EP1724729B1 - Device to measure width by difference of light attenuation - Google Patents

Description

Field of the art

The present invention relates to the field of mail processing. In particular, it relates to a device for measuring the width of an article of mail transported in a franking system.

Prior art

We already know, for example, by the document US 6,006,210 (Pitney Bowes ) a mail processing machine with a possibility of dimensional pricing and in which is made a true measurement of the width of the mail piece via diode strips. This apparently simple solution is, however, extremely expensive in practice because it assumes the use of several bars of significant length.

We still know by the patent US, 6,169,978 (Siemens ) a sophisticated system for determining the dimensions of the item being transported in order to assign a specific amount of postage.

Object and definition of the invention

The present invention thus aims to overcome the aforementioned drawbacks and to allow the measurement of the width L of a mail piece for postage purposes, without the need to resort to complex or expensive technical systems to perform this task. measured. An object of the invention is also to achieve this measurement on the fly, that is to say during the transport of the mail item through the franking system and without stopping it.

These objects are achieved according to the invention by means of a device for measuring the width L of a mail article in a mail processing machine in which the mailpieces are moved parallel to a delivery wall. in reference,

characterized in that it comprises a detection device made active when detecting the presence of a mail piece above a plurality of levers arranged in a fixed pitch determined perpendicularly to said reference wall, a device for emitting a light beam arranged in front of a first lever of said plurality, a device for receiving this light beam, a device for measuring the luminous intensity of the light beam received at said reception device and a processing device for calculating a determined number y of levers activated by the passage of said mail article from a comparison between this measurement of the received light intensity and an initial measurement of the light intensity of the light beam received at said receiving device in the absence of the passage of mail items above said plurality of levers.

Thus, a single transmission / reception assembly suffices for this structure formed around a plurality of mechanical levers to determine with sufficient precision the width of a mailpiece and, since its weight and possibly its length and thickness are known, calculate its postage amount.

It further comprises a device for determining the width L of a mail piece from said determined number y of levers activated by the passage of said mail item.

Preferably, said light intensity measuring device determines a ratio between the received light intensity and a predetermined initial light intensity.

Preferably, each lever is articulated on a common shaft mounted transversely to the direction of travel of the mail items and secured at both ends of a frame of the mail processing machine.

Preferably, each articulated lever has a first end portion intended to pass through an opening of a receiving plate of the mail processing machine and a second end portion intended to be in a rest position corresponding to an absence of passage. mail items above said plurality of levers, to be in the path of the light beam transmitted between said transmitting device and said receiving device.

Between said second end portion and said axis of rotation is hooked a first end of an elastic member whose other end is secured to the frame.

The present invention also relates to a method for measuring the width L of a mail piece in a mail processing machine in which the mail items are circulated parallel to a reference wall,
characterized in that the presence of a mail piece passing over a plurality of levers arranged at a fixed pitch determined perpendicularly to said reference wall is detected, in that it is detected at the level of a receiver receiving a light beam emitted by a transmitter arranged in line with a first lever of said plurality, in that the light intensity of the light beam received at said receiver is measured, and in that a determined number y of levers activated by the passage of said article of mail is calculated from a comparison between this measurement of the light intensity and an initial measurement of the luminous intensity of the light beam received at said receiver in the absence of passing mail items over said plurality of levers.

In an advantageous embodiment, said detection of the presence of a mail piece is performed by a continuous calculation of the light intensity received at said receiver, the variation of this intensity with respect to a reference intensity being characteristic of the presence of a mail item.

The width L of a mail item is then determined from said determined number of levers activated by the passage of said mail item.

The present invention also relates to any mail processing machine comprising a device for measuring the width L of a mailpiece as mentioned above.

