EP0984399A1 - Method for thermal printing - Google Patents

Abstract

The method uses a franking machine having a thermal impression head (80), in front of which a thermally sensitive recording support (86) is passed, predisposed on a predetermined part of the article (68) to be stamped in front of the impression element of the thermal impression head. The next step includes putting the recording support in intimate contact with the impression elements. The heating of the thermal impression elements is also selectively controlled for imprinting the postal imprint on the thermo-sensitive recording support.

Description

Technical area

The present invention relates to the field of machines for franking and more particularly to franking machines provided with a thermal printing device.

Prior art

Machines for franking articles of mail provided with a thermal printing device are well known. Print head of these machines conventionally comprise several printing elements thermal arranged in line transverse to the direction of movement mail items, the implementation of which is carried out by control means according to a heating cycle determined according to the postal imprint to be printed. To allow this printing, a ribbon of thermal transfer is interposed between these printing elements and the article of mail on which the postal imprint must be affixed.

Thermal transfer ribbon is mounted in a cartridge consumable which is debited as the articles progress of mail, which requires the use of means of training and means for synchronizing the rotation of the ribbon with the advance of the mail items. Given the monetary value attached to the postal imprint, these various means must be particularly reliable.

In practice, the use of such ribbons leads to many disadvantages, especially in terms of maintaining or training the ribbon, as illustrated for example by European patent applications n ° 0 494 942, n ° 0 550 227 and n ° 0 714 232 filed in the name of the Company Neopost Limited.

Object and definition of the invention

The object of the present invention is to overcome the numerous problems posed by the implementation of the thermal transfer ribbon in conventional franking machines by proposing a process thermal printing whose reliability is greatly improved. A goal of the invention is to be able to implement this method from a traditional postage meter. Another object of the invention is further ensure consistent print quality over time.

These objects are achieved by a thermal printing process of a postal imprint on a mail item using a mailing machine franking provided with a thermal printing head, process in which first passes a pre-deposited heat-sensitive recording medium on at least a specific part of the mail item to franking in front of thermal printing elements of the head thermal printing, then we put in intimate contact the support recording with the printing elements and then order selectively heating these thermal printing elements to print the postal imprint on this recording medium thermosensitive.

With this new cartridge-free process, all the problems related to the use of the thermal transfer cartridge are obviously deleted and the structure of the corresponding franking machine is all the more simplified while remaining conventional, in particular level of its printing resources.

Preferably, in order to improve the resistance to radiation and scratches on the heat-sensitive recording medium, it is further coated the mail item freed from a coating composition.

The present invention also relates to a franking machine comprising a thermal print head provided with a plurality selectively heatable thermal printing elements and means for pressing a support against the printing elements of heat-sensitive recording pre-deposited on at least part of the mail item to be franked, in order to print a postal imprint.

It is therefore advantageous that the franking machine further comprises a wetting / gluing module to stick the printed label on the postage item to be franked into the mailing machine separately preferably postage by a second transport route for articles of mail.

The invention also relates to any mail item, in particular an envelope, provided at least in part with a recording medium thermosensitive and intended for the implementation of the printing process thermal according to the invention.

Brief description of the drawings

• la figure 1 illustre schématiquement une machine à affranchir selon l'invention,
• la figure 2 représente un exemple de réalisation d'une enveloppe spécialement adaptée pour une utilisation avec la machine de la figure 1, et
• la figure 3 montre de façon schématique une machine à affranchir de l'art antérieur munie d'un dispositif d'impression thermique conventionnel.

Other characteristics and advantages will emerge more clearly from the following description, given by way of non-limiting illustration, with reference to the appended drawings, in which:

• FIG. 1 schematically illustrates a franking machine according to the invention,
• FIG. 2 represents an exemplary embodiment of an envelope specially adapted for use with the machine of FIG. 1, and
• Figure 3 shows schematically a franking machine of the prior art provided with a conventional thermal printing device.

Detailed description of a preferred embodiment

An example of a known type of franking machine provided with a conventional thermal printing device is illustrated in Figure 3.

Conventionally, such a machine comprises a chassis 10 articulated in two parts, an upper part and a lower part, between which is defined a horizontal path 12 for transporting mail items 14. Along this path are at least arranged at the input of the first rolls of transport or drive 16 and at the output of the second rolls of transport or drive 18. One or more sets of rollers intermediaries (not shown) can also be provided on this path between the input and output rollers. Each of these rolls is advantageously controlled from a common motor 20. To ensure the delivery of mail items from the entrance to the postage until it leaves, these motor rollers are of course associated to madly mounted counter rollers, respectively 22, 24.

On the way of transport of the articles of mail is arranged a thermal printing device 26 comprising on the one hand a cassette or removable cartridge 28 containing a thermal transfer ribbon 30 and on the other hand a thermal printing head 32. This head comprises conventionally several thermal printing elements arranged in line in a direction transverse to the direction of movement of the articles of mail 14. Push means 34 are provided under the print head to contact and ensure sufficient pressure of the ribbon thermal transfer on mail items when printing the postal imprint. These thrust means which are controlled in synchronization with printing can consist of a roller printing plate or a printing plate.

Conventionally, different means of command and control (not shown) are also provided to ensure inter alia training, maintenance under tension, guidance, detection and order thermal transfer ribbon before, after and during the impression.

