Identity card

An optically-readable identity card has an inner core layer of material which inhibits light from the optical reader from passing through the body of the card. The inner core material is a plastic vinyl colored either black, gold, silver or any metallic color.

BACKGROUND OF THE INVENTION 
The invention relates generally to identity cards, and more particularly to 
identity cards which are read by infrared or light source readers. 
Plastic identity cards are rapidly becoming the ignition key necessary to 
travel in today's computer-driven society. Plastic credit cards are 
replacing cash and checks for the bulk of commercial transactions. Even 
when a person wishes to cash a check, he must display his plastic 
check-guarantee card. To obtain cash from an automated teller machine, a 
person first accesses the machine by inserting his plastic identity card. 
Many security systems rely on plastic identity cards. An employee inserts 
his plastic identity card to gain access through the door of secured areas 
of the work place. Many pieces of equipment will not work until a plastic 
identity card has been inserted indicating that an authorized user is 
present. Even the photocopier needs a plastic identity card before 
reproduction can be accomplished. 
In one typical application, a plastic identity card carries a magnetic 
strip that is encoded with the appropriate identifying information. The 
identity card is inserted into a magnetic strip card reader. If the reader 
recognizes the proper code, the equipment becomes usable by the card 
holder. 
Magnetic strip identity cards are typically used in automated teller 
systems. The identity card is inserted into the card reader which grabs 
the card and pulls it into the reader at a uniform speed. This is 
necessary because the information encoded on the magnetic strip must pass 
over the sensing station at a uniform speed to ensure accurate detection. 
If the magnetic strip passes over the sensing station too slowly, too 
quickly or non-continuously, the reader will not properly detect the 
information and deny access to the user. Magnetic strips are also subject 
to scratching and other damage which causes the user to be denied access. 
In order to avoid the problems inherent in magnetic strip identity cards, 
many equipment manufacturers are turning to optically-read identity cards, 
particularly infrared or light source readable identity cards. A series of 
apertures are punched through the plastic identity card, arranged in a 
binary code sequence, each vertical column of apertures representing a 
single digit. The plurality of vertical columns results in a multiple 
digit identity number. 
In use, the identity card is inserted into an optical reader. A light 
source on one side of the card is shone toward the card. Light passes 
through the apertures and a sensor on the opposite side of the card 
detects the light associated with each aperture. If the identity card is 
recognized by the reader, the card holder is authorized to use the 
equipment to which the reader is connected. 
Optically read identity cards have advantages over the magnetic strip 
identity cards. The optically read identity card is stationary in the 
reader during use thereby negating the necessity of using rollers or the 
like to grab the identity card and pass it over the reader at a constant 
speed. The user simply inserts the card to a fixed point, the speed of 
insertion being irrevelant. Inadvertent scratching or destruction of the 
magnetic strip is also avoided, as well as the offset of random magnetic 
fields to which a magnetic identity card may be subjected. 
The present invention is, however, directed at solving one disadvantage 
that optically-readable identity cards do have. Optical identity card 
readers are not manufactured with uniformly intensive light sources. 
Depending upon the intensity of the light source, it is possible, using 
conventional optically-readable identity cards, to have light penetrate 
through the body of the identity card and to be detected by the sensor. 
This results in an error reading by the card reader and the user is denied 
access to the equipment. 
It is an object of the present invention to decrease, if not eliminate, 
light passing through the body of optically read plastic identity cards. 
It is a feature of the present invention to provide a plastic identity card 
with an inner core of material which decreases, if not completely 
eliminates, light passing through the body of the identity card. 
It is an advantage of the present invention that optically readable 
identity cards constructed in accordance with the present invention can be 
used in most optical readers and these identity cards will be much more 
reliable than the prior art identity cards. 
BRIEF DESCRIPTION OF THE INVENTION 
A plastic identity card is provided at its inner core with a layer of 
material which inhibits light from the optical reader from passing through 
the body of the identity card. The material is preferably a plastic vinyl 
colored either black, gold or silver. Alternatively, the vinyl core can be 
colored with any metallic color. The term "colored" is intended to include 
both incorporating a color pigment into the vinyl during the manufacture 
of the vinyl, and alternatively, the color can be printed onto the surface 
of the vinyl during the manufacture of the vinyl.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows an optically-readable plastic identity card 10 of the present 
invention. The body 12 of the identity card is generally a five layer 
laminated material. A series of small generally rectangularly shaped 
apertures 14 are provided in the identity card 10, most usually in the 
upper left hand corner. These apertures are arranged in a regular series 
of rows and columns. Alternatively, round apertures can also be used. 
In use, the identity card is placed in an optical reader. A light source 
shines light toward one side of the identity card. The light passes 
through the apertures 14 and is sensed by a sensing station on the 
opposite side of the identity card 10. The arrangement of the apertures 
according to columns and rows is recognized by the sensing station as a 
code, typically a binary number code. 
