Thermal printing cassette mountable in a thermal printer
BACKGROUND OF THE INVENTION 
     (1) Field of the Invention 
     The present invention relates to a thermal printing cassette and a thermal printer, and particularly, to a thermal printer that makes various modes of label printing and label applying possible through a particular printing cassette. 
     (2) Description of the Prior Art 
     Since thermal printers are small in size and light in weight, they have been used as various output means in recent years, and they have also been employed for printing price labels and tags in retail shops. 
     Desk type printers are convenient for printing a large number of price labels at one time, in the rear service areas of supermarkets, for example. However, such printers are inconvenient for use in shop fronts because it is difficult to carry them and move them through shops. Meanwhile, a portable thermal label printing and applying machine has been proposed, as in Japanese Patent Publication No. 58-15376 (1983), which corresponds to U.S. Pat. No. 4,264,396. This thermal printer is convenient for use in printing and applying labels at the front of the shops. However, it is inconvenient for printing a large number of labels at one time. 
     SUMMARY OF THE INVENTION 
     It is, therefore, the primary object of the present invention to provide an improved thermal printing cassette and a thermal printer which are free from the above-described disadvantages. 
     Another object of the present invention is to provide a thermal printing cassette and a thermal printer which facilitate additional or supplemental printing of a large number of price labels at the shop fronts. 
     A further object of the present invention is to provide a thermal printing cassette and a thermal printer which are capable of printing both labels and tags. 
     Still a further object of the present invention is to provide a thermal printing cassette and a thermal printer which are efficient in operation but simple in structure. 
     According to the present invention, the mechanism for printing is in the form of a thermal printing cassette. This printing cassette can be detachably mounted on the main body of either a desk type or a portable type printer, thereby making it possible to meet various conditions of printing and applying labels and tags. 
     The thermal printing cassette of the invention comprises a main body which includes a path for travel of heat-sensitive price labels, a printing means for printing desired characters, patterns, or the like on the price labels following a print starting signal, a data input means, a data display means, feeding means for feeding the price labels, detecting means for detecting the price labels, and controlling means for controlling each of the foregoing. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects and features of the invention will become more apparent from the following description taken in connection with the accompanying drawings in which: 
     FIG. 1 is a schematic illustration of a thermal printing cassette according to the present invention; 
     FIG. 2 is a schematic side view of a desk type printer main body on which the cassette of FIG. 1 is mounted; and 
     FIG. 3 is also a schematic side view of a portable printer main body on which the cassette of FIG. 1 is mounted. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A thermal printing cassette 1 according to the present invention, is shown in FIG. 1. A number of the means mentioned below may be of the type shown in above noted U.S. Pat. No. 4,264,396. 
     The cassette includes a main body. There is formed in the main body 2 of the printing cassette 1 a path 4 which is traversed by a heat-sensitive label strip 3. This path 4 includes in sequence, a label sensor 5 for sensing each label of the strip, guide rollers 6 which determine the path of the strip, a thermal head 7 for printing the labels through a thermal printing medium, a platen roller 8 against which the head 7 operates to apply printing pressure, and also a feed roller 10 bracketed by the rollers 6 and that is driven by a step-motor 9. 
     The label strip 3 is of a known type and includes labels 12 which are temporarily stuck to a strip of backing paper 11. The backing paper 11 is turned sharply rearwardly back on the platen 8, and it engages the underside of the feed roller 10 and then it is paid out of the rear of the main body 2. The labels 12 released from the label strip 3 at the platen are discharged beneath the underside of a label applying roller 13. 
     The label sensor may be like the sensing means 8 in U.S. Pat. No. 4,264,396. 
     A keyboard 14 which serves as a data input means and a display means 15, including a liquid crystal image screen, light emitting diode, or the like, are installed on the upper part of the main body 2. A unit like the keyboard 14 can be found in U.S. Pat. No. 4,264,396 at 18, 19. A display means like means 15 can be found in U.S. Pat. No. 4,264,396 at 35. 
     In the main body 2, there is a control means 16 that is electrically connected to all of the sensor 5, the thermal head 7, the step-motor 9, the keyboard 14, the display means 15 and an electrical connecting section 17 that is led to the outside. All of these connections are illustrated schematically by single lines. The control means 16 functions like means 21 in the RAM in U.S. Pat. No. 4,264,396. 
