RIBBON ASSEMBLY

Abstract: A ribbon assembly having a ribbon supply spool (10) and a ribbon take-up spool (12). Attached to either the ribbon supply spool or the ribbon take-up spool is a bar code (44). The bar code is machine readable and is encoded with data relevant to the operation of printing means suitable to employ the ribbon assembly. The printing means comprises reading means (58) for reading the bar code present on the ribbon assembly. Based on the information encoded on the bar code and read by the reading means, the operating parameters of the printing means are adjusted for the specific ribbon assembly employed.

Description: BACKGROUND OF THE INVENTION The present invention concerns a ribbon assembly. Specifically, it concerns a ribbon assembly for printers and other devices which utilize a printing ribbon. Ribbon assemblies for various printing devices typically comprise a ribbon supply reel, a ribbon take-up reel, and a length of printing ribbon. The ribbon supply reel is usually disposed on one side of a printhead with the ribbon take-up reel being disposed on the opposite side of the printhead. In operation, the ribbon supply reel rotates about a center axis in a direction which allows ribbon to be removed from the ribbon supply reel. Similarly, the ribbon take-up reel rotates about a center axis in a direction which allows the ribbon take-up reel to collect ribbon dispensed by the ribbon supply reel. As the ribbon moves from the ribbon supply reel to the ribbon take-up reel, it passes in front of a printhead which causes a printing medium, such as ink, provided on the ribbon to transfer to a printing surface (JP-A-61-222 772). If the printing ribbon is designed for multiple uses, it is often necesary to reverse the direction of rotation of the ribbon supply reel and ribbon take-up reel in order to allow the ribbon to be moved in a reverse direction. This allows the printing ribbon to pass in front of the printhead more than once. Typically, this has been achieved by manually reversing the direction of rotation of the ribbon supply reel and ribbon take-up reel. Many printing ribbons are thermally operated wherein the printing medium is transferred to the printing surface upon application of thermal energy. A thermal printhead is adapted to supply the thermal energy to the thermal printing ribbon in an appropriate manner. In thermal printing, to assure consistent printing performance, it is desirable to control various operating parameters including the temperature of the printhead, the speed of printing, the speed with which the print ribbon passes in front of the printhead, and the like. With known ribbon assemblies and printheads, these operating parameters have typically been set manually and adjusted as printing conditions change. For instance, if a first thermal printing ribbon is replaced with a second thermal printing ribbon, it may be necessary to manually adjust the thermal energy output of the printhead in order to assure consistent printing, GB-A-2184708 discloses a ribbon cassette comprising holes or markings on a rotational member connected to the ribbon spool. These markings can be read by means of a sensor arrangement and a control unit is addressed by the signal at the sensor output. The markings are preferably formed by a number of equidistant circumferential holes in the rotational members. The angle of rotation formed by each two adjacent holes defines the type of ribbon and can also be used to determine the remaining supply of ribbon. However, the angle of rotation formed by adjacent holes cannot provide sufficient information or data to define and/or initiate more complex or more numerous control procedures. SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for automatically controlling various operating parameters of a printer. According to the present invention, this is accomplished by providing a printer which is adapted to alter its operating parameters based on data provided to said printer. Data is provided to the printer from a reading means which reading means reads coded indicia such as a bar code carried by a printer ribbon spool of a ribbon assembly used with the printer. It is a further object of the present invention to provide a printing assembly which is capable of automatically altering operating parameters of the printing assembly based on changing printing conditions. According to the present invention, this is accomplished by a printing assembly comprising a printer which is adapted to automatically alter operating parameters in response to data provided thereto. The assembly further comprises a ribbon assembly adapted for use with the printer and comprising coded indicia such as a bar code encoded with data relevant to the operation of the printer. Finally, the assembly comprises a means for reading the coded indicia (bar code) and providing data encoded therein to the printer. In operation, the reading means reads the coded indicia (bar code) and provides data concerning operating parameters of the printer to the printer which automatically adjusts to said operating parameters. Finally, the present invention concerns a ribbon assembly which comprises a bar code containing encoded data concerning the conditions suitable for printing with the ribbon assembly. Such conditions include ribbon speed, printing temperature, and the like. