Medium detecting method, medium detecting device, medium discharge device and printing apparatus
According to one embodiment, a medium detecting method includes conveying a medium in a first direction along a first conveying path, and allowing the medium conveyed from the first conveying path to enter a second conveying path arranged with the first conveying path so that the medium is conveyed in a second direction opposite to the first direction. The method also includes allowing light emitting elements of first and second detecting sensors to irradiate light such that the light intersects the first and second conveying paths, and detecting the presence or absence of the medium based on whether or not light receiving elements of the first and second detecting sensors receive the light.
1. A medium detecting device comprising:
a first conveying path configured to convey a medium in a first direction;
a second conveying path configured to convey the medium from the first conveying path to the second conveying path so that the medium is conveyed in a second direction opposite to the first direction;
first and second detecting sensors comprising a light emitting element and a light receiving element; and
a temporary holding unit configured to receive the medium conveyed from the second conveying path until a rear end of the medium being conveyed in a conveyed direction is detected by the second detecting sensor, the temporary holding unit having a cylindrical shape and the medium being held in a rolled state within the temporary holding unit,
wherein the light emitting elements of the first and second detecting sensors irradiate light such that the light intersects the first and second conveying paths, and the presence or absence of the medium is detected based on whether or not the light receiving elements of the first and second detecting sensors receive the light.
2. The medium detecting device recited in claim 1 , wherein the second conveying path is parallel to the first conveying path.
3. The medium detecting device recited in claim 1 , wherein the distance between each of the first detecting sensors is shorter than the length of the medium.
4. The medium detecting device recited in claim 1 , wherein the distance between each of the second detecting sensors is shorter than the length of the medium.
5. A medium detecting device comprising:
a first conveying path configured to convey a medium in a first direction;
a second conveying path configured to allow the medium conveyed from the first conveying path to enter the second conveying path so that the medium is conveyed in a second direction at least opposite to the first direction;
first and second detecting sensors comprising a light emitting element and a light receiving element;
a temporary holding unit configured to receive the medium conveyed from the second conveying path until a rear end of the medium being conveyed in a conveyed direction is detected by the second detecting sensor, the temporary holding unit having a cylindrical shape and the medium being held in a rolled state within the temporary holding unit; and
a controller configured to control the medium held temporarily in the temporary holding unit to be conveyed in a reverse direction through the second conveying path,
wherein the light emitting elements of the first and second detecting sensors irradiate light such that the light intersects the first and second conveying paths, and the presence or absence of the medium is detected based on whether or not the light receiving elements of the first and second detecting sensors receive the light.
6. The medium detecting device recited in claim 5 , wherein the second conveying path is parallel to the first conveying path.
7. The medium detecting device recited in claim 5 , wherein the distance between each of the first detecting sensors is shorter than the length of the medium.
8. The medium detecting device recited in claim 5 , wherein the distance between each of the second detecting sensors is shorter than the length of the medium.