FR2600590A1 - Method for forming characters engraved in relief on a portable memory support - Google Patents

Abstract

The invention relates to a method for forming characters engraved in relief 14 on a memory support 1, for example an integrated circuit board, which involves discharging a binding material onto the memory support with the aid of a character-tracing means comprising a means 11 for discharging the binding material 15 at constant pressure, a means 17 capable of displacing the discharge means in the X and Y directions, and a means for controlling the two preceding means.

Description

 The present invention relates to a method for forming characters engraved in relief on a portable memory medium, for example an integrated circuit card.

 In a portable memory medium, for example an integrated circuit card as shown in FIGS. 1A and 1B, a card substrate 1 made of pocket-size plastic material is provided with a built-in semiconductor chip (not shown) comprising a microcomputer and a memory unit; and several external terminals 2 formed on the surface of the card substrate 1 so as to be able to be connected to external devices such as a data reading or reading device, a data writing or recording device , etc. and a supply voltage. In addition, a magnetic strip 3 is formed on the surface of the card substrate 1 so that it can be used at the same time, like a conventional magnetic card. The dimensions of the integrated circuit card substrate 1 obey the standards defined by the international Standard Organization, the thickness being for example 0.76 mm.

In the above-mentioned integrated circuit cards, certain characters embossed in relief 4, which indicate
The name of the owner by #example, are usually formed on the card 1 so as to allow the realization of a transaction slip.

 FIG. 2 shows a method of the prior art for forming characters embossed in relief on the integrated circuit card substrate 1, by which a desired embossed character 4 can be formed on the surface of the card substrate 1 by pressing a male mold 5 against the back of the substrate 1 in cooperation with a female mold 6 placed on its upper surface.

 Recently, integrated circuit cards have been developed which have a keyboard 7 and a liquid crystal display unit 8 on the back of the card, as shown in Figure 3, so that 'It is possible to manually operate the internal microcomputer without the aid of external devices, for example by displaying data stored in the memory unit.

 In the prior art method of forming embossed characters on an integrated circuit card, however, there is a problem that it is impossible to form the characters on the surface of the integrated circuit card. above mentioned which is provided with the keyboard 7 and the display unit 8 by pressing a male mold 5 against the back of the card, since the keyboard 7 and the display unit 8 would be damaged by the mold 5 .

 Faced with such problems, it is the main object of the invention to provide a method of forming characters engraved in relief on a portable memory medium without applying mechanical force to the memory medium.

 To achieve the aim stated above, the method for forming characters engraved in relief on a portable memory medium according to the invention comprises the following operations: (a) discharging a binding agent on the memory medium via means describing characters; and (b) curing the discharged binding agent by curing means.

 The character describing means includes an agent dispenser for intermittently discharging the binding agent under constant pressure; a position control mechanism for moving the bonding agent discharge means in a controlled manner and a pressure control device for controlling the dispenser and the mechanism by means of pressure.

 The binding agent is a resin hardening under the action of ultraviolet radiation or a thermosetting resin.

 To make the height of the characters engraved in relief uniform, the distributor stops discharging the binding agent in positions where at least two lines of a letter intersect or overlap each other. In addition, it is preferable to form a layer of reinforcing binding agent beforehand before discharging the agent on the storage medium and simultaneously hardening the two agents.

The following description, intended to illustrate the invention, aims to give a better understanding of its characteristics and advantages; it is based on the accompanying drawings, among which
FIG. 1A is a perspective view showing an integrated circuit card constituting an example of a memory medium;
Figure 18 is a side view showing the integrated circuit card shown in Figure 1A;
FIG. 2 is a representation intended to help explain the process for forming a character engraved in relief on the integrated circuit card according to the prior art;
Figure 3 is a perspective view showing another integrated circuit card with a keyboard and a display unit;
FIG. 4 is a representation containing a block diagram which helps to explain an embodiment of the method for forming characters engraved in relief on a portable memory medium according to the invention;
FIG. 5 is an enlarged cross-section view showing an embossed character which has been formed by the method of the invention;
Figures 6A, 68 and 6C are representations which help to explain the process of writing certain letters using a dispenser;
Figures 7A and 78 are perspective views showing a device for applying a reinforcing binder which is used in the method of the invention; and
FIGS. 8A, 8B and 8C are perspective views which help to explain another embodiment of the method of the invention, by which characters embossed in relief of binder are hardened using another ultraviolet light source.

 In Figure 4, there is shown an apparatus for forming on a portable memory medium characters engraved in relief, according to the method of the invention.

