Sheet thickness detection device and image forming apparatus
AssigneeCanon Kabushiki Kaisha
InventorsYoshitaka YAMAZAKI, Taishi TOMII
Life of this patent
Estimating the term…
Abstract
A sheet thickness detection device capable of accurately detecting a thickness of sheets of various types. In a case that information about sheets stored in a sheet feed unit is set by a user through an operation unit or through an external host PC, a CPU of the sheet thickness detection device sets a pressure changeover solenoid to ON to obtain a strong nip pressure between a detection roller and a fixed roller, if a sheet basis weight specified in the information about sheets is larger than a predetermined value, and sets the pressure changeover solenoid to OFF to obtain a weak nip pressure, if the sheet basis weight specified in the information about sheets is equal to or less than the predetermined value.
Claims21
A sheet thickness detection device for detecting a thickness of a sheet being conveyed, comprising:
- a conveyance unit configured to convey a sheet along a conveyance path;
- an acquisition unit configured to acquire information about the sheet being conveyed;
- a driven member disposed in the conveyance path for contact with the sheet being conveyed and configured to be displaced to follow a thickness of the sheet being conveyed;
- a pressure changeover unit configured to change a pressure applied by said driven member to the sheet being conveyed;
- a displacement amount detection unit configured to detect an amount of displacement of said driven member;
- a thickness computation unit configured to compute the thickness of the sheet being conveyed based on a result of detection by said displacement amount detection unit;
- and
- a control unit configured, based on the sheet information acquired by said acquisition unit, to control said pressure changeover unit to change the pressure applied by said driven member to the sheet.
A sheet thickness detection device for detecting a thickness of a sheet being conveyed, comprising:
- a conveyance unit configured to convey a sheet along a conveyance path;
- a driven member disposed in the conveyance path and configured to be displaced to follow a thickness of the sheet being conveyed;
- a pressure changeover unit configured to change a pressure applied by said driven member to the sheet being conveyed;
- a displacement amount detection unit configured to detect an amount of displacement of said driven member;
- a thickness computation unit configured to compute the thickness of the sheet being conveyed based on a result of detection by said displacement amount detection unit;
- and
- a control unit configured to control a pressure applied to a subsequent sheet of same type based on the thickness of the sheet computed by said thickness computation unit.
A sheet thickness detection device for detecting a thickness of a sheet being conveyed, comprising:
- a storage unit configured to store sheets;
- a conveyance unit configured to convey a sheet from said storage unit along a conveyance path;
- a driven member disposed in the conveyance path for contact with the sheet being conveyed and configured to be displaced to follow a thickness of the sheet being conveyed;
- a pressure changeover unit configured to change a pressure applied by said driven member to the sheet being conveyed;
- a displacement amount detection unit configured to detect an amount of displacement of said driven member;
- a thickness computation unit configured to compute the thickness of the sheet being conveyed based on a result of detection by said displacement amount detection unit;
- a determination unit configured to determine whether a sheet changeover operation in said storage unit has been performed;
- and
- a control unit configured, in a case where it is determined by said determination unit that the sheet changeover operation has been performed, to control said pressure changeover unit to apply a predetermined pressure to a first sheet conveyed by said conveyance unit after determination by said determination unit and to control a pressure applied by said driven member to second and subsequent sheets based on the thickness of the first sheet computed by said thickness computation unit.
Dependencies are inferred from the claim text.