CA1247738A

CA1247738A - Updatable micrographic pocket data card

Info

Publication number: CA1247738A
Application number: CA000506052A
Authority: CA
Inventors: Jerome Drexler
Original assignee: Drexler Technology Corp
Current assignee: LaserCard Corp
Priority date: 1985-04-09
Filing date: 1986-04-08
Publication date: 1988-12-28
Also published as: WO1987003117A1; EP0245281A1; US4680459A

Abstract

Abstract Updatable Micrographic Pocket Data Card A strip of optical contrast laser recording material is disposed on a wallet-size card, and has laser written micrographic characters recorded thereon. The characters are formed of a matrix of laser recorded character spots and are eye readable using twenty power magnification. The characters are recorded in situ on the card, after the strip is disposed in the card, by a laser having a beam focused on the strip. A light detector reads the reflected beam to confirm laser writing. Either raster-like or zig-zag scanning of the beam creates each character matrix. Each of the character spots may be made up of one laser spot or by a group of laser spots.

Description

~ t~7 Technical Field The invention relates to optical data infor-mation storage and more particularly to a method for recording laser written updatable micrographic informa-tion on a pocket-or wallet-size card.
Background Art In optical data storage cards, reliability and ease of reading the data are important. Data may be recorded in an office environment, but need to be read in a dirty environment or when no card reading machine is available, such as in an emergency. For example, medical-record cards should be readable in an ambulance, at the scene of an accident, or on a battlefield. In such conditions, it may be dlfficult or impossible to read digitally recorded data on a card or paper copies in a file.
In U.S. Patent 4,254,329 to Gokey et al., an information retrieval system includes a microfiche data base of two types of ~icrofiche cards. One type is machine readable only, while the other has both machine Dl:l readable and visually readable information. This infor-mation cannot be updated.
In U.S. patent 4,236,332, Domo discloses a medical record card containing a microfilm portion having some data visible to the eye and other data visible by magnification. The directly visible data is alphanumeric character codes pertaining to emergency medical con-ditions of the patient and the magnifiable data portions detail the medical history. This information cannot be updated.
An object of the invention is to provide a method and system for recording laser written information on a card that can be visually read by a person with the help of magnifying optics.
It is another object of the invention to pro-vide a card in which visually read information can be recorded in place on the card.
It is another object of the invention to pro-vide a method and system for updating information on a wallet-size card that can be read visually by a personn Disclosure of the Invention The above objects have been met with a method and system for recording in situ microscopically visually readable information on a strip of optical contrast laser recording material, disposed on a pocket- or wallet-size card.
A laser beam records microscopically visually readable information on a strip of optical storage material, in situ, either by ablat-,on, melting, physicai or chemical change, thereby forming spots representing changes in reflectivity. The recording process produces differences in reflectivity detectable by a light detector. Micrographic characters are sequentially recorded as matrices of spots on the laser recordable material, and are readable with a magnifier. These spots are written by scanning in a zig-zag or raster-like pattern over the matrix and writing laser spots at desig-nated locations so that characters can be formed one by one. Such micrographic characters are formed directly by the spots or by groups of laser spots, called character spots.
Microscopically visually read characters created by the spots may i~clude alphanumerics, dates, script writing, foreign language alphabets and numerics, maps, foreign language picture characters such as Chlnese and Japanese characters, mathematical symbols, logic symbols, scientific and musical notations, and other symbols and notations. It could also include emblems, logos, codes, and trademarks.
The uniform surface reflectivity of this re-flective strip before recording typically would range between 8% and 65%. For a highly reflective strip the average reflectivity over a laser recorded spot might be in the range of 5% to 25%. Thus, the reflective contrast ratio of the recorded spots would range between 2:l and 7:l. Laser recoxding materials are known in the art that create either low reflectivity spots in a moderate to high reflectivity field or high reflectivity spots in a low reflectivity field. An example of the latter type~is described in U.S. patent 4,343,879. When the reflec-tivity of the field is in the range of 8% to 20% the reflective spots have a reflectivity of about 40%. The reflective contrast ratio would range from 2:l to 5:l.
Photographic pre-formatting would create spots having a 10% reflectivity in a reflective field or 406 in A low reflectivity field. No processing after laser recording is required when the recording strip is a direct-read-after-write material. Laser recording materials also may be used that require heat processing after laser recording.
By means of in situ laser recording, informa-tion that needs to be read in an emergency where no card reading machine is available is written in microscopical-ly readable form. The information would include personal and medical information, transactions, office forms, multiple language information, the date of the most recent up-date of information on the card, titles and instructions. Maps, charts, tables, graphs, diagrams, and written music could also be recorded in this form.
Brief Description of the Drawings Figure 1 is a top plan view of a pocket data card hav-ing micrographic information in accord with the present invention.
Figure 2a is a top enlarged view showing raster-scan writing of micrographic characters in accord with the present invention.
Figure 2b is a top enlarged view of another style of writing micrographic characters in accord with the present invention.
Figure 2c is a top enlarged view of a micrographic map on a card in accord with the present invention.
E'igure 3 is a partial sectional view of a micrographic data card formed by an alternate storage medium.
Figure 4 is a plan view of optical apparatus for read-ing and writing on the data strip portion of the medium illus-trated in Figure 1.
Best Mode for Carrying Out the Invention With reference to Figure 1, a data card :ll is :illu5-trated having a size common to most credit cards. The width dimension of such a card is approximately 54 nlm and the length dimension is approximately 85 mm. These dimensions are not critical, but preferred because such a size easily fits into a wallet or pocket and has historically been adopted as a conven-ient size for automatic teller machines and the like. The card's base 13 is a dielectric, usually a plastic material such as poly-vinyl chloride or similar material. Polycarbonate plastic is - 4a - ,;L~

