JPH0435966A - Printing data writing method - Google Patents

Abstract

PURPOSE:To reduce capacity of a storage part without lowering printing speed by a method wherein printing data are written in required two storage areas in the storage part consisting of three storage areas, the data are read out to be printed, and when two of the storage areas are empty, next printing data are written in the areas. CONSTITUTION:A storage part 1 is divided into an area A' (0000) - (1FFF), area B' (2000) - (3FFF), and area C' (4000) - (5FFF). In each area, printing data for 0.5 line are stored. In a writing action, printing data for the first line are written in the areas A' and B', and the data are read out from an address (0000) to be printed rightward. After the read out of the area A' is completed, the read out of the area B' is started, and printing data for the second line are written in the area A' and the area C'. Thereafter, the printing data in the area C' are read out from an address (5FFF) to be printed leftward as the second line. After the read out is completed, the read out of the area A' is started, and printing data for the third line are written in the area B' and the area C'. In this manner, as soon as empty areas for one line are prepared, printing data for a next line are written in the areas.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a print data writing method.

[Prior Art] Conventionally, as a method of storing print data for high-speed printing processing in a printer, a storage unit having multiple storage areas for storing print data for one line is used to store print data in one storage area. When reading is completed, the next line of print data is stored in the empty area. For example, as shown in Figure 7, there are storage areas X and Y that each store one line of print data. First, the first line of print data is stored in area X, and printing is started by reading this out. At the same time, the print data of the second line is stored in area Y. Next, when the reading of the print data of the area X is completed, the reading of the print data of the area Y is started, and when the area X becomes an empty area, the print data of the third line is stored there. In other words, while the print data in one area is being read out, the print data for the next line is stored in the other area.

[Issues to be resolved] In the conventional method described above, in order to store multiple lines of print data, a storage unit with a large capacity that is an integral multiple of the storage capacity for storing one line of print data is required. , the circuit becomes larger and the cost amplifier increases accordingly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a print data writing method that can reduce the capacity of a storage unit without reducing printing speed.

[Means for Solving the Problems] The present invention provides a storage unit that is composed of three storage areas and is capable of storing a predetermined unit of print data using two storage areas, and prints data in two desired storage areas. Write data, read this print data and print, 2
The above problem is solved by writing the next print data into these two empty areas when one storage area becomes empty.

[Embodiment] Hereinafter, an embodiment in which the present invention is applied to a bidirectional printing printer will be described based on the drawings.

In FIG. 1, reference numeral 1 denotes a storage section consisting of three storage areas, and one storage area stores print data for 0.5 lines. That is, the storage unit 1 can store one line of print data in two storage areas, and has a total storage capacity of 1.5 lines. Reference numeral 2 denotes an area selection circuit that specifies a storage area of the storage unit 1 when writing and reading print data, and 3a and 3b switch signals to the area selection circuit 2 when writing and reading print data. 4 is a latch circuit for latching each storage area selection signal when writing and reading print data; 5 is a print head; 6 is a bin drive circuit for the print head 5; 7 is a control for writing and reading print data; This is a control circuit that controls the pin drive circuit 6 and the like.

FIG. 2 shows a specific circuit configuration of the area selection circuit 2, and FIG. 3 shows the signal output state of each part.

FIG. 4 is for explaining the write operation of print data. In the figure, 1 is the same storage unit as in FIG. 200
0) ~ (3FFF) and C' (4000) ~ (5FF
F), and each area stores 0.5 lines of print data.

8 indicates an address for accessing the storage section 1 from the control circuit 7, and the control circuit 7 indicates that the storage section 1 is located in the area A (
0000) ~ (IFFF) and B (2000) ~ (3FF
Addressing is performed assuming that it has only F).

The memory space seen from the control circuit 7 is (0000) to (3F
FF), and 24 bytes from (0000) to (5FFF) for the accessed area on the storage unit 1. The storage unit 1 is divided into three areas A′ to C′, and the area of the storage unit 1 to be actually accessed is designated as the address (0000) to (IFFF) from the perspective of the control circuit 7.
(2000) to (3) from the viewpoint of the B-1 control circuit 7
Memory unit 1 that is actually accessed by addresses up to FFF)
By providing a switching circuit that switches the area A' to C' to B' or C', writing and reading of print data can be done by selecting any two combinations of areas A' to C' in the storage section 1 and continuously writing and reading them. Access as an address.

An outline of the write operation according to the present invention will be explained based on FIG. 6. First, the first line of print data is in area A'
is written in B', reading is started from address (0000), and printing is performed in the right direction ((a) in the same figure).

When the reading of area A' is completed, reading of area B' is started, and the print data of the second line is written in areas A' and C' (FIG. 3(b)). When the reading of area B' is completed, that is, the printing of the first line is completed2, the print data of area C' is subsequently read from address (5FFF'), and the second line is printed in the left direction. (Same figure (C))
. When reading from area C' is completed, reading from area C' starts, and the print data of the third line is written into areas B' and C' (FIG. 3(d)). In this way,
As soon as one line of empty space is created, print data for the next line is written, and bidirectional high-speed printing is performed.

Next, the above writing operation of print data will be explained in detail along the flowchart of FIG. 5(a).