Brief description of the drawings

• la figure 1 est une vue en perspective d'une machine de traitement de courrier intégrant un dispositif de mesure de la largeur d'un article de courrier selon l'invention ;
• la figure 2 illustre en détail le dispositif de mesure de la figure 1 ;
• les figures 3 et 4 sont des vues schématiques du dispositif de la figure 2 selon deux modes de réalisation différents respectivement dans une position de repos et dans une position d'activation ;
• la figure 5 est un schéma-bloc montrant les éléments principaux d'un exemple de circuit de traitement pouvant être incorporé dans le dispositif selon l'invention; et
• la figure 6 est un organigramme montrant un exemple de diverses étapes mises en oeuvre dans le procédé de mesure au vol de la largeur d'un article de courrier selon l'invention.

Other characteristics and advantages of the invention will emerge from the following description of particular embodiments, given by way of example, with reference to the appended drawings, in which:

• Figure 1 is a perspective view of a mail processing machine incorporating a device for measuring the width of a mail piece according to the invention;
• Figure 2 illustrates in detail the measuring device of Figure 1;
• Figures 3 and 4 are schematic views of the device of Figure 2 according to two different embodiments respectively in a rest position and in an activation position;
• Figure 5 is a block diagram showing the main elements of an exemplary processing circuit that can be incorporated in the device according to the invention; and
• Figure 6 is a flowchart showing an example of various steps implemented in the method of measuring the theft of the width of a mailpiece according to the invention.

Detailed description of preferred embodiments

The pricing of mail items is based on criteria of weight and size of the mail items (thickness, length of the envelope, width of the envelope). It is either to verify that the dimensions of the envelope are greater than thresholds, or to verify that the ratio between the length and the width of the envelope is between two limits (examples: 1.3 <R < 2.5 for USA, R <square root of 2 for Germany).

To automatically allocate the tariff adapted to each mail item in a non-homogeneous batch, it is available, upstream of the franking module of a mail processing machine, usually at the level of its feed module also called feeder, a device that measures the weight and dimensions of each envelope, and transmits this information to a fare calculator. The weight measurement can also be carried out separately by means of an independent weighing module arranged in the transport path of the envelopes, for example between the feeder and the franking module.

FIG. 1 illustrates a mail processing machine incorporating a device for measuring the width L of a mail article according to the invention. It typically includes downstream elements (according to the direction of movement of mail items through the machine): a supply module 10 provided with a receiving tray 12 on which are placed in a compact stack homogeneous or not (depending on whether the articles are of the same size or not ) mail items to be franked, drive rollers 14 and jogging means (advantageously lateral 16 and / or rear) of these mail items against a reference wall (also called fold-guide 18); a selection module (of which only the lower rollers 20 are shown) for extracting, one by one, from the bottom of the stack, the mail items to be franked; and a franking module 22 for printing a postal imprint on the selected mail article.

According to the invention, this machine further comprises a device 24 for measuring the width of each article of mail, advantageously arranged at the output of the selection module, and comprising a plurality of retractable members 26 regularly distributed along a line perpendicular to the referencing wall 18 and preferably across the width of the mail processing machine. Each retractable member is in the form of a lever 26 hinged to a common shaft 28 mounted transversely to the direction of travel of the mail items and secured at both ends of the frame of the mail processing machine, preferably the receiving tray of the feed module as shown in Figure 2.

Indeed, each articulated lever which may for example have a generally gooseneck shape has a first end portion, for example a triangular end 26A, intended to pass through an opening 12A of the receiving plate 12 and a second end portion 26B, for example example opposite to the first relative to the axis of rotation on the common shaft 28, intended in a rest position corresponding to an absence of mail item to intercept the light rays, that is to say to be on the path of the light rays transmitted between a light emitting device (transmitter 30A), typically a light emitting diode, and a receiving device 30B transmitted light rays.

Between this second end portion and the axis of rotation traversed by the common shaft is hooked a first end of a resilient member 32 whose other end is secured to the frame, for example by hooking on a support bar 34 mounted transversely in the chassis. This elastic element, a spring for example, is adjusted so as not to hinder the movement of mail items through the machine and thus to allow the lever 26 to both fade under the weight of a mail item during his passage to his level and return to his original position once this passage made.

