Photoelectric apparatus for document counting and overlap detection
AssigneeBrandt-Pra, Inc.
InventorAlan P. Jones
Life of this patent
Estimating the term…
Abstract
Electronic counting and control means are provided which are sensitive to the transmissivity of light and include feedback means for controlling the brightness of the light source to extend its life. Additionally, integrating means are provided for determining when there is an overlap of documents being handled by the counting means. Further, specific circuit arrangements are provided for insuring that an exact count is obtained even when perforated documents are being counted and there is a gap between successive documents.
Claims8
Sensing means for distinguishing between single and double fed documents moving along a feed path at spaced intervals so that the trailing edge of each document is normally spaced from the leading edge of the next succeeding document, said means comprising:
- sensing means including a light sensing element positioned to one side of said path;
- a light source positioned on the opposite side of said path and aligned so that its light rays are directed toward said light sensing element;
- comparator means for comparing the output of said light sensing means, which varies as a function of the light transmission characteristic of the passing documents, against a predetermined threshold for generating a constant level output when the level of the sensing means output reaches the threshold valve;
- means coupled to the output of said comparator means for averaging the signal at said comparator means output;
- and
- means for generating a doubles sense signal when the level of the averaged signal reaches a predetermined threshold.
Apparatus for distinguishing between single and double fed documents moving along a feed path at spaced intervals so that the trailing edge of each document is spaced from the leading edge of the next succeeding document, said means comprising:
- sensing means including a light sensing element positioned to one side of said path;
- a light source positioned on the opposite side of said path and aligned so that its light rays are directed toward said light sensing element;
- comparator means for comparing the output of said light sensing means, which varies as a function of the light transmission characteristic of the passing documents, against a predetermined threshold for generating a constant level output when the level of the sensing means output reaches the threshold value;
- means responsive to the output of said light sensing element for controlling the brightness of the light output of said light source so that it is inversely proportional to the magnitude of the output signal generated by said light sensing element.
Dependencies are inferred from the claim text.