GB2211971A

GB2211971A - Printer

Info

Publication number: GB2211971A
Application number: GB8825125A
Authority: GB
Inventors: Atsushi Murakami
Original assignee: Brother Industries Ltd
Current assignee: Brother Industries Ltd
Priority date: 1987-10-30
Filing date: 1988-10-27
Publication date: 1989-07-12
Anticipated expiration: 2008-10-27
Also published as: GB2211971B; GB8825125D0; JPH01118454A

Abstract

A printer system for printing characters (including bar codes) in a wide variety of fonts or styles has an internal memory 210 for storing internal dot-pattern data 211 and an internal program 212 for driving a printing mechanism using the internal dot-pattern data. An external memory 310, independent from but connectable to the printer body, stores external dot-pattern data 311 corresponding to a character style which differs from that of the internal dot-pattern data, and an external program 312 for driving the printing mechanism using the external dot-pattern data. <IMAGE>

Description

PRINTER SYSTEM WITH AN EXTERNAL MEMORY FOR PRINTING CHARACTERS IN VARIOUS STYLES AND FIGURES The present invention relates to a printer system for printing characters in a large variety of styles and other figures such as bar codes. A dot matrix printer is representative.of such a printer system but other printer systems that generate a character outline by any method can apply this invention.

Currently, printer systems (hereinafter referred to as printers) are expected to have various capabilities, e.g., high-speed printing, flexible switching of the point number (character size) and of the character style, and so on.

Among these various capabilities, those required by most users of the printers are regarded as basic functions, and are provided on printers as standard equipment. For example, recent models generally have a high-speed printing function, a point switching function, and a character style selecting function for selecting one of a few basic lettering styles. However, some users require a broader choice in the styles. To cope with a variety of users' requests for the printing character styles, the following mechanisms have been implemented on the printers.

Printers are typically furnished with a program that controls the printing mechanism that prints additional characters whose styles (hereinafter referred to as supplementary styles) are different from the basic styles.

Moreover, the above-mentioned control program uses several memories storing dot-pattern data for the supplementary styles so a user can select a style as is required. Thus, the printer has additional memory containing the dot-pattern data corresponding to a desired supplementary style for printing characters in the selected supplementary style.

The control program, however, cannot fully meet a wide variety of users' needs for the supplementary styles. Some styles cannot be printed merely by changing the dot-pattern data memory. For example, when a text is printed in a cursive style, the image of separate cursive letters may look unnatural. In such a case, an additional printing operation to link neighboring letters is required. Further, when a special character (e.g. the mathematical integral operator) having a larger-than-standard height is printed, the character cannot be completed until the two or three lines spanned by the character are printed. In this case, special coordination between the line feed (paper feed) movement and the printing head movement is required. It is difficult for prior-art printers to satisfy these requirements.

Some recent printer models can print bar code patterns.

However, the pattern data for an entire bar code requires careful integration of all of the component code data.

Irregular correspondence between the code data and the pattern data is an unsolved problem for conventional printers.

If the printer is provided with a function for printing characters in a large variety of supplementary styles and for printing non-character figures including bar codes, the program for controlling the printing head, the printing head driver, the paper feeder and other mechanisms becomes unwieldy. The lengthy program requires an enormous memory region and long development period. As a result, manufacturing costs increase, and manipulation becomes more complex. Such printers no longer satisfy the users' needs.

Moreover, meeting the users' interminable requests for different supplementary styles becomes difficult. New styles frequently require changes in the design of the controlling mechanism including the control program stored in the memory, or the replacement of the whole controlling mechanism. The users, therefore, may need several printers, each corresponding to different desired character styles.