The levers are spaced apart from each other by an identical fixed pitch determined so that it is possible to discriminate without possible failure the different postal formats addressed by the mail processing machine. If we refer to the postal standards in force in Europe, a spacing of 10 mm for example will allow to separate without difficulty formats C6, B6, E6 whose envelope widths are respectively 114 mm, 125 mm and 140 mm . The average width of a mail processing machine is currently 250 mm in Europe (to allow the passage of C4 format envelopes in landscape mode or C5 in portrait mode), it is envisaged in this example to have 25 levers across this machine. Of course, these numbers and widths are given for purely illustrative purposes and any other combination is obviously conceivable in particular according to the type of mail processed or the type of postal standards used, for example American.

Figure 3 shows schematically the arrangement of the levers 26 in their initial rest position in the absence of passage of mail items for a preferred embodiment of the invention. In this mode, the measurement of the width of a mail piece is based on the attenuation of the light intensity of the light emitted as a function of the medium traversed, the light propagating in a direct line between the emitter 30A and the 30B receiver.

Each lever is made of the same material having a damping coefficient determined μ ^cloth preferably very different from that of the air μ ^air and has a determined width d ^drap . The distance between two ^air levers is known and fixed during the construction of the machine according to the postal standards in force and the characteristics of the envelopes treated. A first lever 26p is arranged at the ^air distance from the reference wall 18. Similarly, the distances d ^E between the transmitter 30A and the first lever 26p are determined by construction and d ^R between a last lever 26d and the receiver 30B on the other hand.

If Ieo is the constant luminous intensity emitted by the transmitter, it is possible to determine the luminous intensity received at the receiver Ir0 after passing through all the levers at the determined number of x. We thus easily obtain the following equality: $$\mathrm{I}\mathrm{r}0=\mathrm{I}\mathrm{e}0*\exp \left[-{\mathrm{d}}^{\mathrm{E}}{\mathrm{\mu }}^{\mathrm{air}}\right]*\exp \left[-\mathrm{x}{\mathrm{d}}^{\mathrm{sheet}}{\mathrm{\mu }}^{\mathrm{sheet}}\right]*\exp \left[-\left(\mathrm{x}-1\right){\mathrm{d}}^{\mathrm{air}}{\mathrm{\mu }}^{\mathrm{air}}\right]*\exp \left[-{\mathrm{d}}^{\mathrm{R}}{\mathrm{\mu }}^{\mathrm{air}}\right]$$

An article of mail during its crossing of the mail processing machine necessarily passes at the level of the line of the levers and therefore activates during its passage a fixed number of y levers corresponding to its width. Figure 4 shows the arrangement of the levers opposite the transmitter and receiver after activation of some of them by a mail piece 36.

soit encore : $$\mathrm{I}\mathrm{r}\mathrm{y}=\mathrm{I}\mathrm{r}0\ast \exp \left[\mathrm{y}\left({\mathrm{\mu }}^{\mathrm{drap}}-{\mathrm{\mu }}^{\mathrm{air}}\right){\mathrm{d}}^{\mathrm{drap}}\right]$$

d'où l'on peut extraire le nombre y de leviers activés par l'article de courrier concerné : $$\mathrm{y}=\left[\ln \left(\mathrm{I}\mathrm{r}\mathrm{y}/\mathrm{I}\mathrm{r}0\right)\right]/\left[{\mathrm{d}}^{\mathrm{drap}}\left({\mathrm{\mu }}^{\mathrm{drap}}-{\mathrm{\mu }}^{\mathrm{air}}\right)\right]$$