     The platen 8 is attached to the bottom cover 18 of the main body. When the bottom cover 18 is opened by being turned around a rear pivot, the label strip 3 can be passed along its pathway and eventually out of the main body. 
     FIG. 2 shows a desk type printer main body 20 on which the thermal printing cassette 1 of FIG. 1 is mounted. When the printing cassette 1 is mounted on the desk type printer main body 20, the electrical connection 21 and mechanical linkage (not shown) between the cassette and the printer are established. The main body 20 is provided with a supporting means 23 for a label strip roll 22. The control means 16, on the one hand, and a plug 25 that is connected to an AC power source, on the other hand, are joined to a main body control means 24 that is installed in the main body 20. The control means 24 also functions like means 21 in U.S. Pat. No. 4,264,396. The main body control means 24 is connected via an interface 26 to a data input port 27 that is led from the outside. The control means 24 also is connected to a switch 28 and a step-motor 29. The step-motor 29 is connected through belt 32 to a pair of delivery rollers 30 and through belt 33 to a take-up roll 31 for the printed labels. 
     It is possible to provide the take-up roll 31 with a different take-up cassette mechanism 34 such as those disclosed in Japanese Laid-Open Patent Publication No. 59-163139 (1984). 
     Just as heat-sensitive price labels can be printed, heat-sensitive tags (not shown) can also be printed. When the tags are printed, a cutting means (not shown) is provided for cutting tags at a prescribed pitch or length, which tags have been previously printed and discharged outside the cassette main body 2. Also, an arranging means (not shown) for arranging the cut tags can be provided, in place of the take-up roll 31 or the take-up cassette mechanism 34. 
     FIG. 3 shows the main body 40 of a portable printer on which the above-described thermal printing cassette 1 may also be mounted. When the printing cassette 1 is mounted on the printer main body 40, the electrical connection 41 and mechanical linkage (not shown) between the cassette and the printer main body are established. The main body 40 is provided with a label supporting means 43 for supporting a label roll 42. Further, the main body 40 is provided with a switch 46 for turning on and off the label feed roller 10 and with a storage battery 45 with a connector 44. The main body 40 may also be provided with a strap 47, or the like, for facilitating carrying the main body 40. 
     The functions of the printer are now described. 
     The thermal printing cassette 1 is mounted either upon the desk type printer main body 20 or upon the portable type printer main body 40 to serve them as a thermal printer. For example, when the printing cassette 1 is set to the printer main body 20 in FIG. 2, the data inputted from the keyboard 14 are stored in a memory means in the control means 16 and the data also are displayed on the display means 15. Then when the switch 28 is turned on, the motor 9 is driven, thereby printing characters, figures, bar codes, or the like, having desired patterns by means of the thermal head 7. The printed label strip 3 is taken-up, through the delivery rollers 30, by the take-up roll 31 or by an alternate take-up cassette 34 as desired. 
     If it is necessary that the labels 12 first be released from the backing paper 11 before the labels are taken up, the backing paper 11 of the label strip is turned around the platen 8 to peel off the printed labels 12. 
     When tags are printed in place of the label strip 3, it is also possible that the tags will be engaged with the feed roller 10 and will be delivered by being pinched between the delivery rollers 30. 
     Data input from an external floppy disk or other data source (not shown) besides the input from the keyboard 14 can be done by way of the data input port 27 and the interface 26. 
     By means of the above printer, a large number of printed labels or tags can be made in a rear service area of a business establishment. 
     If the printing cassette 1 is set to the portable printer main body 40, as shown in FIG. 3, the motor 9 and the thermal head 7 are driven, by the input from the keyboard 14 and the switch 46, to print the labels 12. Concurrently, the labels 12 are released from the backing paper 11 and they are stuck to the surfaces of goods by applying roller 13. 
     Of course, if the backing paper 11 is not turned around or bent on the platen 8, the label strip 3 consists of printed labels which are still carried on the backing paper 11. 
     In place of the printing cassette 1, the whole body of the thermal printer shown in FIG. 3 can be detachably mounted on the printer main body 20 that is shown in FIG. 2, in a modified printer system. 
     As described above, according to the present invention, it is possible to make a large number of price labels or to print many labels and tags. Furthermore, additional labels can easily be made not only in rear service areas but also in shop front service areas. 
     Further, if printing cassettes of various types are provided, label printing and label applying work can be done simultaneously using any of various desk type printers and portable type printers. 
     Although the present invention has been described in connection with a plurality of preferred embodiments thereof, many other variations and modifications will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.