Field of the Invention
This invention relates to readers for cards bearing bit-encoded data, i.e., data that is digitally-encoded in data strips on the face of the cards. The data is encoded on calling cards, credit cards, or the like by printing, thermal transfer, direct thermal, dot matrix, photography, or similar methods.
The amount of data that can be encoded by use of data strips exceeds that found in a bar code or a magnetic code occupying the same amount of space by at least an order of magnitude. Because of this, however, to obtain accurate readings, the data strip must be accurately aligned on the card, the card must be accurately aligned in the reader, and the reader must be capable of reading microscopic bits.
Related Applications
Two patent applications, owned by a common assignee, are presently pending, the disclosures of which are incorporated in this application by reference. These are:
For the reader: Application Ser. No. 718,219, filed Apr. 1, 1985, now U.S. Pat. No. 4,692,603, issued Sept. 8, 1987, for Optical Reader For Printed Bit-Encoded Data and Method of Reading Same, herein the "reader application". For the data strip: Application Ser. No. 799062, filed Sept. 23, 1985, now U.S. Pat. No. 4,782,221, issued Nov. 1, 1988, for Printed Data Strip Including Bit-Encoded Information and Scanner Control.
Brief Summary of the Invention
A card reader is provided for reading data strips carried on cards. The reader includes a housing with an input slot carrying a removable card alignment tray to receive the cards. Sensing means are located within the housing to detect the presence of a card and to control card-alignment driving mechanisms. The cards, once sensed, are drawn into the unit and forced into three-dimensional alignment for scanning. A detector senses when the card is in its aligned position and actuates an optical scanner to scan the data strip on the cards. Scanning is done through a transparent or open window to be certain that the plane of the card is properly aligned for scanning. When scanning is completed, the input mechanism is reversed to eject the card.
To assure proper alignment of the data strip relative to the scanner, (a) the scanner itself is positioned by a track, (b) the alignment tray (which holds the cards being read) has end and side alignment guides to position the card relative to the scanner, and (c) the data strip is in a known, predetermined position on the card.
The alignment tray can be removed and replaced with others having alignment guides in different positions. This allows the data strip to be printed in different positions upon the card and yet, by use of the proper tray, still be aligned with the scanner.
Description of the Drawings
FIG. 1 is a plan view of a card having a data strip bearing bit-encoded data.
FIG. 2 is a perspective view of our reader showing a card being inserted into the input slot of the reader.
FIG. 3 is a front elevation showing the removable tray and the slot to receive a card.
FIG. 4 is a rear elevation showing the power switch and the electrical connections to the reader.
FIG. 5 is a partial front perspective view showing the alignment tray being inserted into the reader.
FIG. 6 is a perspective view of a modified form of alignment tray, shown upside down.
FIG. 7 is a top plan view of the inside of the reader showing the card-alignment mechanism.
FIG. 8 is a view similar to FIG. 7 except showing a card in place and showing the scanner on its tracks.
FIG. 9 is a transverse section on line 9--9 of FIG. 7. showing a card in place within the reader and the optical scanner in scanning position over the card.
FIG. 10 is a bottom plan view, a view from underneath, showing details of the card-alignment mechanism.
Detailed Description of the Invention
FIG. 1 shows a typical card 1 bearing a data strip 3. The data strip includes bit-encoded data. It is the same as the data strip disclosed in the data strip application. It includes a header to provide needed scanning information for the optical reader followed by a data portion including transverse lines of bit-encoded data.
A typical data strip, as used on a card of credit card size, might measure about 16 mm (5/8 inch) wide and 68 mm (2.5 inches) long. The maximum length on a card of this size is about 76 mm (3.0 inches). The encoded bits are generally rectangular and might measure 0.25 mm (0.010 inches) in each direction (This could vary, however, depending upon the desired density of encoding); and, for greater accuracy, data is recorded in dibit form. As a result, a typical card would carry some 1000 bytes of information.
Card 1 includes a leading edge 7 and a side edge 9. Data strip 3 is located upon card 1 at a known, predetermined distance 8 from edge 7 and at a known predetermined distance 10 from edge 9. Preferably, it is parallel to edge 9. This exact positioning is necessary so that, when the card is properly aligned with the scanner, the data strip will be properly aligned for scanning.
Data strip 3 is put on card 1 in any desired manner, such as by printing or one of the methods suggested above.
The reader 15 is shown in FIGS. 2, 3, and 4. Reader 15 includes a card aligning tray 17 which fits in position in a slot 18 in the end of the reader 15 and is held by guides within the reader. Slot 18 and the lower side of tray 17 together form a slot 19 to receive card 1. (Note that in this preferred embodiment the card is positioned beneath tray 17). The insertion of a tray 17 into slot 18 of reader 15 is shown in FIG. 5.
