FR2717938A1 - Portable reader to decode and display data from bar code label - Google Patents

Abstract

The reader and price display is inside a compact box (1,2) containing a memory storing data to be displayed on corresponding labels and a circuit to control writing of the data. A bar code reader (4) on one face of the box allows a bar code to be read into the unit. The bar code information is used to access the memory to determine what should be written on the product label. The box also has a screen (3) to display data to be written, and on the opposite face a head (6) to write data on a label. A mechanism (8) displaces the label relative to the write head. The write head makes use of one of several multi-point writing techniques. The label is driven by a toothed wheel.

Description

 The present invention relates to display devices and relates more particularly to devices for displaying product prices in points of sale of the supermarket type which often require rapid modifications from a management unit.

 An important problem in supermarkets or points of sale where there are many products is to be able to display or modify the prices of these products without more or less manual writing work and, during promotional campaigns, to be able to change very quickly the prices on the labels of a number of products.

 Different systems have been proposed and good used in the past.

 We know for example liquid crystal diode labels provided with a small microprocessor receiving price display indications and a product name by a chain wiring constituted by a bus transmitting the power supply power of the microprocessor and the signals from a central management unit.

 However, such complex wiring of all rows of product supports, such as gondolas and the like and the high price of labels have discouraged users.

 The invention aims to remedy the drawbacks of known systems by creating a display device on a cheap, modifiable label, requiring no wiring from one label to another, which is also of very low cost. modest and which allows rapid intervention.

 It therefore relates to a portable device for displaying information on a label, characterized in that it comprises a box containing a memory for storing data to be displayed on corresponding labels and means for controlling writing said data on the labels, the housing having on one of its faces a screen for displaying the data to be written and on an opposite face, a head for writing data on the label, and means for moving at least an element of writing of the head compared to the label.

The invention will be better understood on reading the description which follows, given solely by way of example and made with reference to the accompanying drawings, in which
- Fig.1 is a schematic perspective view of a portable device for displaying information on labels according to the invention;
- Fig.2 is a partial perspective view of a magnetic writing head according to a first embodiment of the portable display device of Fiv.1;
- Fig.3 is a perspective view of a magnetic label on which inscriptions can be made using the portable device shown in
Fig. 1 and 2;
- Fig.4 is a vertical sectional view of the label of Fig.3;
- Fig.5 is a horizontal sectional view of a magnetic label of the liquid crystal type usable with the portable device according to the invention;
- Fig.6 is a partial front view of another embodiment of the writing head of the portable device of Fig.1;
- Fig.7 is a schematic sectional view of the portable device of Fig.l;
- Fig.8 is a view similar to Fig.7 of another embodiment of the portable device according to the invention;
- Fig.9 is a schematic view showing the layout of the electrical components of the portable device according to the invention; and
- Fig.10 is a block diagram showing a portable device according to the invention, and a management computer provided with means of remote communication.

 The portable display device according to the invention shown in FIG. 1, comprises a housing 1 provided with a handle 2.

 The box 1 of generally parallelepiped shape has on one of its faces a screen 3 for displaying data relating to the labels concerned by the display to be made, and a bar code reader 4. On its face opposite to that carrying the screen 3 and the bar code reader 4, the box comprises in the present embodiment a magnetic head 6 for writing data on the labels, which, as shown in FIG. 2, has a rounded shape, curved towards the outside of the case to facilitate writing by pressing on a label.

 The head 6 has a slot 7 for emitting a magnetic field corresponding to the information to be transmitted to a label to be printed.

 On either side of this slot, toothed pinions 8 are arranged intended to cooperate with tracks provided on the edges of the labels in a manner which will be described later.

 The display device also comprises means for storing data to be displayed as well as reading and writing control means which will be described in detail with reference to FIGS. 7 to 9.

 In Figure 3, there is shown in perspective, a first embodiment of label usable with the portable display device according to the invention.

 The label 10 shown in this figure comprises a support 11 of generally rectangular shape made of a non-magnetic material, for example plastic or a Zamak or other light alloy, having on its two opposite horizontal edges 12, teeth 13 of shape and dimensions complementary to the teeth of the sprockets of the writing head in order to ensure regular movement of the writing head relative to the label when the display device of FIG. 1 is applied against that -this to ensure data writing.