According to the present invention there is provided a printer system, responsive to external code data, for printing characters and figures corresponding to the external code data, the system comprising: a printer body including a printing mechanism; an internal memory in the printer body for storing internal pattern data corresponding to at least one font of the characters or one assortment of the figures to be printed, and an internal program corresponding to the internal pattern data; an external unit separate from and attachable to the printer body, the external unit comprising an external memory for storing external pattern data corresponding to a font of the characters or an assortment of the figures to be printed and an external program for printing the characters and figures based exclusively on the external pattern data;; an interface unit in the printer body for receiving the external unit; and a control unit in the printer body, responsive to the external code data, for controlling the printing mechanism to print the characters or figures corresponding to the external code data based, in response to an external command signal, on either the internal program and the internal pattern data stored in the internal memory or the external program and the external pattern data stored in the external memory.

The present invention makes it possible to provide a printer system that simplifies the design of the control program that drives various printing mechanisms based on a predetermined character code data, and thus decreases the program development period. The invention can also provide a printer system that minimizes the memory region required for storing the control program, and that inexpensively enables users to easily select and print one of the basic or supplementary styles as needed. A wide variety of characters and non-character figures can be printed.

The invention may be best understood by reference to the following description of a preferred embodiment which is provided by way of example only.

Fig. 1 is a schematic diagram indicating the fundamental structure of the present invention; Fig. 2 is a block diagram showing the electronic control unit and peripheral equipment of a printer according to an embodiment of the present invention; Fig. 3 is a flowchart indicating a control program executed in the embodiment of the present invention; and Figs. 4A and 4B illustrate some of the printing patterns that are possible with the embodiment of the present invention.

An embodiment of the present invention is described with reference to Fig. 2. A dot matrix printer 10 prints characters and figures including bar codes on a paper 40 by selectively driving the printing wires 50 of a printing head 20. The printing head 20 and a printing ribbon 55 are mounted on a carriage 70 which is movably supported on a guide bar 60. The carriage 70 is driven, via a belt 80, by a carriage stepping motor 90. The carriage 70 moves the printing head 20 along the axis of a platen 30. The platen 30 is rotated, via gears 95, by a line-feed stepping motor 100 so as to vertically move the paper 40.

The stepping motors 90 and 100 and the printing head 20 are controlled by an electronic controlled unit (ECU) 110.

After a power switch 120 is turned on, the ECU 110 receives character code data from an external device 105 and from a card reader 305, and signals sent from various switches. For example, a cover OPEN/CLOSE signal is sent from a cover sensor 140 attached to a cover 130 (only partially shown in Fig. 2).

The ECU 110 includes a CPU 200, a ROM 210, a RAM 220, an input/output (I/O) port 230 and an interconnecting bus 240.

The CPU 200 executes various calculations for controlling the printer mechanisms. The ROM 210 stores, in a font data region 211, internal dot-pattern data of characters for use with character code data from the external device 105 and, in a program region 212, stores an internal program including a main routine that controls the stepping motors 90 and 100 and the printing wires 50. The RAM 220 includes an input buffer 221 for temporarily storing the character code data from the external device 105, and an image buffer 222 for storing a preset number of lines of dot patterns corresponding to the character code data. The I/O port 230 converts the input and output signals to and from the motors, switches and sensors into signals appropriate for the CPU 200. The bus 240 connects the CPU 200, the ROM 210 and the RAM 220 to the I/O port 230.

The I/O port 230 is also connected to a card reader 305 that reads information stored in a ROM 310 on a memory board (hereinafter referred to as an IC card) 300 when the IC card 300 is inserted into the card reader 305. The card reader 305 is provided in the printer body 10. The ECU 110 reads the information stored in the card ROM 310 of the IC card 300 via the card reader 305. The card ROM 310 stores, in a font data region 311, an external dot-pattern data of a font or an assortment of figures. More specifically, the card ROM 310 provides dot matrix patterns, whose style differ from that of the internal dot-pattern data stored in the ROM 210, for the characters in the input character code from the external device 105.The card ROM 310 also stores an external program, in an external program region 312, of a subroutine that is called from the main program in the internal program region 212. The subroutine is used for controlling the motors 90 and 100 and the printing wires 50 to print characters or figures based exclusively on the dot-pattern data'in the external font data region 311.