Reader 15 also includes power switch 20 and the necessary electrical connections 21 to receive power and to transmit data from the data strip to a monitor, computer, or other type of receiver.
Details of the tray 17 and the structure for aligning card 1 for scanning are shown in FIGS. 6, 7, 8, 9, and 10. Preferably, window 25 of the tray is molded of clear plastic material and the undersurface of the tray includes three guides, i.e., two side guides 45 and 49 and end guide 47 (guide 47 is located at the end farthest removed from slot 19). The tray 17 includes a window 25 over the place where the data strip 3 will be located when it is scanned; and the window, or its edges if the window is open, serves as additional guide, keeping the data strip in the right plane. The window preferably is the size of the data strip to be read, or just slightly larger. There is also a lower entrance guide 51 at the slot 19, to support the card.
The dimensioning of the tray, guides, and window is such that, when the card is pressed tightly against end guide 47 and side alignment guide 45 and window, three-dimensional alignment is achieved and the card is in the proper position to be scanned.
Drive rollers 27 and 29 are below tray 17 and press upwardly slightly through openings 26 and 28, respectively, in the tray, so they will press the card firmly against the lower surface of the tray. The rollers are normally made of soft, foamed rubber or polyurethane which can frictionally grab and move the inserted card, but which will permit slippage when the card is in place.
The rollers are set at an angle to, rather than parallel to, the longitudinal dimension of the card. Thus, when actuated in the forward direction, the rollers not only pull the card into the reader but also press it against end guide 47 and side alignment guide 49. They also press it against the undersurface of window 25, or, if the window is an opening rather than a sheet of transparent plastic, they press the card against the edges of window 25. Thus, the rollers 27 and 29 serve to force the card 1 into three-dimensional alignment, i.e., against end guide 47, against side alignment guide 49, and against window 25. This alignment is valuable for achieving the most accurate scanning.
Drive rollers 27 and 29 are driven by motor 30 which drives roller 29 and which is connected to roller 27 by belt 50.
Actuation of the rollers and of the scanning cycle is controlled by photodetectors 31 and 33 receiving light for LEDs 32 and 34 (and associated circuitry, not shown, found in printed circuit board 41). Detector 31 is positioned above tray 17 and close enough to slot 19 to initially detect the presence of the leading edge 7 of a card as it is inserted. Upon this initial detection, the rollers 27 and 29 are caused to move in their forward (inward) direction to draw the card into the reader and align it. Detector 33 is positioned to detect the trailing edge of the card when the card has reached its aligned position. This serves to stop the rollers and to start the scanning cycle.
Tray 17 is preferably made of clear plastic. If it is not, however, it is necessary that it have holes in it to permit light from the LEDs to reach the detectors. Use of holes will also serve as a check to be certain that the tray is fully seated within the housing.
The structure and operation of scanner 35 is disclosed in the reader application; and this scanner is presently being sold under the trademark "Softstrip". The scanner has an alignment wheel 38 which fits in longitudinal track 37 and a supporting wheel 40 which rolls along a surface. It also includes a spring-pressed roller 39 pressing against the upper inner surface 51 of the reader housing to hold the scanner down in position. Correction for any possible remaining angular alignment errors between the scanner and the data strip is accomplished in the manner set forth in the reader application.
Scanner 35 moves from one end of the data strip 3 to the other and, at the same time, scans the data strip transversely along its transverse data lines. Consequently, when the scanner reaches the end of the data strip, all of the dibits of information will have been scanned. Window 25 is in the plane of focus of the scanner; and the scanning is done through this window. To keep the data strip in focus, it is important that the strip be held against the window so that it will be in the plane of focus of the scanning lenses. Rollers 27 and 29 hold it in this place. So that the scanning is directly along the transverse data lines of data on the data strip, it is important that the card bearing the data strip be aligned tightly against side alignment guide 49 and end alignment guide 47.
After the data strip 3 has been scanned, the scanner circuit signals the roller motor to drive rollers 27 and 29 in the reverse direction to eject the card from the reader. This reverse direction has a sidewise component of motion, pressing the card against exit guide 45 which causes it to be directed out the slot 19. This time, when the leading edge 7 of card 1 (now the following edge) passes the first detector 31, the rollers are signalled to stop. The scanner circuit also signals the scanner to return to its home position.
It is possible, by having removable trays, to accommodate different sizes of cards and different placements of the data strips on the cards. For example, one may use a tray such as tray 17a in FIG. 6. This has side alignment guide 49 further removed from window 25a, meaning that the data strip 3 should be on the card at a greater distance 10 than in the former example. The important thing, in any arrangement, however, is for the data strip 3 to be at a predetermined distance from the leading and side edges 7 and 9, that the guides 47 and 49 be located accordingly, and that all serve to locate and hold the data strip in properly aligned position in relationship to the scanner 35.