JPH0740604A - Method of developing character - Google Patents

Abstract

PURPOSE:To embody the improvement of a whole printing speed by minimizing a stopping time of a print carriage. CONSTITUTION:The development of print data A-R of n-th line in a print buffer 1 indicated by (b) has been finished, that of print data S-Z of n+1-th line in a print buffer 2 indicated by (c) has been finished. Printing of the print data A-I from the left and of the print buffer 1, i.e., a lower address to a print pointer indicating an intermediate address on a paper has been finished as indicated by (a). The area in which the print data A-I was developed in the print buffer 1 becomes again the area in which new data can be developed so that print data 1, 2,... of n+2-th line is developed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a dot pattern of characters such as Chinese characters, alphanumeric characters and symbols on a cut sheet or continuous paper such as a wire dot printer, an ink jet printer, a thermal printer and an electrophotographic printer in a line unit. The present invention relates to a character expansion method for expanding and performing print recording.

[0002]

2. Description of the Related Art A typical conventional printer is equipped with two or more print buffers for storing dot patterns for one line, and character expansion processing in such a printer is performed for one line first. After the print code of No. is expanded to the first print buffer, the print code of the next line is expanded to the second print buffer in parallel with the printing operation of the first print buffer, and then the second print buffer. In parallel with the printing operation of, the print code of the next line is expanded in the first or third print buffer, and then the character expansion buffer and the printing buffer are alternately switched to continue printing. Is.

FIG. 15 is a timing chart showing an example of a conventional character expansion method. In a printer having two print buffers, print buffer 1 and print buffer 2, first, a line consisting of a dot pattern is printed in print buffer 1 during a period in which a carriage having a print head or the like is executing the printing operation of the preceding line. Minute print data is expanded, the expansion process is completed, the carriage is stopped after that, and when the predetermined time required for re-driving the carriage elapses, the print operation of the print data expanded in the print buffer 1 is performed. To start. This printing operation is performed by interrupt processing for the main program. On the other hand, the main program expands the print data of the next line in the print buffer 2. Print buffer 2
When the expansion of the print buffer 1 is completed and the printing operation of the print buffer 1 is completed, the driving of the carriage is stopped for a predetermined time period in which the carriage needs to be redriven again. By repeating such operations, continuous printing by the two print buffers is performed.

[0004]

However, in the conventional character expansion method, since one line of print data corresponds to the expanded print data of one line, a print buffer having a large storage capacity is required. There is.

Further, as shown in FIG. 16, a line (A) consisting of a large amount of print data is followed by a line (B) consisting of a small amount of print data, and a line consisting of a large amount of print data (C). ) If the sentence pattern that a line comes is repeated,
Even if a predetermined time for re-driving the carriage elapses from the time when the printing of the line (B) is completed, the carriage stop period becomes long because the character expansion of the next line (C) is not completed. .

FIG. 17 is a timing chart showing a character expanding operation in the sentence pattern of FIG. First,
While the carriage is printing the (A) line, the print data of the (B) line is expanded in the print buffer 1. At this time, since the amount of data in the row (B) is small, the expansion is completed in a short time. Next, after the elapse of a predetermined time for re-driving the carriage, the printing operation of the (B) line expanded in the print buffer 1 is performed, and the print data of the (C) line is expanded in the print buffer 2. At this time, since the data amount of the (B) line is small, the printing is completed in a short time, but since the data amount of the next (C) line is large, the time required for expansion becomes long. Therefore, even if a predetermined time for re-driving the carriage after the printing of the (B) line has elapsed, if the development of the (C) line is not completed, the carriage will stop more than necessary.

As described above, it is important to control the operation of the carriage, which is slower than that of the signal processing system, so as not to stop the operation of the carriage as much as possible in order to improve the printing speed of the printer. The expansion and contraction of the stop time causes the user to feel uncomfortable, and there is a problem that the overall print throughput is reduced.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a character expanding method capable of improving the overall printing speed by minimizing the stop time of the print carriage in order to solve the above-mentioned problems.

