A method is provided for printing an image on a substrate on a support body of a printing apparatus, the method including the steps of: providing a masking sheet on the support body; deriving from the image a boundary outline of the image; selecting a location on the support body for printing the image; printing the boundary outline of the image on the masking sheet at the selected location of the support body; printing at least one distance marker on at least one side of the printed boundary outline on the masking sheet, said distance marker indicating a distance from the boundary outline; placing the substrate on the masking sheet at the selected location of the support body using the boundary outline; determining an offset of the substrate relative to the printed boundary outline by way of the printed distance marker, after the substrate placing step; and printing the image on the substrate based on the determined offset of the substrate relative to the printed boundary outline.

A medium conveying apparatus includes a first roller to convey a medium, a movement mechanism to move the first roller between a first position in contact with the medium and a second position spaced apart from the medium, a second roller located on a downstream side of the first roller in a medium conveying direction to convey the medium, and a processor to detect a skew of the conveyed medium, and control the movement mechanism to move the first roller to the second position, and correct the skew of the medium using the second roller when the skew of the medium is detected.

A medium conveying apparatus includes a first roller to convey a medium, a movement mechanism to move the first roller between a first position in contact with the medium and a second position spaced apart from the medium, a second roller located on a downstream side of the first roller in a medium conveying direction to convey the medium, and a processor to detect a skew of the conveyed medium, and control the movement mechanism to move the first roller to the second position, and correct the skew of the medium using the second roller when the skew of the medium is detected.

A sheet detecting apparatus includes a sheet supporting surface, a first sensor flag including a first flag portion, a first contact portion, and a third contact portion, a second sensor flag including a second flag portion, and a second contact portion, a first detection sensor configured to transit to a first state of outputting a first detection signal and to a second state of outputting a second detection signal, the first detection sensor transiting to one of the first state and the second state in response to a position of the first flag portion, and a second detection sensor configured to transit to a third state of outputting a third detection signal and to a fourth state of outputting a fourth detection signal, the second detection sensor transiting to one of the third state and the fourth state in response to a position of the second flag portion.

A sheet detecting apparatus includes a sheet supporting surface, a first sensor flag including a first flag portion, a first contact portion, and a third contact portion, a second sensor flag including a second flag portion, and a second contact portion, a first detection sensor configured to transit to a first state of outputting a first detection signal and to a second state of outputting a second detection signal, the first detection sensor transiting to one of the first state and the second state in response to a position of the first flag portion, and a second detection sensor configured to transit to a third state of outputting a third detection signal and to a fourth state of outputting a fourth detection signal, the second detection sensor transiting to one of the third state and the fourth state in response to a position of the second flag portion.

A sheet detecting apparatus includes a sheet supporting surface, a first sensor flag including a first flag portion, a first contact portion, and a third contact portion, a second sensor flag including a second flag portion, and a second contact portion, a first detection sensor configured to transit to a first state of outputting a first detection signal and to a second state of outputting a second detection signal, the first detection sensor transiting to one of the first state and the second state in response to a position of the first flag portion, and a second detection sensor configured to transit to a third state of outputting a third detection signal and to a fourth state of outputting a fourth detection signal, the second detection sensor transiting to one of the third state and the fourth state in response to a position of the second flag portion.

A sheet detecting apparatus includes a sheet supporting surface, a first sensor flag including a first flag portion, a first contact portion, and a third contact portion, a second sensor flag including a second flag portion, and a second contact portion, a first detection sensor configured to transit to a first state of outputting a first detection signal and to a second state of outputting a second detection signal, the first detection sensor transiting to one of the first state and the second state in response to a position of the first flag portion, and a second detection sensor configured to transit to a third state of outputting a third detection signal and to a fourth state of outputting a fourth detection signal, the second detection sensor transiting to one of the third state and the fourth state in response to a position of the second flag portion.

A paper feeding device includes a lower cover, an upper cover pivotally connected to the lower cover, at least one motor mounted to the lower cover, a feeding roller assembly and a paper skew judging module. The feeding roller assembly is pivotally connected to the lower cover and connected with the at least one motor. The paper skew judging module disposed to the lower cover, has an infrared light emitter, an infrared light receiver, a cantilever arm rotatably assembled to the lower cover, a sensing roller pivotally connected with the cantilever arm, and a lens. The infrared light emitter is mounted to the lower cover. The infrared light receiver is mounted to the lower cover and is disposed opposite to the infrared light emitter. The lens is fastened to the cantilever arm, and disposed between the infrared light emitter and the infrared light receiver. The lens has different photopermeabilities.

A paper feeding device includes a lower cover, an upper cover pivotally connected to the lower cover, at least one motor mounted to the lower cover, a feeding roller assembly and a paper skew judging module. The feeding roller assembly is pivotally connected to the lower cover and connected with the at least one motor. The paper skew judging module disposed to the lower cover, has an infrared light emitter, an infrared light receiver, a cantilever arm rotatably assembled to the lower cover, a sensing roller pivotally connected with the cantilever arm, and a lens. The infrared light emitter is mounted to the lower cover. The infrared light receiver is mounted to the lower cover and is disposed opposite to the infrared light emitter. The lens is fastened to the cantilever arm, and disposed between the infrared light emitter and the infrared light receiver. The lens has different photopermeabilities.

A paper feeding device includes a lower cover, an upper cover pivotally covered to the lower cover, at least one motor mounted to the lower cover, a feeding roller assembly and a paper skew judging module. The feeding roller assembly is pivotally connected to the lower cover and connected with the at least one motor. The paper skew judging module disposed to the lower cover, has an infrared light emitter, an infrared light receiver, a cantilever arm rotatably assembled to the lower cover, a sensing roller pivotally connected with the cantilever arm, and a lens. The infrared light emitter is mounted to the lower cover. The infrared light receiver is mounted to the lower cover and is disposed opposite to the infrared light emitter. The lens is fastened to the cantilever arm, and disposed between the infrared light emitter and the infrared light receiver. The lens have different photopermeabilities.