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JP-2026075776-A - Sheet feeding device

JP2026075776AJP 2026075776 AJP2026075776 AJP 2026075776AJP-2026075776-A

Abstract

[Problem] To improve sheet feeding performance while reducing the frequency of jams during feeding, even when the sheets being fed are thin paper or other materials with weak stiffness. [Solution] The system comprises a feeding means 6 for feeding sheets onto a transport path, a separating means 7 that contacts the feeding means 6 to form a nip region and separates the sheets fed by the feeding means 6 into individual sheets, a transport means 17 for transporting the sheets separated and fed into individual sheets by the feeding means 6 and the separating means 7 onto a transport path, a first sheet detection sensor 31 positioned alongside the nip region in a direction perpendicular to the sheet transport direction for detecting the sheets, and a control means 45 for controlling the feeding of the feeding means 6. The system is characterized in that when the first sheet detection sensor 31 determines that a sheet has been nipped into the nip region while the feeding means 6 is feeding at a first speed, the feeding speed of the feeding means 6 is controlled to be changed to a second speed which is faster than the first speed. [Selection Diagram] Figure 1

Inventors

  • 福田 法旦

Assignees

  • キヤノン電子株式会社

Dates

Publication Date
20260511
Application Date
20241023

Claims (11)

  1. A sheet loading platform on which the sheets are placed, A feeding means for feeding the sheets placed on the sheet loading platform to a transport path, A separation means that contacts the feeding means to form a nip region and separates the sheet fed by the feeding means into a single sheet, A conveying means for conveying the sheets, which have been separated and fed into one sheet by the feeding means and the separating means, along the conveying path at a constant conveying speed, A first sheet detection sensor is positioned alongside the nip region in a direction perpendicular to the sheet transport direction and detects the sheet. The system includes a control means for controlling the feeding of the feeding means, The control means determines whether or not a sheet is nipped in the nip region based on the detection result of the first sheet detection sensor. A sheet feeding device characterized by controlling the feeding speed of the feeding means to change to a second speed that is faster than the first speed when it is determined that a sheet has been nipped into the nip region while the feeding means is feeding at a first speed.
  2. The sheet feeding device according to claim 1, characterized in that the second speed is set to a speed less than or equal to the conveying speed.
  3. The conveying means is located downstream and has a second sheet detection sensor that detects the arrival of the sheet, When the control means detects the arrival of a sheet using the second sheet detection sensor, it stops the feeding means. If the feeding means has not determined that the sheet is nipped in the nip region before resuming sheet feeding, the feeding means starts feeding at the first speed. The sheet feeding device according to claim 1 or 2, characterized in that when the feeding means determines that a sheet has been nipped in the nip region before resuming sheet feeding, it controls the feeding means to start feeding at the second speed.
  4. The first sheet detection sensor is arranged with at least one on each side in a direction perpendicular to the transport direction of the nip region. The sheet feeding device according to claim 1, characterized in that the control means determines that a sheet has been nipped into the nip region when both of the first sheet detection sensors detect a sheet.
  5. The sheet feeding device according to claim 4, characterized in that the control means determines that the sheet has been nipped into the nip region after a predetermined time has elapsed from the time when one of the first sheet detection sensors detects a sheet, after the feeding of the sheet by the feeding means has started.
  6. The sheet feeding device according to claim 5, characterized in that the predetermined time is the time it takes for a sheet, transported at the maximum angle of inclination, to reach the center of the nip region, determined based on the arrangement of the first sheet detection sensor and the feeding means, the expected maximum angle of inclination of the sheet, and the first speed.
  7. A third sheet detection sensor is located downstream of the nip region and upstream of the conveying means, and detects the arrival of the sheet. The sheet feeding device according to claim 1, characterized in that the control means determines that a sheet has been nipped into the nip region when it has determined that a sheet has not been nipped into the nip region and the third sheet detection sensor detects a sheet.
  8. The first sheet detection sensor is positioned at least once within the rectangular region including the nip region. The sheet feeding device according to claim 1, characterized in that the control means determines that the sheet has been nipped into the nip region when the first sheet detection sensor detects a sheet.
  9. The sheet feeding device according to claim 1, characterized in that the first sheet detection sensor is located downstream in the conveying direction of the line dividing the nip region at its center in the conveying direction, and upstream in the conveying direction of the line connecting the downstream ends of the nip region.
  10. The sheet feeding device according to claim 6, characterized in that the control means changes the feeding speed to the second speed at the timing when the leading side of the sheet reaches the transport means, even if the sheet being fed by the feeding means is at the assumed maximum oblique angle.
  11. The sheet loading platform has a loading means for taking in sheets placed on it into the feeding means, The feeding means feeds the sheet taken in by the intake means to the transport path. The sheet feeding device according to claim 1, characterized in that the intake means takes in a sheet at an intake speed of the first speed or less.