The luminous intensity received at the receiver Iry after having crossed the only levers not activated is then given by the following equality: $$\mathrm{I}\mathrm{r}\mathrm{there}=\mathrm{I}\mathrm{e}\mathrm{o}*\exp \left[-{\mathrm{d}}^{\mathrm{E}}{\mathrm{\mu }}^{\mathrm{air}}\right]*\exp \left[-{\mathrm{d}}^{\mathrm{sheet}}{\mathrm{\mu }}^{\mathrm{sheet}}\left(\mathrm{x}-\mathrm{there}\right)\right]*\exp \left[-{\mathrm{d}}^{\mathrm{sheet}}{\mathrm{\mu }}^{\mathrm{air}}\mathrm{there}\right]*\exp \left[-{\mathrm{d}}^{\mathrm{air}}{\mathrm{\mu }}^{\mathrm{air}}\left(\mathrm{x}-1\right)\right]*\exp \left[-{\mathrm{d}}^{\mathrm{R}}{\mathrm{\mu }}^{\mathrm{air}}\right]$$

again: $$\mathrm{I}\mathrm{r}\mathrm{there}=\mathrm{I}\mathrm{r}0*\exp \left[\mathrm{there}\left({\mathrm{\mu }}^{\mathrm{sheet}}-{\mathrm{\mu }}^{\mathrm{air}}\right){\mathrm{d}}^{\mathrm{sheet}}\right]$$

from which we can extract the number y of levers activated by the article of mail concerned: $$\mathrm{there}=\left[\ln \left(\mathrm{I}\mathrm{r}\mathrm{there}/\mathrm{I}\mathrm{r}0\right)\right]/\left[{\mathrm{d}}^{\mathrm{sheet}}\left({\mathrm{\mu }}^{\mathrm{sheet}}-{\mathrm{\mu }}^{\mathrm{air}}\right)\right]$$

It can be noted that d ^E , d ^R and ^air are not included in the calculation of y which facilitates the determination of the width L of the mail piece (the dimensional tolerances on these values do not enter into effect. not in consideration for the result of the calculation) then given by the following inequality: $$\left(\mathrm{there}-2\right)*{\mathrm{d}}^{\mathrm{sheet}}+\left(\mathrm{there}-1\right)*{\mathrm{d}}^{\mathrm{air}}<\mathrm{The}\le \mathrm{there}*{\mathrm{d}}^{\mathrm{sheet}}+\left(\mathrm{there}+1\right)*{\mathrm{d}}^{\mathrm{air}}$$

We therefore know the width L of a mail item +/- 1 step (pas = d ^drap + ^air ).

Note also that the jogging of the mail article against the referencing wall 18 is not necessary, it is only sufficient that it scrolls perpendicularly to this wall.

An example of a processing circuit that can be implemented in the context of the measuring device according to the invention will be described with reference to FIG.

First, it's about detecting the presence of a mail item ready for postage. To do this, the device may comprise a device 40 for detecting the front of a mail article disposed on the transport path of the mail items, preferably slightly downstream of the line of levers, to ensure that during their activation. by a mail piece, a front part of it has already necessarily crossed this line and therefore necessarily activated some of the levers 26. Here activation means the state of the detection device when an article of mail passes to his neighborhood and, for example, in the case of an optical sensor, interrupts a light beam emitted by the sensor.

Note however that this device for detecting the presence of a mail piece 40 may also be of software type and consist, for example, in a continuous calculation of the light intensity received at the Iry receiver, the variation of this intensity. relative to the light intensity Ir0 received at the receiver in the absence of activation of the levers, effectively signifying an activation of the levers and therefore the presence of a mail piece at the entrance of the franking module.

When the sensor 40 is mechanical or optical type activation activates the transmitter 30A to which it is connected. This transmitter and the receiver 30B are furthermore connected to a light intensity measurement module 42 which will measure the luminous intensity received after this activation and determine the ratio between this received light intensity and an initial light intensity received in the absence of passage of mail item and determined beforehand (in practice during the construction of the machine or at the time of its calibration), intensity ratio from which, according to the aforementioned equality, a processing module 44, advantageously a microprocessor module, connected at the output of the measurement module will make it possible, among other things, to calculate the number y of activated levers and to deduce therefrom the width L of the article of mail. According to the envisaged hardware configuration, the receiver may or may not integrate the module for measuring the received luminous intensity and the determination of the ratio of the light intensities may be performed in a hardware manner at the level of this measurement or software module in the processing module. .