[0009]

According to the present invention, a step of sequentially taking out print codes from a first storage means in which a series of print codes is stored, and a second storage means in which a dot pattern corresponding to each print code is stored in advance. To extract a dot pattern corresponding to the print code, and storing the extracted dot pattern in a third storage means for storing a dot pattern for one print line. In the above, in a state where the unprinted dot pattern remains in the storage area of the third storage means, another print line is expanded into a dot pattern and sequentially stored in an area other than the storage area of the unprinted dot pattern. It is a character expansion method that is a feature.

Further, according to the present invention, when the unprinted dot pattern remains in order from the middle address to the lower address or the higher address of the third storage means, the dot pattern of another printed line is stored in the upper storage of the third storage means. It is characterized in that the data is sequentially stored from the address or the lower address toward the intermediate address.

[0011]

According to the present invention, in the state where the unprinted dot pattern remains in the storage area of the third storage means for storing the dot pattern for one print line, the area other than the storage area for the unprinted dot pattern is stored. By expanding another print line into a dot pattern and sequentially storing it in the area, it is possible to minimize the stop time during which the print carriage waits for the completion of the expansion process, and at the same time, in the storage space of the third storage means. It can be effectively used.

When unprinted dot patterns remain in sequence from the intermediate address of the third storage means to the higher address, the dot pattern of another print line is moved from the lower address of the third storage means to the intermediate address. Sequentially storing the data in the same direction as the read direction of the print data from the print buffer, and the expansion process can be continuously performed as the print end area increases. When the unprinted dot patterns remain in sequence from the middle address to the lower address of the third storage means, the dot patterns of different print lines are sequentially stored from the higher address of the third storage means toward the intermediate address. By doing so, similarly to the above, the direction in which the print data is read from the print buffer is the same as the expansion direction, and the expansion processing can be continuously performed as the print end area increases. Therefore, the character expansion process can be executed smoothly.

[0013]

FIG. 1 is a block diagram showing an example of the electrical construction of a printer to which the character expansion method according to the present invention can be applied. This printer includes an MPU (microprocessor unit) 3 that performs data processing such as data transfer and data calculation according to a predetermined program, and a programmable timer 4 that outputs an interrupt signal to the MPU 3 at a predetermined cycle.
A program ROM (Read Only Memory) 5 for storing a control program and data for the MPU 3, a character pattern ROM (Character Generator) 6 for storing a dot pattern corresponding to a print code, and a program operation of the MPU 3 A RAM (Random Access Memory) 7 for storing various generated data, an input / output circuit 8 connected to a printing mechanism 10 having a print head 10a and a drive circuit 9, and a data transfer between them. It comprises a bus 11 and an interface 12 for receiving print commands and print codes from an external host device 11 such as a computer.

The RAM 7 has a receiving buffer for storing received data such as a print control code and a character code sent from the host device 11 through the interface 12, and a number of character dot rows indicating the actual size of a character to be printed. And a conditioner information storage area for storing the data necessary for expanding the dot image from the print code to the print buffer 1 and print buffer 2 to be described later, such as the number of space dot rows indicating the actual size of the space between characters and 1 A print buffer 1 for storing dot patterns for print lines,
The expansion start address indicating the start position of the expansion process in the print buffer 1, the expansion end address indicating the end position of the expansion process, the expansion pointer direction indicating whether the direction of the expansion process is rightward or leftward, and the dots stored in the print buffer 1. An expansion parameter storage area 1 for storing data such as a print left end position and a print right end position when a pattern is printed on paper, and a print buffer 1 and an expansion parameter storage area 1 have the same configuration and have different print lines. The print buffer 2 and the expansion parameter storage area 2 for expansion, the expansion pointer indicating the current expansion position in the print buffer 1 or the print buffer 2 and the print pointer indicating the current print position, and the reading direction indicating the direction of the print pointer Flag and print direction flag indicating the print direction of the print head 10a , And other storage areas are provided.