In the present embodiment, the card ROM 310 stores dotpattern data for cursive-style characters in the font data region 311 and an external program including a program for forming a ligature between two adjacent cursive characters in the program region 312.

The main program executed by the ECU 110 is described with reference to the flowchart in Fig. 3. When the printer 10 is turned on, the program starts. At step Si initialization is executed, i.e., the stepping motors 90 and 100 are set in their initial phases and the carriage 70 is positioned at its starting point. At step S2, the card reader 305 determines whether an IC card 300 is inserted. If the answer is determined to be YES, a signal is sent to the ECU 110 and the program proceeds to step S3. At this step, the ECU 110 determines, based on a switching control signal issued from the external device 105, whether to switch the program from the internal program stored in the ROM 210 to the external subroutine stored in the card ROM 310. If the answer is YES at step S3, printing is executed at step S4 using the external subroutine.To illustrate, in Fig. 4A the cursive characters are printed by driving the motors 90 and 100 and the printing wires 50 using the external program and the external dot-pattern data stored in the card ROM 310.

With this external program, the CPU 200 converts the character code data from the external device 105 into a cursive-style dot matrix pattern based on the external dotpattern data stored in the card ROM 310. Then, the CPU 200 calculates, using the external program, dot matrix patterns for the ligatures 510 and 520 between the adjacent characters, as shown in Fig. 4A. The dot matrix pattern for the linked, cursive characters (Fig. 4A below) is stored in the image buffer 222 of the RAM 220. The ECU 110 uses this dot matrix pattern to drive the printing wires 50 and the carriage motor 90 to print the linked, cursive characters on the paper 40.

If, however, the card reader 305 determines at step S2 that the IC card 300 is not inserted, or if the external device 105 sends no command to switch programs at step S3, the program proceeds to step S5. At step S5, characters in a style corresponding to the internal dot-pattern data stored in the ROM 210 are printed. Using the internal program, the CPU 200 converts each character code from the external device 105 into a predetermined dot matrix pattern, e.g., pica, corresponding to the internal dot-pattern data stored in the font data region 211 of the ROM 210. Then, the converted dot matrix pattern is stored in the image buffer 222 of the RAM 220. By means of the printing wires 50 and carriage motor 90, the ECU 110 prints the dot matrix pattern stored in the image buffer 222 on the paper 40.When the printing operation at step S4 or S5 is finished, the program returns to step S2, and the above-mentioned process begins again.

In this embodiment, the determination at step S3 is omissible. If omitted, the internal program automatically substitutes the external subroutine stored in the card ROM 310 for the corresponding internal subroutine stored in the internal ROM 210 when the IC card 300 is connected to the card reader 305. Thus, by connecting the IC card 300 to the printer 10, the character style can be optionally switched from the one based on the internal data stored in the ROM 210 to the one based on the external data stored in the card ROM 310 of the IC card 300.

A desired character in a desired style can be easily printed from either internal or external memory. For example, the internal ROM 210 may store dot-pattern data corresponding to basic character styles such as pica and boldface as well as the program for driving the printing mechanism to print these styles. On the other hand, the card ROM 310 may store pattern data corresponding to an additional style such as a bar code style (Fig. 4B), a cursive character style or an OCR character style (which is readable by optical machines), as well as the program for printing that style.

As a result, any of the characters in pica and boldface, bar code, or cursive styles can be easily printed by the single printer 10. Moreover, by replacing the IC card 300, a large variety of letters meeting various users' needs can be easily printed by the single printer 10.

With the present embodiment, the additional control programs can be easily designed to print the characters of additional desired styles without restricting the control program for the basic character styles. Since the external program is constructed as a subroutine of the internal main program stored in the main printer body 10, program development for the external program is minimized. It follows that the period required for designing the external program, as well as the internal program, is shortened and that the memory regions required for both programs can be reduced. As a result, an inexpensive and highly efficient printer can be realized and the inexpensive IC card 300 makes it easier to build a printer system having a wide variety of character styles.