The franking machine can also include a dispenser of labels 36 to allow the franking of packages or articles of mail which because of their thickness could not pass by the way of transport of mail items 12. A path 38 of transport of these labels 40 joined this way of transporting mail items to level of the thermal print head 32 upstream thereof.

The printing process implemented in the franking machine mentioned above uses the technology known as non heat transfer and which consists of depositing by means of a heat source (the head thermal printing 32) of hot-melt ink (present on a outer layer of thermal transfer ribbon 30) on a support synthetic or conventional paper (mail item 14 or label 40 which will then be stuck on the postage package).

According to the invention, an improved printing method is proposed by what the thermal transfer ribbon (as well as the cassette that incorporates it and all the organs necessary for its training, its guidance, etc.) is purely and simply deleted, the support to be printed being beforehand covered with a heat-sensitive recording material intended to cooperate with the thermal printing head 32 of the franking machine for by heating the postal imprint. The impression of this imprint mail is made directly on mail items which can be formed entirely of this heat-sensitive recording material or be simply fitted on a part of them, at the place of printing, of a film of this heat-sensitive recording material reactive to a heat source (see below).

The heat-sensitive recording material is composed conventionally of a chromogenic substance such as a leuco dye and a chromogenic developer such as a phenolic compound, which react with heat to form a color. Various examples of such materials are given in application EP 0 111 335 to not from Kanzaki Paper Manufacturing Company limited.

However, this material is relatively fragile, in particular from scratches and radiation. Also, it may be worth protecting it against these attacks by covering it with a coating intended to improve resistance. French patent application FR 2 575 199 illustrates a coating composition intended to improve resistance to oils, solvents and water from heat-sensitive recording paper. Of even, in the French patent application FR 2 731 181, these are the specific characteristics of the heat-sensitive material which are improved to give it better resistance to UV radiation.

FIG. 2 shows an exemplary embodiment of an envelope 50 used for implementing the method according to the invention. This envelope has an envelope body 52, for example made of paper conventional, on which is pre-deposited during its manufacture (by bonding or any other equivalent process), a longitudinal strip 54 of a length substantially equal to that of the envelope and a width sufficient for printing the postal imprint and possibly a slogan or logo, in the range of 25 to 35 millimeters. The band longitudinal comprises the aforementioned heat-sensitive recording material and optionally an additional coating composition such as that described in patent FR 2 575 199. Of course, the envelope can also be carried out entirely and not only in part from only heat-sensitive recording material and therefore not contain all of conventional paper.

Figure 1 shows a franking machine implementing the thermal printing process according to the invention. It has a chassis 60 articulated in two parts, an upper part 62 and a lower part 64, between which is defined a horizontal path 66 for transporting the articles of mail 68. Along this path are arranged several series of rollers transport including at least first drive rollers 70 in input and second drive rollers 72 at output. Each of these rollers is advantageously controlled from a common motor 74. To ensure the delivery of mail items, these motor rollers are of course associated with crazy mounted counter rollers, respectively 76, 78.

A thermal print head 80 conventionally comprising several thermal printing elements arranged in line in a direction transverse to the direction of movement of mail items is arranged on path 66 for transporting mail items. Of pressure means 82 are provided under the print head for placing in close contact with thermal printing elements and material thermosensitive recording.

The franking machine can also include a dispenser of labels 84 powered by labels 86 preferably self-adhesive formed with thermally sensitive recording material. A module of wetting / bonding 88 is advantageously provided downstream of the head to allow if necessary to moisten the labels and to press-on bonding (at eg exit rollers 72, 78) directly on the mail items introduced into the machine's entry preferably by a second transport route for these articles 90.

Likewise. when the envelope has not been previously coated of a coating composition, a coating module 92 can be provided at the exit of the franking machine to add this composition coating on the franked mail item in order to improve in particular its resistance to radiation and scratches.

Thus, with the present invention, almost without changing the structure overview of a conventional franking machine of the printing type thermal (the device for transporting mail items and the means remain the same), it is possible to use a new thermal printing process which completely overcomes numerous and particularly sensitive problems posed by the presence of the removable thermal transfer ribbon cartridge necessarily such a conventional machine.

Claims (5)

Method of thermally printing a postal imprint on a mail item by means of a franking machine provided with a head thermal printing (80) in which first of all a heat-sensitive recording medium (54) pre-deposited on at least one specified part of the mail item to be franked (68) before thermal printing elements of the thermal print head, then the recording medium is brought into intimate contact with the printing elements and then selectively controls the heating of these thermal printing elements to print the postal imprint on this thermosensitive recording medium. Thermal printing method according to claim 1, characterized in that the prepaid mail item is further coated with coating composition to improve resistance to radiation and scratches on the heat-sensitive recording medium. Franking machine comprising a thermal printing head (80) provided with a plurality of thermal printing elements which can be selectively heated and means (82) for pressing against the elements printing a heat-sensitive recording medium (54) pre-deposited on at least a specific part of the mail item to be franked (68), to print a postal imprint. Franking machine according to claim 3, characterized in that it further comprises a coating module (92) for coating the article of mail freed from a coating composition in order to improve the radiation and scratch resistance of the recording medium thermosensitive. Mail item, such as an envelope, provided at least in part a thermosensitive recording medium intended for the implementation of the thermal printing process according to claim 1.

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