Description

This invention relates to a technique for suitably feeding delicate documents, such as thin paper, slips of paper, recycled paper (history books), documents that are already wrinkled, documents that are already folded, documents that are torn, etc., in a sheet feeding device capable of feeding sheets. In conventional sheet feeding devices, when attempting to continuously separate and feed multiple sheets at high speed using a pair of separation rollers (consisting of a feeding roller and a separation roller), if the sheets are thin paper or similar with low rigidity, they can stick to the feeding rollers, causing jams. To address jamming of thin paper sheets, such as those described in Patent Document 1, a solution is proposed. Patent Document 1 proposes a method where a sheet detection sensor is placed downstream of the separation roller pair. The feeding speed is kept low until the sheet detection sensor detects a sheet, and then increased to high speed after detection. This technique prevents thin paper from sticking to the feeding rollers. Patent No. 7143143 A cross-sectional view of an image reading device equipped with a sheet feeding device according to the first embodiment.A control block diagram of the image reading device according to the first embodiment.A perspective view of the separation roller pair of the image reading device according to the first embodiment.A cross-sectional view showing the arrangement around the nip position sensor of the image reading device according to the first embodiment.A perspective view of an example of a pair of separation rollers in an image reading device according to the first embodiment.A cross-sectional view showing an example of the arrangement around the nip position sensor of the image reading device according to the first embodiment.A control flow chart illustrating the procedure for supplying and transferring materials.A control flow diagram showing the procedure for feeding one image at a time using an image reading device according to the first embodiment.A cross-sectional view showing the arrangement around the nip position sensor when an obliquely oriented sheet is captured in the image reading device according to the first embodiment.A cross-sectional view showing the arrangement around the nip position sensor when an obliquely oriented sheet is fed in an image reading device according to the first embodiment.A partial cross-sectional view schematically showing the arrangement of components around a pair of separation rollers in an image reading device according to the second embodiment.Figure 11 is a partial cross-sectional view taken from the upstream side in the transport direction.A cross-sectional view showing the arrangement around the nip position sensor of the image reading device according to the second embodiment.A control flow diagram showing the procedure for feeding one image at a time using an image reading device according to the second embodiment.A cross-sectional view showing the arrangement around the nip position sensor when an obliquely oriented sheet is fed in an image reading device according to the second embodiment. [First Embodiment] First, an image reading device including a sheet feeding device according to the first embodiment of the present invention will be described. Figure 1 is a schematic cross-sectional view showing the configuration of an image reading device equipped with a sheet feeding device according to the first embodiment of the present invention. Here, as an example, the case in which the sheet feeding device of the present invention is applied to an image reading device will be described, but it can be applied to various sheet transport devices, such as printing devices (printers, etc.) that print on sheets, or devices with a sheet transport system such as a multifunction device that combines an image reading device and a printing device. As shown in Figure 1, the image reading device 100 of this embodiment includes a sheet feeding device 101. Multiple sheets are placed on the sheet stacking platform 1, which is configured to be vertically adjustable. The stacking platform drive motor 2 raises and lowers the sheet stacking platform 1. The sheet intake detection sensor 3 detects when a sheet stacked on the sheet stacking platform 1 is in the sheet intake position. The sheet stacking detection sensor 12 detects when a sheet is stacked on the sheet stacking surface 1a of the sheet stacking platform 1. Furthermore, the sheet bounce detection sensor 35 comprises multiple sensors arranged perpendicular to the sheet stacking surface 1a, and detects when a sheet stacked on the sheet stacking platform 1 bounces up. For example, the sheet bounce detection sensor 35 can detect when a sheet that has been stapled or otherwise fastened is stacked on the sheet stacking platform 1 and fed. This allows for control such as stopping the feeding of stapled or otherwise fastened sheets. As an example of a sheet pickup unit, t