Sheet conveyance device capable of detecting shape of sheet, image forming apparatus, sheet shape detecting method
First Claim
1. A sheet conveyance device comprising:
- a first conveyance member provided on an upstream side of an image forming position in a conveyance path along which a sheet is conveyed, the first conveyance member being rotationally driven in a driving cycle in which the first conveyance member enters a driven state where the first conveyance member is driven while decelerated in a stepped manner, and then the first conveyance member is decelerated to a stopped state;
a second conveyance member configured to convey the sheet at the image forming position by being rotationally driven to rotate at a specific speed that is a lowest speed in the driven state;
a shape detecting portion including a light emitting portion and a light receiving portion, the light emitting portion being configured to emit light toward a detection position located between the first conveyance member and the second conveyance member in the conveyance path, the light extending in a width direction of the sheet perpendicular to the conveyance path, the light receiving portion being configured to receive the light that has been emitted from the light emitting portion and reflected on the sheet passing the detection position, and output a detection signal corresponding to an amount of received light, the shape detecting portion being configured to detect a shape of the sheet based on the detection signal;
a first speed detecting portion configured to detect a rotation speed of the first conveyance member;
a second speed detecting portion configured to detect a rotation speed of the second conveyance member;
a determination processing portion configured to determine whether or not a front end of the sheet that is being conveyed has passed an arrangement position at which the first conveyance member is arranged, and determine whether or not a rear end of the sheet that is being conveyed has passed the arrangement position;
a switch control portion configured to, when the determination processing portion determines that the front end of the sheet has passed the arrangement position, switch an output interval at which the detection signal is output from the light receiving portion, to a first interval that corresponds to the rotation speed detected by the first speed detecting portion, and when the determination processing portion determines that the rear end of the sheet has passed the arrangement position, switch the output interval to a second interval that corresponds to the rotation speed detected by the second speed detecting portion.
1 Assignment
0 Petitions
Accused Products
Abstract
A sheet conveyance device includes a shape detecting portion, and a switch control portion. The shape detecting portion detects a shape of a sheet at a detection position between a first conveyance member and a second conveyance member. The switch control portion, when a front end of the sheet has passed a arrangement position at which the first conveyance member is arranged, switches an detection interval at which the shape of the sheet is detected by the shape detecting portion, to a first interval that corresponds to a rotation speed of the first conveyance member, and when a rear end of the sheet has passed the arrangement position, switches the detection interval to a second interval that corresponds to the rotation speed of the second conveyance member.
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Citations
11 Claims
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1. A sheet conveyance device comprising:
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a first conveyance member provided on an upstream side of an image forming position in a conveyance path along which a sheet is conveyed, the first conveyance member being rotationally driven in a driving cycle in which the first conveyance member enters a driven state where the first conveyance member is driven while decelerated in a stepped manner, and then the first conveyance member is decelerated to a stopped state; a second conveyance member configured to convey the sheet at the image forming position by being rotationally driven to rotate at a specific speed that is a lowest speed in the driven state; a shape detecting portion including a light emitting portion and a light receiving portion, the light emitting portion being configured to emit light toward a detection position located between the first conveyance member and the second conveyance member in the conveyance path, the light extending in a width direction of the sheet perpendicular to the conveyance path, the light receiving portion being configured to receive the light that has been emitted from the light emitting portion and reflected on the sheet passing the detection position, and output a detection signal corresponding to an amount of received light, the shape detecting portion being configured to detect a shape of the sheet based on the detection signal; a first speed detecting portion configured to detect a rotation speed of the first conveyance member; a second speed detecting portion configured to detect a rotation speed of the second conveyance member; a determination processing portion configured to determine whether or not a front end of the sheet that is being conveyed has passed an arrangement position at which the first conveyance member is arranged, and determine whether or not a rear end of the sheet that is being conveyed has passed the arrangement position; a switch control portion configured to, when the determination processing portion determines that the front end of the sheet has passed the arrangement position, switch an output interval at which the detection signal is output from the light receiving portion, to a first interval that corresponds to the rotation speed detected by the first speed detecting portion, and when the determination processing portion determines that the rear end of the sheet has passed the arrangement position, switch the output interval to a second interval that corresponds to the rotation speed detected by the second speed detecting portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A sheet shape detecting method executed on a sheet conveyance device which includes a first conveyance member, a second conveyance member, a shape detecting portion, a first speed detecting portion, and a second speed detecting portion, the first conveyance member being provided on an upstream side of an image forming position in a conveyance path along which a sheet is conveyed, the first conveyance member being rotationally driven in a driving cycle in which the first conveyance member enters a driven state where the first conveyance member is driven while decelerated in a stepped manner, and then the first conveyance member is decelerated to a stopped state, the second conveyance member being configured to convey the sheet at the image forming position by being rotationally driven to rotate at a specific speed that is a lowest speed in the driven state, the shape detecting portion including a light emitting portion and a light receiving portion, the light emitting portion being configured to emit light toward a detection position located between the first conveyance member and the second conveyance member in the conveyance path, the light extending in a width direction of the sheet perpendicular to the conveyance path, the light receiving portion being configured to receive the light that has been emitted from the light emitting portion and reflected on the sheet passing the detection position, and output a detection signal corresponding to an amount of received light, the shape detecting portion being configured to detect a shape of the sheet based on the detection signal, the first speed detecting portion being configured to detect a rotation speed of the first conveyance member, the second speed detecting portion being configured to detect a rotation speed of the second conveyance member, the sheet shape detecting method comprising:
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determining whether or not a front end of the sheet that is being conveyed has passed an arrangement position at which the first conveyance member is arranged, and determining whether or not a rear end of the sheet that is being conveyed has passed the arrangement position; and when it is determined that the front end of the sheet has passed the arrangement position, switching an output interval at which the detection signal is output from the light receiving portion, to a first interval that corresponds to the rotation speed detected by the first speed detecting portion, and when it is determined that the rear end of the sheet has passed the arrangement position, switching the output interval to a second interval that corresponds to the rotation speed detected by the second speed detecting portion.
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Specification