Examination grading computer

Claim 2

An examination paper grading machine comprising: a rotatable, hollow drum for carrying a master answer sheet, said drum provided with means for engaging a student answer sheet; a source of illumination mounted inside the drum adjacent the inner surface thereof, said drum provided with means for passing illumination from the inner surface to the outer surface; a plurality of photosensors mounted adjacent the outer surface of the drum and aligned with the source of illumination so that light passing from the source and through the drum will be received by the photosensors; means for rotating the drum; circuit means for receiving a signal from the photosensors when light from the illumination source is received by at least one of the photosensors, said circuit adapted to actuate a wrong answer indicator upon the receipt of said signal; and sensing means comprising an elongate opaque stripe along the circumference of the drum for blocking a portion of the illumination through the drum during that part of the rotation of the drum during which the answer areas on the student answer sheet are not in position for grading so that the rotation means will continue rotation of the drum until the answer area has passed the photosensors.

Claim 3

The apparatus of claim 1 and wherein the student answer sheets are made of translucent materials and have a plurality of columns thereon providing multiple answer marking locations in a row perpendicular to the columns; and wherein the student answers are marked in the approPriate locations by means of substantially opaque marks; the master answer sheet is substantially opaque and has perforations therein in registry with the correct answer locations on the student answer sheets when the student answer sheets and the master answer sheet are placed in juxtaposition in the machine, and the student answer sheet includes an opaque strip near the end thereof and aligned with the answer indication area for the sensing of the presence of the answers in position to be scored.

Claim 4

The apparatus of claim 1 and including means for holding the student answer sheet and the master answer sheet in juxtaposition during approximately one-half revolution of the drum carrying the master answer sheet, and wherein the engaging means on the drum is disposed so as to release the student answer sheet after approximately 270* of rotation from the point of engagement.

Claim 5

The apparatus of claim 4 wherein Apparatus for grading examination papers having answers indicated thereon in at least one of a plurality of columns along a row perpendicular to the columns in an answer indication area comprising: means for carrying an examination answer sheet along a path; a first sensing station along the path for sensing answers on an answer sheet; said first sensing station comprising a plurality of first light sources on one side of the path and a plurality of photoelectric sensors on the other side, each said sensor aligned with a first light source to receive illumination therefrom; a second sensing station for sensing that the answer indication area of the answer sheet is aligned with the first sensing station; the second sensing station comprising a second light source and a photoelectric sensor aligned with each other on opposite sides of the path adjacent one edge of the path so that said second sensing station is adjacent to and aligned with one edge of the answer sheet; a master answer guide having perforations therein in registry with the answer positions in the answer columns indicating the correct answers for that row, said guide being narrower than the answer sheet and adapted to be carried, together with the answer sheet, past the answer sensing station; means responsive to a signal from the first sensing station, said signal being an indicator of an incorrect answer, said responsive means adapted to mark an incorrect answer indicium on the examination sheet adjacent the answer row which has been sensed; the means for carrying the answer sheet along the path comprising a rotatable drum having a substantial portion of the surface thereof transparent and the balance thereof opaque so that illumination from the first light sources will pass through the drum and through the perforations in the master answer guide, and the illumination from the second light source will pass through a transparent portion of the drum adjacent one edge thereof; and means for accumulating the number of incorrect answers in response to said incorrect answer signals.

Claim 6

The apparatus of claim 4 and wherein the second light source is in registry with an opaque portion of the drum when the drum is in position to accept a student answer sheet for carriage along the path; and upon rotation of the drum so that when the answer indication area of the answer sheet comes into alignment with the first sensing station a transparent portion of the drum is in registry with said second light source.