FIG. 2 is a schematic view showing an example of a mechanical structure of a printer to which the character expanding method according to the present invention can be applied. This printer includes a carriage 32 that reciprocates along the width direction of the paper 34, a print head 10a having a plurality of print wires, an ink ribbon 33 that transfers ink to the paper 34 by the impact of a print wire, and the paper 3
4 and the carriage 3
The guide stays 36 and 37 for guiding the reciprocating movement of the two, the drive belt 38 connected to the carriage 32, the pulleys 39 and 40 supporting the drive belt 38, the carriage motor 41 for rotationally driving the pulley 40, and the like. The photo sensor 42 attached to the housing detects the home position 43 of the carriage 32 by detecting the light shielding plate 31 attached to the carriage 32.

FIG. 3 is a functional block diagram showing the operation of the character expansion method which is an embodiment of the present invention. The print position control means 21 analyzes a series of print codes stored in the receive buffer shown in FIG. 1 and locates the actual data to be expanded in the print buffer and the data not to be expanded, for example, the line head or the line tail. By identifying the presence of tabs, spaces, etc., the print start position and print end position are determined.

The print buffer switching means 22 determines which of the two print buffers can be used when the print code is developed into a dot pattern. In principle, the print buffer 1 and the print buffer 2 are used alternately.

The print pointer counter 23 defines, as a print pointer, the current position where the print head 10a is printing in the print data expanded on the print buffer 1 or the print buffer 2, and the numerical value of the print pointer is defined. Remember.

The print pointer direction determining means 24 determines the shortest movement direction and the print direction for the print head 10a to perform printing from the print start position and print end position determined by the print position control means 21. At this time, it is determined whether the print pointer moves on the print buffer in increments of one increment or in decrements of one increment.

The expansion pointer counter 25 defines the last position of the print data being expanded in the print buffer 1 or the print buffer 2 as the expansion pointer, and stores the numerical value of the expansion pointer.

The expansion pointer direction judging means 26 determines the print buffer 1 or the print buffer 2 based on the moving direction of the print pointer determined by the print pointer direction judging means 24.
It is determined from which of the two ends the expansion processing is possible. The moving direction of the expansion pointer and the moving direction of the print pointer are the same.

The pointer comparison control means 27 develops with the numerical value of the print pointer counter 23 in order to determine the print buffer area which is empty after printing is completed in the print data expanded in the print buffer 1 or the print buffer 2. It is compared with the numerical value of the pointer counter 25 to determine whether or not new print data can be expanded in the empty area of the print buffer. Further, the print end position determined by the print position control means 21 is compared with the position indicated by the print pointer, and when the print pointer catches up with the print end position, the print end is judged, and the print buffer switching means 22 prints. The buffer 1 or the print buffer 2 is alternately switched.

The print data expansion means 28 expands the print data consisting of dot patterns in the expandable area indicated by the pointer comparison control means 27 based on the print code in the reception buffer of FIG.

FIG. 4 is a conceptual diagram for explaining the printing operation and the expansion processing in the print buffer 1 and the print buffer 2. The print data “A to R” on the n-th line has been developed in the storage area of the print buffer 1 shown in FIG. 4B, and n + is stored in the storage area of the print buffer 2 shown in FIG. 4C.
The print data “S to Z” on the first line has been expanded, and the print data “A to I” from the left end which is the lower address of the print buffer 1 to the print pointer indicating the intermediate address is
As shown in FIG. 4 (a), the printing on the paper is completed, and the print head continues to move in the printing direction to the right in the figure, while the printing remaining from the print pointer toward the upper right address is printed. Attempting to print data "JR". In the printing of the n-th line, the print direction of the print head is determined based on the print start position and the print end position determined by the print position control means 21, and the print pointer direction determination means 24 based on the print direction. The direction of the print pointer is judged to determine whether the print pointer counter 23 should be incremented or decremented. Based on the direction of the print pointer, the expansion pointer direction determination means 26 determines in which direction the print data is expanded.

As shown in FIG. 4, the print data "A to I" expanded in the print buffer 1 has already been printed,
The empty area becomes the expandable area, and the print data “12 ...” On the (n + 2) th line is expanded. Therefore, the moving direction of the print pointer and the moving direction of the expansion pointer are the same.