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, wherein like numerals designate corresponding parts in the several figures: Figure 1 is a lateral view of a cross-section of the ribbon assembly of the present invention. Figure 2 is a view of the bar code present on the ribbon assembly. Figure 3 is a bottom view of the ribbon assembly of Figure 1. Figure 4 is a flow diagram illustrating a first use of the present invention. Figure 5 is a flow diagram illustrating a second use of the present invention. Figure 6 is a lateral view of the printing assembly of the present invention. DETAILED DESCRIPTION OF THE INVENTION The following description is the best presently contemplated mode of carrying out the invention. This description is made for the purposes of illustrating the general principles of the invention, and is not to be taken in a limiting sense. The scope of the invention is best determined by the appended claims. Figure 1 represents a lateral cross-sectional view of the ribbon assembly of the present invention taken along a central vertical axis. Figure 1 illustrates a ribbon supply spool 10 for holding and supplying ribbon, a ribbon take-up spool 12 for receiving and holding ribbon, and a printing ribbon 14. The ribbon supply spool 10 comprises a supply core 16 for holding a first supply flange 18, and a second supply flange 20 in a spaced, generally parallel relationship. In the embodiment of the present invention depicted in Figure 1, the supply core 16 is depicted as a hollow cylinder. Those skilled in the art will realize that the supply core 16 may vary in shape and diameter. In the illustrated embodiment, the supply core 16 maintains the first supply flange 18 and the second supply flange 20 in a spaced relationship, and the supply core 16 is capable of having the ribbon 14 wound therearound. The supply core 16 may be manufactured from any material possessing sufficient structural integrity to allow the supply core 16 to perform the functions heretofore described. Exemplary of such materials are Kraft paper, Kraft paperboard, metal, organic polymeric material, and the like. Exemplary of suitable organic polymeric material from which the supply core 16 may be constructed are styrene, nylon, ABS, and the like. Attached to one end of the supply core 16 is the first supply flange 18 which provides a boundary for the printing ribbon 14 when wound about the supply core 16. Integrally attached to the first supply flange 18 is a first supply flange gear 22 designed to cooperate with a drive mechanism suitable for causing the rotation of the ribbon supply spool 10. Any method suitable for firmly attaching the first supply flange 18 to the supply core 16 is suitable for use in the illustrated embodiment. In the embodiment of the present invention depicted in Figure 1, the first supply flange 18 is integrally attached to a first supply flange plug 24 which in turn fits firmly within the supply core 16. Alternatively, the first supply flange 18 could be integrally formed with the supply core 16. The second supply flange 20 which provides a boundary for the printing ribbon 14 when wound about the supply core 16, is firmly attached to the supply core 16 in the same manner as described with respect to the first supply flange 18; that is, by second supply flange plug 26. Similarly, a second supply flange gear 28 is integrally attached to the second supply flange 20 and is adapted to cooperate with a drive mechanism. First and second supply flanges, plugs and gears are suitably made from any material possessing the structural integrity necessary to allow the various elements to perform their functions. Exemplary of such materials are metal, organic polymeric material, and the like. Exemplary of suitable organic polymeric material are styrene, ABS, urethanes, acrylates, nylons, and the like. The ribbon take-up spool 12 is adapted to rotate about a central axis and receive, in a winding relationship, the ribbon 14 which is being supplied from the ribbon supply spool 10. The parts of the ribbon take-up spool 12 are similar in design and function to the corresponding parts of the ribbon supply spool 10. The ribbon take-up spool 12 comprises a take-up core 30 for holding a first take-up flange 32 and a second take-up flange 34 in a spaced generally parallel relationship. Attached to one end of the take-up core 30 is the first take-up flange 32 which provides a boundary for the printing ribbon 14 when wound about the take-up core 30. Integrally attached to the first take-up flange 32 is a first take-up flange gear 36 designed to cooperate with a drive mechanism suitable for causing the rotation of the ribbon take-up spool 12. The first take-up flange 32 is integrally attached to a first take-up flange plug 38, which in turn fits firmly within the take-up core 30. The second take-up flange 34, which provides a boundary for the printing ribbon 14 when wound about the take-up core 30, is firmly attached to the take-up core 30 in the same manner as described with respect to the first take-up flange 32; that is, by a second take-up flange plug 40. A second take-up flange gear 42 is integrally attached to the second take-up flange 34 and is designed to cooperate with a drive mechanism to cause the rotation of the ribbon take-up spool 12. The ribbon 14 comprises a substrate and a printing medium. The ribbon 14 is capable of cooperating with a printing device to cause an image to be printed on a printing surface. Suitable printing ribbons are known in the prior art. Exemplary of such printing ribbons are cloth or cloth-like ribbons impregnated with ink; an organic resinous substrate having adhered to one surface thereof a carbonaceous, pressure-sensitive compound; an organic resinous substrate having adhered to one surface thereof, a temperature sensitive printing medium; and the like. In one preferred embodiment of the present invention wherein the printing device is a thermal printer, the ribbon 14 comprises an organic polymeric substrate having adhered to one surface thereof, a temperature-sensitive ink. In use, the thermal printhead applies thermal energy to selected portions of the ribbon 14. The application of such thermal energy causes the temperature-sensitive ink present on one surface of the ribbon substrate to melt and thereby be transferred to a printing surface. Exemplary