 As can be seen more clearly in FIG. 4, the label 10 comprises at mid-distance between its horizontal edges 12, a wall or rib 14 formed integrally with the support or frame 10 and delimiting therein two zones of display 15, 16 in which are arranged corresponding magnetic powders 17, 18 of two different colors, for example one red, the other black.

 The label is completed by a transparent or translucent sheet 20 of Mylar for example, glued to the support and coated with a magnetic coating, covering the two zones or compartments containing the powders 17,18.

 Alternatively, the label may have only one compartment with a powder of one color.

 The label shown in section in FIG. 5 is of the LCD liquid crystal type.

 It comprises a support 22 provided on two of its opposite sides with re-entrant flanges 23 intended to cooperate with ribs 24 of a rail 25 fixed on a display not shown.

 On this support 22 is arranged a solid light conductor 26 made of glass or polycarbonate. On the light conductor 26 is placed a substrate 27 which in turn supports oriented crystals 28 of the liquid crystal type.

 A transparent window or wall 29 maintains the crystals 28 on their substrate.

 The presence of the light conductor 26 allows the label to be illuminated from the inside, which increases the contrast of the display.

 Such a label may also include flanges provided with teeth corresponding to the teeth of the pinions of a magnetic writing head similar to that of the portable display device of FIG. 1.

 It can also receive display data from a display device comprising a writing head with control X, Y such as that shown in FIG. 6.

 The writing head shown in this figure mainly comprises a writing element 30 movable in two directions X, Y on a surface 31 corresponding to the useful dimension of a label, by means of a light mechanism comprising two electric motors stepping drive 32, 33 cooperating with endless belts 34.35 for the motor 33 for driving the writing member in the horizontal direction X and 36.37 for the motor 32 for driving the writing element in the vertical direction Y. The belts 34 to 37 pass over pulleys 39, two of which are driven by the motors 32,33.

 The writing element 30 is mounted on one of two crossed rods 40, 41 slidably mounted relative to one another and linked respectively to the endless belts 34, 35 and 36, 37.

 The stepping motors 32 and 33 are of course controlled by the control means which will be described hereinafter in particular with reference to FIG. 9.

 The writing element 30 is in the present example a magnetic element.

 However, this writing element can also consist of a point intended to be moved in contact with the display surface of a label which then consists of a double film enclosing a product which, under the action of the tip pressing locally the films one on the other, drives out the product and generates on the visible side of the label the desired messages.

 The erasure of the messages can then be obtained by magnetic separation of the two films from the display surface of the label.

 In Figure 7, there is shown in section the portable information display device according to the invention.

 The housing 1 and the handle 2 of this device together define a volume 45 containing a printed circuit board 46 which carries a certain number of components and which is connected at its end contained in the handle 2 to a rechargeable supply battery 47 provided a socket 48 for connection to a battery charger.

At its end opposite to the battery 47, the printed circuit board 46 carries a socket 49 of the type
RS 232 for example, intended to ensure the communication of the display device with a central computer.

 The printed circuit board 46 carries on each of its two opposite faces sockets 50.51 for connection with corresponding layers of wires 52.53 connected respectively to a bar code reading module 4 and to a magnetic writing head 6 The sockets 51 and 52 are connected via the printed conductors of the wafer 46 to suitable components in a manner which will be described below with reference to FIG. 9.

 In the embodiment of FIG. 7, the magnetic printing head 6 comprises toothed pinions 8 intended to cooperate as indicated with reference to FIG. 3 with corresponding toothed tracks 13 of the labels to be printed.

 The pinions 8 are connected to each other by an axis 55 and to one of these pinions is associated a magnetic sensor 56 of the position of the pinion teeth, this sensor being connected to a circuit 57 for controlling the element. 58 written between the pinions 8 and projecting from the wall of the housing 1 of the device.

 The writing head 58 is advantageously a multipoint head in line.

 The display device further comprises a control screen such as the screen 3 shown in FIG. 1 also connected by a sheet of wire 59 to the appropriate components of the printed circuit board 46.

 The device finally comprises a keyboard 60 comprising a write key 61, a read key 62 and an erase key 63. The keyboard 60 is connected by a sheet of wires 64 to a socket 65 for connection to the printed circuit 46 .

The portable display device represented in FIG. 8 is in all respects similar to that which has just been described with reference to FIG. 7 except for the fact that it comprises a writing head 66 comprising an element d single point writing 30 whose displacements along a surface corresponding to that of a label are controlled in two perpendicular directions X and
Y by respective stepping motors 33, 32.

