Marked card reader

• US 4,724,307 A
• Filed: 04/29/1986
• Issued: 02/09/1988
• Est. Priority Date: 04/29/1986
• Status: Expired due to Term

• Current Assignee: GTECH Rhode Island Corporation (International Game Technology)
• Original Assignee: GTECH Corporation (GTECH SpA)
• Inventors: Patterson, William R., Dutton, Clifton C.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US06/857,114
• Time in Patent Office: 651 Days
• Field of Search: 235/455, 382/22, 382/23, 382/26
• US Class Current: 235/455
• CPC Class Codes: G06K 17/0032 Apparatus for automatic testing and analysing marked record carriers, used for examinations of the multiple choice answer type teaching apparatus working with questions and answers G09B7/00

Abstract

A reader for cards having handwritten marks positioned to encode data, is provided with an image recorder for capturing an instantaneous image of the possible mark-bearing area of the card, including the handwritten marks and identification marks printed on the card. A data processor digitizes the data to a matrix of pixels representing grey levels at spaced points in the image. Digital means are provided to locate the identifcation marks and define the expected mark areas of the image field while accounting for positioning error such as skew, and to map the image field into potential mark-bearing areas. A comparator then compares the grey levels at successive pixels or groups of pixels in the mark areas with immediate adjacent pixels or groups, thereby detecting marks by finding contrasting edges. The identification marks printed on the card can be variable in type or position to provide for separate game cards. The reader is adaptable to be reprogrammed for additional games and functions.

Claims

1. A reader for encoding data represented by presence and position of hand-written marks on at least one card having printed areas for receiving them marks, the reader comprising:

an image recorder operative to capture a substantially instantaneous planar image of a surface of the card, the image including data representing grey levels for each pixel in an x-y matrix of pixels, and the image having at least two spaced identification marks, the identification marks being located at predetermined locations on the card and at indeterminate locations in the image;

a comparator operative to detect location of said identification marks in the image and means responsive to detected location of said marks for mapping the matrix of pixels in the image into potential mark areas; and

a discriminator operative to compare the grey levels for pixels at said potential mark areas with the grey levels for pixels surrounding the potential mark areas, whereby marks present at said potential mark areas are sensed.

2. The reader of claim 1, wherein the image recorder includes a card feeder, an illumination means and a memory effectively storing a stationary data image of the surface of the card.

3. The reader of claim 2, wherein the card feeder includes a driven transporter for moving the card to a particular position for recording the image, and the image recorder includes an array of variable-output light sensitive elements.

4. The reader of claim 1, wherein the image recorder comprises an array of light sensitive elements operative for generating analog states representing brightness of spaced points in the image, control means connected to the array for sequentially selecting the analog levels for the spaced points, an analog to digital converter producing a digital representation of the analog levels, and a random access digital memory storing said digital representation.

5. The reader of claim 1, wherein the cards are lottery entries and further comprising means for distinguishing a plurality of card types by distinguishing identification marks, the identification marks being distinctive or particular lottery games of a variety of games offered.

6. The reader of claim 1, wherein the cards are customer order cards marked to indicate an attribute of potential orders of a customer.

7. A data encoding system, comprising:

a supply of sheets having predetermined areas for receiving handwritten marks, the sheets bearing distinctive identification marks at spaced locations, the identification marks being positioned in predetermined relation to the areas for receiving handwritten marks;

illumination means for the sheets and an image recorder operative to record in an image buffer a matrix of data points representing frozen-frame grey levels of pixels within a length and width on the sheets, the length and width including the identification marks;

a data processor operative with the image buffer to define potential mark areas on the sheets relative to the identification marks;

a discriminator having weighting and arithmetic elements operative to discern marks in the potential mark areas by weighting grey levels at a part of the potential mark areas and subtracting from the weighted grey level values of areas nearby said central part, the result indicating a mark present.

8. The system of claim 7, further comprising a feeding apparatus operative to transport successive sheets for recording to an inspection area.

9. The system of claim 7, further comprising means for manually feeding sheets to an inspection area.

10. The system of claim 8, wherein the feeding apparatus is intermittent whereby a frozen frame image is recorded by stopping said sheets in the inspection area.

11. A mark sensing card reader for discerning presence of handwritten marks on potential mark fields on a plurality of cards, the cards having indicia at spaced locations, the indicia being distinctive of a certain product, the reader comprising:

a planar image sensing device with drive and amplification means operative to capture analog data representing an image signal across an entire length and width of a field on successive ones of the cards fed into the reader;

an analog to digital converter operative to digitize the analog signal into a matrix of pixel data points having variable grey levels;

an image memory for storing said data points;

means operable to detect the presence of said indicia distinctive of the certain product and to determine a position thereof in the image memory;

a data processor operable to address data in the image memory to map said pixel data points relative to the indicia distinctive of the certain product and to define potential mark addresses within the matrix of pixel data points; and

a contrast discriminator comparing the grey levels at pixels at said potential mark addresses with grey levels nearby said potential mark addresses, for discerning presence of said marks.

12. The card reader of claim 11, wherein the data processor processes the data in the image memory differently for different suites of indicia distinctive of a plurality of different suites of products, the different suites having differently-formatted cards.

13. The card reader of claim 12, wherein the different products are lottery games.

14. The card reader of claim 12, wherein the different suites of products are fast foods, and the suites correspond to menus.

15. The marked card reader of claim 11, wherein the contrast discriminator is operative to compare said grey levels at the potential mark address with grey levels at addresses at least roughtly symmetrical about and surrounding the potential mark address.

16. The marked card reader of claim 15, wherein the data processor is operable to detect a portion of a mark at each said potential mark address by adding grey level values from N locations nearby the potential mark addres, and subtracting the grey level value located at said address multiplied by N, such that a sufficiently large difference indicates a portion of a mark and a predetermined sufficient number of portions of a mark within the total potential mark area indicates the presence of a handwritten mark.

17. The marked card reader of claim 16, wherein a portion of a mark is considered present at a potential mark address when the absolute value of the subtracted grey level values exceeds one of a predetermined minimum and a calculated minimum, the calculated minimum being determined from the local brightness at the potential mark area and the brightness of an area immediately adjacent thereto.

18. The marked card reader of claim 11, wherein the analog video signal is generated by one of several possible types of two dimensional solid state sensor array including a charge-coupled element array, photodiode array, MOS imaging device array, charge injection device, and photocell array.

19. The marked card reader of claim 11, further comprising a memory element operative to store definitions of said potential mark addresses relative to the indicia distinctive of a certain product, the data processor cooperating with the memory element.

20. The marked card reader of claim 19, wherein a portion of the memory element is nonvolatile memory having tables for the definitions for a plurality of different games.

21. The marked card reader of claim 19, wherein the memory element is at least temporarily programmable, and further comprising means for altering the definitions contained therein.

22. A method for reading a lottery game card having handwritten marks positioned thereon to indicate data, the method comprising the steps of:

recording an instantaneous image of the card, the card having at least two spaced identification marks printed thereon;

defining a plurality of potential mark areas with respect to the identification marks;

comparing contrast between a central part of the potential mark areas and parts adjacent to the central part, thereby discriminating presence and absence of marks; and

,

storing the data.

23. The method of claim 22, further comprising detecting one of a plurality of edges in the image distinctive of different game cards, said defining of potential mark areas being different for different game cards.