of suitable organic resinous polymeric substrates are the polyesters. The substrate generally has a thickness between 1.5 and 10 microns, preferably between about 2.5 and 5 microns, most preferably about 3.5 microns. The temperature-sensitive ink has a melting point below the melting point of the substrate material. Generally, the temperature sensitive ink has a melting point within the range of from about 30°C to about 90°C, beneficially from about 50°C to about 80°C, preferably about 60°C to about 70°C. The ribbon assembly of the present invention has affixed to a printer spool, either the ribbon supply spool or the ribbon take-up spool, at least one machine readable code such as the bar code 44. Bar codes are known to those skilled in the art. The term "bar code" refers to a code consisting of a group of printed and variously patterned bars and spaces and sometimes numerals. The bar codes are designed to be scanned or read by scanning or reading means such as infra-red scanners. It is possible that other suitable machine readable coded indicia may be used as well. Figure 2 is a detailed illustration of a bar code suitable for use in the present invention. The illustrated circular bar code representing one embodiment of the present invention may have encoded therein up to about ten different numbers. The number(s) encoded on the bar code are generally interpreted by scanning or reading means as being either reflective or non-reflective. Typically, the number(s) encoded on the bar code will be associated with a particular pre-determined set of printer operating parameters. The scanning or reading means would read the number, the number would then be compared to stored numbers, each of which is associated with particular printer operating parameters. When the encoded number is matched with a "stored number", the operating parameters associated with said "stored number" are implemented by the printer. In one preferred embodiment of the present invention, illustrated in Figure 2, the bar code 44 represents 1 of 10 numbers. The bar code is adapted to be affixed to one of the flanges 18 or 34. The bar code itself comprises a start bar 46, a fat bar 48, nine clock bars 50a-i and a stop bar 52. The term "bar" refers to a non-reflecting (dark) portion of the bar code. In the illustrated embodiment, the bar code is divided into 30 spaces with each space representing 12 degrees of rotation. Each clock bar and each reflecting (white) area represent 1 space. The start bar is twice as wide as a clock bar, the stop bar is 3 times as wide as a clock bar and the fat bar is 4 times as wide as a clock bar. The start bar indicates the beginning of the reading cycle and the stop bar indicates the end of the reading cycle. The encoded number itself is equal to the number of clock bars between the start bar and the fat bar. The reading cycle always runs; start bar, y clock bars (y = 0 to 9), fat bar, w clock bars ( w = 9 - y ), stop bar. The encoded number is equal to y. Therefore, in the illustrated embodiment, the encoded number is 0. Figure 3 depicts a bottom view of the ribbon assembly. In the embodiment of the present invention illustrated in Figure 3, the bar code 44 is shown as being carried by ribbon take-up spool 12, specifically by the second take-up flange 34. Means suitable for scanning or reading the bar code 44 are known to those skilled in the art. Typically, such scanners or readers function by generating some form of electromagnetic radiation. This eletromagnetic radiation is directed onto the bar code. Since the bar code comprises reflecting and non-reflecting areas, some of the electromagnetic radiation directed onto the bar code is reflected and some is not. The reflected electromagnetic radiation is sensed by a sensing means such as an optical sensor present within the scanning or reading means. This pattern of reflected and non-reflected electromagnetic radiation is interpreted by the scanning/reading means as a specific number. In practice, the bar code is read by scanning or reading means and the information encoded in the bar code is used to automatically set various operating parameters of a printing mechanism. For example, an optical sensor is employed to read the bar code. As discussed above, in one preferred embodiment, the bar code represents one of ten numbers (0 - 9). A microcomputer is employed to receive data from the optical sensor and decoded it as a number from 0 - 9. The microcomputer then compares the number read from the bar code with a stored range of numbers to ensure that the number is within a preset range of acceptable values, i.e., 0 - 9. If the number read and decoded is not within the proper range, it is assumed an error has been made in the reading of the bar code and a new reading is taken and the process begins again. If the number read and decoded is within the correct range, a pointer is set up to a stored table which matches certain preset operating parameters with each of the numbers 0 - 9. The microcomputer then indexes into the table via the pointer and the operating characteristics associated with the indicated number are instituted by the microcomputer. Those skilled in the art will recognize that a number of microcomputers are suitable for use in the present invention. One example of a suitable microcomputer is a microcomputer sold by Intel under the trade number 8031. The above described process of comparing a number encoded on the bar code to a stored number associated with specific operating parameters is illustrated in the flow diagram of FIGURE 4. For example, based on input provided from data encoded on the bar code, a thermal printer may be automatically set to employ a single pass ribbon. Alternatively, a different ribbon assembly may be employed in the same thermal printer which ribbon assembly comprises a bar code which