FIG. 2 shows the identity card 10 of the present invention in an exploded 
view so that the layers can be identified. The central core layer 20 is a 
plastic vinyl material. When the vinyl is being made, the color is mixed 
directly into or printed on the vinyl so that the central core 20 is 
colored. Any color that will inhibit, if not completely eliminate, the 
passage of light through the body 12 of the identity card can be used. 
Preferably black, gold and silver colors are used. Also any metallic color 
will be acceptable. A metallic color is formed during the vinyl 
manufacturing process by taking a conventional base color pigment and 
adding metallic chips or flakes thereto. When the vinyl is formed into 
sheets, the resulting sheet has a metallic sheen regardless of the 
particular base color used. Metallic colored vinyl can be obtained from a 
number of manufacturers, including General Tire and Rubber Co., Canton, 
Ohio. 
A first intermediate layer 22 and a second intermediate layer 24 are 
plastic vinyl material, preferably colored to provide a suitable surface 
for printing, most preferably colored white. A suitable surface for 
printing is a surface that accepts the printing of either single or 
multiply-colored characters or other information or depictions without 
affecting the intended colors to be shown. A first outer layer 26 and a 
second outer layer 28 are each clear plastic coating material. The plastic 
vinyl material of layers 20, 22 and 24 is a rigid vinyl that meets 
A.N.S.I. specifications which have been established for automated teller 
machines. 
A typical plastic identity card is approximately 0.030" thick. The central 
core layer 20 has a thickness preferably in a range of between 0.003 and 
0.010 inches, most preferably approximately 0.010 inches. Each 
intermediate layer 22, 24 has a thickness preferably in a range between 
0.003 and 0.010 inches, most preferably approximately 0.007 inches. Each 
outer layer 26, 28 has a thickness preferably in a range between 0.001 and 
0.005 inches, most preferably approximately 0.003 inches. 
A test has been devised to determine whether a specific identity card is 
susceptible to permitting light to pass through the body of the card 
thereby causing the sensing station to improperly read the identity card. 
A typical optical identity card reader using an infrared light source is 
Model #PT 200, manufactured by Electronic Display Technology, Las Vegas, 
Nev. The intensity of the light passing through the body of an identity 
card mounted in the optical reader was measured using a radiometric filter 
light detector Model #S 351A manufactured by United Detector Technology, 
Hawthorne, Calif. Using this detection equipment, the intensity of the 
light source is measured in milliwatts. 
The light detector Model #S 351A has a light range of between 1.70 and 1.80 
milliwatts when no identity card is placed in the reader. It has been 
determined that an acceptable level of light intensity passing through the 
body of an identity card is preferably less than 0.035 milliwatts, most 
preferably less than or equal to 0.025 milliwatts. If the light intensity 
passing through the body of the identity card is below this acceptable 
level, the optical reader will only sense the light passing through the 
apertures in the card and thus accurately read the identity card. 
When the central core layer 20 is made of vinyl which is colored black, 
gold, silver or any metallic color, the light intensity passing through 
the body 12 of the identity card is negligible, generally less than 0.010 
milliwatts, and usually closer to approximately 0.002 milliwatts. A white 
vinyl central core 20 results in cards that vary in permitting light 
having an intensity in a range of generally 0.020 to 0.070 milliwatts to 
pass through the body of the identity card. Because of the variation of 
light intensity that may pass through individual cards, the use of a card 
having a white vinyl central core 20 is not acceptable There will be no 
assurance that each card will work in the plethora of optical readers in 
which the card is intended to be used. 
It is only necessary to color the central core layer 20 of the identity 
card 10 in order to inhibit light passage through the body of the card. It 
is preferable that intermediate layers 22, 24 be initially white as this 
color provides the most suitable surface for printing. Most card users 
desire that printing be placed on intermediate layers 22, 24 to identify 
the card, depict the name and logo of the company and set out information 
as to the use of the card. The outer layers 26, 28 are clear plastic 
layers that merely provide a protection layer for the printing to inhibit 
scratching or other defacement of the card. 
The present invention is also applicable to optically readable identity 
cards which do not utilize the clear outer layers 26, 28 but rather have 
only a three layer laminated construction. Alternatively, optically 
readable identity cards can be made having an overall thickness of 
approximately 0.024 inches, with the outer layers being each approximately 
0.003 inches thick and the intermediate layers and the central core layer 
being each approximately 0.006 inches thick. In each of these alternative 
identity card constructions, the central core is a colored vinyl, 
preferably black, gold, silver or any metallic color, that inhibits the 
passage of light through the body of the identity card. The outer two 
layers are white to provide a suitable surface for printing information on 
the front and back of the card. 
While the invention has been illustrated with respect to several specific 
embodiments thereof, these embodiments should be considered as 
illustrative rather than limiting. Various modifications and additions may 
be made and will be apparent to those skilled in the art. Accordingly, the 
invention should not be limited by the foregoing description, but rather 
should be defined only by the following claims.