaller than the first clamping force. By adjusting the clamping force of the conveying roller pair, the clamping force of the conveying roller pair can not only meet the requirements of the image detection performance of the sheet, but also meet the requirements of the sheet multi-feeding performance.

[0088] Although the present disclosure has been disclosed above, the present disclosure is not limited thereto. Any changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present disclosure, and the scope of the present disclosure should be determined by the appended claims.