JP2016169081A5 - - Google Patents

Description

The flag type sensor described above includes a flag that can be tilted when the sheet comes into contact therewith. Since the state of the left flag is standing when the sheet has not arrived, the sensor output is turned ON. On the other hand, when the flag is defeated by the arrived sheet, the sensor output is turned off . In the optical sensor, the light emitted from the light emitting unit is blocked by the arrived sheet, and the output from the light receiving unit is turned off. Of course, when the sheet has not arrived, the output from the light receiving unit is ON.

The sheet detection unit of the present invention for achieving the above object includes a light emitting unit that emits light at a first angle with respect to a direction perpendicular to the surface of the sheet, and the light emitting unit that emits light. A light reflecting portion that reflects light transmitted through the light receiving portion, a light receiving portion that is reflected by the light reflecting portion, is irradiated at a second angle with respect to a direction perpendicular to the surface of the sheet, and receives light transmitted through the sheet; And a control unit that determines presence or absence of the sheet based on a light reception result of the light receiving unit.

Claims (16)

A light emitting unit that emits light from a direction oblique to the surface of the OHT sheet;
A light receiving unit that receives the light irradiated by the light emitting unit and transmitted through the OHT sheet;
An OHT sheet detection unit, comprising: a control unit that determines presence or absence of the OHT sheet based on a light reception result of the light receiving unit.   The control unit determines that the OHT sheet is present when the amount of light received by the light receiving unit is smaller than a predetermined threshold, and when the amount of light received by the light receiving unit is larger than the predetermined threshold The OHT sheet detection unit according to claim 1, wherein it is determined that there is no OHT sheet. Said light emitting portion and a light receiving portion is, OHT sheet detection unit according to claim 1 or 2, characterized in that it is arranged on the opposite side respectively to the conveying path which the OHT sheet is conveyed. OHT sheet detection unit according to any one of claims 1 to 3 wherein the light emitting unit is characterized by irradiating light at an angle of more than 40 degrees with respect to a direction perpendicular to the surface of the OHT sheet.   5. The OHT sheet detection unit according to claim 1, wherein the light emitting unit emits light in a direction orthogonal to a conveyance direction of the OHT sheet. OHT sheet detection unit according to any one of claims 1 to 5, characterized in that a polarizing film is disposed between the light emitting unit and the light receiving unit. The OHT sheet detection unit according to any one of claims 1 to 6,
A transport unit that transports the OHT sheet;
The OHT sheet transport apparatus, wherein the transport unit controls a transport speed of the OHT sheet based on a timing at which the control unit determines that the OHT sheet is present. A light emitting unit that emits light at a first angle with respect to a direction perpendicular to the surface of the sheet;
A reflecting portion that reflects light that has been irradiated by the light emitting portion and transmitted through the sheet;
A light receiving portion that receives the light that is reflected by the reflecting portion and is irradiated at a second angle with respect to a direction perpendicular to the surface of the sheet, and transmitted through the sheet;
And a control unit that determines the presence or absence of the sheet based on a light reception result of the light receiving unit.   The control unit determines that the sheet is present when the amount of light received by the light receiving unit is smaller than a predetermined threshold, and when the amount of light received by the light receiving unit is larger than the predetermined threshold, The sheet detection unit according to claim 8, wherein the sheet detection unit determines that there is no sheet. The reflective portion and the light emitting portion, said seat being arranged on opposite sides respectively conveying path is conveyed, the light emitting portion and the light receiving portion is disposed on the same side respectively with respect to the conveying path The sheet detection unit according to claim 8, wherein the sheet detection unit is provided.   11. The sheet detection unit according to claim 8, wherein the light receiving unit is arranged in a direction opposite to a direction of light emitted from the light emitting unit and reflected by the sheet. . Sheet detection unit according to any one of claims 8 to 11, wherein the first angle and the second angle is an angle greater than 40 degrees, respectively.   The light emitting unit irradiates light in a direction orthogonal to the conveyance direction of the sheet, and the reflection unit reflects light in a direction orthogonal to the conveyance direction of the sheet. The sheet detection unit according to any one of 12. The sheet detection unit according to any one of claims 8 to 13 , wherein a polarizing film is disposed between the light emitting unit and the reflecting unit, or between the reflecting unit and the light receiving unit.   The sheet detection unit according to claim 8, wherein the sheet includes an OHT sheet. The sheet detection unit according to any one of claims 8 to 15,
A transport unit that transports the sheet;
The sheet conveying apparatus, wherein the conveying speed of the sheet is controlled by the conveying unit based on a timing at which the control unit determines that the sheet is present.