 The writing element 30 projects relative to the outside wall of the device housing.

 In addition, an interlocking frame 67, for example molded with the part of the housing 1 carrying the writing head, makes it possible to position the writing head relative to the label by "covering" the upper edges. and lateral thereof which constitute complementary positioning means of the aforementioned frame.

 In Figure 9, there is shown the block diagram of the portable display device according to the invention.

 The printed circuit board 46 has a shape corresponding to the interior housing 45 defined by the housing 1 and the handle 2 of the device. At its end engaged in the handle, the printed circuit board is connected to the supply battery 47, provided with a socket 48 intended for recharging it.

At its opposite end, the plate 46 is connected to the socket 49 of RS 232 type connected to a microcontroller 68 for example of the 80 C52 type from the company
INTEL which is associated with a RAM memory block 68a for storing data relating to the products whose labels must be registered or modified.

 The microcontroller 68 is connected to the screen 3 and to the keyboard 60. It is also connected via conductors 69, 70 to circuits 71, 72 for controlling the writing and reading modules which are ASIC type circuits, ie circuits with high integration.

 Of course, conductors 74 connect all of the circuits carried by the printed circuit board 46 to the rechargeable battery 47.

 One also sees in FIG. 9, one of the sockets 50 for connection with the bar code reading module 4 represented in FIG. 7.

 In FIG. 10 is shown a portable display device 75 of construction similar to that of the devices which have just been described with reference to FIGS. 1 to 9, but which also comprises transmission and reception means connected to the device microcontroller and an antenna 76 for communication with a corresponding antenna 77 of a transceiver 78 connected to a central management computer 79 provided with a monitor 80.

 It can therefore be seen that thanks to such an arrangement, it is possible to load data relating to prices to be modified on the product displays, remotely without the operator of the portable display device being required. connect the device to the central computer.

 The operation of the portable display device which has just been described is as follows.

 The recording of the price and name data of a product on a label is ensured by passing near the face of the label such as the label 10 of FIG. 4, the magnetic head 6 of the device.

This magnetic head is composed as indicated in particular in FIG. 7, of magnetization elements arranged in line, for example of 48 or 64 sources of magnetization, spaced by 0.5 mm and inducing points from 0.3 to 0.8 mm in diameter.

 Since a movement of the hand of the operator who holds the portable device cannot guarantee a sufficiently regular movement, to inscribe characters of regular shape, the teeth of the pinions 8 (Figures 2 and 7) cooperate with the teeth 13 parallel tracks 12 of the label, so that the magnetic sensor 56 associated with one of the pinions 8 as shown in FIG. 7, can trigger, at determined angular intervals, the printing of useful data on the label at desired locations thereof.

 When the hand holding the portable display device applies the magnetic head 6 to the label at one of its ends, the pinion (s) 8 mesh with the corresponding teeth of the tracks 12 and the scanning movement of the the label can be made at a variable speed, because the pinions, by turning on their axis, give an angular scanning indexing by one or more "tops" obtained by a reference not shown carried by one of the pinions 8 which turns in front of the magnetic sensor 56 so as to measure the value of the angular displacement and the direction thereof.

 It is thus possible to obtain a generation of characters as in an on-line multipoint head printer.

 Of course, the magnetic sensor 56 can optionally be replaced by an opto-electronic sensor.

 The registration points are activated by synchronization with the pinion axis 8 and distributed by the microcontroller 68 (Fig. 9) incorporated in the portable device and intended to manage the bar code reading and magnetic writing signals by the writing head 6.

 In the case of a portable display device equipped with means for transmitting and receiving data, the microcontroller also manages the transmission and reception of herzian signals for communication with the central computer 79.

 The powder type labels such as those represented in FIGS. 3 and 4 are of very similar construction to that of the tables with magnetic inscription by magnetic powder fixed on a film coated with a magnetic layer of opposite direction of magnetization and this by action of a magnetic writing head which increases locally and in the suitable direction, that is to say in the direction of attraction of the powder, the magnetic field in the magnetic layer, which brings about the attraction and the fixation powder.

 To ensure the erasure of a label of this type, it is sufficient to vigorously shake the assembly or else to pass over the label the portable device whose print head delivers an induction of direction opposite to the direction used for the writing.