 The apparatus is a distributor 11 of binding agent provided with a needle 11a used to discharge a binding agent onto a card substrate 1. This distributor 1 is connected to a container 15 of binding agent under pressure by means of 'a pipe 12 for binding agent and a # 13 pressurization pipe # n. The container 15 contains a binding agent which can be cured by ultraviolet rays. The binding agent inside the container 15 is supplied to the dispenser 11 under constant pressure through the pipe 12 so that a predetermined amount of the agent can be discharged via the needle 11a onto the On the other hand, the discharge or absence of discharge of the agent (pressure of the distributor) is controlled by applying pressure from the container 15 to the distributor II via the pressurizing pipe 13. The pressure of the binding agent and the pressure of the distributor are both controlled by a pressure control device 16 via the container 15 of the binding agent.

 The distributor 11 is supported by a control arm 18 that can be moved in three directions by a position control mechanism 17. The dispenser 11 moves in the X and Y directions so as to move the needle 11a of the dispenser according to predetermined diagrams on the card substrate 1 in order to describe certain letters thereon. In addition, the distributor 11 moves slightly upwards (in the direction Z) after the formation of a letter and slightly downwards (in the direction Z) before the formation of a letter. The position control mechanism 17 is also actuated by control signals produced in the pressure control device 16.

Reference number 19 designates a source of ultraviolet radiation. The ultraviolet rays emitted by the source 19 are guided via an optical fiber 21 to the binding agent which has been discharged on the card substrate 1 in order to harden
the binding agent discharged.

 We will now describe the operation of the device shown in FIG. 4.

 A card substrate 1 is fixed at a predetermined position under the distributor 11. To form any desired character on the card substrate 1, the distributor 11 is moved in any direction by the position control mechanism 17; a binding agent delivered from the container 15 of agent under constant pressure is discharged via the needle 11a of the distributor under control of the pressure applied from the pressure control device 16 via the container 15 of the 'agent; and, simultaneously, the discharged binding agent is irradiated by the ultraviolet rays emitted from the ultraviolet light source 9 on the card substrate 1, which has the effect of making it harden and transforming it into characters engraved in relief such as shown in Figure 5.

 The above-mentioned binding agent is a urethane-acrylic resin of the type curing under the effect of ultraviolet rays, which has instant curing properties. The physical properties (hardness, chemical resistance, etc.) of the binding agent must be equivalent to that of the card substrate 1, which is made of polyvinyl chloride for example.

Thus, the characters engraved in relief thus formed according to the method of the invention are equivalent to those formed by the molds of the prior art (shown in Figure 2) as regards the resistance as well as the appearance.

 In addition, other thermosetting resins can be used in place of the resin curing under the action of ultraviolet rays, provided that the curing temperature is not high enough to exert a harmful thermal influence on the substrate. menu. In practice, since polyvinyl chloride (the card substrate) hardens at around 140 C, an epoxy-based bonding agent with a thermosetting temperature below 100 C will preferably be used as a bonding agent to form engraved characters in relief.

 In the above-mentioned method, the card substrate 1 is fixed and the dispenser 11 moves under the action of the position control mechanism 17. However, it is also possible to draw desired characters on the card substrate 1 using a binding agent by making the dispenser 11 fixed and by moving the card substrate 1 in an adjusted manner in all directions.

 Figures 6A, 6B and 6C show how to write characters on the card substrate 1 using the dispenser 11, knowing that the discharged binder does not overlap with itself.

 In more detail, the number 4 is plotted in three lines, as shown in Figure 6A. The first line begins at a and ends at b after passing through an elbow c; the second line, which is short, is designated by d and leaves a space A between b and d; the third line begins at e and ends at f after passing through space A. Thus, the liaison agent is not discharged at the level of spaces to remove any overlapping of the lines and give the character height uniform.

 The number 0 is drawn in a single stroke and leaves a space B between the start a and the end h. Similarly, we can draw the letter A in three lines, which leave spaces C.

 The space A, B or C between two lines must be determined taking into account various factors such as the speed of movement of the needle 11a, the viscosity of the binding agent, the diameter of the needle 11a (for example 0.25 mm), the width of the line (for example 0.5 mm), etc., so that the discharged binding agent comes into contact with the adjacent line and so that a uniform and constant height can be maintained for the character engraved in relief. If the space is too wide, the embossed character will be concave, while if it is too narrow, the character will be convex.

 The size, shape and length of the strokes of each letter as well as the spaces left between two strokes of each letter are parameters which are all controlled by the pressure control device-16 used to actuate the position control mechanism 17 and simultaneously applying the agent discharge pressure to the distributor 11 via the agent container 15, according to a program stored in the control device 16.

 It is preferable to apply a reinforcing binding agent beforehand on the areas where embossed characters are to be formed, so as to increase the bond strength of the engraved characters, by means of an apparatus as shown in the figures. 7A and 7B. This device comprises a screen screen 23 and a cylinder 25 to which a reinforcing binding agent is applied. The screen printing screen has certain openings at positions which correspond to certain areas of the card substrate 1 where characters engraved in relief must be formed.

