Double sheet detector method for automated transaction machine

A method of distinguishing a single sheet from a multiple sheet comprised of a plurality of overlapping sheets, comprising:

• (a) illuminating a first face of a sheet with a first radiation source positioned on a first side of the sheet;
• (b) sensing with a first detector on a first side of the sheet, a first level of radiation from the first radiation source reflected from the first face of the sheet;
• (c) sensing with a second detector positioned on a second side of the sheet, a second level of radiation from the first radiation source transmitted through the sheet;
• (d) illuminating a second face of the sheet with a second radiation source positioned on a second side of the sheet;
• (e) sensing with the second detector on the second side of the sheet, a third level of radiation from the second radiation source reflected from the second face of the sheet;
• (f) generating at least one value responsive to the first level, the second level and the third level;
• (g) comparing the at least one value to at least one threshold, wherein a relationship of the at least one value to the at least one threshold is indicative of whether the sheet is a single sheet or a multiple sheet.

A method of distinguishing a single sheet from a multiple sheet comprised of a plurality of overlapping sheets, comprising:

• (a) illuminating a first face of a sheet with a first radiation source positioned on a first side of the sheet;
• (b) sensing with a detector on a first side of the sheet, a first level of radiation from the first radiation source reflected from the first face of the sheet;
• (c) sensing with a detector positioned on a second side of the sheet, a second level of radiation from the first radiation source transmitted through the sheet;
• (d) illuminating a second face of the sheet with a second radiation source positioned on a second side of the sheet, wherein at least one of the first radiation source and the second radiation source comprises an infrared radiation source;
• (e) sensing with a detector on the second side of the sheet, a third level of radiation from the second radiation source reflected from the second face of the sheet;
• (f) generating at least one value responsive to the first level, the second level and the third level;
• (g) comparing the at least one value to at least one threshold, wherein a relationship of the at least one value to the at least one threshold is indicative of whether the sheet is a single sheet or a multiple sheet.

A method of distinguishing a single sheet from a multiple sheet comprised of a plurality of overlapping sheets, comprising:

• (a) illuminating a first face of a sheet with a first radiation source positioned on a first side of the sheet;
• (b) sensing with a detector on a first side of the sheet, a first level of radiation from the first radiation source reflected from the first face of the sheet;
• (c) sensing with a detector positioned on a second side of the sheet, a second level of radiation from the first radiation source transmitted through the sheet;
• (d) illuminating a second face of the sheet with a second radiation source positioned on a second side of the sheet;
• (e) sensing with a detector on the second side of the sheet, a third level of radiation from the second radiation source reflected from the second face of the sheet;
• (f) generating at least one value responsive to the first level, the second level and the third level;
• (g) comparing the at least one value to at least one threshold, wherein a relationship of the at least one value to the at least one threshold is indicative of whether the sheet is a single sheet or a multiple sheet;
• (h) moving the sheet along a sheet path;
• and
• (i) diverting the sheet from the sheet path responsive to the relationship of the at least one value and the at least one threshold compared in step (g) being indicative that the sheet is a multiple sheet.

An apparatus comprising:

• a sheet, wherein the sheet comprises a first face and a second face;
• at least one first radiation source on a first side of the sheet;
• at least one first detector on the first side of the sheet, wherein the at least one first detector is operable to sense a first level of radiation from the at least one first radiation source reflected from the first face of the sheet;
• at least one second radiation source on a second side of the sheet opposed of the first side;
• at least one second detector on the second side of the sheet, wherein the at least one second detector is operable to sense a second level of radiation from the at least one first radiation source transmitted through the sheet and to sense a third level of radiation from the at least one second radiation source reflected from the second face of the sheet;
• at least one processor in operative connection with the at least one first radiation source, the at least one first detector, the at least one second radiation source, and the at least one second detector, wherein the at least one processor is operable to distinguish the sheet as a single sheet or as a multiple sheet comprised of plural overlapping sheets.

A method for distinguishing a single sheet from a multiple sheet comprised of a plurality of overlapping sheets, comprising the step of:

• (a) illuminating a first face of a sheet with a first radiation source positioned on a first side of the sheet;
• (b) sensing with a detector on a first side of the sheet, a first level of radiation from the first radiation source reflected from the first face of the sheet;
• (c) sensing with a detector positioned on a second side of the sheet, a second level of radiation from the first radiation source transmitted through the sheet;
• (d) illuminating a second face of the sheet with a radiation source positioned on a second side of the sheet;
• (e) sensing with a detector on the second side of the sheet a third level of radiation from the second radiation source reflected from the second face of the sheet;
• and
• (f) determining if the sheet is a single sheet or a multiple sheet responsive to the first level, the second level and the third level.