indicates that the printing ribbon is a multipass ribbon. Through the present invention adjustments necessary to employ the second ribbon assembly can be automatically instituted. Another example of the present invention would be the use of bar code to signal an operator as to the near depletion of the printing ribbon contained on the ribbon supply spool 10. This is accomplished in the following manner. The bar code is adapted to be read and decoded by scanning or reading means. The scanning or reading means is capable of determining the speed of rotation of the bar code. If, as illustrated in Figure 3, the bar code appears on the take-up spool 12, as the supply of ribbon 14 contained on the ribbon supply spool 10 is depleted, the speed of rotation of the ribbon take-up spool 12 is decreased. Based on the speed of rotation of the bar code affixed to the ribbon take-up spool 12, it is possible to determined the relative amount of ribbon remaining on the ribbon supply spool 10. In other words, as the amount of ribbon remaining on the ribbon supply spool 10 decreases, the speed of rotation of the bar code affixed to the ribbon take-up spool 12 decreases. Upon reaching a pre-determined speed of rotation, the means for scanning or reading the bar code generates a signal to an operator indicating a low amount of ribbon remaining on the ribbon supply spool 10. Specifically, the ribbon take-up spool is driven by a stepper motor through a slip drive system. A "stepper motor" is a motor which operates on pulses of power with each pulse causing the motor to rotate a fixed amount. The stepper motor is driven by a microcomputer at a constant rate. However, as the take-up spool fills up with ribbon, it rotates at a decreasing rate of speed. As described above, the scanning or reading means is capable of reading reflecting and non-reflecting areas on the bar code. The scanning or reading means (including the microcomputer) is therefore capable of determining when the bar code has rotated one complete revolution, that is, when the scanning or reading means has, in the illustrated embodiment, registered 12 non-reflecting bars. The scanning or reading means counts the number of stepper motor pulses occuring from the start of one bar to the start of the next (both reflecting and non-reflecting). In the illustrated embodiment, the bar code comprises 12 bars. Accordingly, there will be 12 series (from the start of one bar to the start of the next) of stepper motor pulses in a complete rotation of the bar code. The microcomputer stores the last 12 series of stepper motor pulses. The sum of the 12 stored values equals the number of stepper motor pulses required to produce one complete rotation of the take-up spool. The microcomputer is programmed with a reference value. This reference value is the number of stepper motor pulses per revolution of the take-up spool at which the supply of ribbon on the ribbon supply spool is considered low. When the number of stepper motor pulses required to produce one revolution of the take-up spool equals or is greater than the stored reference value, the microcomputer generates a signal which indicates a low ribbon condition. FIGURE 5 illustrates a flow diagram which represents the above described process steps employed in determining whether or not a low ribbon condition should be indicated based on the number of stepper motor pulses required to produce a full revolution of the ribbon take-up spool. According to practice of the present invention, there is provided a ribbon assembly as hereinbefore described. There is also provided printing means and means for reading the bar code appearing on the ribbon assembly. After initial attachment of the ribbon assembly to the printing means, reading means reads the data encoded in the bar code affixed to the ribbon assembly. Based on the data encoded in the bar code, various operating parameters of the printing means are automatically set. If, at a later date, a ribbon assembly requiring different printing parameters is attached to the printing means, the reading means reads the bar code affixed to said ribbon assembly and automatically adjusts the printing parameters of the printing means to print with such new ribbon assembly. Figure 6 illustrates a printing assembly 54 in accordance with the present invention. The printing assembly comprises a ribbon assembly 56, a reading means 58, and a printing means 60. The ribbon assembly 56 is shown mounted in the printing assembly in a generally horizontal position. That is, the ribbon assembly 56 is positioned within the printing assembly so that the longitudinal plane of the printing ribbon 57 is generally horizontal. The readings means 58 is located to be able to read a bar code located on the ribbon assembly 56 as hereinbefore described. Guide means 59 serve to position the printing ribbon 57 in an operable relation with the printig means 60. Finally, the printing means 60 is located on one side of a printing area 62 and a printing surface 64 is located on the opposite side of the printing area 62. The printing means 60 is located in an operative relationship with printing area 62 and printing surface 64. Data read by reading means 58 from the bar code on ribbon assembly 56 is supplied to printing means 60 along data transmission means 66. The above description of the presently preferred embodiment of the present invention is intended to illustrate, by way of example, the novel features that are believed to be characteristic of the present invention. It is to be expressly understood, however, that the specific embodiment is for the purpose of illustration and description only, and is not intended as a definition of the limits of the invention. Other embodiments of the present invention are therefore included within the scope of this invention as defined by the appended claims.