 The coercive field transmitted by the head is strong enough (a few oersteds) to make it difficult for the inscription to shake off. This is advantageous when it is important to combat malevolence.

 In such conditions, it is necessary to carry out an induction sweep in the opposite direction to that of the induction used for registration.

 In order to emit inductive erasure signals, it suffices to tilt the label horizontally and to sweep it with the magnetic inscription head by meshing pinions 8 on the toothed edges 12 (FIG. 3).

 The microcontroller 68 described with reference to FIG. 9, includes a memory making it possible to easily store data corresponding to several hundred products.

 Indeed, it takes about 500 bytes for the data corresponding to a product (10 bytes for the digits, plus 20 bytes of character, plus 30 bytes of barcode). Therefore, a thousand products represent only 60 K bytes, which is a small memory capacity for the current possibilities.

 We can even consider that storing data relating to 40,000 products in a hypermarket, would only take 2.4 megabytes, which fits on three "Sim bars of 8 megabits or 4 RAM boxes of 4 megabits which can easily be contained in the housing of the portable display device according to the invention.

 Each operator can therefore charge their portable device in the space of a minute with the data of 2 or 300 products intended for promotion by price reduction for example and then go to the shelves where these products are found after finding the list of products to modify which are displayed by scanning on the liquid crystal screen 3 of their portable device, enter the product whose price is to be modified, read the corresponding bar code, write on the associated label, check by display on the liquid crystal screen 3 and go to the next product. Such an operation takes around 2 thousandths of an hour on average for fairly close products. A set of 200 products can therefore be processed by four operators in ten minutes, which is fast enough for most promotional applications.

 It should be noted that the portable device may possibly include a voice transceiver of the “walkie talkie n” type for the purpose of exchanging instructions between the operator and the central management organization.

 In the wireless version of the portable device described with reference to FIG. 10, such an arrangement requires having a switch between the voice transceiver and that intended for the transmission of data between the device. display and central computer.

 In the variant of the portable display device comprising a writing head with a single writing element whose movements are controlled in X and Y, (FIG. 6), the operation of the device is the same except for the fact that the printing of the labels is obtained by controlling the movements of the writing element 30 in the X and Y coordinates without having to move the portable display device relative to the label during the write operations.

 The portable display device which has just been described can also be used for printing magnetic labels of the liquid crystal type, such as that shown in FIG. 5.

 The liquid crystals 28 form small inclusions in the polymer matrix of the substrate 27 which carry them and which is for example a copolymer with side chains of the polysiloxane type with a mesogenic group and a chiral group. The effects of an electric field on films comprising a nematic liquid crystal are known and are also used for display.

However, a good contrast can be obtained by using a fairly strong magnetic field taking into account the type of liquid crystal, which is physically possible with a writing tip having an area of the order of mm2.

 The characters written on such a label are erased by an X, Y command writing mechanism, for example by scanning the space of the label in the X direction and advancing each step in the direction Y.

 According to another variant of the invention, writing on a liquid crystal label can be carried out by operating by thermo-optical effect. For this purpose, a label cell is used containing a dielectric type A smectic material and of homeotropic structure.

 The writing head is then produced according to the same principles as above for magnetic writing, that is to say that it comprises, in place of the magnetic writing head, a laser emission diode or aligned diodes depending on the type of head envisaged.

 The laser beam of the diode creates local heating in the originally transparent label cell and induces a disorganization of the structure of the label's liquid crystals by passing to the isotropic state. During cooling, the smectic phase reappears with a different, stable structure, thus ensuring the memorization of the inscription and therefore the display of the characters induced by the laser writing head.

 The total or partial erasure is then ensured by application of an electric field, that is to say by energizing the label cell by means of the portable display device which is applied to the periphery of the label. so as to ensure an electrical contact putting it under a low voltage, of 12 volts for example.