In this way, the expansion direction is determined, and n + 2
While starting the expansion of the line, the pointer comparison control means 27
Always compares the value of the print pointer counter 23 with the value of the expansion pointer counter 25, and if the moving directions of both are incremented, control is performed so that (print pointer counter)> (expansion pointer counter) is satisfied. When the moving direction of is decremented, control is performed so that (print pointer counter) <(expansion pointer counter) holds. If the pointer comparison control means determines that the expansion pointer has caught up with the print pointer counter,
That is, when the two values are equal, the print data expansion means 28 suspends the expansion process until the print operation proceeds and the print pointer advances. In this way, when the print pointer moves to the right in the figure and the printing of the nth line ends, and the expansion pointer moves to the right in the figure and the expansion processing of the n + 2th line ends in the empty area, the print buffer The switching means 22 switches to the print buffer 2 for the next print operation or expansion process.

FIG. 5 is a conceptual diagram for explaining the operation when the movement directions of the print pointer and the expansion pointer are opposite to those in FIG. In the storage area of the print buffer 1 shown in FIG. 5B, when the print pointer is decremented and the left side of the figure is the print direction, the expansion pointer is also decremented and the upper address of the print buffer 1 is moved. The print data consisting of dot patterns is expanded from a certain right end to the left. When the decrementing process is performed in this way, the dot pattern is developed so as to be mirror-inverted, as shown in FIG. To explain this in detail, as shown in FIG. 6A, the dot pattern corresponding to the character “A” is bit data “abc”, and the dot pattern corresponding to the character “B” is “de”.
Assuming that the bit data is “f”, FIG.
As shown in (b), when the character "AB" is expanded in the storage area of the print buffer in the increment direction from left to right, a dot pattern "abcdef" is created, while as shown in FIG. 6 (c). Further, when the character "AB" is expanded in the decrement direction from right to left in the storage area of the print buffer, a dot pattern "fedcba" is created. Next, as shown in FIG. 6D, when the character “AB” is printed from the left end of the paper, the print pointer moves from left to right in FIG. 6B, and in FIG. 6C. The print pointer will move from right to left. Therefore, by adopting such a character expansion method,
It is possible to create continuous dot patterns regardless of whether the free area of the print buffer is on the right side or the left side.

7 to 12 are flowcharts showing the operation of the character expansion method which is an embodiment of the present invention. Figure 7
In step a2, the MPU 3 of FIG. 1 receives a series of print codes sent from the host device 11 through the interface 12 in step a2. Then, in step a3, the received print codes are sent to the reception buffer. Write. Next, the print code stored in the reception buffer is converted into conditioner information on a character-by-character basis to form an intermediate code, which is stored in the conditioner information storage area of the RAM 7. Next, in step a5, CR
(Carriage return) or LF (Line feed)
It is judged whether the conditioner information for one line has been generated by checking whether the code of
If the line has not been generated, the process returns to step a2 and the above steps a2 to a4 are repeated. If the conditioner information for one line can be generated, the process proceeds to step a6 to execute the image development process, and then returns to step a2.

FIG. 8 is a flow chart showing the operation of the image development processing in step a6 of FIG. First, in step b1, a usable print buffer is selected from the print buffer 1 and the print buffer 2, and then in step b2, it is checked whether or not the print data which has been expanded is present in the print buffer to be expanded. If it does not exist, the process proceeds to step b3, the moving direction of the expansion pointer is set to the increment direction, the print data for one line is expanded in the selected print buffer, and then the process moves to step b13. . On the other hand, if there is print data that has been developed in step b2, the process proceeds to step b4 to determine whether the print data that has already been developed is currently being printed, and the print data must be currently printed. Step b to continue data reception
After shifting to step 5 and receiving the print code from the interface 12, the print code received in step b6 is written in the reception buffer, and the process returns to step b4 again.