preferred. The surface finish of -the base should have low specular reflectivity, preferably less than 10%.
Base 13 carries strip 17. The strip is typically 16 or 35 millimeters wide and extends the length of the card. Alternatlvely, the strip may have other sizes and orientations. The strip is relatively thin, approximately 60-200 microns, although this is not critical. Strips of laser recording material may be applied to both sides of card 11. The strip may be applied to the card by any convenient method which achieves flatness.
The strip 17 is adhered to the card with an adhesive and is covered by a transparent laminating sheet 76 seen in Fig. 3 which serves to keep strip 17 flat, as well as protecting the strip from dust and scratches.
Sheet 76 is a thin, transparent plastic sheet laminating material or a coating, such as a transparent lacquer.
The material is preferably made of polycarbonate plastic.
The high resolution laser recording material which forms strip 17 may be any of the reflective re~
cording material which have been developed for use as direct read-after-write (DRAW) optical disks, so long as the materials can be formed on thin subst-rates. An advantage of reflective materials over transmissive materials is that the write equipment is all on one side of the card and automatic focus is easier, and twice as-much data can be stored by using both sides. For example, the high resolution material described in U.S.
patent 4,230,939 issued to de Bont, et al. teaches a thin metallic recording layer of reflective metals such as Bi, Te, Ind, Sn, Cu, Al, Pt, Au, Rh, As, Sb, Ge, Se, Ga.
Materials which are preferred are those having high re-flectivity and low melting point, particularly Cd, Sn, Tl, Ind, Bi and amalgams. Suspensions of reflective metal particles in organic colloids also form low melting temperature laser recording media. Silver is one such metal. ~ypical recording media are described in U.S.
patents Nos. 4,314,260, 4,298,684, 4,278,758, 4,278,758, 4,278,756 and 4,269,917, all assigned to the assignee of the present invention.
The laser recording material whicn is selected should be compatible with the laser which is used for writing on it. Some materials are more sensitive than others at certaln wavelengths. Good sensitivity to infrared light is preferred because infrared is affected least by scratches and dirt on the transparent laminating sheet. The selected recording material should have a favorable signal-to-noise ratio and form high contrast spots with the write system with which it is used.
The material should not lose data when sub-jected to temperatures of about 180F (82C) for long periods. The material should also be capable of recording at speeds of at least se~eral thousand laser spots/sec. This generally precludes the use of materials that require long heating times or that rely on slow chemical reactions in the precence of heat, which may permit recording of only a few laser SpOts/seG. A large number of highly reflective laser recording materials have been used for optical data disk applications.
Strip 17 also has microscopic visually readable information 20. The information is recorded as a matrix of character spots by a laser by scannlng in a zig-zag or raster-like pattern over the matrix and writing laser~
spots at designated locations to form micrographic characters. The information matrices are generally about 200 microns high, so they are read by magnification, such as through optical magnifier 21.
A laser forms spots in the surrounding field of the reflective layer itse].f, by ablation, melting, physi-cal or chemical change, thereby altering the reflectivity in the spot. The information is read by viewing with magnifying optics the optical reflective contrast between the surrounding reflective field of unrecorded areas and the recorded spots. Spot reflectivity of less than half of the reflectivity of the surrounding field produces a contrast ratio of at least two to one, which is suffi-cient contrast for reading. Greater contrast ispreferred. Reflectivity of the strip field of about 50%
is preferred with reflectivity of a spot in the reflec-7 ~ ,~ S ~ j,ct'~