An example of data processing implemented in the aforementioned circuit will be explained with reference to the flowchart of FIG. 6.

A test 100 examines whether a mail item is present (because for example the sensor 40 is activated). If this is not the case, there is a return to the entry of this test 100. If this presence is confirmed, it proceeds to the step 102 of triggering the transmitter 30A (of course this step does not exist not when the presence detection is done continuously, the transmitter having been triggered well before). When a test 104 detects the reception of a light signal by the receiver 30B, successively passes to step 106 of measurement of the received luminous intensity, at step 108 of determining the ratio between this received intensity and a predetermined initial intensity, then at step 110 of determining the number y of activated levers and the value L of the mail item. The process can then be restarted for a new mail item with stopping or no 30A transmitter after each measurement depending on the nature of the device used for the presence detection.

In order to overcome possible errors of measurement or a slight biasing of the article of mail, it should be noted that this measurement can be repeated several times during the passage of the article of mail, an average of the results being then carried out after setting aside extreme values.

Claims (10)

1. A device for measuring the width L of a mail item on the fly in a mail handling machine in which mail items (36) are caused to move parallel to a reference wall (18);
   said device being characterised in that it comprises: a detector device (40) rendered active when the presence of a mail item (36) passing over a plurality of levers (26) is detected, said levers being disposed at a determined set pitch (d^drap+d^air) perpendicularly to said reference wall; an emitter device (30A) for emitting a light ray, which emitter device is disposed facing a first lever (26p) of said plurality; a receiver device (30B) for receiving said light ray; a measurement device (42) for measuring the light intensity of the light ray received at said receiver device; and a processor device (44) for computing a determined number y of levers activated by said mail item going past, on the basis of a comparison between said measurement of the received light intensity and an initial measurement of the light intensity of the light ray received at said receiver device when no mail items pass over said plurality of levers.
2. A device according to claim 1, characterised in that it further comprises a device (44) for determining the width L of a mail item on the basis of said determined number y of levers activated by said mail item going past.
3. A device according to claim 1 or claim 2, characterised in that said measurement device for measuring the light intensity determines a ratio between the received light intensity and a predetermined initial light intensity.
4. A device according to any one of claims 1 to 3, characterised in that each lever (26) is hinged to a common shaft (28) mounted transversely relative to the direction of movement of the mail items and secured at both of its ends to a frame of the mail handling machine.
5. A device according to claim 4, characterised in that each hinged lever has a first end portion designed to pass through an opening (12A) in a deck (12) of the mail handling machine, and a second end portion (26B) that, in a rest position corresponding to no mail items passing over said plurality of levers, is designed to find itself in the path of the light ray transmitted between said emitter device and said receiver device.
6. A device according to claim 5, characterised in that a first end (32A) of a resilient element (32) is fastened between said second end portion and said pivot axis, the other end (32B) of said resilient element being secured to the frame.
7. A method of measuring the width L of a mail item in a mail handling machine through which the mail items (36) are caused to travel parallel to a reference wall (18);
   said method being characterised in that the presence of a mail item passing over a plurality of levers (26) disposed at a determined set pitch (d^drap+d^air) perpendicularly to said reference wall is detected, in that reception of a light ray emitted by an emitter (30A) disposed facing a first lever (26p) of said plurality is detected at a receiver (30B), in that the light intensity of the light ray received is measured at said receiver, and in that a determined number y of levers activated by said mail item going past is computed on the basis of a comparison between said measurement of the light intensity and an initial measurement of the light intensity of the light ray received at said receiver device when no mail items pass over said plurality of levers.
8. A method according to claim 7, characterised in that said detection of the presence of a mail item is performed by continuously computing the light intensity received at said receiver, the variation of said intensity relative to a reference intensity being characteristic of the presence of a mail item.
9. A method according to claim 7, characterised in that the width L of a mail item is determined on the basis of said determined number y of levers activated by said mail item going past.
10. A mail handling machine including a measurement device for measuring the width L of a mail item on the fly according to any one of claims 1 to 6.

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