On the other hand, if it is determined in step b4 that printing is currently in progress, the process proceeds to step b7, and the print direction flag in the RAM 7 is referenced to read whether the moving direction of the print pointer is the increment direction or the decrement direction. Then, in step b8, the moving directions of the expansion pointers are set to be the same based on the moving directions of the print pointers. If the moving directions of both pointers are increment directions, the process proceeds to step b9. , The expansion processing for one line is performed in the increment direction of the expansion pointer.

FIG. 9 is a flow chart showing the operation of the expansion processing in the increment direction in step b9 of FIG. First, in step c1, the size of the print pointer is compared with that of the expansion pointer. If the print pointer is larger, the process proceeds to step c2 and the print data is expanded in the increment direction of the expansion pointer based on the conditioner information. , In step c3, 1 is added to the value of the expansion pointer and the process returns. If the print pointer is equal to or smaller than the expansion pointer in step c1, the process proceeds to step c4 to continue data reception, the print code is received from the interface 12, and then the print code received in step c5 is written in the reception buffer. And then return.

Returning to FIG. 8, in step b10, 1
It is determined whether or not the line expansion processing has been completed. If not completed, the expansion processing of step b9 is repeated. If the expansion processing for one line is completed, the process proceeds to step b13.

On the other hand, in step b8, if the moving directions of the print pointer and the expansion pointer are the decrement direction, the process proceeds to step b11, and the expansion processing for one line is performed in the decrement direction of the expansion pointer.

FIG. 10 is a flow chart showing the operation of the decrement direction expansion processing in step b11 of FIG. First, in step d1, the size of the print pointer is compared with that of the expansion pointer. If the print pointer is smaller, the process proceeds to step d2, and the print data is expanded in the decrement direction of the expansion pointer based on the conditioner information. , In step d3, 1 is subtracted from the value of the expansion pointer and the process returns. If the print pointer is equal to or larger than the expansion pointer in step d1, step d4 is executed to continue data reception.
After receiving the print code from the interface 12 by shifting to step 1, the print code received in step d5 is written in the reception buffer and the process returns.

Returning to FIG. 8, when the expansion processing for one line in the print buffer is completed next, in step b13, the expansion parameters for the selected print buffer, that is, the expansion start address and the expansion end address shown in FIG. The expansion pointer direction, the print left end position, and the print right end position are set in the selected expansion parameter storage area, and in step b14, the print pointer preparation process is executed.

FIG. 11 is a flow chart showing the operation of the print pointer preparation process in step b14 of FIG. First, in step e1, the expansion parameter of the print buffer to be printed is read from the above-mentioned expansion parameter storage area, and then in step e2, the print direction of the print head is set to the forward direction or to the forward direction based on the print left end position and print right end position of the expansion parameter. Either the reverse direction is determined and the print direction flag is set. Then step e3
In step S4, it is determined whether the expansion pointer direction of the expansion parameter is either, and if it is the increment direction, the process proceeds to step e4. If the print direction of the print head is further determined and if it is the forward direction, the process proceeds to step e5. do it,
The direction of the print pointer is determined to be the increment direction from the expansion start address of the expansion parameter, the read direction flag is set, the numerical value of the print pointer is set to the expansion start address in the next step e6, and then the process returns.

In step e4, if the print direction of the print head is the reverse direction, the process proceeds to step e7, the direction of the print pointer is determined from the expansion end address of the expansion parameter to the decrement direction, and the read direction flag is set. In the next step e8, the value of the print pointer is set to the expansion end address, and then the process returns.

On the other hand, in step e3, if the expansion pointer direction of the expansion parameter is the decrement direction,
In step e9, the print direction of the print head is further determined, and if the print direction is forward, the process moves to step e10 to determine the direction of the print pointer from the expansion start address of the expansion parameter to the decrement direction and read it. The direction flag is set, and in the next step e11, the numerical value of the print pointer is set to the development start address, and then the process returns.

If the print direction of the print head is the reverse direction in step e9, the process proceeds to step e12, in which the direction of the print pointer is determined from the expansion end address of the expansion parameter to the increment direction and the reading direction flag is set. In the next step e13, the value of the print pointer is set to the expansion end address, and then the process returns.