First, it is assumed that the print data of the first line is stored in areas A' and B', and that the print data is read from the address (0000) of area A' to perform rightward printing. Note that when printing in the right direction, the print data is read from the smaller address to the larger address, and in the case of printing in the left direction, the reverse is done.

First, it is determined whether rightward printing is in progress. Since rightward printing is currently in progress, the control circuit 7 then determines whether the address of the print data being read out is greater than (IFFF).
(Step ■).

When the read address becomes larger than (IFFF),
That is, when printing of the print data in area A- is completed, it is determined whether the printing areas are areas A' and B' (step 2).

At present, areas A'' and B' are being printed, and printing of area A'' has been completed, so areas A'' and C' have become empty areas in the storage unit 1.

Therefore, the print data of the second line is in these empty areas A' and C'.
All you have to do is write in the areas A' and C in step
′ is selected. This selection is performed by setting the input signals to the terminals SL1 and SL2 of the region selection circuit 2 to "0, 1", respectively, as shown in FIG. 3(b). In other words, as shown in FIG. 3(b), the address outputs (0000) to (IFFF) from the control circuit 7 are directly supplied to the addresses (0000) to (IFFF) of the storage unit 1, and the address outputs (2000) For ~(3FFF), address (4000) ~(5FFF) of storage unit 1
Areas A' and C' are selected by supplying (step 2).

In this way, the print data of the second line is written in areas A' and C' (step 2).

Then, by reading the print data, which will be described later, the area A
The print data of the second line previously written in "C' is read from the address (5FFF), and printing is performed in the left direction.

During this printing, the write routine in FIG. 5(a) is executed, for example, by interrupt processing every 101S, and in the case of leftward printing, step 3 determines whether the print address exceeds (4000) or not. A judgment will be made. In other words, it is determined whether or not printing of the print data in area C' has been completed, and if this becomes yes, area B''
, C- is being printed. Currently, area AC゛ is being printed, so a no judgment is issued and area B-
C- is selected. In this way, upon completion of printing in area C', it is determined that area B''C' has become an empty area, and the print data of the third line is written in this area.

Next, the third line is printed, and if the read address is larger than (IFFF) during rightward printing, but the area is not being printed with ゛ and B-, the read address is (3FFF).
F) It is determined whether it is larger than (step ■). That is, it is determined whether or not printing of area B' has been completed. When this becomes yes, it is determined that the area A-B- has become an empty area, and the signal state of each terminal of the area selection circuit 2 is switched as shown in FIG.
' is selected and the print data of the 4th line is written (
Step ■-).

Next, the fourth line is printed, and the control circuit 7 determines whether the read address is smaller than (4000) (step ■), and when the read address is smaller than (4000), the area It is determined whether or not B' and C' are being printed (step 2).

Since areas B' and C' are not currently being printed, it is determined whether the read address is smaller than (2000) (
Step ■). That is, it is determined whether or not printing of area B' has been completed.

If the answer is yes, it is determined that the area B-C- has become an empty area, and the signal state of each terminal of the area selection circuit 2 is switched as shown in FIG. 3(c), and the areas B' and C' is selected (step ■'). In this way, the print data of the fifth line is written in areas B- and C''.

The above is the print data write operation, and when one line of empty space is available in the storage section 1, the next line of print data is stored.

Next, the print data reading operation will be explained with reference to the flowchart of FIG. 5(b).

When printing of the nth line is completed, the signal states of terminals A-SELI and A-9EL2 of latch circuit 4 at this time are transferred to terminal B-
Latch as the signal status of SELL and B-8EL2 (
Step ■′). In other words, during printing on the nth line, terminal A-
Since the print data of the n+1th line is written based on the signal states of 9ELL and A-9EL2, the terminal A-9
By looking at the signal states of EL1 and A-8EL2, it can be determined in which area the print data of the (n+1)th line is stored.

Next, the signals at terminals B-8ELI and B-3EL2 are passed through switching circuits 3a and 3b to area selection circuit 2.
The signal is supplied to the terminals SLI and SL2 of (step 2). That is, if the print data written in areas A' and B' is to be read, the signal state of each terminal of the area selection circuit 2 is switched as shown in FIG. 3(a), and the areas A' and B' are selected.

The readout area is selected as described above, and the print data is read out sequentially from the smallest address in the case of rightward printing and from the largest address in the case of leftward printing (step 2).

By the above-described operation, high-speed printing is realized using a storage section with a storage capacity of 1.5 lines.

[Effects] According to the present invention, the capacity of the print data storage section can be reduced without reducing the printing speed, which is highly effective in reducing the size and cost of the printer.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the circuit configuration of a printer using the present invention, Fig. 2 is an electric circuit diagram showing the specific circuit configuration of the main part of Fig. 1, and Fig. 3 is the same as Fig. 2. An explanatory diagram showing the signal states of each part of the circuit, Figures 4 and 6 are explanatory diagrams for explaining the operation of Figure 1, and Figures 5 (a) and (b).
is a flowchart for explaining the operation of FIG.
The figure is an explanatory diagram for explaining a conventional example. 1... Storage section and above Applicant Seikosha Co., Ltd.

Claims (1)

[Claims] Writing print data into two desired storage areas of a storage unit that is composed of three storage areas and is capable of storing a predetermined unit of print data using two storage areas;
This print data writing method is characterized in that the print data is read and printed, and when two storage areas become empty areas, the next print data is written into these two empty areas.