A significant feature of the present embodiment is that the style of the characters corresponding to the internal data is different from that corresponding to the external data. It is possible, instead, to store pattern data of the cursive font in the internal ROM 210 to print cursive characters separately, and to store the external card ROM 310 only data and program for linking the end of one cursive character to the beginning of the next cursive character.

Thus, the printer with the IC card 300 connected can print characters which cannot be printed by the internal pattern data and the internal program stored in the internal ROM 210 alone. Of course, the external font data region 311 may also contain dot-pattern data of the same style as the basic style stored in the internal font data region 211, but having a different size.

The IC card 300 may contain several sets of dot-pattern data for different character styles with corresponding external programs. In this case, one of these external sets is selected by the main routine or by the operator.

While the invention has been practically shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various other modifications may be made without departing from the spirit and scope of the invention. For example, the character style data stored in the internal and external font data regions 211 and 311 are dot matrix pattern data in the above embodiment. But they may be replaced by another type of data that can generate a particular style of characters, such as outline font data.

Claims

1. A printer system, responsive to external code data, for printing characters and figures corresponding to the external code data, the system comprising: a printer body including a printing mechanism; an internal memory in the printer body for storing internal pattern data corresponding to at least one font of the characters or one assortment of the figures to be printed, and an internal program corresponding to the internal pattern data; an external unit separate from and attachable to the printer body, the external unit comprising an external memory for storing external pattern data corresponding to a font of the characters or an assortment of the figures to be printed and an external program for printing the characters and figures based exclusively on the external pattern data; an interface unit in the printer body for receiving the external unit; and a control unit in the printer body, responsive to the external code data, for controlling the printing mechanism to print the characters or figures corresponding to the external code data based, in response to an external command signal, on either the internal program and the internal pattern data stored in the internal memory or the external program and the external pattern data stored in the external memory.

2. A printer system, responsive to external code data, for printing characters and figures using a dot matrix pattern, the system comprising: a printer body including a printing mechanism; an internal memory in the printer body for storing internal dot-pattern data corresponding to at least one font of the characters or one assortment of the figures to be printed1 and an internal program corresponding to the internal dot-patte= data; an external unit separate from and attachable to the printer body, the external unit comprising an external memory for storing external dot-pattern data corresponding to a font of the characters or an assortment of the figures to be printed and an external program for printing the characters and figures based exclusively on the external dotpattern data; an interface unit in the printer body for receiving the external unit; and a control unit in the printer body, responsive to the external data, for controlling the printing mechanism to print the characters or figures corresponding to the external code data based, in response to an external command signal, on either the internal program and the internal dot-pattern data stored in the internal memory or the external program and the external dot-pattern data stored in the external memory.

3. The printer system according to claim 2, wherein: the external unit further comprises a means for responding to a detection signal externally input to the external unit by generating a return signal; and the control unit comprises a means for outputting the detection signal, via the interface unit, to the external unit, and for receiving the return signal, and a means for selecting the external dot-pattern data and the external program for controlling the printing mechanism if the return signal is received and for selecting the internal dot-pattern data and the internal program otherwise.

4. The printer system according to claim 2 or 3 wherein the external dot-pattern data correspond to a font of cursive letters and the external program comprises a subroutine for controlling the printing mechanism in order to print a ligature between adjacent cursive letters.

5. The printer system according to claim 2 or 3 wherein the external dot-pattern data correspond to an assortment of bar codes and the external program comprises a subroutine for controlling the printing mechanism in order to print the bar codes using the external data.

6. The printer system according to any preceding claim wherein the external unit is an IC card comprising a read-only memory as the external memory.

7. The printer system according to any preceding claim wherein the internal program is a main program that controls the printer system and the external program is a subroutine that is called, in response to the external command signal, from the main program to print the characters and figures based exclusively on the external pattern data.

8. A printer system substantially as hereinbefore described with reference to and illustrated in the accompanying drawings.