Returning to FIG. 8, the print interrupt process is enabled (permitted) in step b15. The print interrupt process is a routine in which the print period and the number of print columns are set as timer parameters in the programmable timer 4 of FIG. 1 in advance, and the programmable timer 4 issues an interrupt signal to the MPU 3 to print only one line. , Is periodically repeated according to the movement of the motor.

FIG. 12 is a flow chart showing the operation of the print interrupt process which is periodically executed by the print interrupt enable in step b15 of FIG. First, in step f1, the print data in the print buffer indicated by the print pointer is read in one column, the print processing for one column is performed in the next step f2, and then in step f3, if the movement direction of the print pointer is the increment direction. 1 is added to the value of the print pointer, while 1 is subtracted from the value of the print pointer if the print pointer direction is the decrement direction. In the next step f4, it is determined whether or not the printing process for one line is completed. If not completed, the process returns to step f1 and if completed, the process returns. In this way, a series of print data is printed.

FIG. 13 is a conceptual diagram for explaining an operation example and a printing example of the character expanding method according to the present invention. FIG.
When the text shown in FIG. 13A is printed on the paper, first, the print data “123456789” of the first line is expanded in the print buffer 1 shown in FIG. The print data “ABCDEFGH” is expanded. Then, during the character expansion of the print buffer 2,
As shown in FIG. 13C, the print operation of the first line is performed in order from the left end of the print buffer 1, the print pointer moves in the increment direction, and the print data of the third line is printed in the area where printing is completed. “Irohanihohet” is developed in order, and the development pointer moves in the increment direction so as to follow the print pointer.

Next, when the printing of the print data "1 to 9" of the first line expanded in the print buffer 1 is completed, FIG.
As shown in (d), the second data expanded in the print buffer 2
The print operation of the print data “A to H” of the line is the print buffer 2
Is performed from right to left, the print pointer of the print buffer 2 moves from the right end in the decrement direction. At this time, in the area where the printing is completed, the print data "Ai Ueoki" in the fourth row is sequentially developed while mirror-inverting, and the development pointer moves in the decrement direction so as to follow the print pointer. Then, while the character expansion of the print buffer 2 is being executed, as shown in FIG. 13E, the print data of the third line expanded in the print buffer 1
Is printed, the print pointer moves in the decrement direction, the print data “abcdefghijkklmnopq” on the fifth line is sequentially developed in the area where the printing is completed, and the expansion pointer moves in the decrement direction so as to follow the print pointer.

Next, as shown in FIG. 13 (f), the printing operation of the print data “A to K” of the fourth line expanded in the print buffer 2 is performed from the left to the right of the print buffer 2. , The print pointer moves from the left end in the increment direction. At this time, in the area where printing is completed, the print data “123456789” of the sixth line is sequentially expanded,
Move in the increment direction so that the expansion pointer follows the print pointer. Then, during the character expansion of the print buffer 2, the print data “a to q” of the fifth line expanded in the print buffer 1 is printed as shown in FIG. 13 (g), and the print pointer is decremented. The print data "ABCDEFGHIJ" on the seventh line is sequentially expanded in the area where the printing is completed, and the expansion pointer moves in the decrement direction so as to follow the print pointer.

Next, as shown in FIG. 13H, the printing operation of the print data “1 to 9” of the sixth line expanded in the print buffer 2 is performed from right to left of the print buffer 2. , The print pointer moves from the right end in the decrement direction. At this time, in the area where printing is completed, the print data "Irohanihohet" on the eighth line is sequentially expanded, and the expansion pointer moves in the decrement direction so as to follow the print pointer.

By repeating the above operation,
A print as shown in FIG. 13A can be obtained.

