Printing Apparatus Which Can Specify a Font Memory Irrespective of a Mounting Position Thereof, and a Method of Specifying a Font Memory

The present invention relates to a printing apparatus which can print using a font memory specified from a plurality of font memories irrespective of mounting position, and a specifying method therefor.

Various conventional printing apparatuses can print single documents with several fonts (e.g., gothic, italic, etc.). Such printing apparatuses have a cartridge mounted thereon containing a plurality of font memories which store font data to effect the operation described above. Therefore, when font memories or cartridges are exchanged in accordance with a font to be printed, a document featuring various fonts can be produced.

In such a printing apparatus, each font memory is uniquely determined by a font specifying number corresponding to its physical mounting position in the cartridge. More specifically, a printing operation is carried out by a font memory corresponding to the font specifying number specified by a user in a program, and the printing apparatus itself has no determination means for specifying the font memory. For this reason, when a user selects a desired font (i.e., a desired font memory), a printing program must be modified to correspond to a given font specifying memory, or a mounting position of the font memory in the cartridge must be changed. Therefore, conventional apparatus are very inconvenient to use because erroneously selected fonts can only be found by checking the printed output.

The present invention has been made in consideration of the above situation, and has as its object to provide a printing apparatus which can select an appropriate font memory from a plurality of font memories irrespective of its mounting position in a cartridge and perform a printing operation using the selected font memory, and to provide a method of specifying a font memory.

In order to achieve the above object of the present invention, there is provided a printing apparatus which can specify a font memory irrespective of its mounting position, comprising: a character pattern memory means comprising at least one font memory storing character pattern data for generating character pattern data corresponding to input character code data using a specified font memory; a font memory specifying means for sequentially searching the font memories in said character pattern memory means to specify the font memory to be used in a printing operation in response to a font specifying instruction, an output means for outputting character code data to said character pattern memory means in response to a printing instruction; and printing means for printing the character pattern data from said character pattern memory means.

Furthermore, according to the present invention, there is provided a method of specifying a font memory irrespective of a mounting address, comprising: sequentially inquiring font memories to search the specified font memory, and determining the font number corresponding to the physical mounting position of the specified font memory; and performing a printing operation using a currently specified font memory.

According to the printing apparatus of the present invention as described above, if one font name is specified, the desired font memory can be specified from a plurality of font memories irrespective of its mounting position, and a desired printed output can be obtained. As a result, the work load of a user can be reduced, and a printing operation can certainly be performed using the specified font memory.

FIG. 1 is a block diagram of a printing apparatus according to an embodiment of the present invention;

FIG. 2 is a view showing a storage content of a font memory in FIG. 1; and

FIGS. 3A to 3C are flow charts, in which FIG. 3A is a flow chart showing a general operation, FIG. 3B is a flow chart showing a printing operation, and FIG. 3C is a flow chart when a font memory is specified and alarm processing is executed.

A printing apparatus according to an embodiment of the present invention will now be described with reference to the accompanying drawings. As shown in FIG. 1, the printing apparatus of the present invention comprises interface section 10, controller section 12, pattern generator section 14, and printer driver section 16. Interface section 10 comprises interface 20 connected to system bus 17, and receives a data signal, a command signal, and control signal from external apparatus (e.g., host computer) 32. In addition, section 10 outputs a control signal necessary for a signal-receiving operation to external apparatus 32. Furthermore, section 10 can include a circuit for generating a signal to apparatus 32. Pattern generator section 14 comprises at least one fixed font memory 24 and at least one detachable cartridge 25 consisting of at least one font memories 26 and/or 27, and is connected to system bus 17. Font memory 24 or 26 stores, for example, a gothic or italic font pattern.

Each font memory is constituted by a ROM, and a storage area thereof is divided into two areas, as shown in FIG. 2. One of the storage areas stores a font name of the ROM for identification, and the other stores character pattern data. In this embodiment, the font name is stored in the ROM itself, but can be stored in an external circuit of the ROM. When each font memory is accessed, it outputs the font name and the character pattern data corresponding to the input character code data. Printer driver section 16 is connected to system bus 17, and comprises controller driver 28, mechanism 29, and alarm 30. Controller driver 28 receives an input character pattern data and controls mechanism 29 to print the data, under the control of CPU 21. When CPU 21 detects some abnormality, alarm 30 generates an alarm under the control of controller driver 28. Controller section 12 comprises microprocessor (CPU) 21, ROM 22, and RAM 23, and CPU 21 controls the overall apparatus of this invention in accordance with a program written in ROM 22. RAM 23 stores data and information necessary for the printing operation.

The operation of the printing apparatus of the present invention shown in FIG. 1 will now be described with reference to FIGS. 3A to 3C. The general operation will first be described with reference to FIG. 3A. Character code data and a font specifying command data for specifying the font memory which are input from external apparatus 32 (e.g., a host computer), are received by interface 20 under the control of CPU 21 (step S1). Interface 20 is controlled by CPU 21 in accordance with a normal communication technique so that data does not overflow RAM 23. CPU 21 checks whether the received data is a font specifying command or character code data (step S2). When the received data is the character code data, normal printing processing is executed (step S3). FIG. 3B shows the printing processing in detail. When the received data is the font specifying command, a font name specified by the input font specifying command is temporarily stored, and the font memories in section 14 are sequentially referred to specify the corresponding font name, i.e., the font memory (step S4). The flow then returns to step S1, and the apparatus awaits the next input data.

