A sheet feeding device includes a feeding roller pair, a detecting portion, a first changing portion, a second changing portion, and a controller for controlling the first changing portion and the second changing portion. The controller starts a first feeding operation for feeding a sheet toward the obliquely feeding roller pair in a nipping state of the feeding roller pair and then starts a second feeding operation for feeding the sheet for abutting a side end of the sheet against the reference member in the nipping state of the obliquely feeding roller pair. The controller changes, after the first feeding operation is started and before the second feeding operation is started, a start timing of the second feeding operation on the basis of a detection result of a position of the side end of the sheet detected by the detecting portion.

A sheet feeding device includes a sheet feeding roller, a following roller, a rotational speed detection part, and a control part. The rotational speed detection part is configured to detect a rotational speed of the following roller. The control part is configured to accelerate a rotation of the sheet feeding roller and to adjust a sheet interval. The control part obtains a rotational rate of the following roller to the sheet feeding roller based on the rotational speed of the following roller, obtains an actual linear velocity of the sheet based on the rotational rate of the following roller and a theoretical linear velocity of the sheet after accelerating the rotation of the sheet feeding roller, and then adjusts the sheet interval based on the actual linear velocity of the sheet.

A method of measuring properties of a moving cellulose, paper or board sheet. A first parameter of a first resonance caused by the moving sheet in a frequency range 1 GHz to 25 GHz of electromagnetic radiation is measured. A second parameter of an electromagnetic signal transmitted between at least a pair of transceiver parts of a transceiver sensor located on opposite sides of the moving sheet through the moving sheet is measured in a frequency range 25 GHz to 1000 GHz. A minimum difference between the frequency ranges related to the first parameter and the second parameter being at least 5 GHz. Both the dry stuff content and the weight of water per unit of area are determined on the basis of the first parameter, the second parameter and available information related to a distance travelled by the electromagnetic signal.

A method of measuring properties of a moving cellulose, paper or board sheet. A first parameter of a first resonance caused by the moving sheet in a frequency range 1 GHz to 25 GHz of electromagnetic radiation is measured. A second parameter of an electromagnetic signal transmitted between at least a pair of transceiver parts of a transceiver sensor located on opposite sides of the moving sheet through the moving sheet is measured in a frequency range 25 GHz to 1000 GHz. A minimum difference between the frequency ranges related to the first parameter and the second parameter being at least 5 GHz. Both the dry stuff content and the weight of water per unit of area are determined on the basis of the first parameter, the second parameter and available information related to a distance travelled by the electromagnetic signal.

A sheet conveying device includes a sheet loader, a sheet feeder, an optical sensor, and a rotary member. The sheet loader is configured to load a sheet. The sheet feeder is configured to feed the sheet loaded on the sheet loader. The optical sensor is configured to detect the sheet at a predetermined position on the sheet loader in a width direction of the sheet and at a predetermined position in a sheet conveyance passage in the width direction of the sheet. The rotary member is configured to rotate to a first position when the sheet is not at the predetermined position on the sheet loader and a second position when the sheet is at the predetermined position. The rotary member has a detection target portion configured to be detected by the optical sensor when the rotary member is located at the first or second position.

A sheet conveying device includes a sheet loader, a sheet feeder, an optical sensor, and a rotary member. The sheet loader is configured to load a sheet. The sheet feeder is configured to feed the sheet loaded on the sheet loader. The optical sensor is configured to detect the sheet at a predetermined position on the sheet loader in a width direction of the sheet and at a predetermined position in a sheet conveyance passage in the width direction of the sheet. The rotary member is configured to rotate to a first position when the sheet is not at the predetermined position on the sheet loader and a second position when the sheet is at the predetermined position. The rotary member has a detection target portion configured to be detected by the optical sensor when the rotary member is located at the first or second position.

According to the present disclosure, a first guide unit is provided with a first opening portion through which light in an optical path connecting a first optical element unit and a second optical element unit passes, a second guide unit is provided with a second opening portion through which light in the optical path connecting the first optical element unit and the second optical element unit passes, the first guide unit is provided with a duct for sending air to the first optical element unit, and the air coming out from the first opening portion hits the second optical element unit via the second opening portion.

According to the present disclosure, a first guide unit is provided with a first opening portion through which light in an optical path connecting a first optical element unit and a second optical element unit passes, a second guide unit is provided with a second opening portion through which light in the optical path connecting the first optical element unit and the second optical element unit passes, the first guide unit is provided with a duct for sending air to the first optical element unit, and the air coming out from the first opening portion hits the second optical element unit via the second opening portion.

A single material sheet is picked from a support member. A gripping member is aligned above the support member, where the gripping member includes a pair of spaced apart pinching members movably coupled with a main frame, and each pinching member includes an exposed gripping surface that is substantially planar and that faces an exposed surface of the material sheet. The gripping member is moved a first distance toward the exposed surface of the material sheet such that the gripping surfaces of the pinching members engage a portion of the material sheet. The pinching members for the gripping member are moved toward each other while the pinching members engage the portion of the material sheet so as to pinch the portion of the material sheet between the pinching members and vertically displace the material sheet from the support member.

A single material sheet is picked from a support member. A gripping member is aligned above the support member, where the gripping member includes a pair of spaced apart pinching members movably coupled with a main frame, and each pinching member includes an exposed gripping surface that is substantially planar and that faces an exposed surface of the material sheet. The gripping member is moved a first distance toward the exposed surface of the material sheet such that the gripping surfaces of the pinching members engage a portion of the material sheet. The pinching members for the gripping member are moved toward each other while the pinching members engage the portion of the material sheet so as to pinch the portion of the material sheet between the pinching members and vertically displace the material sheet from the support member.