tive field being less than 10%, thus creating a contrast ratloof greater than five to one. Alternatively, data may also be recorded by increasing the reflectivity of the strip. For ex-ample, the recoxding laser can melt a field of dull microscopic spikes on the strip to create flat shiny spots. This method is described in SPIE, Vol. 329, Optical Disk Technology (1982), p. 202. A spot reflectivity of more than twice the surrounding spiked field reflectivity produces a contrast ratio of at least two to one, which is sufficient contrast for reading.
In Figure 2a, microscopic visually readable informa-tion is recorded on a portion of strip 17. The information may be personal information, medical records, transactions, office forms, instructions, multiple language information, the date of the most recent update of information on the card, or titles for the digital record on the strip. The information is in the form of characters, such as the alphanumeric characters "M" 80 and "Y"
82, shown in Figure 2a by way of example. The characters 80 and 82 are made up of matrices of laser recorded character spots. In this embodiment, each character spot is made of a single laser spot. The spots may or may not touch adjacent spots and may be written in raster scan fashion 81 or zig-zag fashion 83.
The matrices may be five spot sites by seven spot sites, such as in Figure 2a, seven spot sites by ten spot sites, ten by fourteen or some other combination of spot sites. These spots are written by scanning in a raster-like pattern over the matrix and writing laser spots at designated locations so that char-acters can be formed. Such characters are formed directly by the spots or by groups of laser spots, termed character spots 84, 85. Multiples of five by seven are convenient owing to existing software ~or CRT displays and dot matrix printers which - 8 - ~ f~