 In use, the screen screen 23 is placed on a card substrate 1 by establishing a predetermined geometric relationship between them, then the roll on which the reinforcing binder has been applied is rolled on the screen screen 23 applying the reinforcing binding agent only to the areas ai, a2 and a3 of the card substrate 1.

 This reinforcing binding agent has the same chemical properties as the binding agent curing under the effect of ultraviolet radiation which is discharged by the distributor 11.

In other words, this reinforcing binding agent has an affinity for the agent intended to form the characters engraved in relief. In addition, it is also preferable to adopt a resin hardening under the action of ultraviolet radiation for the reinforcing binder.

 In addition, the reinforcing binding agent can be applied to the entire card substrate 1, without limiting the application to the areas ai, a2 and a3. In addition, it is also possible to use a screen through which the binding agent can pass without the need to form openings.

 When the reinforcing binding agent has previously been deposited under the characters engraved in relief, it is possible to markedly increase the bonding resistance of the characters engraved in relief with the card substrate, as well as their resistance to 'tearing.

 FIGS. 8A, 8B and 8C show another method according to the invention, in which the reinforcing binding agent is previously formed under the characters engraved in relief.

First, a reinforcing binding agent, of the type hardening under the action of ultraviolet radiation, is applied to the areas ai, a2 and a3 where the characters engraved in relief must be formed by means of the screen printing screen 23 and the cylinder 25 described in Figure 8A; secondly, the card substrate 1 is placed under the dispenser II so as to form certain characters 14 on the areas ai, a2 and a3 using the binding agent, as described in FIG. 8B; lastly, the card substrate 1 is irradiated using ultraviolet rays emitted from other sources of ultraviolet light in order to make the binding agent for characters embossed in relief even more harden together with the agent reinforcing binder, as depicted in Figure 8C. In the curing process, it is preferable to irradiate the card substrate 1 with ultraviolet rays from the light source 20, even after the binder has been hardened by the light from the source 19 provided for the distributor 11, so as to harden even more stable the characters connected in relief.

 Using the method according to the invention, it is possible to form characters engraved in relief on the surface of any card substrate, without applying any mechanical or thermal shock to the substrate. In addition, since the characters engraved in relief can be given a uniform height, there appears to be no problem at the time of insertion into other equipment (such as a read-write device), while, moreover, the card substrate can meet the requirements for ISO standards.

 Of course, those skilled in the art will be able to imagine, from the method whose description has just been given by way of illustration only and in no way limitative, various variants and modifications not departing from the scope of the invention. .

Claims (11)

RESELL iCATi0! \ TS 1. A method for forming characters engraved in relief (14) on a portable memory medium (1), characterized in that it comprises the following operations  (a) placing a binder material on the memory medium to form characters; and  (b) hardening the binder material. 2. Method for forming characters engraved in relief (14) on a portable memory medium (1), characterized in that it comprises the following operations  (a) discharging a binder material onto the memory medium by means (11) for tracing characters; and  (b) curing the discharged binder material using a means (19) for curing the discharged binder material. 3. Method according to claim 2, characterized in that said character tracing means comprises  (a) means (11) for discharging the binder material (15) at constant pressure intermittently in response to first pressure signals;  (b) means (17) for moving said binder material discharge means in the X and Y directions in response to second pressure signals; and  (c) means (16) for producing the first pressure signals to said means for discharging binder material and the second pressure signals to the means for moving in the directions X, Y in a combined manner in order to discharge the binding material on the memory medium in configurations in the form of characters. 4. Method according to claim 2, characterized in that the binder material is a resin hardening under the effect of ultraviolet rays and in that the hardening means is a source of ultraviolet light. 5. Method according to claim 4, characterized in that the portable memory medium is made of polyvinyl chloride, and in that said binder material is a resin based on urethane-acrylic. 6. Method according to claim 2, characterized in that the binder material is a thermosetting resin and the curing means is a light source. 7. Method according to claim 6, characterized in that the binder material is an epoxy-based resin. 8. Method according to claim 2, characterized in that said means for discharging binder material stops discharging the binder material in positions (A, B, C) where at least two lines of a letter intersect or overlap, to form an embossed character of uniform height.  9. Method according to claim 2, characterized in that it further comprises the following operations  (a) applying reinforcing material over at least one area at which embossed characters are to be formed, before discharging the binding material, intended to form the characters, onto the portable memory medium; and  (b) curing the reinforcing material after discharging the character-forming binder material onto the reinforcing binder material, both together. 10. Method according to claim 9, characterized in that the reinforcing material is the same as the binding material for character formation. 11. Method according to claim 2, characterized in that said portable memory medium is an integrated circuit card substrate.