FIG. 14 is a timing chart showing the operation of the character expansion method according to the present invention. First, the print data for the nth line is expanded in the print buffer 1 while the carriage is executing the print operation for the (n-1) th line which has been expanded in the print buffer 2. At this time, when the expansion of the nth line is completed, the data expansion of the (n + 1) th line is continued in the area where the printing is completed in the print buffer 2. Where n-
When the printing of the first line is completed, the carriage waits for a predetermined re-driving time required for the next printing operation, and then the printing operation of the print data of the nth line expanded in the print buffer 1 is started. The printing operation continues and n is displayed in the empty area of the print buffer 1.
The print data of the + 2nd line is expanded. In this way, even if the amount of print data for one line fluctuates, character expansion of the subsequent print line can be performed in the empty area of the print buffer, eliminating the time for the carriage to wait for the end of character expansion. The overall printing speed is improved.

In the above embodiment, an example in which two print buffers are switched to perform the expansion processing and the print operation has been described, but the present invention can be similarly applied to a method of sequentially switching three or more print buffers. . Further, even with a configuration using only the print buffer 1, by applying the present invention, it is possible to obtain a print throughput similar to that using two print buffers.

[0049]

As described above in detail, according to the present invention, 1
Even if the amount of print data for a line increases or decreases and fluctuates, the stop time for the print carriage to wait for the end of character expansion processing can be reduced as much as possible, improving the overall print speed and reducing the storage space. Can be effectively used.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of an electrical configuration of a printer to which a character expansion method according to the present invention can be applied.

FIG. 2 is a schematic diagram showing an example of a mechanical configuration of a printer to which the character expansion method according to the present invention can be applied.

FIG. 3 is a functional block diagram showing an operation of a character expansion method which is an embodiment of the present invention.

FIG. 4 is a conceptual diagram illustrating a printing operation and a developing process in the print buffer 1 and the print buffer 2.

FIG. 5 is a conceptual diagram illustrating an operation in the case where the moving directions of the print pointer and the expansion pointer are opposite to those in FIG.

FIG. 6 is a conceptual diagram illustrating an operation in the case where the moving directions of the print pointer and the expansion pointer are opposite to those in FIG.

FIG. 7 is a flowchart showing an operation of the character expansion method according to the embodiment of the present invention.

8 is a flowchart showing the operation of image expansion processing in step a6 of FIG.

FIG. 9 is a flowchart showing an operation of expansion processing in the increment direction in step b9 of FIG.

10 is a flowchart showing an operation of a decrement direction expansion process in step b11 of FIG.

11 is a flowchart showing an operation of print pointer preparation processing in step b14 of FIG.

FIG. 12 is a flowchart showing the operation of print interrupt processing in step b15 of FIG.

FIG. 13 is a conceptual diagram illustrating an operation example and a printing example of the character expansion method according to the present invention.

FIG. 14 is a timing chart showing the operation of the character expansion method according to the present invention.

FIG. 15 is a timing chart showing an example of a conventional character expansion method.

FIG. 16 is a conceptual diagram showing a sentence pattern composed of a plurality of lines.

17 is a timing chart showing a character expanding operation in the sentence pattern of FIG.

[Explanation of symbols]

 3 MPU (microprocessor unit) 4 Programmable timer 5 Program ROM 6 Character pattern ROM 7 RAM 8 Input / output circuit 9 Drive circuit 10 Printing mechanism 11 Host device 12 Interface

Claims (2)

[Claims] 1. A step of sequentially taking out print codes from a first storage means that stores a series of print codes, and a second storage means that stores a dot pattern corresponding to each print code in advance corresponding to the print code. A method for expanding a character, comprising: a step of extracting a dot pattern; and a step of storing the extracted dot pattern in a third storage means for storing a dot pattern for one print line, in the third storage means. A character expanding method, wherein while another unprinted dot pattern remains in the area, another print line is expanded into a dot pattern and sequentially stored in an area other than the storage area of the unprinted dot pattern. 2. When the unprinted dot pattern remains in order from the middle address to the lower address or the higher address of the third storage means, the dot pattern of another printed line is set to the third pattern.
2. The character expansion method according to claim 1, wherein the characters are sequentially stored from a higher address or a lower address of the storage means toward the intermediate address.