can be adapted for use in laser recording. The actual char-acter set recordable by this method would depend on the software used. The spots in a seven by ten matrix have a diameter of about 20 microns, making the height of a character about 200 microns. The micrographic characters are seen by magnification, such as through a pocket-type optical magnificatiorl device.
~haracters seen through a 20 power or greater device will appear to be about four millimeters high or greater. A magnification of at least ten powçr will be required to read the characters.
The characters are small enough so that they cannot be resolved easily by an average eye with a 5 power magnification or less.
In Figure 2b, characters 86 and 88 are recorded on strip 17. Figure 2b is similar to Figure 2a except that the character spots are formed from a group of four laser spots 90, 91, 92, 93. Each laser spot is approximately 10 microns in dia-meter, making a character spot 20 microns square, as in Figure 2a. The format is more convenient for some media with high melting points. Alternatively, character spots can be made of 16 five micron laser spots in a square or some other number of spots.
In Figure 2c a map ln micrographic form covers the entire side of a card or at least most of the card. Such a map is pre-recorded and then mounted on a card with laser-written annotations superimposed. ~lternatively, the map is written entirely in-situ on the card, with annotations. Micrographic characters in the form of clusters of spots define map features, with the characters forming map features, such as roads and cities, using dot patterns. Laser spots may be aligned in a straight line defining a micrographic character which defines a road. Other characters may be established to define cities, airfields, forests, streams and the like. Such a map would be ~ _ 9 ~ ~ 9~ 1 b useful to a solider or traveler~
With reference to Figure 3, a card substrate 70 carries a secondary substrate 72 which is a thin flexible mater-ial, only a few mils thick carrying a laser recording material 74. The secondary substrate 72 is adhered to the primary sub-strate 70 by means of an adhesive or sticky substance, simila to dry adhesives found on plastic tape. The laser recording material may be any of the materials previously discussed. A
protective coating 76 is applied over the laser recording mate-rial.
Remarks in the form of microscopically visually read-able alphanumerics, foreign language characters, mathematical symbols, and the like, may be laser recorded. Transaction or other information related to a person may be recorded on the card.
Such transaction information could be banking information~ such as a record of deposits and withdrawals. ~n former years, such transactions were recorded in a passbook, but because of the amount of time taken for sequential entries in a passbook, and because of automation, passbook banking was abandoned, even though it was more favorable to consumers. Now, sequential trans-actions may be recorded automatically so that a consumer may once again have a complete record oE prior transactions, although a card reader is neccssary. Lnsurance transactions, immigration matters and the like all involve sequential transac-tions involv-ing personal data. While it is important to record the trans-action, it is also important to relate the transaction to eye readable personal data so that a human judgerllent may be formed.
For example, a card user may have a frequently used card for recording transactions which he carries in his wallet, and a second duplicate card for backup in the event the Eirst card is - 9a ~

damaged, lost or stolen. The second duplicate card would be updated periodically~ It would be important for the user to know when the duplicate card was last updated so a judgement could be made whether further updating is needed. The user would also need to be able to distinguish the two cards. Micro-scopically visually readable information in the form of the date for the last transaction or update of information on a card would permit such distinguishing and judgement. The date is recorded onto the strip of optical storage medium when a trans-action or other update of information on the card is recorded.
Of course, while the microscopic visually readable information may be read by conventional optical means, a laser recording apparatus must be used to write the information on the data strip. A laser apparatus is illustrated in Figure 4, which illustrates the side view of the lengthwise dimension of the medium of Figure 1 consisting of a data strip capable of storing microscopic ~isually readable information on a card. The data strip portion 41 of the medium is usually received in a movable holder 42 which brings the strip into the trajectory of a laser beam. A laser light source 43, preferably a pulsed semi-conductor laser of infrared wavelength emits a beam 45 which passes through collimating allcl ~ocusing optics 47. The beam is -then directed to a f:irst servo controlled mirror 55 which is mounted for rotation along axis 57 in the direction indicated by arrows B. The 7~