Claims: A ribbon assembly suitable for use with a printer operable according to an operating parameter, the ribbon assembly having a ribbon supply spool (10), a ribbon take-up spool (12), a length of ribbon (14) wound about the ribbon supply spool (10) and attached to the ribbon take-up spool (12), at least one machine readable coded indicia (44) being carried by either the ribbon supply spool or the ribbon take-up spool, the coded indicia comprising an array of x indicia elements (x > 1), characterized in that the array of x indicia elements (44) include y (y ≧ 0) first elements, the number y representing the operating parameter. A ribbon assembly as claimed in claim 1, characterized in that the array of x indicia elements comprises a rotatable annular bar code (44) having x bars. A ribbon assembly as claimed in claim 1, characterized in that the array of x indicia elements further comprises u start indicia element(s)(46), v stop indicia element(s) (52), w second element(s), and z separating element(s) (48), arranged between the y first element(s) and the w second element(s), wherein x = u+v+w+y+z , and o ≦ y ≦[x - (u+v+z)] . A ribbon assembly as claimed in claim 3, characterized in that u = 1, v = 1, Z = 1 and x = 12. A ribbon assembly as claimed in claim 1, comprising: an indicia detector, the array of x indicia elements movable adjacent the indicia detector upon rotation of the ribbon spool; drive means for incrementally driving the ribbon spool and the array, and for moving the x indicia elements adjacent the detector for each full rotation of the ribbon spool; characterized in that the ribbon assembly further comprises: first counting means for counting the number of drive increments driven by the drive means upon movement of x indicia elements adjacent the indicia detector; comparison means for comparing the number of drive increments counted by the first counting means with a predetermined value; signaling means for signaling a low ribbon condition upon the number of increments counted by the first counting means being at least as great as the predetermined value; second counting means for counting the number of first element(s) moved adjacent the indicia detector by the drive means and identifying means for identifying the printer parameter in dependence on the number counted by the second counting means. A printing assembly comprising the ribbon assembly of claim 1 and having a printer adapted to alter operating parameters based on data provided by the ribbon assembly, characterized in that the printing assembly comprises means for reading the coded indicia, determining the number y, and providing data represented by the number y to the printer. A method of controlling the operating parameters of a printer adapted to alter operating parameters based on data provided by the ribbon assembly of claim 1, characterized in that the method comprises the steps of reading the coded indicia and providing data corresponding to the number y to the printer, wherein the printer alters its operating parameters based on the data so provided. A method of indicating a low ribbon condition of the printer operable according to operating parameters and having a ribbon assembly of claim 1, characterized in that the method comprises the steps of rotating the ribbon supply spool and ribbon take-up spool; determining the speed of rotation of the ribbon supply spool or the ribbon take-up spool by reading the code indicia; and indicating a low ribbon condition based on the speed of rotation of the ribbon supply spool or the ribbon take-up spool. A printing apparatus operable with up to t types of ribbon spools of ribbon assemblies of claim 1, characterized in that: t = [x - (u+v+z)] + 1. The printing assembly of claim 6 wherein the printer is a thermal printer. The ribbon assembly of claim 2 wherein the bar code is affixed to the ribbon take-up spool. The ribbon assembly of claim 1 wherein the printing ribbon is a thermal printing ribbon. The ribbon assembly of claim 12 wherein the thermal printing ribbon comprises a polymeric substrate having a temperature sensitive ink adhered to one surface thereof. The printing assembly of claim 6 wherein the printer is a thermal printer comprising a thermal printhead and the data encoded on the machine readable coded indicia concerns the operating temperature of the thermal printhead.

Inventors: BURNARD, JONATHAN J., FEE, BRENDAN
Applicants: DATAPRODUCTS CORPORATION
Application year: 1989
Main classification: B41J35
IPC codes: B41J32, B41J35