The printing operation will now be described with reference to FIG. 3B. Received printing data is supplied to a font memory (e.g., memory 24), which is currently specified by a PFN (physical font name) register in CPU 21 (step S31). The currently specified font memory generates character pattern data corresponding to the input character code data. The converted data is then stored in RAM 23 of section 12 (step S32) and is output to driver 28 under the control of CPU 21. Driver 28 drives mechanism 29 under the control of CPU 21 to cause it to print the character pattern data (step S33). In this way, the input character code data from external apparatus 32 is printed. In the above description, the character code data is output to the font memory immediately after it is supplied to interface 20. However, CPU 21 can perform control such that the input character code data from interface 20 is temporarily stored in RAM 23 and the stored data is then supplied to the font memory specified by the PFN register in the printing operation, so as to supply the converted character pattern data from the font memory to driver 28.

The operation for searching the font memory in accordance with the font specifying command will now be described with reference to FIG. 3C. When it is determined in step S2 that the data received by interface 20 is a font specifying command, the font name specified by the command is temporarily stored in an LFN (logical font name) register (step S50). The LFN register can be a register allocated in CPU 21 or RAM 23. CPU 21 supplies to external apparatus 32 through interface 20 signals indicating that CPU 21 is currently searching the specified font memory (step S51), so as to temporarily interrupt the receiving operation. Therefore, external apparatus 32 cannot transmit any data, including character code data. CPU 21 then sets a minimum of font numbers i corresponding to physical mounting positions of font memories in section 14 of the PFN register (step S52). Next, CPU 21 checks if a font memory corresponding to font number i is mounted (step S53). In this case, all the output terminals constituting the font memories must be connected to a power source voltage through a pull up resistor to be pulled up. A given address of the font memory is accessed and it is checked if the data read out therefrom is "FF" in hexadecimal notation. When the data is "FF", it is determined that the specified font memory is not mounted. More specifically, when the specified font memory is not mounted, since the output terminals of the memory are pulled up, "FF" is read out as if it is stored in the memory when the given address is accessed. Therefore, it can be determined that the specified font memory is not mounted. It should be noted that no "FF" data must be stored at the given address on the font memory. Thus, if N (NO) in step S53, font number i in the PFN register is incremented by one (step S54), and the flow returns to step S53. However, if Y in step S53, CPU 21 accesses the font memory corresponding to font number i, and loads the font name thereof (step S55). CPU 21 then checks if the loaded font name coincides with that in the LFN register (step S56). When Y in step S56, font number i of the PFN register (i.e., the specified font memory) is determined (step S57). When the font memory is determined, CPU 21 supplies to external apparatus 32 through interface 20 signals indicating that searching of the font memory is completed (step S58). Thereafter, CPU 21 awaits the next input (normally, character code data) from external apparatus 32. When no coincidence is found between the loaded font name and the font name in the LFN register, font number i of the PFN register is again incremented by one (step S54) and the flow returns to step S53. The above operation is repeated in this manner, and the specified font memory is searched. In this case, CPU 21 first searches fixed font ROM 14, and then searches the font memories in the loaded cartridge.

After font number i in the PFN register is incremented by one in step S54, CPU 21 checks in step S60 if number i exceeds a maximum physical font number (i.e., a maximum of numbers corresponding to physical mounting positions of font memories). If N in step S60, step S53 is executed again, and the searching operation is continued. However, when Y in step S60, i.e., when the number i exceeds the maximum number, alarm processing is executed (step S61). In step S61, controller driver 28 drives alarm 30 under the control of CPU 21 to signal, by means of one or both of an LED and a buzzer, that the specified font memory is not mounted. This control loop is repeated until the cause of the alarm is removed. At the same time, CPU 21 can supply to external apparatus 32 through interface 20 signals indicating that the specified font memory is not mounted (step S62). The alarm processing is continued until an appropriate cartridge is mounted. When this is accomplished, the alarm processing is cancelled (step S63). More specifically, the LED and the buzzer are disabled, and no alarm signal is supplied to apparatus 32 (step S64). Next, the minimum font specifying number of the font memories in the cartridge is loaded in the PFN register (step S65), and step S53 is executed.

In the apparatus of the present invention, when a power source is turned on, default processing can be performed. In default processing, a font number corresponding to a pre-specified font memory (e.g., a minimum of font numbers corresponding to the fixed font memories) is loaded in the PFN register. In this apparatus, transmission of the font specifying command can be requested from external apparatus 32 at the same time the power source is turned on.

In this way, processing for searching a font name specified by the external apparatus is executed with respect to the font memories with preset font names. Thereby, a printing operation can be executed based on the font memory with the specified font name. Since the font memories can be accessed irrespective of their mounting positions, their positions in a cartridge need not be changed. In addition, a printing program need not be modified to correspond with a font specifying number of a given font memory in a cartridge, thus preventing the font memory from being erroneously specified. Furthermore, since the alarm processing can be executed, a user can detect a non-mounted state of the specified font memory before the printing operation begins. For this reason, the specified font memory can be effectively chosen or changed, as needed.