purpose of the mirror 55 is to find the lateral edges of the data strip in a coarse mode of operation and then in a fine mode of operation identify character sites which exist predetermined distances from the edges.
From mirror 55, the beam is directed toward a mirror 61. This mirror is mounted for rotation at pivot 63. The purpose of mirror 55 is for fine control of motion of the beam along the length of the data strip.
Coarse control of the lengthwise portion of the data strip relative to the beam is achieved by motion of the movable holder 42. The position of the holder may be established by a linear motor adjusted by a closed loop position servo system of the type used in magnetic disk drives. Reference position information may be pre-recorded on the card so that position error signals may be generated and used as feedback in motor control. Upon writing one row of characters, the mirror 55 is slightly rotated. The motor moves holder 42 lengthwise so that the next row can be written, and so on.
When writing microscopic visually readable information, mirror 55 is used to identify character sites at predetermined distances from the edges. Mirror 57 moves the scanning beam lengthwise from character site to character site. Upon reading one row of character sites, mirror 55 is slightly rotated. Within a character site, mirrors 55 and 57 cooperate to move the beam in either a zig-zag pattern or a raster-like pattern. Laser spots are written at designated locations within a character site to form a character. When one character is written mirrors 55 and 57 move the beam to the next character site.
As light is scattered and reflected from spots in the laser recording material, the percentaye of re-flected light from the incident beam changes relative to surrounding material where no spots exist. The incident laser beam should deliver sufficient laser energy to the surface of the recording material to create spots, but should be lowered when reading so as not to cause disrup-tion of the surface during the reading mode. The wave length of the laser should be compatible with the recording material to achieve this purpose.
Differences in reflectivity between a spot and surrounding material may be detected by light detector 65 which may be a photodiode. Detector 65 confirms laser writing. Light is focused onto detector 65 by beam splitter 67 and focusing lens 69. Servo motors, not shown, control the positions of the mirrors and drive the mirrors in accord with instructions received from control circuits, as well as from feedback devices. The detector 65 produces electrical signals corresponding to spots.
Other optics, not shown, would be used to visually ob-serve the microscopically visibly readable information after data is written on the data strip. A jeweler's Loupe with a magnification of 20x would in general be adequate for reading the micrographic information recorded on the strip.

3~

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. An updatable micrographic data card comprising, a wallet size card having a strip of optical contrast laser recording material disposed thereon, a plurality of laser written micrographic characters disposed on said strip, each character formed of a matrix of laser recorded character spots, said micrographic characters being eye readable using at least 20 power magnification, but not eye readable using 5 power magnification or less.

2. The card of claim 1 wherein said character spots com-prise a group of laser written spots.

3. The card of claim 1 wherein said strip comprises pre-recorded micrographic characters and in-situ user written micro-graphic characters.

4. The card of claim 1 wherein said strip contains micro-graphic characters defining map features.

5. The card of claim 1 wherein said strip contains micro-graphic characters indicating a date of the most recent update of information on said card.

6. A method for recording information on a card compris-ing, disposing a strip of reflective direct-read-after-write laser recording material in a wallet-size card, recording micrographic indicia onto said strip, in-situ, by means of a laser, said indicia being microscopically visually readable with at least 10 power magnification, but not with 5 power magnification or less.

7. The method of claim 6 wherein said microscopically visually readable information is characters, each made up of a matrix of laser recorded character spots, each of said character spots being made up of at least one laser recorded spot.

8. The method of claim 6 wherein each of said character spots is made up of a group of laser spots.

9. The method of claim 6 further defined by prerecording micrographic indicia on said strip prior to in-situ recording.

10. The method of claim 6 wherein some of said indicia being recorded onto said strip indicate a date of said recording.

11. A system for recording information with a laser com-prising, a wallet-size card having a strip of optical contrast reflective direct read-after-write laser recording material thereon capable of in-situ laser recording of information thereon, said information being microscopically visually readable in-dicia, the strips adapted for laser recording of data, said indicia being microscopically visually readable with at least 10 power magnification, but not with a 5 power magnification or less, laser means having a beam disposed in laser writing relation with respect to said strip for writing thereon, light detector means disposed in reading relation to said strip for reading data, and means providing relative motion between the beam and the card for reading and writing data on the card.

12. The system of claim 11 wherein said microscopically visually readable information comprises characters, each made up of a matrix of individual laser recorded character spots, each of said character spots being made up of at least one laser spot.

13. The system of claim 11 wherein said strip contains micrographic characters defining map features.

14. The system of claim 11 wherein said strip comprises prerecorded micrographic characters and in-situ user written micrographic characters.

15. The system of claim 11 wherein some of said indicia are characters indicating a date of the most recent recording of information on said card.