Claims (18)

 1. Portable device for displaying information on a label (10), characterized in that it comprises a housing (1,2) containing a memory (68a) for storing data to be displayed on corresponding labels and means (68, 71, 72) for controlling the writing of said data on the labels, the housing having on one of its faces a screen (3) for displaying the data to be written and on an opposite face, a head (6) for writing data on the label, and means (8; 32,33,34,35,36,37,40,41) for moving at least one writing element of the head relative to the 'label.  2. portable display device according to claim 1, characterized in that the writing head (6) comprises a multi-point writing element (58) and toothed pinions (8) carried by the displacement housing (1) of the writing element (58) relative to the label which has tracks (12) provided with toothing complementary to that of the toothed pinions (8) and intended to cooperate with said pinions (8) to ensure regular movement of the magnetic head with respect to the label (10).  3. Portable device according to one of claims 1 and 2, characterized in that the means for controlling the writing of data on the label comprise a sensor (56) of the position of the toothing of a toothed pinion ( 8), connected to a circuit (57) for controlling the writing element (58) and intended to establish the writing intervals on the label by the writing head.  4. Portable device according to claim 3, characterized in that the position sensor (56) is a magnetic or opto-electronic sensor.  5. Portable device according to claim 1, characterized in that the writing head comprises a single-point writing element (30) carried by a mechanism (32,33,34,35,36,37,40,41) of displacement of the writing element (30) in two perpendicular directions (X, Y) and means (67) for positioning the writing head relative to the label are associated with the writing head.  6. Portable device according to claim 5, characterized in that the mechanism for moving the writing element (30) comprises two electric stepping motors (33,32) for moving the writing element according to two directions (X, Y), associated respectively with pairs of endless belts (34,35,36,37), rods (40,41) slidably mounted relative to each other being carried each by a pair of belts (34,35 and 36,37), the writing element (30) being fixed to one of said rods (40,41).  7. Portable device according to one of claims 1 to 6, characterized in that the writing head (6) is a magnetic head for writing on a magnetic powder or liquid crystal label.  8. Portable device according to one of claims 1 to 6, characterized in that the writing head (6) is an optical head with at least one laser diode for writing on a liquid crystal label.  9. Portable device according to one of claims 1,5 and 6, characterized in that the writing head is a head with writing element by contact on a label with writing surface formed by two films between which is contains a writing product intended to be driven locally by pressing the writing head.  10. Portable device according to one of claims 1 to 9, characterized in that it further comprises a barcode reader (4) carried by the housing (1) and intended to ensure the recognition of the products concerned by the indications to write on their corresponding labels.  11. Portable device according to one of claims 1 to 10, characterized in that the control means for writing data on the label comprise a microcontroller (68) associated with a RAM memory block (68a) for storage data relating to corresponding labels, said microcontroller being further connected to the display screen (3), to a keyboard (60) for actuating the device and to circuits (71,72) for controlling the barcode reading head (4) and the writing head (6).  12. Portable device according to claim 10, characterized in that it comprises a printed circuit board (46) carrying the microcontroller (68), the RAM memory block (68a) and the control circuits (71,72) as well as sockets (50,51,65) for connecting said components carried by the printed circuit board with plies (52,53,64) of conductors for connection with the head (4) for reading bar codes, the head writing (6), the keyboard (60), the reading screen (3) carried by the housing (1,2), said printed circuit board (46) being connected to a supply battery (48) and to a socket (49) for linking the device with a central computer for loading into the memory block (68a) data relating to the labels to be printed or modified.  13. Portable device according to one of claims 11 and 12, characterized in that it comprises transmission and reception means connected to the microcontroller (68) write control means (68,71, 72) of the device and an antenna (76) for communication with a corresponding antenna (77) of a transceiver (78) connected to a central management computer (79) for remotely recharging the portable device with data relating to the labels to be written or to modify.  14. Label intended to be used with a portable display device according to any one of claims 1 to 13, characterized in that it comprises means (12, 13) for positioning the writing head (6) of the display device with respect to its writing surface.  15. Label according to claim 14, characterized in that it comprises a support or frame (11) in non-magnetic material and a sheet of transparent material defining with the support at least one compartment (16,17) for a magnetic powder, two parallel edges of said support comprising tracks (12) provided with teeth (13) intended to cooperate with complementary teeth of toothed pinions with complementary teeth guiding the movements of the writing head (6) of the device relative to the label .  16. Label according to one of claims 14 and 15, characterized in that it comprises a support (22) provided with re-entrant flanges (23) intended to cooperate with complementary flanges of a slide (25) integral with a display stand.  17. Label according to claim 14, characterized in that it comprises a support (22), a substrate (27) for liquid crystals (28), a light conductor (26) interposed between the support (22) and the substrate (27) and a transparent window (29).  18. Label according to claim 14, characterized in that it comprises a writing surface formed by two films trapping a writing product which can be removed by contact with a writing tip to make inscriptions on the label.